GB2568602A

GB2568602A - A lamp for an insect light trap, and an insect light trap

Info

Publication number: GB2568602A
Application number: GB1817824.4A
Authority: GB
Inventors: Wingett Gary
Original assignee: Rentokil Initial 1927 PLC
Current assignee: Rentokil Initial 1927 PLC
Priority date: 2017-10-31
Filing date: 2018-10-31
Publication date: 2019-05-22
Anticipated expiration: 2038-10-31
Also published as: GB2568602B; GB201717950D0; GB2608963A; GB201817824D0; GB202215613D0

Abstract

A lamp 1 for an insect light trap, comprising a support 2 comprising one or more mounts 6a,b for mounting the lamp 1 within the light trap. There are one or more ultra violet (UV) light emitting diodes (LEDs) 3 mounted on the support 2. Wherein the one or more LEDs 3 are fixed in the support by a conformal coating material (3b figure 6). There may also be a heat sink 4 which may be formed of aluminium. Another lamp is also claimed wherein the heat sink 4 is black in colour.

Description

A lamp for an insect light trap, and an insect light trap

Field of the Invention

The present invention concerns lamps for insect light traps and insect light traps. More particularly, but not exclusively, the invention concerns lamps for insect light traps comprising one or more light-emitting diodes (LEDs) that radiate ultraviolet (UV) light.

Background of the Invention

It is known to use LEDs that radiate UV light in insect light traps, as UV light attracts insects. However, unlike conventional visible-light LEDs, UV LEDs require a greater current and therefore generate more heat than conventional LEDs. If the UV LEDs become too hot, this can have a detrimental effect on the wavelength stability of the LEDs light output, and also on the operating life of the UV LEDs.

Another issue with known lamps for insect light traps that use UV LEDs is that they can be fragile, due to the lens that is mounted over the UV LEDs. To mitigate this, a shatterproof sleeve is provided over the lens, to help protect the lens from breakage and also to prevent contamination by fragments of lens if breakage occurs during use in high dependency areas such as factories where food is prepared. However, the lens and sleeve complicate the construction of known lamps.

The present invention seeks to mitigate the above-mentioned problems. Alternatively and/or additionally, the present invention seeks to provide improved lamps for insect light traps, and improved insect light traps.

-2Summary of the Invention

In accordance with a first aspect of the invention there is provided a lamp for an insect light trap for trapping insects, comprising:

a support comprising one or more mounts for mounting the lamp within the insect light trap; and one or more light-emitting diodes mounted on the support, wherein the one or more light-emitting diodes radiate ultraviolet light;

wherein the one or more light-emitting diodes are fixed in the support by a conformal coating material.

Conformal coating materials, also known as thick film coating, are well known for protecting electronic components from moisture and the like, though not in the context of the present invention of light-emitting diodes for lamps. The conformal coating material may be a copolymer comprising polyurethane and/or polyacrylate. The conformal coating material is able to hold the light-emitting diodes in place in the support, while also providing protection for their covered parts.

Advantageously, the conformal coating material is present around the perimeter of the one or more light-emitting diodes. In other words, the top surfaces of the one or more light-emitting diodes through which light is emitted are not enclosed in the conformal coating material. This allows the conformal coating material to hold the light-emitting diodes in place in the support, but while not disadvantageously affecting the amount and quality of the light emitted by the lightemitting diodes, and in addition, only requiring a minimal amount of conformal coating material to be used.

Alternatively, the light-emitting surfaces of the one or more LEDs may be completely enclosed by the conformal coating material. This allows the conformal coating material to provide protection for the top surfaces of the LEDs in addition to holding them in place in the support.

Advantageously, the lamp does not comprise a lens covering the one or more light-emitting diodes. Further advantageously, the lamp does not comprise a

-3shatterproof sleeve. It has been found that the use of a conformal coating material means that the lens is not required, and then in turn the shatterproof sleeve is not required. Omitting the lens and shatterproof sleeve simplifies the construction of the lamp, improves the UV light output of the lamp and improves the dissipation of heat generated by the LEDs. It has also been found that the dissipation of heat is sufficiently good to allow the lamp to be handled even very soon after the LEDs have been lit, as the LEDs are sufficiently cool that they there is no risk of injury even without any lens or shatterproof sleeve being present to prevent them being touched during handling.

Preferably, the support comprises a printed circuit board assembly, and the one or more light-emitting diodes are fixed to the printed circuit board assembly.

