The invention relates to open display refrigerators and to methods of modifying open display refrigerators.

Open display refrigerators are commonly used in retail environments, such as supermarkets, to store and display products, such as meat and dairy products, which must be kept at lower than ambient temperatures. The open front of such a refrigerator makes it easy for customers to view the products being displayed and to retrieve products they wish to purchase from the refrigerator.

This type of refrigerator has an air curtain, which is established by blowing cold air across the front of the refrigerator. The air curtain issues from an air outlet at the top of the refrigerator towards an air inlet at the bottom of the refrigerator. The air inlet recovers air from the air curtain and recirculates it to the air outlet via a cooling heat exchanger and fan. The air curtain prevents cold air in the refrigerator from mixing with warm air exterior to the refrigerator.

Open display refrigerators often include some form of lighting in order to allow the contents of the refrigerator to be displayed clearly. Such lighting may be incorporated into canopies or side walls of the refrigerator, or may be mounted onto doors or under shelves.

However, this lighting cannot illuminate the front faces of products positioned at the front of the shelves, and cannot always illuminate the full breadth and height of the display at the open front of the refrigerator. Furthermore, this lighting can cause shadows throughout the refrigerator, thus partially obscuring the products on display. For example, canopy lights (which are directed downwards) may illuminate the upper part of the display and the fronts of shelves, but this illuminating effect is much reduced for lower shelves of the refrigerator. Furthermore, downwardly-directed lights create shadows within the refrigerator. Some manufacturers have used extended arms at the tops of open display refrigerators to position lights outside and facing back into the refrigerator, but this system also creates shadows and poor lighting in the lower parts of the refrigerator.

Side wall lighting is ineffective on wide refrigerators as it only illuminates those parts of the shelves closest to the sides of the refrigerator.

SUBSTITUTE SHEET RULE 26 Door lighting can be positioned to face back into the refrigerator, but can only be used if doors are fitted (which is not the case with open display refrigerators).

Under-shelf lighting can illuminate all shelves within the refrigerator, but this lighting again directs light downwards onto the shelf below and so does not illuminate the fronts of products on the shelves. This downwardly-directed lighting also creates shadows in the refrigerator (as discussed above for canopy lighting). A further problem caused by the use of under-shelf lighting is the need to connect the lights to a power source. This introduces power cables inside the refrigerator which can reduce the movement of shelves, and also requires costly fitting.

It would therefore be desirable to provide an open display refrigerator with lighting which is able to: illuminate the front faces of products positioned at the front of the shelves; illuminate the full breadth and/or height of the display at the open front of the refrigerator; and/or avoid shadows being created in areas of the refrigerator where they may impact negatively on the display of products.

In accordance with a first aspect of the invention, there is provided an open display refrigerator comprising: an interior refrigerated space; an air curtain separating the interior refrigerated space from air external to the refrigerator; an air curtain guide for guiding flow of air within the air curtain; at least one light source disposed in the air curtain guide so as to illuminate the interior refrigerated space.

Typically, the air curtain is established by a fan which blows air through an air outlet towards a corresponding air inlet which recovers air from the air curtain for recirculation via a cooling unit

(e.g. a heat exchanger) to the air outlet. The air outlet typically spans transversely across the entire width of the interior space. This ensures that the air curtain similarly spans across the entire width of the interior space.

In a preferred embodiment, the air curtain guide is in the form of an aerofoil. A typical design of aerofoil that can be used is a cambered aerofoil. This will usually be oriented with the leading edge uppermost and the cambered surface facing away from the interior space.

The open display refrigerator typically comprises a shelf disposed in the interior refrigerated space and associated with the air curtain guide. The refrigerator may comprise a plurality of shelves, each shelf being associated with a respective air curtain guide. By the shelf being "associated with an air

SUBSTITUTE SHEET RULE 26 curtain guide", it is meant that the air curtain guide and the shelf are positioned relative to one another such that an inner edge of the air curtain guide (i.e. an edge nearest to a rear interior surface of the refrigerator; also referred to as a proximal edge of the air curtain guide) faces an outer edge of the shelf (i.e. an edge which is nearest to the air curtain; also referred to as a distal edge of the shelf). A gap may be left between the inner edge of the air curtain guide and the outer edge of the shelf. The at least one light source may be disposed in the air curtain guide so as to illuminate the shelf, for example the at least one light source may be disposed in the inner edge of the air curtain guide so as to illuminate the outer edge of the shelf.

