GB2509797A

GB2509797A - Lantern luminaire

Info

Publication number: GB2509797A
Application number: GB1310919.4A
Authority: GB
Inventors: John Desmond
Original assignee: JCC Lighting Products Ltd
Current assignee: JCC Lighting Products Ltd
Priority date: 2013-06-19
Filing date: 2013-06-19
Publication date: 2014-07-16
Anticipated expiration: 2033-06-19
Also published as: GB2509797B; WO2014202987A1; GB201310919D0

Abstract

A lantern luminaire comprises a lantern shaped body, having a light source receiving portion and a light releasing portion, the light releasing portion having one or more sides in which at least one aperture is provided through which light can escape the lantern shaped body, and an LED light source, disposed wholly within the light source receiving portion, for emitting light into the light releasing portion to exit the lantern shaped body via the at least one aperture. This arrangement reduces glare because the light source is not viewed directly under normal viewing angles. Further, any degradation in the light source is only perceivable in terms of the amount of light output by the luminaire there is no concept of undesirable visible effects such as bulb blackening.

Description

LANTERN TYPE LUMINAIRE

Field of the Invention

The present invention relates to a lantern type luminaire.

Background of the Invention

Luminaires (also known as light fittings or light fixtures) having a lantern shape are most commonly of a full lantern type, typically attached to a wall via an arm/bracket, or of a half lantern type, typically mounted directly to a wall. This type of luminaire is particularly popular for outdoors use, although may also be used indoors.

Lantern type luminaires typically comprise a roof portion, a base portion, and a central portion having apertures/windows through which light can be released to the outside, although in some cases the roof portion, base portion and central portion may be manufactured/formed as a single entity. A normal incandescent bulb is generally used with these luminaires, mounted to extend well into the central portion of the luminaire to maximise light output from the luminaire, and to facilitate even heat dissipation from the bulb. This arrangement involves several drawbacks, including substantial glare, the visual and light emitting impact of bulb blackening, and the ingress of water and other environment contaminants [which can cause misting or mould growth on the inside of the lantern) due to the need to be able to take the unit apart to replace the bulb.

Summary of the Invention

According to an aspect of the invention, there is provided a lantern type luminaire, comprising: a lantern shaped body, having a light source receiving portion and a light releasing portion, the Hght releasing portion having one or more sides in which at least one aperture is provided through which light can escape the lantern shaped body; and an LED light source, disposed whofly within the light source receiving portion, for emitting light into the light releasing portion to exit the lantern shaped body via the at least one aperture.

This arrangement has a number of advantages. Firstly, glare is reduced because the light source is not viewed directly under normal viewing angles.

Instead, light from the light source reaches the outside indirectly, passing firstly from within the light source receiving portion to the light releasing portion, and secondly out: of the luminaire through apertures in the light: releasing portion.

Secondly, any degradation in the light source is on'y perceivable in terms of the amount of light output by the uminaire -there is no problem with undesiraNe visible effects such as buth Nackening, since the light source is not normally directly visible. Thirdly, an LED (Light Emitting Diode] light source can be expected to ast much onger than a conventiona' incandescent light source, meaning that the luminaire can be treated as a disposable (potentially sealed) unit rather than being required to be disassembled and reassembkd to permit a buth change to take place.

As a result, the ingress of water and other environmental contaminents can be reduced -partly because the luminaire will not be opened, and partly because the luminaire can, if desired, be sealed to prevent ingress. It will be appreciated that the light source releasing portion is not the same portion of the lantern shaped body as the light releasing portion. The LED light source is disposed outside of the light releasing portion of the lantern shaped body, but emits light into the light releasing portion for it to escape the lantern from the apertures in the light releasing portion.

Preferably, the LED light source is disposed within the lantern shaped body at a position at which it it is not visible through the at least one aperture when the luminaire is viewed from the side. Typically lanterns are structured such thai most light is emitted from the side (light emission via the top and bottom of the lanterns generally being at least partially obscured by opaque roof and base portions]. It is therefore particularly desirable that glare be reduced when the lantern is viewed from the side.

