GB2501187A

GB2501187A - Retrofit LED lamp

Info

Publication number: GB2501187A
Application number: GB1306827.5A
Authority: GB
Inventors: Paul Donegan; Sean Carty
Original assignee: CONNECT ELECTRONICS Ltd
Current assignee: CONNECT ELECTRONICS Ltd
Priority date: 2012-04-13
Filing date: 2013-04-15
Publication date: 2013-10-16
Also published as: GB201206576D0; GB201306827D0

Abstract

A retrofit light emitting diode lamp comprises a casing 3 having a base 5, a front cover assembly 13, 15 releasably attached to the casing, an electronics unit 17, a power connector 19 for connection of the lamp to a light fitting, and a printed circuit board 21 having a plurality of LEDs 23 mounted thereon. The PCB 21 is mounted on a side wall 7 of the casing 3 and extends around the circumference of the side wall, with the LEDs circumferentially arranged in the casing perpendicular to and facing inwardly towards the central longitudinal axis of the casing. A reflector sheet insert 25 is mounted on the base 5. A pair of magnets 27, 29 are adjustably mounted on the casing 3 for engagement of a light fitting. The LED lamp is simple to manufacture, has improved luminance and does not have a tendency to become dislodged during use.

Description

"A retrofit light emitting diode lamp"

Introduction

This invention relates to a retrofit light emitting diode (LED) lamp.

LED lamps are now seen as a viable alternative to incandescent light bulbs and fluorescent light bulbs. Typically, the operational life of an LED lamp is approximately 100,000 hours compared with approximately 5,000 hours for an incandescent light bulb.

Furthermore, LED lamps are known to operate at approximately 80% efficiency whereas incandescent light bulbs usually operate at approximately 20% efficiency. Therefore, the LED lamps last longer and are several times more efficient than incandescent light bulbs resulting in significantly lower maintenance costs and electricity consumption. Similarly, LED lamps tend to last longer and are more efficient than fluorescent bulbs.

The use of an LED lamp is particularly advantageous when the light fitting is located in a relatively inaccessible area or in a location where substantially continuous use of the light is required because the use of an LED lamp virtually eliminates the need for frequent bulb replacement. Although the purchase cost of LED lamps is still relatively expensive when compared with incandescent light bulbs and fluorescent bulbs, when the total cost of operation and maintenance of the LED lamps and incandescent light or fluorescent bulbs are taken into account, the LED lamps compare very favourably relative to the other types of bulbs.

Heretofore, various constructions of LED lamps have been proposed in the art. There are however problems with each of the known constructions of retrofit LED lamps. None of the existing constructions of LED lamps are deemed entirely suitable for the purpose of retrofitting in existing light fittings.

EP2375131 (Engel) describes a down-light bulb that may contain LED modules. In particular, Engel is concerned with the thermal management of such types of down-light bulbs. US7736015 (Osram Sylvania, Inc) describes an LED light having a cup-shaped, substantially rigid base. There is further provided a battery and a FOB overlying the battery within the base. There may be one or more LEDs in apertures on the PCB.

EP2481970 (Ceramate Technical Co., Ltd) describes a magnetic detachable multifunction LED lamp. The LED luminous module of the preferred embodiment is shaped as a disc and the top side of the disc is provided with a plurality of LEDs directed co-axially with the longitudinal axis of the lamp.

It is an object of the present invention to provide a retrofit LEO lamp that is compact, simple and inexpensive to manufacture and that provides a useful choice to the consumer.

