WO2006086998A1

WO2006086998A1 - Illuminated display case

Info

Publication number: WO2006086998A1
Application number: PCT/EP2005/001519
Authority: WO
Inventors: Gabriele Klippel; Klaus Bähr
Original assignee: Carrier Corporation
Priority date: 2005-02-15
Filing date: 2005-02-15
Publication date: 2006-08-24
Also published as: EP1858375A1

Abstract

The invention relates to an illuminated refrigerated display case (1) having at least one door (4) comprising transparent elements, and illumination means (5) comprising punctiform light emitters which are mounted to the at least one door (4).

Description

ILLUMINATED DISPLAY CASE

The present invention relates to an illuminated display case having at least one door comprising transparent elements.

The illuminated display case may be an illuminated refrigerated display case. The term refrigerated display case here refers to refrigeration and to deep-freezing devices and to combinations thereof.

Refrigerated display cases are usually illuminated by one or more fluorescent tubes. For example in a common refrigerated display stand with a couple of shelves the fluorescent tubes are located at the underside of the top cover of the cabinet frame. Therefore the front of the shelves has the best illumination.

The light efficiency of a common fluorescent tube decreases significantly in a cold environment. For example in a deep-freezing cabinet the light efficiency is only about 30% of the light efficiency at 20°C. Due to this effect the location where to place the illumination devices have to be carefully chosen and spots with very cold temperature should be avoided, e.g. the inlet of the cooling air into a refrigerated display case.

The location of the common illumination devices can sometimes be a problem because the common fluorescent tubes are quite huge.

Document DE 203 02 431 Ul discloses the use of punctiform light sources in shelves or rear or side walls of open refrigerated display stands. For closed refrigerated display cases comprising one or more door(s) a problem occurs: light reflec- tions in the doors, which comprise in general glass elements to make the products displayed visible from outside. The reflections might glare the customer and reduce the visibility of the products significantly.

Thus, it is an object of the present invention to develop an illuminated display case having at least one door comprising transparent elements, wherein all products displayed are well illuminated with illumination means that need only few space, and make the products displayed clearly visible for the customer. Illumination means that do only cause low energy consumption would be preferred.

In accordance with the present invention this object is solved by an illuminated display case having at least one door comprising transparent elements, and illumination means comprising punctiform light emitters which are mounted to the at least one door.

In an embodiment of the present invention, the illuminated display case is a refrigerated case.

Punctiform light emitters are very favorable to obtain new illumination concepts due to their very small diameter of the light emitting surface. A plurality of punctiform light emitters can be arranged in narrow space and according to a great variety of patterns a designer is free to choose from. This enables the designer to create new illumination concepts beyond the standards for example given by the need for space of a common fluorescent tube.

The expression ,,door" is meant to include the door frame, the door panel and the timbering set which refers to a door. It can be especially useful to mount the illumination means to the timbering set, because in this case the illumination stays exactly the same not depending on whether the door is open or closed. The products are equally well illuminated for a customer opening the door to pick up a certain product displayed. In addition, in case of a refrigerated display case, the space inside the refrigerated display case is completely available for storing and displaying products for the customer. Compared to a conventional refrigerated display case comprising a plurality of fluorescent tubes there is a significant increase of free storage space. Refrigerated display cases with doors are common for displaying dairy products or deep-frozen products like seafood or ice-cream. For the dairy products doors with transparent glass elements are useful. For the deep- frozen products insulated glass would be preferred due to the greater difference in temperature between the inside of the refrigerated display case and the surrounding in the shop. Under the aspect of undisturbed transparency, glass elements are superior to most transparent plastics, with the exemption of plexiglass which, however, is more expensive than glass if having a high quality transparency.

