WO2001000065A1 - Lighting system for display cabinet - Google Patents

Abstract

A display case to display product on shelves including a frame (36), a light source (42) is positioned adjacent the shelves for illuminating the product. The light source is preferably a plurality of discrete, spaced apart light sources (56) arranged longitudinally relative to each other. The light source are preferably xenon incandescent lamps.

Description

LIGHTING SYSTEM FOR DISPLAY CABINET

BACKGROUND OF THE INVENTIONS Field of the Inventions This invention relates to lighting systems, and components and assemblies for lighting systems, for display cases, for example refrigerated display cases, freezers, coolers and other product cases.

Related Art Typically, display cases are illuminated with fluorescent lighting to allow better viewing of product. Fluorescent lamps come in fixed sizes. It is often difficult to design display cases having the desired size for receiving and displaying product and also accommodating fluorescent lamps of a fixed size while still adequately illuminating the product. For example, many fluorescent lamps are available in increments of one foot lengths and a display case having a three foot inside dimension could use only a two foot lamp or smaller, in order to accommodate the lamps sockets and permit installation and replacement. Consequently, the illumination of product in the display case would not be optimal compared to a situation where a light source could extend about two feet ten inches with two inches remaining for lamp sockets. Once a fluorescent light fixture is installed, the length and distribution of the light source is essentially fixed. If the user wished to change the light distribution, the lamps would have to be changed and/or the circuits would have to be re-installed or reconfigured. Therefore, use of fluorescent light fixtures for illuminating display cases does not provide a lot of flexibility. Fluorescent lamps typically require a ballast to start the lamp and regulate the power applied to the lamp. The voltage required to start the lamp's depends on the lamp length and its diameter, with larger lamps requiring higher voltage. The ballast is designed to provide the proper starting and operating voltage required by the particular lamp. The ballast provides the proper voltage to fire the lamp and regulates the electric current flowing through the lamp to insure stable light output.

Electromagnetic ballast are relatively large and inconvenient to use in display cases. Electronic ballasts operate at significantly higher voltages and frequencies to operate the lamps, and may contribute to potential hazards such as electric shock, lamp breakdown or circuit breakdown. Such potential problems may be compounded in cold environments such as are encountered in refrigerated display cases such as coolers and freezers. Freezers may operate at temperatures as low as minus 20 degrees Fahrenheit, making more difficult the job of the ballast in illuminating the lamp. The extreme environment may contribute to ballast failure or other circuit failure.

The extreme environments of some display cases also affect light output. In colder environments, light output of fluorescent lamps decreases. Consequently, circuits have been designed to drive the lamps at higher voltages to compensate. In other designs, heater wires or booster wires may be included to promote illumination. However, higher driving voltages reduce lamp life. Even with higher driving voltages, light output is not usually consistent over the life of the lamp because of the characteristics of fluorescent lamps. As fluorescent lamps age, their light output decreases. Consequently, illumination of product varies in the display case over time. Because fluorescent lamps have extended length, on the order of feet, any of lamp failure has a significant impact on product illumination. In many display cases, lamps are five feet or six feet in length. If a single lamp fails, the light is produced over the five or six foot length of the case occupied by the lamp. If the display case uses only a single lamp, the product would be dark. If the display case uses multiple lamps, product illumination would be uneven. Therefore, loss of a single lamp has a significant impact on the display case.

Fluorescent lamp connections used in display cases are also often subject to misalignment or damage, which could lead to improper lamp connections. For example, lamp sockets may be installed without the proper spacing or without the proper orientation so that connection with the lamp may lead to arcing or contamination of the lamp-socket junction. Such misalignment may have more significant consequences in refrigerated display cases, where lower temperatures may lead to moisture condensation on contact surfaces and subsequent corrosion. Additionally, inadequate lamp connection may lead to shorter lamp life.

Typical fluorescent lamp connections include sockets referred to as tombstone sockets, where the lamp has two ends each with a pair of pins for engaging respective tombstone sockets. The pins are inserted sideways into the socket until lamp is centered in each socket. The lamp is then rotated about its longitudinal axis, allowing the pins to come into contact after rotation with the contacts in each socket. This socket design reduces the possibility of one end of the lamp becoming live when the opposite end is inserted into a socket. These tombstone sockets, however, are sometimes difficult to achieve a proper connection with the lamp. Proper installation typically requires simultaneous alignment of both ends of the lamp with the respective sockets followed by some rotation to achieve contact. Often the ends do not align correctly with the socket, and the pins or the sockets can be damaged.