In some embodiments, the shelf/shelves have a surface for receiving products to form a product display area. This surface may be an upper surface of the shelf (i.e. a surface nearest to the air outlet, or to the ceiling of the interior refrigerated space) upon which products can be placed to form a product display area. Alternatively, this surface may be a lower surface of the shelf (i.e. a surface nearest to the air inlet, or to the floor of the interior refrigerated space) comprising structures upon which products can be mounted to form a product display area (e.g. hooks from which the products can be suspended). In either of these embodiments, the at least one light source is disposed in the associated air curtain guide so as to illuminate the product display area of the shelf. For example, the at least one light source may be disposed in the inner edge of the associated air curtain guide and angled so as to illuminate the product display area of the shelf. The light source itself may be angled by 20-70° to the horizontal, e.g. by 30-60°, or by about 45° (based on the angle formed between the axis of the light source and the horizontal). The light source may be angled such that light is directed over an angular range of from 10-80° to the horizontal, e.g. from 20-70° from the horizontal.

The refrigerator may comprise a plurality of such shelves, each shelf having a surface for receiving products to form a product display area. In one embodiment, this surface is an upper surface of the respective shelf, as discussed above. In this embodiment, the at least one light source may be disposed in the associated air curtain guide so as to illuminate the product display area of a shelf below that with which the air curtain guide is associated (for example, the at least one light source may be disposed in the inner edge of the associated air curtain guide and angled so as to illuminate the product display area of a shelf below that with which the air curtain guide is associated). In another embodiment, this surface is a lower surface of the respective shelf, as discussed above. In

SUBSTITUTE SHEET RULE 26 this embodiment, the at least one light source may be disposed in the associated air curtain guide so as to illuminate the product display area of a shelf above that with which the air curtain guide is associated (for example, the at least one light source may be disposed in the inner edge of the associated air curtain guide and angled so as to illuminate the product display area of a shelf above that with which the air curtain guide is associated). In either of these embodiments, the light source may itself be angled by 20-70° to the horizontal, e.g. by 30-60°, or by about 45° (based on the angle formed between the axis of the light source and the horizontal); or the light source may be angled such that light is directed over an angular range of from 10-80° to the horizontal, e.g. from 20-70° from the horizontal. The air curtain guide may be attached or connected to the shelf via at least one connecting member (such as a bracket). Alternatively, the air curtain guide may be attached or connected to a casing of the refrigerator via at least one connecting member (e.g. a bracket). For example, the air curtain guide may be attached via the at least one connecting member to an interior side surface of the refrigerator. In any of these embodiments, the at least one connecting member may form part of the air curtain guide.

In any of the above embodiments, the light source may be a low-energy light source. Examples of low energy light sources include LEDs (Light Emitting Diodes), fluorescent lamps (e.g. fluorescent tubes, compact fluorescent lamps (CFLs)), and halogen lamps. When LEDs are used, the light source may be in the form of an LED lamp, i.e. a lamp formed of one or more LEDs. The air curtain guide may include a recess, and the light source may be disposed in the recess such that a surface of the light source is flush with a surface of the air curtain guide, e.g. the recess may be in a surface of the air curtain guide which faces the interior refrigerated space of the refrigerator (or, in one embodiment, a shelf of the refrigerator), and the light source may be disposed in the recess such that a surface of the light source which faces the interior refrigerated space (or the shelf) is flush with the surface of the air curtain guide which faces the interior refrigerated space (or the shelf). For example, the light source could be an LED light source in the form of a strip. Where the surface of the air curtain guide is curved, light sources having a profile which matches that of the surface of the air curtain guide could be used.