The light source receiving portion may be a roof portion of the hntern shaped body, and the light releasing portion maybe a central portion of the hntern shaped body disposed between the roof portion and a base portion of the hntern shaped body. In other words, in a conventiona' lantern housing style the LED light source maybe wholly disposed within the roof of the lantern housing. Preferably in this case the light source is disposed within the roof portion at a position from which it is not visible from outside the lantern when viewed along a viewing direction perpendicular to a longitudina' axis joining the roof and base portions. As described above, it would be generally desirable for glare from a lantern type luminaire to be reduced when the luminaire is viewed from the side. It will be appreciated however that in some cases it may be desirable for the LED light source (and associated components) to be disposed instead within the base portion of the lantern shaped body. In this case, the light source receiving portion is a base portion of the lantern shaped body, and the light releasing portion is a central portion of the lantern shaped body disposed between the base portion and a roof portion of the lantern shaped body. Again, the light source may be disposed within the base portion at a position from which it is not visible from outside the lantern when viewed along a viewing direction perpendicular to a longitudinal axis joining the roof and base portions.

A heat sink may be provided for dissipating heat from the LED light source.

Preferably the heat sink is provided wholly within the light source receiving portion.

The heat sink may be physically secured to the interior of the light source receiving portion of the body, with the LED light source itself being secured to the heat sink.

An LED diffuser lens may be provided to cover the light source and to diffuse the light which is emitted into the light releasing portion. Again, preferably the LED diffuser lens is provided wholly within the light source receiving portion. In some embodiments a diffuser lens may not be provided at all, with the indirect light path taken from the LEDs to the outside of the lamp serving to provide a diffuse light distribution.

By locating the heat sink, LED light source and diffuser outside of the light releasing portion of the luminaire, not only can the above mentioned advantages be achieved, but also the creation of a "void" in the light releasing portion results in a reduction in the number of obstructions to the passage of light. It will be appreciated that a light source usually comes with non light emitting elements. For example, an incandescent bulb is provided with a socket for receiving the bulb, and the bulb itself only emits light from a portion of its structure. These non light emitting parts serve as obstructions, potentially reducing the amount of light exiting the luminaire, and reducing the uniformity of the light emitted. Similarly, an LED light source typically comprises a chip board, and a heat sink, which if provided within the aperture receiving portion of the luminaire would serve as obstructions, potentially reducing the amount: of light exiting the luminaire, and reduciiig the uniformity of the light emitted. By locating these elements outside of the light releasing portion of the luminaire, a reduction in light loss due to obstructions, and a cleaner light output will be provided.

It will be appreciated that it would be very difficult to provide a similar arrangement for an incandescent lamp, because the heat output characteristics of such a light source would cause problems in the confined space of the roof of a lantern type luminaire. For example, the bulb could overheat and fail due to lack of space for heat dissipation, or the heat could melt the roof (if plastic) or make it unsafe to touch (if metal). LED light sources are suitable because they produce less heat [per unit llght output], and that heat which is generated can be efficiently carried away by a heat sink.

Generally, the apertures are provided with a transparent or translucent cover. This cover may be provided internally or externally of the body of the luminaire, and may be provided in the form of a single element shaped to cover multiple apertures, or in the form of multiple panes each being fitted to a single respective aperture.

Embodiments of the present invention may be applied to lantern type luminaires of many different shapes, sizes and configurations, and not only the specific examples of the full lantern shape and half lantern shape described herein.

In general terms, a lantern type luminaire can be expected to have an opaque roof portion, an opaque base portion and a central portion a part of which is either completely transparent or translucent around its circumference, or which has a series of windows or apertures in an opaque frame through which light can pass. It will be appreciated that, in the former case the part of the central portion which is transparent or translucent around the complete circumference of the lantern can be considered to be an aperture in the central portion. The central portion of the luminaire may in some cases be entirely transparent or translucent In other words, the aperture for each of the one or more sides may constitute the whole of the side.

Moreover, the "one or more sides" need not be straight sides, but can be curved, and in the case of a single curved side being provided it will be appreciated that the lantern will have either an elliptical or circular cross section. Not all sides may

S

necessarily bear an aperture. Further, some or all of the sides may bear multiple apertures.

