EP2098140A1

EP2098140A1 - Display apparatus and method of illuminating

Info

Publication number: EP2098140A1
Application number: EP08102313A
Authority: EP
Inventors: Cornelis Jan Weij
Original assignee: LiteCorp Europe BV
Current assignee: LiteCorp Europe BV
Priority date: 2008-03-05
Filing date: 2008-03-05
Publication date: 2009-09-09

Abstract

A display apparatus (1) comprises an object (2) for displaying one or more products and a light source (3) for illuminating at least a portion of a product display zone. The light source (3) is arranged at a distance from the object (2), and is adapted for directing at least a portion (4;4A,4B,4C) of its light towards the object (2). The display apparatus (1) is provided with one or more optical elements (6) for capturing a portion of the light and for redirecting and/or redistributing a portion of the captured light towards at least a portion of a product display zone behind the object (2).

Description

The present invention relates to a display apparatus, more in particular a display apparatus comprising a shelf for displaying products and a light source for illuminating a product display zone. The present invention further relates to a method of illuminating a product display zone of a display apparatus.
It is widely known to illuminate products displayed on shelves of displays apparatuses, such as display cabinets and vending machines. However, in such display arrangements, the shelves, side walls and other objects may cast shadows on products. This is in particular a problem for closed display cabinets.
In addition, in a display apparatus space and energy consumption are at a premium. Furthermore, especially in chilled display apparatus, heat generated by the light sources should be kept at a minimum as this must be carried away by the cooling mechanism and nearby objects or products may be adversely affected or even harmed by the heat.
In the art, various illumination arrangements have been provided to address these issues.
US 6,550,269 discloses a dispensing apparatus with directional Light Emitting Diode (LED) lighting. One or more LEDs are positioned within the apparatus which serve to illuminate an interior portion of the apparatus and the products positioned therein.
EP 1 321 076 discusses a lighting system employing bidirectional optics for illuminating a product display unit including at least first and second product display shelves and a lighting system. The lighting system comprises an illumination source mounted on the first shelf and being adapted to generate light directed toward the second shelf and at least one light control element for redirecting the light to illuminate from substantially the front portion to the rear portion of the product supporting surface of the first shelf.
Further, WO 2006/028802 describes a refrigeration system comprising a display case defining a display space with a front viewing area and a back area. A light source is located near the back area. A reflector is spaced from the light source and reflects light through the display space.
However, these known systems require individual light sources for each shelf. This complicates the systems and renders them relatively expensive. It also causes a relatively high energy consumption.
It is further known to use one or more luminescent light tubes arranged in front of a plurality of shelves and extending along the width of the shelves and/or across a plurality of shelves to illuminate these shelves. In such cases the light tubes may be mounted in a door frame of a display cabinet, e.g. as described in US 6,406,108 .
However, the resulting illumination patterns are not optimal, as products placed closer to the light source or light sources are lit brighter than products positioned more to the centre of the display. In addition, products positioned relatively further to the back of a shelf may also remain relatively poorly lit as they are in the shadow of the shelf above or below. Moreover, such known illumination arrangements may appear unnatural to a consumer and may therefore be not considered attractive.
Thus, there remains a desire for a display apparatus which is illuminated in a fashion that reduces or solves one or more of the problems outlined above.
To that end, a display apparatus is provided which comprises an object, such as a substantially planar object like a board, a panel or a shelf, for displaying one or more products and a light source for illuminating at least a portion of a product display zone. The light source is arranged at a distance from the object and is adapted for directing a portion of the light towards the object, for illuminating at least a portion of a display zone thereof. The display unit is provided with one or more optical elements for capturing a portion of the light and for redirecting and/or redistributing a portion of the captured light towards at least a portion of a product display zone behind the object.
Here, the expression "behind the object" is meant to convey the meaning of: "on the other side of the object as seen from the light source" or, equivalently, "on the other side of the object as seen in the propagation direction of the light".
With the present display apparatus, at least a portion of a product display zone behind an object such as a shelf may be illuminated. Also, portions of product display zones on two sides of the object may be illuminated by the same light source. Thus, the number of light sources in a display device may be reduced and (effects of) shadows may be reduced or even prevented. The present display device may therefore be much more cost efficient, e.g. in terms of space and/or energy consumption.
The display apparatus may comprise a plurality of objects, such as a plurality of boards and/or shelves and optical elements for capturing a portion of the light and for redirecting and/or redistributing a portion of the captured light towards at least a portion of a product display zone behind each of the said objects.
The embodiment according to claim 2 may simplify the apparatus, since the object and the optical elements may be aligned properly in a relatively easy manner.
The light source may be arranged in front and/or above the object or objectx. This provides a relatively natural-looking and relatively pleasing illumination. It also may prevent blinding of a consumer.
In accordance with the above, a method of illuminating at least a portion of a product display zone of a display apparatus comprising an object, such as a substantially planar object like a board, a panel or a shelf for displaying one or more products is provided. The method comprises generating light from a light source arranged at a distance from the object of a display apparatus, directing a portion of the light towards the object, capturing a portion of the light and redirecting and/or redistributing a portion of the captured light towards at least a portion of a product display zone behind the object.
This method allows illumination of product zones otherwise in a shadow or requiring additional light sources.
As an existing display apparatus may be improved and rendered more efficiently by modifying it in accordance with the above, a method for modifying a display apparatus comprising a an object, such as a substantially planar object like a board, a panel or for displaying one or more products and a light source for illuminating at least a portion of a product display zone on the object is provided. The method comprises providing the display apparatus with one or more optical elements for capturing a portion of the light from the light source and for redirecting and/or redistributing a portion of the captured light towards at least a portion of a product display zone behind the object.
Various advantages of the display apparatus and the methods will become apparent to those skilled in the art from the following detailed description of exemplary embodiments shown in the following figures of the drawings:

Fig. 1 is a schematic cross sectional view of a display apparatus;
Fig. 2 is a schematic cross sectional view of an improved display apparatus;
Figs. 3A-3I are several cross sections of possible optical elements attached to a shelf.
Fig. 4 is a schematic cross sectional view of another embodiment of the improved display apparatus.
Figs. 5A and 5B are a schematic front and top view, respectively, of a compound light source.
Fig. 1 and 2 show a schematic cross sectional view of a closed display cabinet 1, such as a chilled vending machine. Parts of the apparatus not relevant to the present disclosure, e.g. doors, legs, a refrigerator etc. are not shown, but will be obvious to the skilled person. Similarly, products or product placement devices, e.g. partition walls, screw worms etc. are not shown. In the Figures, like elements are indicated with like reference numerals.

The shown display cabinet comprises a plurality of shelves 2 for positioning articles to be displayed and a light source 3. A portion of each shelf 2, preferably essentially the entire shelf surface, serves as a product display zone in which the products may be visible for a potential consumer.
The light source 3 is arranged at a distance from the shelves 2 both in horizontal and in vertical direction here at or near the top side of the interior, in particular near the front. The light source 3 is adapted for directing light towards the shelves 2 and illuminating at least a portion of the product display zone on each shelf 2. The light source 3 provides a directed light cone 4 with an opening angle α.
As may be apparent from Fig. 1, essentially the entire surface of the top shelf 2 is illuminated by the light source 3. Lower lying shelves 2 are increasingly poorer illuminated as higher lying shelves cast shadows 5 behind them.
Furthermore, one or more side walls and/or partition walls of the cabinet 1 may also serve as a product display zone, e.g. substantially vertical product display zones such as for propped-up or hanging products, and be at least partially illuminated by the light source 3. Thus, portions of the various product display zones may suffer from shadows cast by the shelves 2 and/or by the respective walls.
Products placed on relatively low shelves 2 may therefore be relatively poorly visible. A relatively high product arranged on a shelf 2 may reach close to the bottom of a shelf 2 directly above it. Thus a portion of such products may be in a shadow. For the lowermost shelf or shelves 2, this may already occur for the frontmost row of products. Similar holds for product display zones behind side walls or partition walls. This may result in a relatively unattractive display. In the prior art, this effect is prevented by employing additional light sources, as outlined above.
Fig. 2 shows an embodiment of an improved display cabinet 1. Compared to Fig. 1, in Fig. 2 each shelf 2, except for the top and bottom shelves 2, is provided with an optical element 6. The optical elements 6 capture a portion of the light of the light source 3 and redirect and redistribute at least a portion of the captured light towards a portion of a product display zone behind the shelf 2 to which the elements 6 are provided. The additional light cones, and thus the additionally lit portions of the product display zones resultant from the optical elements 6 are indicated with reference numeral 7.
Thus, a larger portion of the product display zone of each shelf 2 below the top shelf 2 is illuminated and a more attractive display is provided. The increase of the illuminated area may be sufficient that the entire display cabinet may be properly illuminated from a single light source 3.
Figs. 3A-3I show a cross sectional view of a variety of embodiments of optical elements 6 arranged with respect to or attached on a shelf 2.
Figs. 3A-3C shows mirrors 8 as the optical element 6. The mirrors 8 may have an elongated shape and extend along at least a portion of the shelf 2 (out of the plane of the Figure) and may be attached to the cabinet, a side wall, a partition wall and/or to the shelf. In Fig. 3A, the mirror 8 captures light of a light source arranged above and in front of the shelf, as in Fig. 2, and redirects the light toward a product display zone behind the shelf, as indicated by the dashed lines.
The mirrors 8 in Figs. 3B and 3C are provided with a concave and a convex mirroring surface, respectively. As a consequence, the captured light is not only redirected behind the shelf, but also redistributed with respect to the incoming light over a larger angle, as indicated by the dashed lines.
The mirror 8 may be a facet of a transparent object such as a bar, a rod or a prism which extends along at least a portion of the shelf. Thus its alignment with respect to the shelf 2 may be assured.
Figs. 3D-3H show embodiments wherein the optical element 6 is a refractive element such as a lens 9.