Statements of Invention

According to the invention there is provided a retrofit light emitting diode (LED) lamp comprising: a casing open at one end thereof, the casing having a base and an upstanding side wall extending upwardly from the base; a front cover assembly releasably detachable from the open end of the casing, the front cover assembly comprising a retaining ring and a diffuser plate; an electronics unit centrally mounted on the base internal the casing housing the lamp electronics; a power connector for connection of the lamp to a light fitting, the power connector mounted centrally on the base external the casing and in electrical communication with the lamp electronics in the electronics unit through an aperture in the casing; a printed circuit board (PCB) having a plurality of LEDs mounted thereon, the PCB being mounted on the upstanding side wall of the casing and extending around the perimeter of the side wall with the LEDs arranged around the perimeter of the side wall in the casing facing substantially perpendicular to and inwardly towards the central longitudinal axis of the casing; and a reflector sheet insert mounted on the base extending inwardly from the side wall to the electronics unit and substantially surrounding the electronics unit, the reflector sheet insert being located between the base and the plurality of LEDs.

By having such a retrofit LED lamp, the LED lamp will be compact and relatively shallow.

Furthermore, the retrofit LED lamp will display improved luminance performance. This is achieved predominantly through the combined arrangement of the centrally mounted electronics unit, the wall mounted PCB with LEDs directed inwardly towards the centre of the casing and the reflector sheet. In addition to the above, the construction of retrofit LED lamp is also relatively simple and inexpensive to manufacture. This is important as it helps to reduce the price differential between the retrofit LED lamps and the other types of bulbs.

In one embodiment of the invention there is provided a retrofit LED lamp in which the casing is substantially cylindrical, and in which the PCB extends around the circumference of the side wall with the LEDs circumferentially arranged in the casing facing substantially perpendicular to and inwardly towards the central longitudinal axis of the casing, and in which the retaining ring is annular. The advantage of having such a retrofit LED lamp is that the LED lamp will fit in many existing light fittings and the construction of retrofit LED lamp is seen as particularly suitable for use in light fittings that contained so-called 2D bulbs.

In one embodiment of the invention there is provided a retrofit LED lamp in which the electronics unit is substantially cylindrical. By providing a cylindrical electronics unit, the electronics unit will guide the light outwards through the diffuser plate thereby improving luminance performance of the retrofit LED lamp.

In one embodiment of the invention there is provided a retrofit LED lamp in which the diffuser plate has a central aperture, and in which the electronics unit extends upwardly from the base and protrudes through the central aperture. By providing such a construction, the overall size of the retrofit LED lamp will be relatively compact thereby facilitating use of the lamp with a plethora of disparate light fittings.

In one embodiment of the invention there is provided a retrofit LED lamp in which the PCB is a flexible PCB.

In one embodiment of the invention there is provided a retrofit LED lamp in which there are provided a plurality of rows of LEDs mounted on the POB.

In one embodiment of the invention there is provided a retrofit LED lamp in which the reflector sheet insert is a discontinuous annular ring with a segment cut out of the ring.

Such a reflector sheet insert will be simple to install thereby speeding up and reducing the cost of the manufacturing process.

In one embodiment of the invention there is provided a retrofit LED lamp in which the reflector sheet insert is curved as it extends inwardly from the base towards the electronics unit. By providing a curved reflector sheet, the reflector sheet will act to concentrate the light from the LEDs into a beam thereby providing greater optical efficacy from the LED sources.

In one embodiment of the invention there is provided a retrofit LED lamp in which there are provided a pair of magnets mounted on the base external the casing. This is seen as a particularly advantageous aspect of the present invention. The retrofit LED lamp will be significantly heavier than the existing bulbs. Furthermore, the retrofit LED lamp will often be installed in areas where it is subjected to frequent vibration. In combination, the extra weight and the frequent vibration can result in a lamp becoming dislodged from its light fitting. Many light fittings are metallic and magnetically attracted by the magnets and the pair of magnets provide a simple and inexpensive way to secure the retrofit LED lamp in position relative to those light fittings thereby obviating the possibility of the retrofit LED lamp becoming dislodged inadvertently. In the event of the vibration partially dislodging the power connector from the light fitting, the magnets may ensure that a sufficient electrical connection with the light fitting is maintained.

In one embodiment of the invention there is provided a retrofit LED lamp in which the magnets are adjustably mounted on the base for limited movement towards and away from the base. This is particularly useful as the arrangement will allow for attachment to a number of disparate types of light fitting.