In accordance with an embodiment of the present invention the punctiform light emitters are formed by light emitting ends of fiber optic cables mounted to the at least one door. The light emitting ends of fiber optic cables have a lot of advantages compared to fluorescent tubes, especially for the use in cold environments. They show almost no emission of thermal energy at the point where they emit the light and they do not show a decrease in efficiency in cold environments as the fluorescent tubes do. These are great advantages suitable to reduce the energy consumption of a refrigerated display case compared to prior art. The end where the fiber optic cable emits the light is connected to a light source outside of the refrigerated display case via the fiber optic cable. A gas discharge lamp or halogen lamp can be used as light source. The light from such a light source is coupled into the fiber optic cable. A bright white light can be provided which illuminates the products displayed in a very good manner. In accordance with an embodiment of the present invention the punctiform light emitters are formed by light emitting diodes mounted to the at least one door. Light emitting diodes (LEDs) are a very good choice for punctiform light emitters. The

9o light emitting diode is a semiconductor diode which emits light out of the depletion layer upon application of a forward voltage. Suitable semiconductor materials are in the first place IH/V~semiconductors comprising elements of the third and fifth group of the periodic table of the elements. For example GaP, AlGaAs or InGaN are useful materials to obtain a satisfying light emitting diode. The emitted

95 wavelength depends on the choice of semiconductor material. The radiation of a LED is within a much smaller band of radiation compared to conventional thermal light sources, like a electric bulb, or a fluorescent tube for example.

There is almost no thermal energy brought inside the refrigerated display case by 100 the use of light emitting ends of fiber optic cables as punctiform light emitters and/or by the use of light emitting diodes. Compared to electric bulbs which convert only 10% of the input electric energy into visible light and 90% into thermal energy and compared to fluorescent tubes which even at room temperature convert almost 50% of the input electric energy into visible light and 50% into thermal energy, this 105 is a great advantage especially for the use of the illumination means in cold environments.

In accordance with an embodiment of the present invention the punctiform light emitters are arranged in regular or irregular patterns to create illumination means of no particular shapes and radiation characteristics. As mentioned before, a plurality of punctiform light emitters can be arranged in a great variety of patterns a designer is free to choose from. With regular or uniform patterns in general a homogenous illumination is obtained, wherein irregular patterns can be used to create zones highlighted by illumination next to darker zones. 115 In accordance with an embodiment of the present invention the pattern of punctiform light emitters is arranged at the exterior surface of a tube segment. In an embodiment of the invention, the cross-section of the tube is a segment of a geometric form such as a circle, oval, ellipse, etc. For example a plurality of LEDs are arranged at the exterior surface of a tube segment. The cross-sectional

120 dimension of such illumination means is 1 cm for example. The axial dimension is adaptable to the needs, e.g. to the height of the display case, to the dimensions of the door or to other design concepts. To use a plurality of punctiform light emitters and to distribute these freely over the display case opens a lot of opportunities for designers to create new illumination concepts beyond the standards given by the

125 needs of the common fluorescent tubes. It has been found that the integration of the punctiform light emitters into the door area is especially useful. The direction of the incidence of light can be away from the customer viewing direction, e.g. parallel or almost parallel to the line of sight of the customer. Therefore, the customer is not likely to be glared by the illumination means and the products are clearly visible. In

130 addition, the customer is able to easily read the labels on the products, for example.

Another advantage of the present invention is that there are no elements needed within the display area of a refrigerated display case which would need a voltage of 240 Volt such as common fluorescent tubes. In case of use of LEDs, a low voltage 135 less than 10 Volt is sufficient. If the punctiform light emitters are formed by emitting ends of fiber optic cables, the light sources feeding the opposed ends of the fiber optic cables can be arranged outside the refrigerated display case. This is to be regarded as a gain in safety for the customer.

HO Embodiments of the present invention are described in greater detail below with reference to the Figures, wherein Figure 1 shows a view from above onto an embodiment of refrigerated display case of the present invention with illumination means mounted to the 145 timbering set of the doors,

Figure 2 shows enlarged views of the two types of illumination means as seen in

Figure 1, Figure 3 shows a side view of an embodiment of refrigerated display case of the present invention with the same illumination means,

150 Figure 4 shows an alternative arrangement of the illumination means at the door frame of a refrigerated display case.