SUBSTITUTE SHEET RULE 26 A power source such as solar power, a battery system, mains electricity, or a thermoelectric generator (TEG; sometimes known as a Seebeck generator) may be used to power the light source. Alternatively, the light source could be powered using energy harvested from ambient

electromagnetic radiation, as discussed below. When solar power is used as the power source, flexible photovoltaic power cells may be positioned on an exterior surface of the refrigerator (including the outer surface of the air curtain guide, i.e. an edge furthest from the rear interior surface of the refrigerator - also referred to as a distal edge of the air curtain guide) in order to harvest energy from store lighting and/or sunlight.

When a battery system is used as the power source, the battery system may be contained within (or affixed to) the air guide, the connecting members, or the shelf. In addition to being used as the sole power source for the at least one light source, battery power may also be used in conjunction with the other power sources listed above.

A thermoelectric generator (TEG), when used as the power source, would make use of the temperature differentials between surfaces which are disposed within the interior refrigerated space (e.g. shelf surfaces, interior surfaces of the refrigerator) and surfaces which are outside the interior refrigerated space (e.g. an external surface of the refrigerator). Thermoelectric generators convert heat energy into electrical energy using thermoelectric materials. A temperature gradient across the thermoelectric material is required in order to produce a voltage. If the temperature difference between the surfaces is not sufficiently large to produce electric energy, then an additional surface (whether heated or cooled) could also be introduced in order to provide the required temperature differential. For example, such a surface (e.g. a sheet of metal) could be placed within vents of the refrigerator which exhaust hot air from the heat exchanger to the atmosphere, thus providing a surface with a higher temperature than other exterior surfaces of the refrigerator. The air curtain guide itself may also have a temperature difference across its surface, (e.g. from the leading edge to the trailing edge; or from the distal edge to the proximal edge). Therefore, in one embodiment, a TEG could be incorporated into the air curtain guide, thus enabling the air curtain guide/light source combination to be self-powering. TEGs are available from e.g. European Thermodynamics Limited - see

http://www.europeanthermodynamics.com/products/

SUBSTITUTE SHEET RULE 26 Energy could also be harvested from ambient electromagnetic radiation (such as radiofrequency energy from high-power broadcast signals e.g. digital television (DTV) and mobile network signals e.g. Wi-Fi, Global System for Mobile Communication (GSM), or Long Term Evolution (LTE)). A company which produces and develops this energy-harvesting technology is Drayson Technologies - see http://www.getfreevolt.com/index.php The power source in the present invention may therefore be a harvester which comprises an antenna, rectifier, and power management module. These harvesters can provide perpetual power for low energy consumption devices, such as LEDs. The harvester could be incorporated into the air curtain guide strip.

The power source and/or the light source may have cabling associated therewith. As used herein "cabling associated with the power source" means electrical cables, leads or wires attached to the power source for its connection to the light source. Similarly, "cabling associated with the light source" means electrical cables, leads or wires attached to the light source for its connection to the power source. Cabling associated with at least one of the power source and the light source may be routed through the air curtain guide. Alternatively or additionally, cabling associated with at least one of the power source and the light source may be routed through the at least one connecting member. As used herein, the term "routed through" means "encased within" or "affixed to".

Routing the cabling through the air curtain guide and/or the connecting members allows it to be protected from damage as well as being concealed from view.

In one embodiment, the light source and the refrigerator are both powered by a common power source. In this embodiment, cabling associated with the power source for its connection to the light source may be routed under a shelf of the refrigerator with which the air curtain guide is associated. This provides the advantage that only a single power source (e.g. mains electricity) is required to power both the refrigerator itself and the light source in the air curtain guide.

Provision of an air curtain guide which has at least one light source as described in any of the above embodiments allows light to be directed straight onto the front faces of those products which are positioned at the front of the shelves, and avoids the creation of shadows in areas where they may impact negatively on the display of products. It also allows illumination of the full breadth of the display at the open front of the refrigerator, as light sources may be positioned along the entire length of the air curtain guide (i.e. from one interior side surface of the refrigerator to the opposing interior side surface).

SUBSTITUTE SHEET RULE 26 In accordance with a second aspect of the invention, there is provided an air curtain guide for an open display refrigerator, the air curtain guide comprising at least one light source and at least one connecting member adapted for attachment to a shelf of the refrigerator or to a surface of the refrigerator. In a preferred embodiment, the air curtain guide is in the form of an aerofoil. A typical design of aerofoil that can be used is a cambered aerofoil. When attached to the refrigerator, the aerofoil will usually be oriented with the leading edge uppermost and the cambered surface facing away from an interior refrigerated space of the refrigerator.

