WO2014044232A1

WO2014044232A1 - Lighting element with a body made of fired ceramics

Info

Publication number: WO2014044232A1
Application number: PCT/CZ2013/000108
Authority: WO
Inventors: Tomas Tethal
Original assignee: Iq Structures S.R.O.
Priority date: 2012-09-20
Filing date: 2013-09-17
Publication date: 2014-03-27
Also published as: CZ306453B6; CZ2012650A3

Abstract

A lighting element with a body (1) made of fired ceramics, in which at least one light source (2) with electric supply cables (3) is arranged and a waveguide (4) is arranged in the fired ceramics body (1) at the light source (2). One side of the waveguide (4) is oriented towards the surface of the fired ceramics body (1) and on the opposite side the waveguide (4) is provided with a structure (5) for leading light out of the waveguide (4). The structure (5) for leading light out of the waveguide (4) is arranged on the bottom of a recess (11) in the fired ceramics body (1) and the space around the structure (5) for leading light out of the waveguide (4) in the recess (11) in the body (1) is at least partly filled with cast plastics.

Description

Lighting element with a body made of fired ceramics Technical Field

The invention relates to a lighting element with a body made of fired ceramics, in which at least one light source with electric supply cables is arranged and a waveguide is arranged in the fired ceramics body at the light source, one side of the waveguide is oriented towards the surface of the fired ceramics body and on the opposite side the waveguide is provided with a structure for leading light out of the waveguide.

Prior Art

There exists a range of lighting elements having a ceramic body in which a light source with electric supply cables is arranged. Because the lifespan of conventional light sources (bulbs, fluorescent tubes, discharge lamps, etc.) is significantly shorter than lifespan of a ceramic body, the known lighting elements are construed so that the source of light can be removed from the lighting element and replaced.

With coming of modern light sources such as LED (Light-Emitting Diode) and later newly developed organic OLED (Organic Light-Emitting Diode) or electroluminescent foils, displays with active matrices (AMOLED), flexible displays, etc., the lifespan of these light sources has significantly extended.

In case that the body of the lighting element is made of fired ceramics, the light source, supply cables and other electronic components shall be installed in the ceramic body after firing of ceramics because firing of ceramics (even without any surface glaze) is carried out at high temperatures that could damage or destroy such components. These components therefore do not become any integral part of ceramics during production and are only connected with it (mechanically, by gluing, thread, etc.) after firing of the ceramic body.

In case of a so-called direct illumination, the light source is installed in the lighting element so that the illuminated area is lit either directly or in a combination with a front-embedded reflex of transmission optics. This arrangement is applied with overwhelming majority of lighting elements.

Lighting through a waveguide is other option. In this case the light source is mostly out of the observer's eye axis. Light is transported from the source through a waveguide of which surface or interior is provided with a structure to enable output of light created usually by scattering centres that become multidirectional or oriented sources for the observer after passage or reflection of light. Then the observer can see light that scatters on scattering centres of the light output structure, not light coming directly from the light source.

Also in case of use of a waveguide the waveguide is not any integral part of the ceramic component and is installed later, after the ceramic component is fired, as a separate component that is fixed mechanically, using a glue, etc. Function of the waveguide is independent; the ceramic body surface is not any functional component of the light waveguide. For example, embedding of a LED lighting into a ceramic tile, more precisely, embedding of a LED light into a beforehand prepared hole in the tile. In some cases also some photo-luminescent pigments can be added to the ceramic product or onto its surface. Dimensional inconsistence is certain disadvantage of embedding a complete waveguide into the beforehand fired ceramic body. Firing of a ceramic product causes its significant dimensional changes that can be foreseen in certain extent; however, it is almost impossible to get the same dimensions of the recess in the fired ceramic body as these of the waveguide. Necessity of a partial opening of the recess to enable embedding of a complete waveguide with electronics and light source is another problem.