Brief Description of the Drawings

Embodiments of the present invention will now be described with reference to the following drawings, in which: Figure 1 schematically illustrates an exploded view of a full lantern type luminaire according to a first embodiment of the invention; Figure 2 schematically illustrates the full lantern type luminaire of Figure 1 in a cutaway view, with the LED light source and associated components (internal features which are not normally visible) being shown by cutaway; Figure 3 schematically illustrates the full lantern type luminaire of Figure 1 in a side view, with the LED light source and associated component being hidden within the roof; Figure 4 schematically illustrates the full lantern type luminaire of Figure 1 in an isometric view looking upwards into the roof; Figure 5 schematically illustrates an exploded view of a half lantern type luminaire according to a second embodiment of the invention; Figure 6 schematically illustrates the half lantern type luminaire of Figure 5 in a cutaway view, with the LED light source and associated components (internal features which are not normally visible) being shown by cutaway; Figure 7 schematically illustrates the half lantern type luminaire of Figure 5 in a front view, with the LED light source and associated component being hidden within the roof; and Figure 8 schematically illustrates the half lantern type luminaire of Figure 5 in an isometric view looking upwards into the roof.

Description of the Example Embodiments

Referring to Figure 1, an exploded view of a full lantern type luminaire 100 according to a first embodiment of the invention is schematically illustrated. Starting from the point at which the luminaire 100 is attached to the wall, the luminaire 100 comprises a wall mounting plate 102 for mounting the luminaire 100 to a wall. The wall moundng plate 102 comprises a through hole (not shown) through which a power cable (not shown) can enter the luminaire 100. Additionally, the wall mounting plate 102 comprises a compartment which in some implementations may house passive infrared (PIR) circuitry for switching the luminaire 100 on in response to motion. A cover 104 is provided for the compartment in the wall mounting plate 102. A lantern arm/bracket 106 is provided which attaches at one end to the wall mounting plate 102, and at its other end to a base portion of a lantern body/housing 114 via a finial connector plate and a lower finia connector 112. The finial connector plate comprises a socket for receiving a nut (not shown) for attachment to the lower finial connector 112, which is provided with an outer thread. The lower finial connector 112 is secured to the lantern body 114 by way of a further nut (not shown) positioned within the lantern body 114 which screws onto the end of the lower finial connector 112 which penetrates through the base portion of the lantern body 114. A tower finial 108 is provided for attachment to the lantern arm 106, in the present case for aesthetic purposes only.

The lantern body 114 comprises a plurality of apertures through which light can pass from the inside to the outside of the lantern body 114. The lantern body 114 in the present case is formed of a plastic material, but could equally be formed of metal or any other suitable material. In the base of the lantern body 114 is provided anti-surge circuitry [not shown) which prevents damage to the LED light source in the event of a surge in the power supply. A cover 116 is provided which sits in the base portion of the lantern body 114 to cover up the anti-surge circuitry. A transparent or translucent cover 118 is provided for covering the apertures in the lantern body 114. The transparent or translucent cover 118 in the present case is a single module which fits within the body 114, but could alternatively be provided as a unit which fits outside the body 114, or as a set of individual panes of transparent or translucent material which sits inside or outside each of the apertures. The transparent or translucent cover may be formed of a polycarbonate material or glass for example. The cover 118 may in some embodiments act as a diffuser. The cover 118 comprises a channel 119 formed within the material of the cover 118, which is dimensioned to receive an electric cable (not shown). A diffuser 120 is provided for covering the light emitting face of an LED chip board 122. Each of the diffuser 120 and LED chip board 122 are secured to a heat sink 124 which serves to dissipate heat generated by the LED chip board 122. The diffuser 120, LED chip board 122 and heat sink 124 are mounted into the interior of a roof 126 using an upper finial connector 128 which screws into a threaded bore in the heat sink 124 at one end, and into a threaded bore in an upper finial 130 at its other end. The upper finial connector therefore serves the purpose both of attaching the upper finial to the roof 126 of the luminaire, and of attaching the diffuser 120, LED chip board 122 and heat sink 124 into the interior of the roof 126. This arrangement means that there is no need to provide an extra part for the LED chip board and associated component to attach to.