The connecting member may be a bracket. By "adapted for attachment to", it is meant that the connecting member comprises features which allow it to be attached to the shelf or surface of the refrigerator. Examples of such features include (but are not limited to): a particular orientation with respect to the air curtain guide and the shelf or surface of the refrigerator; a through-hole allowing the connecting member to be attached to the shelf or surface by way of e.g. a screw, a bolt, or a nail; and a structure which allows the connecting member to be received in a

corresponding receiving member located on the shelf or surface. The surface of the refrigerator may be an interior surface, for example an interior side surface. In any of the above embodiments, the at least one connecting member may form part of the air curtain guide.

The at least one light source may be disposed in the air curtain guide so as to illuminate an interior refrigerated space of the refrigerator when the at least one connecting member is attached to the shelf or interior surface. The at least one light source may also illuminate the shelf, for example the at least one light source may be disposed in the inner edge of the air curtain guide so as to illuminate the outer edge of the shelf.

In one embodiment, the at least one light source is disposed in the air curtain guide so as to illuminate a product display area of a shelf of the refrigerator with which the air curtain guide is associated, when the at least one connecting member is attached to the shelf or interior surface. For example, the light source may be angled so as to illuminate the product display area of the shelf. The light source itself may be angled by 20-70° to the horizontal, e.g. by 30-60°, or by about 45° (based on the angle formed between the axis of the light source and the horizontal); or the light source may be angled such that light is directed over an angular range of from 10-80° to the

SUBSTITUTE SHEET RULE 26 horizontal, e.g. from 20-70° from the horizontal. The terms "product display area", and the shelf being "associated with an air curtain guide" (or the air curtain guide being "associated with a shelf") are as described above for the first aspect of the invention. As discussed above, either an upper surface or a lower surface of the shelf may be the surface for receiving products in order to form the product display area.

When the upper surface of the shelf is the surface for receiving products, the at least one light source may be disposed in the air curtain guide so as to illuminate a product display area of a shelf of the refrigerator below a shelf with which the air curtain guide is associated, when the at least one connecting member is attached to the shelf or interior surface. For example, the at least one light source may be disposed in the inner edge of the associated air curtain guide and angled so as to illuminate the product display area of a shelf below that with which the air curtain guide is associated. The light source may be angled by 20-70° to the horizontal, e.g. by 30-60°, or by about 45° (based on the angle formed between the axis of the light source and the horizontal). The light source may be angled such that light is directed over an angular range of from 10-80° to the horizontal, e.g. from 20-70° from the horizontal.

When the lower surface of the shelf is the surface for receiving products, the at least one light source may be disposed in the air curtain guide so as to illuminate a product display area of a shelf of the refrigerator above a shelf with which the air curtain guide is associated, when the at least one connecting member is attached to the shelf or interior surface. For example, the at least one light source may be disposed in the inner edge of the associated air curtain guide and angled so as to illuminate the product display area of a shelf above that with which the air curtain guide is associated. The light source may be angled by 20-70° to the horizontal, e.g. by 30-60°, or by about 45° (based on the angle formed between the axis of the light source and the horizontal). The light source may be angled such that light is directed over an angular range of from 10-80° to the horizontal, e.g. from 20-70° from the horizontal.

In any of the above embodiments, the light source may be a low-energy light source. Examples of low energy light sources include LEDs (Light Emitting Diodes), fluorescent lamps (e.g. fluorescent tubes, compact fluorescent lamps (CFLs)), and halogen lamps. When LEDs are used, the light source may be in the form of an LED lamp, i.e. a lamp formed of one or more LEDs.

SUBSTITUTE SHEET RULE 26 The air curtain guide may include a recess and the light source may be disposed in the recess such that a surface of the light source is flush with a surface of the air curtain guide, e.g. the recess may be in a surface of the air curtain guide which is to face a shelf of the refrigerator, and the light source may be disposed in the recess such that a surface of the light source which is to face the shelf is flush with said surface of the air curtain guide. For example, the light source could be an LED light source in the form of a strip. Where the surface of the air curtain guide is curved, light sources having a profile which matches that of the surface of the air curtain guide could be used.