The refrigerated display case 1 illustrated in Figure 1 comprises a rear wall 2 containing the cooling equipment (not shown), side walls 3 and doors 4. The illumi-

155 nation means 5 are mounted at the timbering sets 6 of the doors 4. Each of the illumination means 5 shown in Figure 1 comprise a tube segment 7 or 8 where a pattern of light emitting ends of fiber optic cables is arranged in a regular or uniform arrangement resulting in the radiation characteristic indicated by arrows. The tubes extend to the whole height of the refrigerated display case in this

160 example. Therefore, a good illumination of all products inside the refrigerated display case 1 is achieved. In another embodiment it could be advisable to use shorter illumination means or another shape of the tubes instead of the shown quartercircular tube 7 or semicircular tube 8, which means that the cross section of the tubes 7 and 8 is a quarter or half, respectively, of a circle. The arrangement of

165 the fiber optic cables might also change, for example over the height of the illumination means, or might be an irregular arrangement to achieve a certain light distribution. An evenly distribution of illumination means, for example over the whole length of all doors, ensures an evenly illumination of the products displayed.

170 Figure 2 shows enlarged views of the quartercircular tube 7 and the semicircular tube 8. There is provided a plurality of light emitting fiber optic cables 9, possibly arranged in the form of one bunch or more bunches, with light emitting ends 10 and a connection to an outside light source at the other end or ends of the fiber optic cable 9 (not shown). The quartercircular tubes are useful to be mounted in corners, 175 e.g. at the timbering sets 6 located adjacent to the side walls 3, and the semicircular tubes are best mounted adjacent to bars or middle walls 11 intersecting the length of the refrigerated display case 1. The radiation characteristic of the shown illumination means 7 and 8 is radial in the respective section, which is a very favorable radiation characteristic.

180

Alternatively or in addition to the fiber optic cables 9 of the above-illustrated embodiment, LEDs could be used. Analog to Figure 2 the LEDs would be at the locations of reference numerals 10, and the cables 9 would be electric cables connecting the LEDs to the power source.

185

Figure 3 is a side view of an embodiment of an inventive refrigerated display case 1 with illumination means 5 being distributed over the height of the refrigerated display case 1 in a regular or uniform pattern. The pattern is adapted to the arrangement of the products 12 inside the refrigerated display case 1 highligthing 190 the displayed and refrigerated products 12 and showing them focused by illumination.

Figure 4 is an alternative arrangement of the illumination means 5 at the doors frames 13 of a refrigerated display case 1. The light is evenly distributed by 195 arranging the illumination means 5 in a row, for example along the upper horizontal part of the door frame 13. Alternatively this row can be mounted to a bar sectioning the door panel or alternatively to a door panel itself, if desired.

200

Claims

CLAIMS205

1. Illuminated display case (1) having at least one door (4) comprising transparent elements, and illumination means (5) comprising punctiform light emitters which are mounted to the at least one door (4).

210 2. Illuminated display case (1) according to claim 1 wherein the punctiform light emitters are formed by light emitting ends (10) of fiber optic cables (9) mounted to the at least one door (4).

3. Illuminated display case (1) according to claim 1 wherein the punctiform light 215 emitters are formed by light emitting diodes (10) mounted to the at least one door (4).

4. Illuminated display case (1) according to one of claims 1-3 wherein the punctiform light emitters are arranged in regular or irregular patterns to create

220 illumination means (5) of particular shapes and radiation characteristics.

5. Illuminated display case (1) according to claim 4, wherein the pattern of punctiform light emitters is arranged at the exterior surface of a tube segment (7, 8).

6. Illuminated display case (1) according to one of claims 1-5, in the form of a refrigerated display case.