Fig. 3D shows a particularly simple embodiment, wherein the optical element 6 is a plano-convex or positive cylindrical lens 9. Here, the lens 9 is arranged underneath the shelf 2 and protrudes therefrom, exposing a light capturing surface 9A. Light from the light source 3 that is captured by the surface 9A is refracted by the lens 9 and exits the lens at the exit surface 9B. Thus, the captured light is redirected and redistributed toward a product display zone behind the shelf 2, as indicated by the dashed lines. A positive lens converges incoming light to a focal region. An elongated positive lens yields a line focus. Behind the focus the light diverges. By suitably selecting the distance between the lens and the focus position, i.e. choosing a particular lens strength, a desired illumination effect may be obtained.
The embodiment of Fig. 3E is a modification of that of Fig. 3D. In Fig. 3E the light capturing surface 9A is arranged essentially perpendicular to the incoming light such that potential undesirable reflections off surface 9A are reduced. The lens 9 is further provided with a (wholly or partially) reflective surface 8A for directing captured light further towards the rear end of the shelf 2 and improving the capturing efficiency of the lens 9.
In the embodiment of Fig. 3F, the exit surface 9B of the optical element 6 is concave. The capturing surface 9A essentially flat. This results in a plano-concave, negative lens 9 which redirects and redistributes the captured light by dispersing it. Here, the lens 9 is also arranged with the capturing surface 9A essentially perpendicular to the incoming light.
In the embodiment of Fig. 3G, the exit surface of the optical element 6 has a compound curvature, i.e. comprising segments of different curvatures. Here, the exit surface has a concave segment 9B' and a convex segment 9B". The resulting light distribution for the illumination depends on the actual shapes of the segments and their combination. Here, the positive focusing part of the lens 9, due to segment 9B" may increase the illumination strength on the frontmost products, such that shadows of the element 6 due to the incoming light of the light source being captured are reduced or prevented. The negative part of the lens 9, due to surface 9B', disperses a portion of the captured light behind and towards the back of the shelf 2.
In Fig. 3H, the optical element is a concave-convex lens 9, resulting in yet another light distribution pattern, which may be essentially homogeneous perpendicular to the direction of extension of the lens 9.
Fig. 3I shows a transparent shelf 2 wherein an optical element 6 similar to that of Fig. 3D is integrated. A portion of the shelf 2 serves as a lens 9, and another portion serves as the light capturing surface 9A. Such arrangement may be relatively smaller and less space-consuming than the embodiments of Figs. 3A-3H. Instead of an essentially entirely transparent shelf 2, an opaque or translucent shelf may be provided with a transparent edge formed according to Fig. 3I.
Thus, a particular illumination effect, making use of the particular arrangement of the shelf 2 and (the incoming angle of the light if) the light source 3, may be obtained by selecting a particular optical element 6. For this, the various aspects of the shown embodiments of an optical element 6 and variants thereof may be suitably combined. E.g., as will be apparent to the skilled person, an optical element 6 may comprise a combination of flat segments and/or have diverse smoothly or abruptly varying curvatures.
Reflective surfaces or mirrors may be fully reflective or partially reflective, reducing the mirrors casting shadows themselves. The reflective surfaces of reflective elements may be smooth, yielding specular, mirror-like reflection, multi-faceted, yielding numerous bright spots for a playful illumination effect, or relatively rough, yielding substantially diffuse reflection and possibly a more homogeneous illumination, etc. Similarly, refractive elements may comprise translucent or transparent materials such as glass or plastic materials such as acrylic glass. The exit surfaces of refractive optical elements may be smooth, e.g. polished, multi-faceted or rough, e.g. ground or sanded, for providing different illumination effects, etc. Combinations are equally conceivable.
An optical element may extend along the full width of a shelf, or in general along a full extension (length, width or height) of an object. Also, different optical elements may be arranged next to each other along a shelf for providing different optical effects e.g. spot-lighting. It is conceivable to have one row of relatively low products, such as small bags of candy, being illuminated relatively far towards the back of the display, whereas in an adjacent row of relatively high products, such as "king-size" candy bars or bottles standing up, it is desired to have the frontmost products illuminated essentially homogeneously over their full height.
Optical elements 6 may be arranged in different ways, e.g. formed integrally with a shelf (e.g. Fig. 3I), be attached thereto separately (e.g. Figs. 3C-3H), and/or be mounted to side walls of a display cabinet etc. Suitable means and/or ways of attachment may be clamping, gluing, screwing etc. of the element, or fitting it into a holding or mounting arrangement, e.g. one or more hooks, cradles or clamps.