A power source such as solar power, a battery system, mains electricity, or a thermoelectric generator (TEG; sometimes known as a Seebeck generator) may be used to power the light source. Alternatively, the light source could be powered using energy harvested from ambient

electromagnetic radiation. Each of these power sources may be as discussed above for the first aspect of the present invention.

The power source and/or the light source may have cabling associated therewith. The meaning of the phrases "cabling associated with the power source" and "cabling associated with the light source" are as discussed above for the first aspect of the present invention. Cabling associated with at least one of the power source and the light source may be routed through the air curtain guide. Alternatively or additionally, cabling associated with at least one of the power source and the light source may be routed through the at least one connecting member. The meaning of the term "routed through" is as discussed above for the first aspect of the present invention. The light source and the refrigerator may both be powered by a common power source, as discussed above for the first aspect of the present invention.

In accordance with a third aspect of the invention, there is provided a method of modifying an open display refrigerator comprising an interior refrigerated space and an air curtain separating the interior refrigerated space from air external to the refrigerator; the method comprising disposing in the refrigerator an air curtain guide for guiding flow of air within the air curtain, such that the air curtain guide comprises at least one light source disposed in the air curtain guide so as to illuminate the interior refrigerated space.

By "such that the air curtain guide....so as to illuminate the interior refrigerated space", it is meant that, for example, the at least one light source is positioned in the inner edge of the air curtain

SUBSTITUTE SHEET RULE 26 guide (i.e. an edge nearest to a rear interior surface of the refrigerator; also referred to as a proximal edge of the air curtain guide) so that light therefrom is directed into the interior refrigerated space towards a rear interior wall of the refrigerator.

The method may further comprise disposing the air curtain guide in the refrigerator so that the air curtain guide is associated with a shelf of the refrigerator. The meaning of the air curtain guide being "associated with a shelf" (or the shelf being "associated with an air curtain guide") is as discussed above for the first aspect of the invention. A gap may be left between the inner edge of the air curtain guide and the outer edge of the shelf. The at least one light source may be disposed in the air curtain guide so as to illuminate the shelf, for example the at least one light source may be disposed in the inner edge of the air curtain guide so as to illuminate the outer edge of the shelf.

In one embodiment, the at least one light source is disposed in the air curtain guide so as to illuminate a product display area of a shelf of the refrigerator with which the air curtain guide is associated. The term "product display area" is as described above for the first aspect of the invention. As discussed above, either an upper surface or a lower surface of the shelf may be the surface for receiving products in order to form the product display area.

In the case of the upper surface of the shelf being used, the at least one light source may be disposed in the air curtain guide so as to illuminate a product display area of a shelf of the refrigerator below a shelf with which the air curtain guide is associated (for example, the at least one light source may be disposed in the inner edge of the air curtain guide and angled so as to illuminate the product display area of a shelf below that with which the air curtain guide is associated). In the case of the lower surface of the shelf being used, the at least one light source may be disposed in the air curtain guide so as to illuminate a product display area of a shelf of the refrigerator above a shelf with which the air curtain guide is associated (for example, the at least one light source may be disposed in the inner edge of the air curtain guide and angled so as to illuminate the product display area of a shelf above that with which the air curtain guide is associated).

The light source may be any of the light sources as discussed above for the first aspect of the invention. The light source may be powered by any of the power sources as discussed above for

SUBSTITUTE SHEET RULE 26 the first aspect of the invention. The air curtain guide may include a recess and the light source may be disposed in the recess, as discussed above for the first aspect of the invention.

The method may include attaching the air curtain guide to a shelf or surface of the refrigerator by way of a connecting member. The connecting member may comprise any of the features as discussed above for the second aspect of the invention. Cabling associated with at least one of the power source and the light source may be routed through the air curtain guide. Alternatively or additionally, cabling associated with at least one of the power source and the light source may be routed through the at least one connecting member. The meaning of the terms "routed through", "cabling associated with the power source" and "cabling associated with the light source" are as discussed above for the first aspect of the present invention. The light source and the refrigerator may both be powered by a common power source, as discussed above for the first aspect of the present invention.

