The present invention relates to a luminous slab made of transparent or translucent material (glass, for example), lighted from the undemeath, by using SMD LEDs, being used for plating floors, walls and ceiling surfaces, for decorative or safety purposes.

From among them we specify the lighted flooring plates, for premises, containers lighted from the undemeath with bulbs, LEDs, protected at the exterior with transparent and translucent tiles, fastened through a metallic frame on the surface whereof are written various messages, information. The main disadvantage of such lighting systems consists in the high price that is required for the make of such containers or premises.

There are also other luminous plates which are using electronic sub-assemblies for energy supply. The main disadvantages of these systems consist in high investment resources for purchasing and making the sub-assemblies and in necessity of using specialists for installation and maintenance.

DE20200400810U1 discloses a luminous slab comprising a tile made of a transparent material witch is resistant to mechanical stress, lightly fixed on a printed circuit board by means of a distance separator and an adhesive, wherein an enclosed space is formed between said tile distance separator and printed circuit board. A plurality of LEDs are mounted on said printed circuit board so as to be located in said enclosed space, and electric contacts are placed on the other side of printed circuit board; an electrical circuit for a controlling said LEDs is also located in said enclosed space. Said electric contacts are connected, by means of a cable, to a power supply.

The technical issue solved by this invention for the purpose aimed at, is the making of a luminous slab, the dimensions whereof are compatible with those of stone/ceramic tile and which can be installed by the tiler with low costs without any assistance of an technician, using the same adhesive stuff used for the stone/ceramic tiles.

The luminous slab, according to this invention, is defined in the claim. It comprises a tile made of transparent or translucent material resistant to mechanical stress, such as, for instance glass, lighted from the underneath with SMD LEDs mounted on a printed circuit board, which is fixed on the glass tile using an A+B adhesive and a distance separator so that the thickness of the glass tile - printed circuit board assembly is compatible to the thickness of a stone/ ceramic tile. On the lower side of the printed circuit there are two electric contacts where two electric wires for the electrical power supply are tin solder fixed, after which on the side and rear face of the assembly formed by the glass tile - distance separator - printed circuit board there will be applied a continuous layer of a known silicone type, for tightness purpose.

The proposed invention has the following advantages:

• > Low electricity consumption;
• > Simple execution;
• > It does not require personnel skilled in the electronic or electrical field;
• > It can be installed by the tiler who has nothing else to do than lay the electric wires in the joints between the stone/ceramic tiles so that those wires can reach to the place where the power supply will be located.

It is given hereunder an exemple for the achievement of the invention, in connection, as well, with, fig: 1, 2, 3 and 4, wherein:

• fig. 1, exploded vue of the luminous slab;
• fig. 2, horizontal cross-section vue of the luminous slab;
• fig. 3, electrical wiring diagram of the printed circuit;
• fig. 4, example of a printed circuit.

The luminous slab according to the invention comprises a transparent or translucent tile 1, made of an apropriate material resistant to mechanical stress, glass for example, a distance separator 2 fixed on the printed circuit board 3 on which the SMD LEDs 4 are mounted, as per drawing, and laid in order to obtain the desired luminous effect and on the lower side of the printed circuit 3 there are the electric contacts 5 where two electric wires 8 are tin solder joint, and which will be connected to an electric power supply, not shown in the drawing. The power supply, not shown in the drawing, may be a DC with the indicated polarization power supply or AC power supply, and in both cases, the voltage may range from 3 to 12 volts. The DC power supply, not shown in the drawings, can be a battery, an accumulator or a AC rectifier which can supply from 3 to 12 volts. On the printed circuit board 3, the LEDs 4 are mounted in parralel, and are serially connected with the power supply and the diode 6, which has the protection function in case of wrong polarization or rectification function in case of AC power supply. The used diode 6 is a rectifying diode which has the breakdown voltage higher than the supply voltage, for example 50-100 volts, and it can carry 1-2 ampers enough for supplying the LEDs 4 and the resistor 7. Both the diode 6 and the resistor 7 are used to balance the electric currents in the circuit depending on the number of LEDs and their electric features. The resistor 7 has a value between 56 and 220 ohm. The transparent or translucent tile 1 together with the separator 2 and the printed circuit board 3, compose a solid assembly sealed tight on the side and rear face with a known solution, such as silicone, which forms a continuous layer in order to prevent water infiltration into the assembly glass tile 1 - distance separator 2 - printed circuit board 3.