AN ILLUMINATION DEVICE

The invention relates to an illumination device for introducing light into the interior of a transparent plate for illuminating of a pattern, image or the like in form of engravings in at least one surface of the plate .

Background of the invention

It is known in the art to introduce light into edge surfaces of transparent plates to illuminate engravings performed in a surface of the plate. As examples of disclosures of this technique may be mentioned CA 2466815 and FR 2863094. The engravings will in this way reflect the light out from the transparent plate, which creates a very striking appearance of a pattern or image engraved into the plate. However, the illumination devices shown in these documents will be very conspicuous and dominating in the completed product, since at least one entire edge surface of the plate will be occupied by the illumination device. Accordingly, with such a configuration it is in most cases impossible to integrate the illumination discrete in the product .

Moreover, when illuminating one edge of the plate, the light beams will be emitted in essentially one main direction only in the plate. This has to effect that in general, only those engravings having an length extension perpendicular to the light beams, i.e. being parallel to the illuminated edge, will be satisfactory illuminated, whereas engravings being parallel to the light beams, i.e. perpendicular to the illuminated edge, will be poorly illuminated. One solution to this problem could be to provide two or more edges angled in relation to each other, with illuminating devices, but that would naturally render the illumination devices yet more dominating in the appearance of the product.

Summary of the invention

An object of the invention is to provide an improved illumination device for introducing light into a transparent or translucent plate. More precisely it is an object of the invention to provide an illumination device, which can be incorporated into a product or a structure in a discrete way and which will spread the light in essentially all directions. At least this object is achieved by an illumination device according to claim 1.

The invention is thus based on the understanding that the above-mentioned object may be achieved by combining the illumination device with a fastener for attaching the plate to a support structure, the combined illumination and fastener device being in form of a shank presenting an inner cavity and being light permeable from the cavity to the outside in at least some sections around its circumference. According to the invention, the combined illumination and fastener device is inserted into a hole in the plate and an electrical light source is positioned in the cavity, such that when emitting light from the light source, the emitted light will be spread in essentially all directions in the transparent plate . Within this general idea, the invention may be realized in many different ways. For example, the shank can be formed with a transparent portion in an area surrounding the light source cavity in the shank. In this way the light can be emitted in all directions from the light source. However, in a hereinafter described and illustrated preferred embodiment, the shank is formed of a light impermeable material, preferably a metal, which in the area of the light source is formed with alternating recessed sections and connecting sections. The connecting sections form connection ribs, which connect portions of the shank on both sides of the light source position. In this way it will not be a free

radiation path in all directions from the centre of the cavity. However, by forming the connection ribs sufficiently narrow, an acceptable spreading of the light can be achieved and if the width of each connection rib is considerably thinner than the width of the emitting part of the light source, it is possible to emit light in all directions around the ^' circumference . Generally, it is preferred that the proportion of the surface of the shank circumference covered by connection ribs in relation the proportion of the surface having openings is less than

50%, more preferred less than 65% and most preferred less than 80%.

Moreover, the hole in the transparent plate need not be a through hole . Instead the attaching of the transparent plate could be performed by a threaded shank, which is partly screwed into a blind hole in the plate. In the preferred embodiment, the hole in the plate is a through hole and the shank is extended through the entire plate and a threaded cap, having a larger cross sectional dimension than the dimension of the hole, is screwed into the outer portion of the shank, which will sandwich the plate between the cap and a surface _. on the- inner side of the plate.

The transparent plate can be mounted close to the support structure, such as a door, a wall or the like, wherein the shank is attached directly into the support structure by means of for example threads . In the preferred embodiment, the shank is provided on a spacer element, which has a cross sectional dimension being larger than the diameter of the through hole in the plate and which is mounted onto the support structure. Accordingly, the plate will be sandwiched between the spacer element on the inside and the cap on the outside and will be positioned on a distance from the support structure. This is advantageous since the heat generated by the light source, easily can be transported away by air in the gap between the plate and the support

structure. If, on the other hand, the plate is mounted close to the support structure, measures can be made to lead away the generated heat from the light source into the support structure. The invention may be modified in many different ways within the scope of the associated claims. In the exemplified embodiment, an illumination device according to the invention is applied to a door of a refrigerator or a freezer. However, it should be understood that the invention also could be applied to other kinds of support structures, such as other types of doors or walls. The invention need not be vertically positioned but could ■ also be positioned horizontally, e.g. as an illuminated transparent table top. The invention is described and illustrated in connection with images and patterns of decorative character. However, the invention could also be used for images and signs for informative purpose.