Scattering structures for output of light from the waveguide may comprise of non- homogenous particles distributed inside the light waveguide or a relief structure on its surface. The relief created usually by sanding, laser ablation, etching, mechanical scratching, etc. has a randomly created structure in these cases. Light scattered on such centre is usually distributed evenly in all directions. Therefore there is used an additional reflective (mostly white) layer from the side opposite to the direction of the required emission of light from the light waveguide, to increase intensity of scattered light into the observed direction. Scattering centres of the structures for output of light from the waveguide (mostly on the waveguide surface) are often distributed non-homogeneously so that overall impression is homogenous when looking at the main area of the waveguide. In other words, uneven distribution of light scattering centres compensates gradual loss of light in the waveguide caused by scattering and emissions on these centres when passing through the waveguide. Density of scattering centres is lower close to the light source and increases with increasing distance from this source.

Waveguides are often provided with a reflective (mostly white) layer on sides from which light is not brought, e.g. with plastic foils, paper, paint, etc. The same can be made e.g. on the observer's opposite side, this from the side of application of scattering centres. This increases intensity of light coming finally to the observer's eye. Another arrangement can be used in particular if scattering centres are inside the waveguide volume.

The purpose of the invention is to create a fired ceramics lighting element that enables easily and effectively install the light waveguide into the body.

Disclosure of the Invention

According to the invention, the mentioned goal can be achieved by a lighting element having a body made of fired ceramics, in which at least one light source with electric supply cables is arranged and a waveguide is arranged in the ceramics body at the light source, one side of the waveguide is oriented towards the fired ceramics body surface and on the opposite side the waveguide is provided with a structure for leading light out of the waveguide. The structure for leading light out of the waveguide is arranged on the bottom of a recess in the fired ceramics body and the space around the structure for leading light out of the waveguide in the recess is at least partly filled with cast plastic.

Unlike the existing technology according which a completed waveguide is embedded into the recess, the solution according to the invention arranges a structure for leading light out of the waveguide on the bottom of the recess in the fired ceramics body and this structure is then filled with plastic. This solution enables creation of a waveguide with high efficiency, without creation of any undesired gaps between the waveguide and ceramic body. It is also not necessary to let any partially open recess in the fired ceramics body for mechanical embedding of the waveguide. Both advantages allow achieving significantly better parameters of the design of the resulting product with the implemented waveguide.

According to a useful embodiment the structure for leading light out of the waveguide can be created by partial glazing of the surface of the bottom of the recess in the fired ceramic body.

In other useful embodiment the structure for leading light out of the waveguide can be created in a layer of a geo-polymer composite, in a layer of a geo-polymer composite with a surface layer, in a layer of cast plastic or in a layer of cast plastic with a surface layer, arranged on the fired ceramic body bottom.

In another useful embodiment the structure for leading light out of the waveguide can be created by a beforehand created relief arranged on the bottom of the recess in the fired ceramic body.

The next useful embodiment the waveguide includes a transparent and/or diffusional plastic material applied in the fired ceramic body recess above the structure for leading light out of the waveguide.

In other useful embodiment the waveguide outer surface is provided with a top layer. According to another useful embodiments the top layer is diffusional or transparent.

The structure for leading light out of the waveguide can be adapted for homogenous or controlled distribution of light.

The structure for leading light out of the waveguide may also comprise of a diffractive relief or a layer that creates diffraction. In another embodiment the light source comprises LED and/or OLED and/or AMOLED.

Brief Description of Drawings

The lighting element according to the invention will be described in details, with references to examples of different embodiments, shown schematically on drawings; Fig. 1 represents a lighting element for homogeneous distribution of light. Fig. 2 shows a section of the same element. Fig. 3 shows a lighting element, where a coat in form of a reflective layer is applied on the structure for leading light from the waveguide. Fig. 4 shows a lighting element, where a levelling layer of transparent plastic material is applied on the structure for leading light from the waveguide. Fig. 5 shows a lighting element with a layer of transparent plastic material between the top layer and waveguide body.

Description of Preferred Embodiments

The lighting element in Fig. 1 a 2 comprises of a wall tile with a body 1 made of fired ceramics. Fired ceramics is common material and therefore its composition is not described in details here.