Detailed Description of the Invention

The invention will now be more clearly understood from the following description of some embodiments thereof given by way of example only with reference to the accompanying drawings, in which:-Figure 1 is a perspective view of a retrofit LED lamp according to the invention; Figure 2 is a perspective view of the retrofit LED lamp shown in Figure 1 with the front cover assembly removed; Figure 3 is an exploded view of the retrofit LED lamp; Figure 4 is a side view of the retrofit LED lamp; Figure 5 is a perspective view from below of the retrofit LED lamp; Figure 6 is a plan view of the retrofit LED lamp with front cover assembly and reflector sheet insert removed; Figure 7 is a plan view of the casing of the retrofit LED lamp; Figure 8 is a plan view of the power connector of the retrofit LED lamp; Figure 9 is a side, part cross-sectional view of the retrofit LED lamp showing the curved reflector sheet insert; Figure 10 is a side view of the retrofit LED lamp connected to a light fitting; Figure 11 is a plan view of an alternative embodiment of retrofit LED lamp with the front cover assembly and reflector sheet insert removed; and Figure 12 is a plan view of the casing of the retrofit LED lamp shown in Figure 11.

Referring to Figures 1 to 5 inclusive, there is shown a retrofit LED lamp, indicated generally by the reference numeral 1, comprising a cylindrical casing 3 having a base 5 and an upstanding side wall 7 extending upwardly therefrom. The cylindrical casing has an open mouth 9 about which a front cover assembly 11 is mounted. The front cover assembly comprises an annular retaining ring 13 and a translucent diffuser plate 15 held in position relative the casing by the annular retaining ring 13. An electronics unit 17 containing the lamp electronics (not shown) is mounted centrally on the base 5 internal the casing and a power connector 19 for connecting the lamp to a light fitting is mounted centrally on the base 5 external the casing 5. The power connector 19 is in electrical communication with the lamp electronics in the electronics unit 17 through an aperture in the base 5. The diffuser plate 15 has a central aperture 20 for through passage of the electronics unit 17.

The retrofit LED lamp further comprises a flexible printed circuit board (POB) 21 having a plurality of LEDs 23 mounted thereon. The PCB 21 is mounted on the upstanding side wall 7 of the casing 3 and extends around the circumference of the side wall with the LEDs circumferentially arranged spaced apart from each other in the casing facing substantially perpendicular to and inwardly towards a central longitudinal axis of the casing. A reflector sheet insert 25 is mounted on the base and extends inwardly from the side wall 7 to the electronics unit 17 and substantially surrounds the electronics unit 17.

The reflector sheet 25 insert is located between the base 5 and the plurality of LEDs 23 and comprises a radial cut 26 to provide a degree of adjustability to the reflector sheet insert 25 to facilitate insertion of the insert into the retrofit LED lamp 1. The reflector sheet insert 25 assumes a curved, substantially convex in cross section, configuration once inserted into the retrofit LED lamp as will be explained in greater detail with reference to Figure 9 below.

There is further provided a pair of magnets 27, 29 mounted on the base of the casing.

The magnets are adjustably mounted for limited movement towards and away from the base 5. The magnets each comprise a mounting leg 31, 33 respectively with a helical thread thereon and there is provided a retaining nut 35, 31 for engagement of the thread on the mounting leg 31, 33 respectively. The mounting legs 31, 33 are each passed through one of a pair of apertures (not shown) in the base and the retaining nuts are secured onto the mounting legs thereby securing the magnets to the base. The nuts are not rotated all the way to the bottom of the thread so that the magnets are allowed to move a liriiited amount towards and away from the base 5. Ideally, the casing 3 is constructed from aluminium or like material that will not be attracted to the magnets.

Referring specifically to Figure 5, it can be seen that the magnets 27, 29 are in turn housed in a magnet casing 34, 36 respectively that is connected to the mounting leg 31, 33. This simplifies the mounting of the magnets 27, 29 however the magnets could be connected directly to the mounting leg if preferred.