Display case lighting systems, especially those in refrigerated display cases, are relatively complicated when multiple light sources are used. Often, multiple ballasts are required, depending on the number of light sources, and the wiring complexity increases as a function of the number of lights and ballasts. Similarly, the number of junctions between components increases.

SUMMARY OF THE INVENTIONS

The present inventions provide for a lighting system for a display case which is easy to install and maintain, improves illumination of product, is less sensitive to extreme temperature conditions and is safer than many conventional display case lighting systems. Lighting systems incorporating one or more aspects of the present inventions can operate at relatively low voltage and at line frequency, thereby reducing the risks of damage. The lighting system is simple in design and can be easily configured to accommodate a variety of dimensions and locations in a display case.

In one aspect of the inventions, a display case is provided for displaying items and includes a frame and a support for supporting items to be displayed. A plurality of light sources is positioned adjacent to the support for illuminating the items to be displayed. In one preferred embodiment, the plurality of light sources are discrete, separate and spaced apart lamps arranged longitudinally relative to each other. In another preferred embodiment, the light sources are a plurality of lamps and each lamp includes a longitudinal dimension and each lamp is positioned so that the longitudinal dimensions of the lamps are parallel. In another embodiment, the lamps are oriented vertically in the display case. Preferably, the lamps are xenon lamps having a high light output and capable of operating at low voltage levels.

In another aspect of one or more of the present inventions, the lamps are preferably connected in parallel to maximize the light output for a given voltage level. In another embodiment, the lamps can be arranged in groups, each group coupled in parallel relative to the other groups, and each lamp within a group coupled in series relative to the other lamps in the group. When coupled in parallel, all other lamps coupled in parallel are not affected if one lamp goes out. Additionally, the loss of one lamp typically does not noticeably affect the illumination of product. Lamps are easy to install and service, and a complete lighting system is relatively easy to design and install for a given display case.

In a further form of one of the inventions, the lighting system includes a supply of electrical energy, such as may be provided through a flexible, insulated two wire conductor pair, mounted to or supported by a mullion or other frame member in a refrigerated display case. The light sources may be positioned behind one or more lenses and/or in front of one or more reflectors to control the way product is illuminated. The light sources may be placed on or adjacent shelves or other product supports instead of or in addition to placement on mullions. The light sources are well-suited to operating in the extremes of refrigerated display cases, including freezer cases, and do not require as much wiring as conventional fluorescent lighting systems in such cases.

In another aspect of one form of the inventions, a display case for displaying items includes a support for supporting items to be displayed and at least one light source. The light source includes a largest outside dimension, such as an outside diameter, and further includes a conductive element for supplying current to the light source, wherein the conductive element has an outside dimension that is at least 10% and preferably more than 50% of the largest outside dimension of the light source. In one disclosed embodiment, the contact diameter is about the same as the lamp diameter, and preferably at least 75% of the lamp outside diameter. The lamp may have a glass envelope having a first diameter and further including first and second contacts extending longitudinally relative to the light source and having a largest outside dimension at least half the first diameter.

Where the light source conductor has an outside dimension at least 10% that of the light source outside dimension, at least one connector may be provided for the light source, for supplying current to the light source, which has a contact surface for contacting the light source contact longitudinally and wherein the light source contact is insertable into the at least one connector in a direction other than longitudinally. For example, engagement may be achieved by moving the light source and connector laterally or transversely relative to each other, or perpendicular to a longitudinal axis of the light source. These and other aspects of the present inventions are considered in conjunction with the drawings, a brief description of which follow, along with the detailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view of a refrigerated display case having glass doors permitting viewing of product inside the case and permitting access to product on shelves inside the case.

FIG. 2 is a top plan and partial cutaway view of the refrigerated display case of FIG. 1 showing end and center mullions and light sources for illuminating product on the shelves.