It should also be understood that the term transparent plate, as used herein, also comprises the use of a translucent plate, i.e. a plate which can not be clearly seen through but which allow light to pass through.

Brief description of the drawings

An exemplary embodiment of the invention will now be described with reference to the drawings, in which: Fig 1 is a perspective view of a refrigerator provided with a transparent plate having decorative images;

Fig 2 is an exploded view of a lower corner of a refrigerator door, a transparent plate and a combined illumination and fastener device according to the invention; Fig 3 is an exploded perspective view of the illumination and fastener device according to fig 2; and

Fig 4 is a cross section through a part of a refrigerator door, a part of a transparent plate and an illumination and fastener device.

Detailed description of a preferred embodiment of the invention

The invention will now be described by way of example with reference to a refrigerator 1, as shown in fig 1, the door 2 of which is on the outside provided with a transparent plate 3, which is attached with a small distance from the refrigerator door 2 by means of combined illumination and fastener devices 4. In the depicted embodiment, four illumination and fastener devices 4 are used to attach the plate 3 to the door 2, one in each corner area of the plate. The illumination and fastener devices 4 illuminate decorative engravings in form of images or patterns into at least one surface of the plate.

In fig 2 is shown more in detail the way of attachment of the transparent plate 3 to the door 2 by means of an illumination and fastener device 4. As can be seen, the device 4 is circular in cross section and comprises a spacer element 5, from an outer end of which a shank 6 projects. The shank 6 has a cross sectional dimension comparing to or being slightly smaller than the cross sectional dimension of a through hole 7 in the plate, whereas the spacer element 5 has a larger cross sectional dimension. When mounting the plate 3 onto the door 2, the plate is positioned such that the through hole 7 is passed over the shank 6 and a cap 8 is screwed - into a threaded hole in the shank. Accordingly, the plate will be sandwiched between the cap 8 and an abutment surface 9 on the outer end of the spacer element 5.

Reference is now made to figs 3 and 4 in combination, in which the more detailed design of the illumination and fastener device 4 is illustrated. As can be seen, the shank 6 includes an inner cavity 10 and in

the circumference of the shank surrounding the cavity 10, the shank is alternating provided with recessed sections 11 opening into the cavity 10, and connecting sections, in form of narrow connection ribs 12, connecting the outer and inner portions of the shank on each side of the recessed sections.

The spacer element 5 is formed as a sleeve having an inner space into which a holder 13 is inserted. The holder 13 is in an outer end provided with a mounting recess into which a light source in form of a LED 14

(Light Emitting Diode) is insertable . The LED 14 is of a type having a disc-formed substrate 15, including a circuit board, and a light emitting bulb 16. To insulate the substrate 15 electrically from the rest of the device, a cover 17 of an elastic and insulating material, is fitted over the substrate 15. When the holder 13 is mounted into the spacer element 5, as is illustrated in fig 4, and fixated by means of screws 18, the bulb 16 of the LED will project into the cavity 10. The holder 13 is at an inner end provided with a threaded rod 19, which is mounted into a corresponding threaded hole in the door 2. The threaded rod 19 is tubular for accommodating power supply wires 20 to the LED 14. The LED is of a kind emitting light 360° around its- circumference. Since the connection ribs 12 are considerably thinner than the width of the bulb 16, the light will be emitted essentially in all directions in the transparent plate 3 without being hindered, to any appreciable extent, by the connection ribs 12. The fact that the illumination and fastener devices are located in the vicinity of each corner of the plate 3, will contribute to increased spreading of the light beams since each edge surface 21 of the plate will act as a reflector for the light.

The illustrated and described embodiment of the invention, is favourable also in that respect that it

provides excellent cooling for the LED ₇ especially if the illumination and fastener device is manufactured of a metal, e.g. aluminium, since air can flow through the spacing between the plate and the support structure and around the spacer elements. The cooling may be increased by making the fit between the holder 13 and the spacer element 5 as close as possible.