The body 1 shaped as a wall tile is provided with a recess 11 for a light source 2 on its face side and a waveguide 4 that includes a structure 5 for leading light out of the waveguide 4; this structure comprises of scattering centres created according to one of the embodiment examples by a partial glazing of the bottom of the recess 11 in the body 1 made of fired ceramic material.

After firing the body 1 the light source 2 with electric supply cables 3 is put into the recess 11 in the body 1 made of fired ceramics; the cables are led to non-shown electric contacts on the body 1. In the embodiment shown on Fig. 1 and 2 the light source 2 comprises of a set of well-known LED. Specialists know that there can be also used another known light sources 2 such as OLED, AMOLED, electroluminescent foils, etc. The waveguide 4 is terminated so that the recess 11 in the body 1 is filled with transparent and/or diffusive plastic material. Surface of the plastic material in the waveguide 4 can also be provided with a diffusional or transparent top layer 6 made of plastic material, glass, etc. An air gap 7 can be left between the top layer and waveguide 6.

The embodiment in Fig. 3 is different from the embodiment on Fig. 1 and 2 so that a coat 8 in form of a reflective layer, high-index layer, etc. for modification of reflectance or optical interface is applied on the structure 5 for leading light from the waveguide 4 on the bottom of the recess 11 in the body 1.

The embodiment on Fig. 4 is different from the embodiment on Fig. 3 so that a thin levelling layer 9 of a transparent plastic material is applied on the structure 5 for leading light from the waveguide 4 on the bottom of the recess 11 in the body 1 instead of the coat 8; this layer has another refraction index for weakening or strengthening of reflection than the plastic material of the waveguide body 4.

The embodiment on Fig. 5 is different from the embodiment on Fig. 4 so that the air gap 7 between the top layer 6 and waveguide body 4 is replaced by a layer of transparent material 10, e.g. plastic.

In a non-shown embodiment the structure 5 for leading light from the waveguide 4 can be created in a layer cast on the bottom of the recess 11 in the body 1 made of fired ceramics. This cast layer may comprise of a geo-polymer composite or a geo- polymer composite with a surface layer (e.g. plating), or a plastic or plastic with a surface layer (e.g. plating), etc.). This created structure 5 for leading light out of the waveguide 4 may be significantly finer and with a specifically organised structure to enable much better results in lighting as for homogeneity of light or just in formation of light into desired directions and with specified effects.

In another non-shown embodiment the structure 5 for leading light from the waveguide 4 can be created by a beforehand made relief (a plastic foil with a relief or a surface layer, a metal plate with a relief) put onto the bottom of the recess 11 in the body 1 made of fired ceramics and filled with a transparent and/or diffusional plastic. Scattering centres of the structure 5 for leading light from the waveguide 4 may be arranged for homogeneous or controlled distribution of light. Density of scattering centres of the structure 5 for leading light from the waveguide 4 is lower close to the light source and increases with increasing distance from this source to achieve homogeneous distribution of light (see Fig. 1). Such uneven distribution of scattering centres compensates gradual loss of light in the waveguide 4 caused by scattering and emission on these centres when passing through the waveguide 4. For controlled distribution of light, the given distribution of scattering centres of the structure 5 for leading light from the waveguide causes intentional non-homogeneity that may create a graphic pattern, alphanumerical symbol, bitmap, etc. This enables directing of light or a certain portion of light into one or more preset directions or generation of two-dimensional pictorial perception or generation of three-dimensional perception.

The waveguide 4 according to the shown examples is shaped as a flat plate, provided with a structure 5 for leading light from the waveguide on one side and on the other side it is either clear or provided with a diffusional surface. However, specialists know that there can also be created other shapes of the waveguide 4, e.g. a cylindrical waveguide or a waveguide with a square, rectangular or half-round profile, a linear waveguide, with different diameter along the waveguide axis, with a graphic motive, etc. The waveguide 4 outer surface may not flush with the surface of the body 1 and may protrude geometrically or graphically, create depressions, irregular surfaces, etc. In such case it is necessary to use an additional mould for casting of a waveguide of transparent plastic; this mould should copy the desired profile of the waveguide section, non-bordered by the ceramic material.