FIG. 3 is a detailed top plan view of a center mullion and lighting system similar to that depicted in FIG. 2.

FIG. 4 is a side elevation and partial cutaway view of a mullion and light source for use in a display case such as that shown in FIG. 1.

FIG. 5 is a partial, detail side elevation view of the mullion and a light source in accordance with one aspect of the present inventions.

FIG. 6 is a front elevation view of a part of a mullion and light sources extending through a reflector for use in a display case such is that shown in FIG. 1. FIG. 7 is a schematic diagram of a lighting circuit for use in the display case of FIG. 1.

FIG. 8 is a partial side elevation view of a shelf and lighting system in accordance with one further aspect of the present inventions for use in a display case such as a refrigerated display case. FIG. 9 is a side elevation view of a portion of a lighting system in accordance with another aspect of the present inventions.

FIG. 10 is an end elevation view of the portion of the lighting system shown in FIG. 9.

FIG. 11 is a schematic and partial side sectional view of a lighting system in accordance with a further aspect of the present inventions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following specification taken in conjunction with the drawings sets forth the preferred embodiments of the present inventions in such a manner that any person skilled in the art can make and use the inventions. The embodiments of the inventions disclosed herein are the best modes contemplated by the inventor for carrying out the inventions in a commercial environment, although it should be understood that various modifications can be accomplished within the parameters of the present inventions.

In accordance with several aspects of the present inventions, a display case is provided for displaying items which can be illuminated through a plurality of light sources which are easy to configure and install in a wide variety of display case configurations. The light sources have a relatively high light output and can operate at line frequency and low voltage. While the inventions will be considered in the context of a refrigerated display case, it is possible that they can be extended to other display cases. However, it is believed that the present inventions are particularly suited to refrigerated display cases, having extreme environmental conditions and often having space and other design limitations. Therefore, the following discussion will be directed primarily to refrigerated display cases, including coolers and freezers. A display case, such as a refrigerated display case 20 (FIG. 1) includes doors 22 mounted in a surrounding frame 24. The doors 22 have glass panels 26, which allow someone, such as a customer in a supermarket, to look through the panels 26 at items 28 displayed on shelves 30 inside the case 20. The items 28 inside the display case 20 may or may not be refrigerated items, such as frozen foods. Typical refrigerated display cases, for example, use shelves that are assembled in units approximately 30 inches in length, across the front of the unit. Other details about conventional refrigerated display cases are included in U.S. patent number 5,895,111, the specification and drawings of which are incorporated herein by reference. The doors 22 can be swing doors supported on hinges 32 (FIG. 2) or sliding doors (not shown). Most refrigerated display cases having multiple shelves for holding and displaying product are closed with doors, but some display cases are open units using a moving sheet of cold air over the front of case to keep the product refrigerated. The doors close and create a thermal and airtight seal against the frame 24 (FIG. 1) using gaskets (not shown). Along the tops and bottoms of the doors, the doors seal against horizontal frame members, and along the sides, the doors seal against a side frame member 34 or a mullion 36 (FIG. 2). Each mullion 36 extends vertically between the top and bottom frame members, and are typically considered frame elements which support the structure and provide sealing surfaces for the sides of the doors.

Considering the mullions 36 in more detail (FIG. 3), common mullions are typically extruded aluminum structures 38 mounted at the tops and bottoms by suitable brackets (not shown) and covered by a plastic mullion cover 40. Typically, mullions also house wiring for supplying electricity to various electrical components such as heater wires and lighting systems, as well as ballasts for energizing fluorescent light sources. This wiring and ballasts take up considerable room in the mullion and produce relatively complicated wiring schemes to supply the electrical energy to the fluorescent lamps.