As used throughout, the term "disposed in" means either embedded in or attached to a surface thereof. In accordance with a fourth aspect of the invention, there is provided an open display refrigerator substantially as hereinbefore described with reference to the accompanying drawings.

In accordance with a fifth aspect of the invention, there is provided an air curtain guide

substantially as hereinbefore described with reference to the accompanying drawings.

In accordance with a sixth aspect of the invention, there is provided a method substantially as hereinbefore described with reference to the accompanying drawings.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 shows an open display refrigerator according to a first embodiment of the invention; Figure 2 is an expanded view of the upper section of the refrigerator of Figure 1;

Figure 3 shows an open display refrigerator according to a second embodiment of the invention; Figure 4 shows an open display refrigerator according to a third embodiment of the invention.

SUBSTITUTE SHEET RULE 26 Figure 1 shows a cross-section through an open display refrigerator 1. The refrigerator has an interior space 2 that is maintained at a lower than ambient temperature. Within the interior space 2, there are five shelves 3a-3e. The refrigerator 1 establishes an air curtain by blowing cold air from an air outlet 4 towards an air inlet 5. Air inlet 5 recovers air from the air curtain and a fan (not shown) within the refrigerator 1 recirculates the air to the air outlet 4. A cooling unit (not shown) within the refrigerator 1 maintains the recirculated air (and hence the air blown through the air outlet 4 to form the air curtain) at a desired temperature. The desired temperature is chosen to be lower than ambient and acts to prevent cold air in the interior space 2 from mixing with warm air exterior to the refrigerator 1.

Also shown in Figure 1 are aerofoils 6a-6e, each of which is fitted to the front edge of a respective one of shelves 3a-3e by way of brackets (not shown). The aerofoils 6a-6e assist in constraining the air curtain to the desired path and prevent warm air exterior to the refrigerator 1 from being entrained into the air curtain. In this case, the air curtain runs vertically from the air outlet 4 to the air inlet 5. The aerofoils 6a-6e are thus aligned vertically beneath an outer edge of the air outlet 4. More generally, they will be aligned to be parallel with the direction that the air curtain is intended to follow as it runs from the air outlet 4 to the air inlet 5 and roughly coincident with the outer edge of the air curtain.

Each aerofoil 6a-6e comprises a respective light source 7a-7e. Each light source 7a-7e is affixed to the inner edge of the aerofoil 6a-6e (i.e. the edge of the aerofoil which faces the front edge of the respective shelf 3a-3e). The light sources 7a-7e illuminate the interior space 2 of the refrigerator 1. The light sources 7a-7e are powered by a power source (not shown). Cabling (not shown) which connects the power source to the light sources 7a-7e is contained within the aerofoils 6a-6e and routed through the brackets (not shown). In this embodiment, each light source 7a-7e is embedded within the inner surface of the respective aerofoil 6a-6e, and is angled so as to illuminate the front edge of the shelf 3a-3e with which the aerofoil is associated. This is shown in more detail in Figure 2, in which light emitted by the light sources 7a-7e is denoted by arrows. In this embodiment, products lOa-lOe (of which products 10c- lOe are not shown) are placed on the upper surfaces 8a-8e (of which surfaces 8b-8e are not shown)

SUBSTITUTE SHEET RULE 26 of the shelves 3a-3e, so as to form a product display. The light sources 7a-7e illuminate the product display. In this embodiment, the light sources 7a-7e positioned in the inner edges of the aerofoils 6a-6e are angled so as to illuminate both the product display of the shelf 3a-3e to which the aerofoil 6a-6e is fitted, and the product display of the shelf immediately below. Figure 3 shows an embodiment similar to that of Figure 2, but in which the light sources 7a-7e are angled so as to illuminate only the product display of the shelf 3a-3e to which the aerofoil 6a-6e is fitted.

Figure 4 shows an embodiment similar to that of Figure 2, but in which the light sources 7a-7d are angled so as to illuminate only the product display of the shelf 3b-3e below the shelf 3a-3d to which the aerofoil 6a-6d is fitted.

SUBSTITUTE SHEET RULE 26