The light waveguide 4 or waveguides can be designed so that they lead into surface of the body 1 in a distribution that corresponds to functional, graphical or aesthetical requirements for the lighting element.

Colour of the body 1 in the area of the structure 5 for leading light from the waveguide 4 is chosen usefully to function as a good reflective layer, particularly white colour. Light from the light source 2 is transported by the waveguide 4, whilst scattering centres of the structure 5 for leading light from the waveguide 4 become multidirectional or oriented source for the observer after passage or reflection of light. Then the observer can see light that scatters on scattering centres of the structure 5 for leading light from the waveguide 4, not light coming directly from the light source 2.

Points of the waveguide used for leading light out of the waveguide, may also comprise of a controlled structure that allows more than diffusion of light only, e.g. also its diffraction, directing of light or a certain portion of light into one or more preset directions, generation of a three-dimensional perception, etc. The topology of scattering points themselves may create graphics and in case of use of diffraction even colour graphics.

Industrial applicability

The lighting element according to the invention can be used as a lighting element for household, industrial, interior, exterior purposes, as a structural component of constructions (e.g. public transport passenger shelters), lighting or information components in interior and exterior facing (wall tiles), as kitchen, bathroom, residential room, corridor, production hall, office accessories, etc.

The lighting element according to the invention can also be used as a component of sanitary facilities (washbasins, brackets, toilet bowls, bidets, bathroom tubs, shower enclosures, saunas, etc.), as a component of machines and equipment, transport means, information and warning systems, furniture, etc.

Claims

1. A lighting element with a body (1) made of fired ceramics, in which at least one light source (2) with electric supply cables (3) is arranged and a waveguide (4) is arranged in the fired ceramics body (1) at the light source (2), one side of the waveguide (4) is oriented towards the outer surface of the fired ceramics body (1) and on the opposite side the waveguide (4) is provided with a structure (5) for leading light out of the waveguide (4), characterised in that the structure (5) for leading light out of the waveguide (4) is arranged on the bottom of a recess (11) in the fired ceramics body (1) and the space around the structure (5) for leading light out of the waveguide (4) in the recess (11) in the body (1) is at least partly filled with cast plastics.

2. The lighting element according to the claim 1 , characterised in that the structure (5) for leading light out of the waveguide (4) is created by partly glazing of the surface of the body (1) made of fired ceramics.

3. The lighting element according to the claim 1 , characterised in that the structure (5) for leading light out of the waveguide (4) is created in a layer of a geo-polymer composite or in a layer of a geo-polymer composite with a surface layer, or in a cast plastic layer with a surface layer, arranged on the bottom of the recess (11) in the body (1) made of fired ceramics.

4. The lighting element according to the claim 1 , characterised in that the structure (5) for leading light out of the waveguide (4) is created by a beforehand made relief, arranged on the bottom of the recess (11) in the body (1) made of fired ceramics.

5. The lighting element according to any of the claims above, characterised in that the waveguide (4) comprises a transparent and/or diffusional plastic arranged in the recess (11) in the fired ceramics body (1) above the structure (5) for leading light out of the waveguide (4).

6. The lighting element according to any of the claims above, characterised in that the outer surface of the waveguide (4) is provided with a top layer (6).

7. The lighting element according to claim 4, characterised in that the top layer (6) is diffusional.

8. The lighting element according to claim 4, characterised in that the top layer (6) is transparent.

9. The lighting element according to any of the claims above, characterised in that the structure (5) for leading light out of the waveguide (4) is adapted for homogeneous distribution of light.

10. The lighting element according to any of the claims above, characterised in that the structure (5) for leading light out of the waveguide (4) is adapted for controlled distribution of light.

11. The lighting element according to any of the claims above, characterised in that the structure (5) for leading light out of the waveguide (4) is created by a diffractive relief or a layer providing diffraction.

12. The lighting element according to any of the claims above, characterised in that the light source (2) includes LED and/or OLED and/or AMOLED.