The mullion cover 40 supports a light source 42, describe more fully below, for illuminating the items to be displayed (28 in FIG. 1) and preferably a reflector 44 for reflecting light from the light source 42 back into the case. The mullion cover also preferably supports one or more lenses 46 coupled by a bridge 48 and retained in place on the mullion cover by one or more retaining clips 50. The bridge may be painted or formed with a matte white color to improve light distribution. Mirrored surfaces may also be included. The lenses 46 preferably have the optical characteristics set forth in the '111 patent. However, it should be understood that the lenses can take any number of configurations, generally with the goal of improving the illumination of product on the shelves or other product support in the display case. In the preferred embodiment, the lighting system, which includes the light source 42, primarily, as well as any reflector and/or lenses that may be included. Preferably, the lighting system is designed to make the illumination of the product as clear and bright as possible without producing glare or excessive brightness. The lighting system also preferably produces a uniform illumination of the product across the front of the shelf, at all levels, and preferably at all depths from the front of the shelf to the back of shelf. However, because light intensity diminishes with the square of the distance from the light source, uniform illumination from the front of the shelf to the back of the shelf is more difficult to achieve. Considering the light source in more detail (FIGS. 4-6), light source is preferably a plurality of discrete light sources 52. In the preferred embodiments, the individual light sources can be arranged, inserted, removed, configure or positioned separately to provide more flexibility in the lighting configurations, including positioning, illumination, and the like. Individual light sources also provide for continued illumination even if one or several of the individual light sources fail. Some discrete and individual light sources, such as incandescent lamps, are easy and simple to install, easy to service, have a relatively high light output, even in low temperatures, have relatively longer lives compared to conventional lighting systems, and can use very simple wiring designs. The light sources can be light emitting diodes (LED), incandescent lamps or halogen filled incandescent lamps. Other light sources are possible as well.

The light sources can be placed in any number of positions to illuminate the product as desired. For example, light sources can be placed around the end of a case, around the frame openings of a case, on, about or under the shelves or other product supports, all one place or distributed. In one preferred embodiment (FIG. 4), the light sources 52 are arranged to be coaxial with their neighbors and mounted to the mullion 36 to illuminate the fronts of the shelves, from the top of the case to the bottom. In another embodiment (FIG. 8), the light sources can be arranged, again preferably co- axially, along the front or underside of a shelf 30 for illuminating product on the same shelf and/or product on an adjacent shelf. Each of these configurations will be discussed in more detail below. However, it is understood that other configurations of the lighting system can be used. Generally, it is helpful to have the light sources mounted to the energy source, such as the wire pair, so that the placement of the wire also positions the light sources. Additionally, having a flexible or bendable energy source to which the light sources are mounted allows easier positioning and mounting of the light sources relative to the display case and product to be illuminated. Furthermore, the light sources and their carriers do not need to be fixed to a substrate as in conventional display cases, but can be removably supported by the energy source, such as the wire pair in the preferred example.

In one preferred embodiment, each individual light source 52 is a xenon bulb such as produces 10 watts at 24 volts available from Lighting and Electronic Design of Palmdale, California, under their model number BL-X10-24. Each bulb preferably mcludes a glass envelope 54 (FIG. 5) capped at each end by a pointed metal contact end cap 56 for energizing the filament 58 through conductors 60. Alternating electrical energy is supplied to the end caps 56 through resiliently biased contact clips 62 A and 62B. The contact clips 62 are retained in and supported by a bulb carrier 64, which may be made of clear plastic or a colored plastic such as white urea. In the preferred embodiment, the lamps are supported by the bulb carrier as close to the mullion 36 possible, so as to provide a low-profile and take up as little space as possible.

In one preferred embodiment, the bulb carrier 64 is based against a substrate such as the flat surface 66 (FIG. 3) of the mullion cover 40 and extends outwardly toward the interior of the case through an opening in the reflector 44 so the lamp 56 extends on the product side of the reflector 44. In the preferred embodiment, the spacing between the lamp 56 and the reflector 44 is kept at a minimum. The bulb carrier 64 preferably extends over and on each side of, and is supported by, an insulated wire pair 68 for supplying alternating current preferably at about 24, 28 or 30 volts to respective contact clips 62A and 62B. As in the bulb carrier supplied by Lighting and Electronic Design, the contact clip 62A includes a barb or other projection punched from the base 70 of the contact clip 62A to pierce the insulation on a first conductor 68 A of the insulated wire pair 68 to supply energy from the first conductor 68A to the contact clip 62A. Likewise, the contact clip 62B includes a base (not shown) having a barb or other projection punched from it which pierces the insulation on the second conductor 68B in the wire pair for supplying electrical energy to the contact clip 62B. 28 volt alternating current is provided through the wire pair 68 to energize the lamp 56. In an alternative embodiment, one or more of the bulb carriers can be mounted to and supported by a fixed or removable bus, whereby each bulb carrier can be received in a receptacle to support the bulb carrier and to provide electrical energy to the bulb. They can also be received in a track aπangement, whereby the position of the bulb and carrier can be adjusted, while still providing energy to the bulb.