In operation, power is provided to the LED chip board 122 via an electrical supply path starting with cabling received through the wall mounting plate, and passing optionally through!-IR circuitry, and through anti-surge circuitry, into the LED chip board 122. The LED chip board 122 comprises an array of LEDs each of which emit light through the diffuser 120 and into the lantern body 114. Heat generated by the LEDs and its associated circuitry is dissipated by the heat sink 124. Light entering the lantern body 114 passes out through the transparent or translucent material in the apertures to emit light from the luminaire 100. In the present example, the LED chip board 122 is AC driven, however in alternative embodiments a DC based LED chip board may be provided, in which case an AC-DC convertor circuit will be provided. This could be provided within the roof 126, or in the compartment of the wall plate 102.

Referring to Figure 2, the full lantern type luminaire of Figure 1 is schematically illustrated in a cutaway view, with the LED light source and associated components (internal features which are not normally visible from this viewpoint) being shown by cutaway. For clarity, only a subset of the components described in Figure 1 are labelled, these being the lantern arm 106, the lantern body 114, the roof 126, the diffuser 120, the LED chip board 122, the heat sink 124, the upper finial connector 128 and the upper finial 130. As can be seen from Figure 2, the light source (formed by the LEDs on the LED chip board) is mounted wholly within the roof 126 of the luminaire. No part of the light source itself projects into the lantern body 114. Moreover, the diffuser 120 is also mounted wholly within the roof 126 of the luminaire, as is the heat sink 124. As a result, individuals viewing the luminaire will under normal circumstances not be able to see the light source, nor the diffuser, nor the heat sink. A reduction in glare is therefore achieved from these normal viewing angles. The fixing of the heat sink 124 into the roof 126 via the upper finial connector 128 [which is secured also into the upper finial) is also visible in Figure 2.

Referring to Figure 3, the full lantern type luminaire of Figure 1 is schematically illustrated in a side view. As can be seen, the LED light source and associated components are hidden within the roof. As a result, the interior of the lantern body appears empty to the casual observer, but light is still emitted from within.

B

Referring to Figure 4, the full lantern type luminaire of Figure 1 is schematically illustrated in an isometric view looking upwards into the roof From this angle, the diffuser 120 is visible, but the LED chip board 122 and heat sink 123 are obscured behind the diffuser 120. It will therefore be understood that light from the LEDs of the LED chip board 122 is able to pass through the diffuser 120 into the void within the lantern body 114 before exiting the luminaire. It will be appreciated that while Figure 4 illustrates that the diffuser 120 can in some cases be seen from outside the lantern, the view provided by Figure 4 is not representative of normal viewing angles for a lantern type luminaire. In any case, several of the advantages associated with the provision of the LED light source outside of the lantern body 114 are not predicated on whether or not the light source/diffuser is visible.

Referring to Figure 5, an exploded view of a half lantern type luminaire 200 according to a second embodiment of the invention is schematically illustrated. Starting from the point at which the luminaire 200 is attached to the wall, the luminaire 200 comprises a wall mounting plate 202 for mounting the luminaire 200 to a wall. The wall mourning plate 202 comprises a through hole 203, for receiving a protective grommet 213, through which a power cable (not shown] can enter the luminaire 200. Pins 205 are provided on the wall mounting plate 202 for holding a terminal block 215 in place.

A channel 207 is provided in the wall mounting plate 202 to permit an electric cable to pass between the top and the bottom of the luminaire 200. A cover 209 is provided, which when attached to the wall mounting plate 202 forms a compartment for holding anti-surge circuitry (not shown) which prevents damage to the LED light source in the event of a surge in the power supply, and which in some implementations may house passive infrared (PIR) circuitry for switching the luminaire 100 on in response to motion. The channel 207 permits electric cabling to pass down from the hole 203 via the terminal block 215 to the anti-surge circuitry (and optionally the PIR circuitry), and then back up to the LED circuitry (described below).

A half lantern body 214 is provided which comprises a plurality of apertures through which light can pass from the inside to the outside of the lantern body 214.