The power connector 19 has a central aperture 41 for through passage of cabling (not shown) thiough an aperture in the base 5 and into the electronics unit 17. The power connector 19 fuithei compiises a pail of screi apertuies 43, 45, each for reception of a screw (not shown) which passes thiough the apertuie 43, 45, thiough the base 5 and into the electronics unit 17 thereby securing the electronics unit 17 and the power connector 19 to each other and to the base 5.

Referring to Figure 6, there is shown a plan view of the retrofit LED lamp 1. It can be seen that the plurality of LEDs are all directed inwardly towards the central longitudinal axis of the casing. A pair of apertures, 51, 53 are provided in the base 5 of the casing 3 to permit through passage of the mounting legs of the magnets (not shown).

Furthermoie, wires 55, 57 are provided to supply power to the LEDs 23 mounted on the flexible POB 21. The LEDs mounted on the flexible POB are electiically connected to each othei. The PCB 21 is mounted on the casing by way of an intermediate layer of tape 59.

Referring to Figure 7, there is shown a plan view of the casing 3 with the electronics unit 17 removed. The casing 5 has three further apertures 61, 63, 65, one of which 61 is for throughpassage of wiring (not shown) between the electronics unit 17 and the power connector 19 and the other two of which 63, 65 are coincident with the screw apertures 43, 45 in the power connector 19 and are for reception of the screws (not shown) that pass through the power connector 19, through the base 5 and into the electronics unit 17.

Referring to Figure 8 theie is shotn a plan view of the power connectoi 19. The powei connector 19 comprises a four pin connector 71 for engagement of a complementary connector on a light fitting however it will be understood that different arrangements of connectors could be provided if desired.

Referring to Figure 9, there is shown a part cross-sectional side view of the retrofit LED lamp 1 according to the invention. It can be seen that the reflector sheet insert 25 is curved in a substantially convex shape as it extends inwardly and upwardly from the base 5 and the upstanding side wall 7 towards the electronics unit 17. Effectively, the reflector sheet insert 25 is shaped like an inverted bowl with a hole in the center for throughpassage of the electronics unit 17. This configuration of reflector sheet insert acts to concentrate the light from the LEDs into a beam that emanates through the diffuser plate (not shown).

Referring to Figure 10, there is shown a side view of the retrofit LED lamp I connected to a light fitting 91. The power connector 19 of the ietrofit LED lamp I engages a complementary connector 93 on the light fitting. The magnets 27, 29 also engage the light fitting 91 and together with the power connector 19 secure the retrofit LED lamp ito the light fitting 91.

It can be seen from the foregoing that the retrofit LED lamp is of very simple construction and will be relatively inexpensive to manufacture. The power connector 19, casing 3 and electronics unit 17 are connected together by passing screws through the power connector apertures 43, 45, through the casing apertures 63, 65 and into the electronics unit. The flexible PCB 21 is then attached, preferably using tape or a suitable adhesive, to the side wall 7 of the casing and the power wiring 53, 55 between the electronics unit 17 and the LEDs 23 is connected up. The reflector sheet insert 25 is then placed around the electronics unit between the base 5 of the casing 3 and the LEDs 23 before finally the diffuser plate 15 and annular retaining ring 13 are secured to the casing 3. Suitable apertures in the annular retaining ring 13 and the casing 3 may be provided and screws (not shown) may be used to secure the annular retaining ring 13 to the casing or alternatively the annular retaining ring may provide a close push-fit onto the casing sufficient to hold the annular retaining ring 13 in engagement with the side wall 7 of the casing.