Using the wire pair to support and mount the bulb carriers gives a measure of flexibility in positioning and orienting the light sources. The light sources can be positioned in any number of configurations, depending on where the wire pair can be placed in the display case. Mounting and positioning any portion of the wire pair will also position and orient the bulb carriers that are supported by the wire pair in the same area. Additionally, mounting the wire pair to be removable will also make the light sources removable and repositionable. Therefore, there are configurations of the lighting system that allow it to be more easily removable or repositionable than conventional lighting systems in display cases. The lamps can then be considered to follow the substrate to which they are mounted, and they can be removable. Likewise, to the extent the light sources are mounted to or supported by a substrate such as the wire pair, and the wire pair is movable and repositionable, the light sources will be movable and repositionable as well. The lamps, therefore, can follow a straight-line arrangement where their longitudinal axes are aligned, or they can follow a curved path where the wire pair, for example, is positioned to follow a curved path. The lamps can also be considered to follow the positioning of the energy source, when the lamps are supported by the wire pair.

Each of light sources 52 is mounted in a corresponding bulb carrier which is supported by the wire pair, which in rum is supported by the mullion cover 40, to extend through a corresponding opening in the reflector 44. The wire pair 68 preferably extends the entire length of the reflector 44, and bulb carriers are preferably positioned at the desired spacing through openings punched or formed in the reflector 44 for providing the spacing desired for maximum illumination of the product. Therefore, for maximum illumination, all of the bulb carriers would be provided with a bulb. To reduce the illumination, change the light distribution or otherwise change the lighting provided by the lighting system, selected bulbs can be removed from their carriers. Additionally, removing one bulb, which may be about an inch or more in length, does not have a very noticeable effect on the illumination of product where the bulb is a relatively small percentage of the total number of bulbs in the lighting system. The reflector 44 is preferably removably retained in place on the mullion cover by inserting the opposite edges 72 and 74 under respective tabs 76 and 78 on the mullion cover 40. Holding the reflector on the mullion cover 40 also helps to hold the assembly of the bulb carriers 64 and wire pair 68 against the flat surface 66 of the mullion cover 40. This would reduce the possibility that expansion or contraction in the environment of the display case would affect the mounting and positioning of the assembly. Other methods are available for mounting the assembly to the mullion or other support structure. For example, double sided tape or foam, Velcro hook-and- eye loops or other positioning elements can be applied to the back of the wire pair along the entire length or along one or more segments of the wire pair to help hold the assembly in place. Alternatively, or in addition, clips, brackets or other mounting elements can be used to hold the wire pair or individual bulb carriers against a support surface. Such mounting and fastening elements as cable ties, staples, fasteners and bayonet mounting elements can also be used to hold the lamp assembly in place. In the preferred embodiment, the assembly is a removable, such as by removing the reflector 44 and any fasteners that may be used. Having the flexibility to remove and replace the lighting system permits variations in the configuration of the lighting system and easy repair and replacement.

The lenses 46 are preferably designed, positioned and configured so as to produce the desired illumination for the product. Where the lighting system is not on a mullion such as 40 for illuminating product on shelves 30, the lenses and light system are preferably configured to provide uniform illumination over the front of the shelves. Therefore, the product will appear uniformly illuminated, minimizing any glare or shadows across the product from one side to another and up and down. In the preferred embodiment, the lighting system preferably includes a standard connector 80 (FIG. 7) for connecting the wire pair 68 to a transformer 82. The transformer 82 is coupled to a standard supply 84 of line voltage and current add a standard frequency. The transformer preferably steps down the voltage to less than 60 volts and preferably around 30 or 24 volts. At the lower voltages, there is a reduced potential for shock or injury arising from damaged wiring, or the like.