When attached to the wall mounting plate 202 and cover 209, the base of the lantern body 214 will contain the anti-surge circuitry (not shown) and optionally the PIR circuitry. A transparent or translucent cover 218 is provided for covering the apertures in the lantern body 214. The transparent or translucent cover 218 in the present case is a single module which fits within the body 214, but could alternatively be provided as a unit which fits outside the body 214, or as a set of individual panes of transparent or trans'ucent material which sits inside or outside each of the apertures. The transparent or translucent cover may be formed of a polycarbonate material or glass for example. A diffuser 220 is provided within the roof of the body 214 for covering a light emitting face of an LED chip board 222. Each of the diffuser 220 and LED chip board 222 are secured to a heat sink 224 which serves to dissipate heat generated by the LED chip board 222. The diffuser 220, LED chip board 222 and heat sink 224 are mounted into the interior of a roof of the body 214.

In operation, power is provided to the LED chip board 222 via an electrical supply path starting with cabling received through the wall mounting plate 202, and passing along the channel 207 optionally through PIR circuitry, and through anti-surge circuitry, and then back along the channel 207 into the LED chip board 222. The LED chip board 222 comprises an array of LEDs each of which emit light through the diffuser 220 and into the lantern body 214. Light directed toward the wall mounting plate 202 is reflected back out through the apertures in the body 214 by a reflective sheet 211.

Heat generated by the LEDs and its associated circuitry is dissipated by the heat sink 224. Light entering the lantern body 214 passes out through the transparent or translucent material in the apertures to emit light from the luminaire 200. In the present example, the LED chip board 222 is AC driven, however in alternative embodiments a DC based LED chip board may be provided, in which case an AC-DC convertor circuit will be provided. This could be provided within the roof of the lantern body 214, or in the compartment formed between the wali plate 202, the casing 214 and the cover 209.

Referring to Figure 6, the half lantern type luminaire of Figure 5 is schematically illustrated in a cutaway view, with the LED light source and associated components (internal features which are not normally visible from this viewpoint) being shown by cutaway.

For clarity, only a subset of the components described in Figure 5 are labelled, these being the lantern body 214, the diffuser 220, the LED chip board 222 and the heat sink 224. As can be seen from Figure 6, the light source (formed by the LEDs on the LED chip board) is mounted wholly within the roof of the luminaire. No part of the light source itself projects into the lantern body 214. Moreover, the diffuser 220 is also mounted wholly within the roof of the luminaire, as is the heat sink 224. As a result, individuals viewing the luminaire will under normal circumstances not be able to see the light source, nor the diffuser, nor the heat sink. A reduction in glare is therefore achieved from these normal viewing angles.

Referring to Figure 7, the half lantern type luminaire of FigureS is schematically illustrated in a front view. As can be seen, the LED light source and associated components are hidden within the roof As a resuk, the interior of the lantern body appears empty to the casual observer, but light is still emitted from within.

Referring to Figure 8, the half lantern type luminaire of Figure 5 is schematically illustrated in an isometric view looking upwards into the roof. From this angle, the diffuser 220 is visible, but the LED chip board 222 and heat sink 224 are mostly obscured behind the diffuser 220. It will therefore be understood that light from the LEDs of the LED chip board 222 is able to pass through the diffuser 220 into the void within the lantern body 214 before exiting the uminaire. It will be appreciated that while Figure 4 illustrates that the diffuser 220 (and in some cases the LED chip board 222 and heat sink 224) can in some cases be seen from outside the lantern, the view provided by Figure 4 is not representative of normal viewing angles for a lantern type luminaire. In any case, several of the advantages associated with the provision of the LED light source outside of the bntern body 214 are not predicated on whether or not the light source/diffuser is visible.

The particular full lantern and half lantern designs shown in the Figures are for representative purposes only. The two example embodiments usefully demonstrate the applicability of the present invention to multiple different lantern type luminaires. The first embodiment (full lantern) also demonstrates that the part of the luminaire carrying/containing the light source may be a separate component to the part of the luminaire bearing the apertures. The second embodiment (half lantern] also demonstrates that the part of the luminaire carrying/containing the light source may be a part of the same component as the part of the luminaire bearing the apertures. In other words, the light source receiving portion and the light releasing portion of the lantern shaped body may be formed as separate manufacturing entities, or co-formed as a single entity. The present invention may find application in many different lantern designs. For examp'e, lanterns with a circular cross section, square cross section or a cross section of any other regular or irregular shape may benefit from the present invention. Furthermore, lanterns with only a single aperture (such as of a lantern with a circular cross section and one continuous aperture running around the circumference of the lantern) are also envisaged. 1l

Although an LED chip board is described above as the light source, the LEDs need not necessarily be provided on a chip board. In some cases a duster of unmounted LEDs might be appropriate, or for low intensity applications it may be sufficient to use a single LED as the light source.