An effective illumination which is essentially uniform over the width of the shelf may be achieved by a homogeneous single light source substantially extending for the width of the shelf or shelves. Due to the optical elements 6, the light source may be positioned relatively close to the front surface of the shelf or shelves and still adequately illuminate a product display zone relatively far towards the rear of the shelf than in known displays. Thus a more compact display may be constructed, or conversely, deeper shelves may be used allowing more space for displaying products in a given display apparatus. Thus the products may be placed further apart, giving a relatively luxurious appearance, or more products may be stored possibly reducing the required restocking frequency.
A more compact arrangement, or a smaller volume providing the same storage space may also render a chilled display apparatus such as a chilled vending machine more energy efficient.
Also, providing an existing display device with optical elements such as those discussed above may generally improve the illumination thereof. For this, it should be noted that humans tend to appreciate relatively bright illumination coming from above as being natural and pleasing, and tend to turn away from (objects placed in) shadow areas. A properly illuminated display may thus may attract and increase (positive) attention for displayed products.
For essentially uniform lighting across the width of a shelf, the light source 2 may be a luminescent light tube or an array of light sources such as relatively small incandescent light bulbs. However, both the energy consumption and generated heat of such light sources may be overcome by using one or more Light Emitting Diodes (LEDs). This is particularly useful for closed display cabinets, such as chilled vending machines.
In a suitable arrangement for a display cabinet the light source 3 is formed as an array of a plurality, e.g. five, six or seven, of lamps such as relatively high-power LEDs. One or more LEDs may be provided with reflectors and/or lenses for providing a suitable light cone. Preferably, the light cones are directed to overlap for providing an essentially uniform illumination.
Fig. 4 shows a variant of Fig. 2, provided with a light source 3 having individual lamps. The light source 3 is shown in Figs. 5A and 5B. As shown in Fig. 4, the individual light cones 4A, 4B, and 4C have different, relatively narrow opening angles α, e.g. in the range of about 45-20, 30-10 and 15-5, e.g. about 30, 15 and 6 degrees opening angle. Each light cone 4A,4B,4C is suitably directed for illuminating particular sets of shelves or product display zones thereof, narrower light cones (4B,4C) being suitable for illuminating (sets of) shelves at a steeper angle such as lower lying (sets of) shelves.
As shown in Fig. 5A and 5B, the light source 3 comprises a plurality of individual LEDs 10A-10D, arranged in three pairs (10A; 10B; 10C) and a single LED 10D. The LEDs are provided with a reflector 11 and a lens 12 for adapting them for providing light with a relatively narrow light cone. The reflectors 11 and/or lenses 12 are used for shaping the light cones. The LEDs 10A (10B; 10C) yield light cone 4A (4B; 4C) of Fig. 4. Due to the longer distance between the lamps and the lower shelves, a narrower light cone may still result in an substantially homogeneous illumination of a shelf. The single LED 10D may be used to illuminate one or more shelves (such as an overall light cone 4 as in Fig. 2) and/or for providing spotlight effects.
The invention is not restricted to the above described embodiments which can be varied in a number of ways within the scope of the claims. For instance, the display apparatus need not be closed. The light source 3, or constituent individual light sources thereof may be movable and/or programmable. In a vending machine comprising a door, the light source may be arranged on or in the door. The light source may also be arranged as a separate object from a cabinet. Additional light sources may also be used.
Further, the shelves, walls or other objects for displaying products may have various edge shapes. An optical element may closely follow the shape of the edge along at least a portion thereof and it may extend along the full length of the shaped edge or along a portion thereof. One or more objects for displaying products and/or optical elements may comprise or be provided with parts for identifying the displayed goods, such as labels and/or price tags. Also a side object such as a top and/or bottom shelf may be provided with optical elements. A wall or shelf may also comprise a grid-portion.
The light source and optical element(s) may be arranged for illumination from other directions than from above and from the front as shown in the Figures. Optical elements may also be added to vertically arranged panels or boards or other objects. Portions of optical elements may be coloured. Surfaces of optical elements may be coated, e.g. anti-reflection coated.