Additionally, ballasts and complex wiring used to energize fluorescent lamps can be avoided, thereby simplifying the lighting system. In the preferred embodiment, the connector 80 is preferably located close to the mullion so that the wiring pair and accompanying bulb carriers can be easily removed from the mullion and disconnected for repair or replacement. For example, the connector 80 can be positioned within the mullion on the opposite side of the mullion cover from the wire pair. The connector 80 can be positioned at the top or at the bottom of the mullion or elsewhere that is convenient.

The bulb carriers 64 are shown in FIG. 7 as being mounted in parallel. It should be understand that one or more of the light sources can be mounted in series with respect to each other and then coupled to the wire pair 68. The series mounted light sources would then be grouped together and treated as a unit or group. Multiple groups of series-connected light sources can be arranged to be connected to the wire pair in parallel with respect to each other, and even in parallel with respect to individual light sources mounted to the wire pair 68. Any number of combinations of series and parallel groups and individual light sources can be made. Different combinations will produce different light outputs as well as different circuit combinations. For example, series connected light sources will have lower light output but longer bulb life. However, when any light source in a series goes out, all of the series connected light sources will turn off.

The transformer 82 can be configured to be adjustable. An adjustable transformer would allow adjustment of the light output for the lighting system. Therefore, having an adjustable transformer 82 provides another degree of adjustability for the lighting system.

Other bulb carriers and bulb designs can be used in the lighting system of the present inventions. As shown in FIGS. 9 and 10, a wire pair 90 supplies electrical energy through one or more bulb sockets 92 for pairs of bulbs 94 and 96. The bulb permits passage of light out of the glass envelope along a longitudinal axis of the bulb in addition to radially, which allows a wider angle of illumination than is possible with many fluorescent lamps. The bulb and socket may be similar to the Quantum bulbs and sockets marketed by Lighting and Electronic Design. The bulbs can be incandescent bulbs, xenon bulbs, or other halogen light sources. Other lighting configurations are also possible. As shown in FIG. 8, a light system 98 can be mounted to the front or underneath the front of a shelf 30 for illuminating product on an adjacent shelf, or for illuminating product supported by the same shelf as the light sources are mounted to. In the embodiment shown in FIG. 8, the lighting system is for illuminating product on a next lower shelf. The lighting system includes a wire pair 100 similar to wire pair 68 A and 68B for supplying electrical energy to one or more light sources 102, for example light sources similar to lamps 52 or 94, for producing light. The light passes through a lens 104 to be directed to product supported by an adjacent shelf. In the embodiment shown in FIG. 8, light is directed to product at the front of the adjacent shelf underneath the shelf 30. Current for the wire pair 100 can be obtained from a transformer or other suitable source through a conductor which may pass underneath or along one side of the shelf 30.

The lens 104 can take any number of configurations, depending primarily on the type of light distribution desired. In one preferred embodiment, the lens is configured in a manner similar to that described in the '1 1 1 patent.

Light source 98 can also be configured (FIG. 1 1) to illuminate product in more than one direction. In FIG. 11, a light source 106 mcludes one or more lamps 108 supplied by a wire pair 1 10 for producing light to be distributed by a first lens 1 12 and a second lens 1 14. For example, the light source 106 may be mounted on the front of a shelf, such as shelf 30, and the lens 112 is used to distribute light to product on the shelf 30, while the lens 1 14 is used to distribute light to illuminate product on the shelf below. The lenses 112 and 114 are preferably designed to project the light in the desired direction as a beam or with the desired convergence or divergence. Other arrangements are possible for illuminating product using light sources such as those shown in FIG. 3, FIG. 8 and FIG. 1 1.

Having thus described several exemplary implementations of the invention, it will be apparent that various alterations and modifications can be made without departing from the inventions or the concepts discussed herein. Such operations and modifications, though not expressly described above, are nonetheless intended and implied to be within the spirit and scope of the inventions. Accordingly, the foregoing description is intended to be illustrative only.

Claims

WHAT IS CLAIMED IS:

1. A display case for displaying items, the case comprising: a frame; a support for supporting items to be displayed; a light source positioned adjacent the support for illuminating the items to be displayed, the light source including a plurality of discreet light sources arranged longitudinally relative to each other.