Claims

CLAIMS1. A lantern type luminaire, comprising: a lantern shaped body, having a light source receiving portion and a light S releasing portion, the light releasing portion having one or more sides in which at least one aperture is provided through which light can escape the lantern shaped body; and an LED light source, disposed wholly within the light source receiving portion such that light from the LED light source is emitted into the light releasing portion to exit the lantern shaped body via the at least one aperture.
2. A lantern type luminaire according to claim 1, wherein the LED light source is disposed within the lantern shaped body at a position at which it is not visible through the at least one aperture when the luminaire is viewed from the side.
3. A lantern type luminaire according to claim 1 or claim 2, wherein the light source receiving portion is a roof portion of the lantern shaped body, and the light releasing portion is a central portion of the lantern shaped body disposed between the roof portion and a base portion of the lantern shaped body.
4. A lantern type luminaire according to claim 3, wherein the light source is disposed within the roof portion at a position from which it is not visible from outside the lantern when viewed along a viewing direction perpendicular to a longitudinal axis joining the roof and base portions.
5. A lantern type luminaire according to claim 1 or claim 2, wherein the light source receiving portion is a base portion of the lantern shaped body, and the light releasing portion is a central portion of the lantern shaped body disposed between the base portion and a roof portion of the lantern shaped body.
6. A lantern type luminaire according to claim 5, wherein the light source is disposed within the base portion at a position from which it is not visible from outside the lantern when viewed along a viewing direction perpendicular to a longliudinal axis joining the roof and base portions.
7. A lantern type luminaire according to any preceding claim, comprising a heat sink for dissipating heat from the LED light source, the heat sink being provided wholly within the light source receiving portion.
8. A lantern type luminaire according to any preceding claim, comprising an LED diffuser lens covering the light source and diffusing the light to be emitted into the light releasing portion, the LED diffuser lens being provided wholly within the light source receiving portion.
9. A antern type luminaire according to any preceding claim, wherein the apertures are provided with a transparent or translucent cover.
10. A lantern type luminaire according to any preceding claim, wherein the lantern shaped body has one of a full lantern shape and a half lantern shape.
11. A lantern type luminaire substantiafly as hereinbefore described with reference to the accompanying drawings.Amended claims have been filed as follows:-CLAIMS1. A lantern type luminaire, comprising: a lantern shaped body, having a light source receiving portion and a light releasing portion, the light releasing portion having one or more sides in which at least one aperture is provided through which light can escape the lantern shaped body; and an LED light source, disposed wholly within the light source receiving portion such that light from the LED light source is emitted into the light releasing portion to exit the lantern shaped body via the at least one aperture; wherein the light source receiving portion is a roof portion of the lantern shaped body, and the light releasing portion is a central portion of the lantern shaped body disposed between the roof portion and a base portion of the lantern shaped body; and wherein the lantern type luminaire further comprises an LED diffuser lens covering the light source and diffusing the light to be emitted into the central portion of the lantern shaped body, the LED diffuser lens being provided wholly 0 within the roof portion of the lantern shaped body. aD(\J 20 2. A lantern type luminaire according to claim 1, wherein the light source is disposed within the roof portion at a position from which it is not visible from outside the lantern when viewed along a viewing direction perpendicular to a longitudinal axis joining the roof and base portions.3. A lantern type luminaire according to any preceding claim, comprising a heat sink for dissipating heat from the LED light source, the heat sink being provided wholly within the roof portion.4. A lantern type luminaire according to any preceding claim, wherein the apertures are provided with a transparent or translucent cover.5. A lantern type luminaire according to any preceding claim, wherein the lantern shaped body has one of a full lantern shape and a half lantern shape.6. A lantern type luminaire substantially as hereinbefore described with reference to the accompanying drawings. r aD (4