In use, light from the LEDs 23 is directed by the reflector sheet insert 25 and the electronics unit 17 out through the diffuser plate 15. Even though the LEDs are directed inwardly towards the central longitudinal axis of the casing, the configuration of LEDs provides a very efficient lamp with improved luminance performance. This is due in part to the combined arrangement of the centrally mounted electronics unit, the wall mounted PCB with LEDs directed inwardly towards the centre of the casing and the reflector sheet. Tests carried out on the retrofit LED lamp in a photometric laboratory have shown a performance of greater than 70 lumens per watt which is highly efficient compared with the known embodiments of retrofit LED lamps.

Referring to Figure 11, there is shown a plan view of an alternative embodiment of retrofit LED lamp, indicated generally by the reference numeral 101, where like parts have been given the same reference numeral as before. It can be seen that the plurality of LEDs 23 are all directed inwardly towards the central longitudinal axis of the casing. A pair of apertures, 51, 53 are provided in the base 105 of the casing 103 to permit through passage of the mounting legs of the magnets (not shown). Furthermore, wires 55, 57 are provided to supply power to the LEDs 23 mounted on the flexible FOB 21.

The LEDs 23 mounted on the flexible FOB 21 are electrically connected to each other.

The FOB 21 is mounted on the upstanding side wall 107 of the casing by way of an intermediate layer of tape 59 connecting the FOB to the side wall 107. The electronics unit 117 is substantially cuboid in shape rather than the cylindrical shape shown in the embodiment illustrated in Figures Ito 10. In this way, the electronics unit 117 will match the contour of the upstanding side wall 107 of the casing 103.

Referring to Figure 12, there is shown a plan view of the casing 103 with the electronics unit 117 removed. The casing 103 has three further apertures 61, 63, 65, one of which 61 is for throughpassage of wiring (not shown) between the electronics unit 117 and the power connector 19 and the other two of which 63, 65 are coincident with the screw apertures 43, 45 in the power connector 19 and are for reception of the screws (not shown) that pass through the power connector 19, through the base 5 and into the electronics unit 17. Although not shown in Figures 11 and 12, the power connector is preferably identical to the power connector illustrated in Figures ito 10 inclusive.

In the embodiments shown in Figures 11 and 12, the front cover assembly has been removed for clarity. However, the components of the front cover assembly for the lamp assembly shown in Figures 11 and 12 will be similar to the front cover assembly 11 of the embodiment shown in Figures Ito 10 with the exception that the parts of the front cover assembly for the embodiment shown in Figures 11 and 12 will be suitably dimensioned for mounting on the rectangular-shaped casing 103 and side wall 105.

More specifically, the front cover assembly for the embodiment shown in Figures 11 and 12 comprises a rectangular retaining ring and a rectangular translucent diffuser plate that is held in position relative the casing 103 by the rectangular retaining ring.

Furthermore, the translucent diffuser plate may be provided with a suitably dimensioned aperture for through passage of the electronics unit 117 if required.

It is envisaged that various modifications could be made to the construction of retrofit LED lamp without departing from the spirit of the invention. For example, the casing and electronics unit may be substantial cuboid in construction, as illustrated in Figures 11 and 12, with the remaining components including the retaining ring, diffuser plate and reflector sheet insert altered accordingly. In the embodiments shown, the casing and the electronics unit are either cylindrical (Figures 1 to 10) or cuboid (Figures 11 and 12) in shape. It is envisaged that both the casing and the electronics unit could have one, two, three, four, five or more upstanding side walls. For example, the components of the lamp could be elliptical, triangular, square, rectangular, pentagonal, hexagonal or like shape in plan view. Furthermore, in the embodiments shown, the shape of the electronics unit 17, 117, when viewed in plan view, matches the shape of the upstanding side wall 5, 105 of the casing 5, 105 and this is the preferred implementation. However, it is envisaged that different shapes of electronics unit 17, 117 and upstanding side wall 5, 105 of the casing 3, 103 could be used together to good effect.

In this specification the terms "comprise, comprises, comprised and comprising" and the terms include, includes, included and including" are all deemed totally interchangeable and should be afforded the widest possible interpretation.

The invention is in no way limited to the embodiments hereinbefore described but may be varied in both construction and detail within the scope of the claims.