2. The case of claim 1 wherein the light sources are xenon lamps.

3. The case of claim 1 further comprising an electrical conductor extending longitudinally and wherein the plurality of light sources are mounted to the conductor.

4. The case of claim 3 wherein the electrical conductor extends a distance that is substantially straight and wherein the light sources have a longitudinal axis and wherein the lamp axis extends parallel to the electrical conductor.

5. The case of claim 3 wherein the conductor is an insulated two conductor wire pair connected to a low voltage source.

7. The case of claim 5 wherein the low voltage source is less than 60 volts

8. The case of claim 5 wherein the source is less than 30 volts.

9. The case of claim 5 wherein the wire pair is mounted to a mullion.

10. The case of claim 9 wherein the wire pair extends substantially the entire length of the mullion.

11. The case of claim 9 wherein the wire pair is removably mounted to the mullion.

12. The case of claim 5 wherein the wire pair supports the light sources.

13. The case of claim 5 wherein the wire pair includes approximately one lamp per two inches.

14. The case of claim 5 wherein the light sources are coupled to and supported by the wire pair through a carrier having a base and conductors supported by the base extending into the wire pair for electrically connecting the lamp to the conductors in the wire pair.

15. The case of claim 14 wherein the wire pair is coupled to the low voltage supply through a removable connector.

16. A refrigerated display case for displaying product on shelves, the case comprising: a frame; a shelf for supporting product to be displayed; and a plurality of light sources positioned adjacent the support for illuminating the items to be displayed, the light sources including a plurality of discreet spaced apart xenon light sources arranged longitudinally relative to each other.

17. A method for assembling a display case with a light source, the method comprising the steps of: assembling a case frame and product supports for supporting product to be displayed in the display case; providing an electrical energy supply to the case; positioning a series of discreet light sources in the display case by positioning a light source support having the discreet light sources in the display case and adjacent the product supports and setting the light source support in a substantially stationary position relative to the product support so that at least some of the light sources are capable of illuminating product on the product support.

18. The method of claim 17 wherein the step of positioning includes the step of positioning a flexible light source support.

19. The method of claim 17 further comprising the step of attaching at least one of the discreet light sources to the light source support and wherein the light source support includes a conductor carrying current and the step of attaching includes the step of making electrical contact between the at least one light source and the conductor.

20. A display case for displaying items, the case comprising: a frame; a support for supporting items to be displayed; at least one light source for illuminating the items to be displayed, the light source including a glass envelope having a first diameter and further including first and second contacts extending longitudinally relative to the light source and having a largest outside dimension at least half the first diameter; and at least one connector for the light source, for supplying current to the light source and having a contact surface for contacting one of the first and second light source contacts longitudinally and wherein the light source contact is insertable into the at least one connector in a direction other than longitudinally.

21. A display case as in claim 20 wherein the outside dimension of the first contact is approximately the same length as the first diameter.

22. A display case as in claim 20 wherein the at least one connector includes a longitudinally extending contact surface extending a first length approximately equal to a length of the at least one connector.

23. A display case as in claim 22 wherein the contact surface extends about a cylindrical contact body and the connector contacts the contact surface over about at least half of the contact surface area.

24. A display case as in claim 20 wherein the contact is cylindrical, wherein the largest outside dimension of the contact is a contact diameter and wherein the contact diameter is at least half the first diameter.

25. A display case as in claim 24 wherein the contact diameter is approximately equal to the first diameter.

26. A display case as in claim 20 wherem the light source includes first and second ends and includes one contact on each end of light source and wherein the at least one connector includes a connector for each contact on the light source and the connector has a length on the same order of magnitude as the contact length of the light source.

27. A display case as in claim 20 wherein the light source includes first and second ends and wherein the light source includes first and second contacts on respective ends of the light source.

28. A display case as in claim 20 wherein the at least one connector is configured to permit the light source to enter the connector in a direction substantially peφendicular to the longitudinal direction of the light source.

29. A display case as in claim 20 wherein the contact has a first length and the connector has a second length and wherein the contact length is greater than the connector length.

30. A display case as in claim 20 wherein the contact has a first length and the connector has a second length and wherein the contact length is less than the connector length.