Claims

Display apparatus (1) comprising an object (2) for displaying one or more products and a light source (3) for illuminating at least a portion of a product display zone, wherein the light source (3) is arranged at a distance from the object (2), and is adapted for directing at least a portion (4;4A,4B,4C) of its light towards the object (2), and wherein the display apparatus (1) is provided with one or more optical elements (6) for capturing a portion of the light and for redirecting and/or redistributing a portion of the captured light towards at least a portion of a product display zone behind the object (2).
Display apparatus (1) according to claim 1, wherein the object (2) is provided with the one or more optical elements (6).
Display apparatus (1) according to any one of the preceding claims, wherein the one or more optical elements (6) comprise a reflective element (8).
Display apparatus (1) according to any one of the preceding claims, wherein the one or more comprise a refractive element (9).
Display apparatus (1) according to any one of the preceding claims, wherein the one or more optical elements (6) are arranged along substantially the full extension of the object (2).
Display apparatus (1) according to any one of the preceding claims, wherein the light source (3) comprises a plurality of light sources (10A,10B,10C,10D) for directing light in mutually differently directions.
Display apparatus (1) according to any one of the preceding claims being a vending machine.
Method of illuminating a product display zone of a display apparatus (1) comprising an object (2) for displaying one or more products, the method comprising generating light from a light source (3) arranged at a distance from the object (2) of a product display apparatus (1), directing a portion (4;4A,4B,4C) of its light towards the object (2), capturing a portion of the light and redirecting and/or redistributing a portion of the captured light towards at least a portion of a product display zone behind the object (2).
Method according to claim 8, wherein the captured light is redirected and/or redistributed by means of a reflective (8) and/or refractive (9) optical element (6).
Method for modifying a display apparatus (1) comprising an object (2) for displaying one or more products and a light source (3) for illuminating at least a portion of a product display zone on the object, the method comprising providing the display apparatus with one or more optical elements (6) for capturing a portion of the light from the light source (3) and for redirecting and/or redistributing a portion of the captured light towards at least a portion of a product display zone behind the object (2).