Preferably, the support comprises a heat sink.

Preferably, the heat sink is substantially the length of the lamp.

Preferably, the heatsink is formed of aluminium.

Preferably, the support comprises a thermal tape.

In accordance with a second aspect of the invention there is provided a lamp for an insect light trap for trapping insects, comprising:

wherein the surface of the support is black in colour.

It is usual for the LEDs in an LED lamp to be mounted on a support that has a surface that is white in colour, so that light radiated by the LEDs is reflected by the surface of the support and does not increase its temperature. However, surprisingly it has been found that by having a black surface for the support, despite the support absorbing rather than reflecting light and heat, a lower operating temperature of the LEDs can be achieved. This appears to be due to as the black surface absorbing heat from the critical areas of the LEDs, which is then transmitted away by the material of

-4the support. This can increase both the wavelength stability and the operating life of the LEDs.

In addition, the greater contrast between the UV light radiated by the LEDs and the black surface of the support, even though not visible to the human eye, can increase the attractive effect of the LEDs to insects.

It will be appreciated that in practice no real-life black surface can absorb all light in the (human) visible spectrum (wavelengths of around 390 to 700 nm). The total reflectance of light for all wavelengths of the visible spectrum may be less than 10%. More preferably, the total reflectance may be less than 5%. More preferably again, the total reflectance may be less than 1%. The reflectance of light across the wavelengths of the visible spectrum may be substantially uniform. The reflectance may be spectacular reflectance or, more preferably, diffuse reflectance.

The UV light radiated by the one or more LEDs preferably includes light of wavelength 365nm. Similarly to above for visible light, the total reflectance of UV light radiated by the one or more LEDs may be less than 10%, more preferably less than 5%, more preferably again less than 1%.

Preferably, the support comprises a heat sink. In this case, preferably the heat sink is substantially the length of the lamp. In this way, the heatsink can provide the main structure and support for the other components of the lamp. Preferably, the heatsink is formed of aluminium. Aluminium has been found to be a particularly convenient and effective material for the heatsink. Preferably, the aluminium heatsink has an anodised coating.

Preferably, the support comprises a thermal tape. Where the support comprises a printed circuit board assembly and a heatsink, preferably the thermal tape is between the printed circuit board assembly and a heatsink. This improves the transfer of heat generated by the LEDs to the heatsink.

At least a part of the support may be coated with a black coating. The entire support may be coated with the black coating (other than the LEDs of course), or

-5only the surface of the printed circuit board assembly may be coated, for example. Alternatively and/or additionally, at least a part of the support may be impregnated with a black dye. Similarly, the entire support may be impregnated with the black dye (again other than the LEDs), or only the surface of the heatsink may be coated, for example. This may particularly be the case where the heatsink is formed of aluminium and has an anodised coating.

Advantageously, the one or more light-emitting diodes are fixed in the support by a conformal coating material. Conformal coating materials, also known as thick film coating, are well known for protecting electronic components from moisture and the like, though not in the context of the present invention of LEDs for lamps. The conformal coating material may be a copolymer comprising polyurethane and/or polyacrylate. Further advantageously, the light-emitting surfaces of the one or more LEDs are completely enclosed by the conformal coating material. This allows the conformal coating material to provide protection for the LEDs in addition to holding them in place in the support. In this case, advantageously the lamp does not comprise a lens covering the one or more light-emitting diodes. Further advantageously, the lamp does not comprise a shatterproof sleeve. It has been found that the use of a conformal coating material means that the lens is not required, and then in turn the shatterproof sleeve is not required. Omitting the lens and shatterproof sleeve simplifies the construction of the lamp, improves the UV light output of the lamp and improves the dissipation of heat generated by the LEDs. It has also been found that the dissipation of heat is sufficiently good to allow the lamp to be handled even very soon after the LEDs have been lit, as the LEDs are sufficiently cool that they there is no risk of injury even without any lens or shatterproof sleeve being present to prevent them being touched during handling.

In accordance with a third aspect of the invention there is provided an insect light trap for trapping insects, comprising:

a housing; and a lamp as described above, mounted within the housing.

-6In accordance with a fourth aspect of the invention there is provided a kit comprising an insect light trap for trapping insects, and a lamp as described above.

It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention.

Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings of which:

Figure 1 is a top view of a lamp for an insect light trap for trapping insects in accordance with an embodiment of the invention;

Figure 2 is a side view of the lamp of Figure 1;

Figure 3 is an exploded view of the lamp of Figure 1;

Figure 4 is a top view of a portion of the lamp of Figure 1 comprising an LED;

Figure 5 is a side view of a portion of the lamp of Figure 4; and

Figure 6 is a side view of a portion of a lamp in accordance with another embodiment of the invention.

Detailed Description

A lamp for an insect light trap for trapping insects in accordance with an embodiment of the invention is now described with reference to Figures 1 to 5.

The lamp 1 comprises a printed circuit board assembly (PCBA) 2, which is in shape a long rectangular strip, though with shaped ends. In particular, a first end of

-7the PCBA 2 comprises electrical contacts 9, via which a supply of electricity can be provided to the components on the PCBA 2.

The PCBA 2 is formed of black anodised aluminium. Mounted on the PCBA 2 are six UV LEDs 3, equally spaced along the length of the PCBA 2. The mounting of the UV LEDs 3 in the PCBA 2 is described in more detail below. The UV LEDs 3 are specialist LEDs designed to transmit light at UV wavelength (as well as other wavelengths, such as some visible light), so around the wavelength of 365nm in the present embodiment. However, it will be appreciated that in other embodiments, LEDs transmitting light at other UV wavelengths could be used.

The lamp 1 further comprises a heatsink 4. Similarly to the PCBA 2, the heatsink 4 is formed of black anodised aluminium. Further, the heatsink 4 is also a long rectangular strip, shaped so as to match the PCBA 2. A strip of thermal conductive heat transfer tape 5 is provided between the PCBA 2 and heatsink 4.

At the first end of the PCBA 2 is a silicone gasket 8, through which the electrical contacts 9 extend. A mounting cap 6b is positioned at the end of the PCBA 2 and corresponding end of the heatsink 5, fixed in place by a pin 7b. A further mounting cap 6a is positioned at the other end of the PCBA 2 and corresponding other end of the heatsink 5, similarly fixed in place by a pin 7a.

The mounting of the UV LEDs 3 in the PCBA 2 is now described in more detail, with particular reference to Figures 4 and 5 which show a portion 10 of the PCBA 2 of the lamp 1 in which an LED 3a is mounted.

As can be seen, the LED 3a is positioned within a square recess 11 in the PCBA 2. The LED 3a is fixed in place in the recess by a conformal coating material 3b. The conformal coating material (also sometimes known as a thick film coating), is a liquid material that hardens (or cures) to a solid. The conformal coating material is a copolymer of polyurethane and polyacrylate, but it will be appreciated that in other embodiments other conformal coating materials can be used.

As can be seen from Figure 5 in particular, the conformal coating material 3b is only applied around the edges of the LED 3a, so that the conformal coating

-8material 3b forms a ring-shaped layer around the perimeter of the LED 3a. As can be seen from Figure 4, as the LED 3a is circular in cross-section while the recess 10 is square, there are corners of the recess 10 where the body of the LED 3a is not present. The conformal coating material 3b thus fills these corners, as well as covering the electrical contacts of the LED 3a. However, the conformal coating material 3b does not cover the upper surface of the LED 3a, and in particular does not cover the silicone surface 3c of the LED 3a through which light is emitted.

In this way, the conformal coating material 3b holds the LED 3a in place in the recess 11 of the PCBA 2, and acts to protect its electrical contacts, but does not cover the lens 3c of the LED 3a so does not have any disadvantageous effect on the amount and quality of the light emitted by the LED 3a. In addition, only a minimal amount of conformal coating material 3b needs to be used, in comparison for example to if the entire LED 3a were covered with the conformal coating material 3b.

The mounting of the UV LEDs 3 in the PCBA 2 in accordance with another embodiment of the invention is now described, with particular reference to Figure 6.

As can be seen from Figure 6, in this alternative embodiment of the invention, the conformal coating material 13 provides a dome-shaped covering that completely encloses the LED 3a from above.

In use, the lamp 1 is mounted within a housing by means of the mounting caps 6a and 6b, with the housing proving power to LEDs 3 of the lamp 1 via the electrical contacts 9. The LEDs 3 then radiate UV light, including in particular light of wavelength 365nm, and also certain amounts of other light such a visible purple light. The LEDs 3 generate heat while they operating, but the black surface of the PCBA 2 and heatsink 5 absorbs this heat which is then transmitted away. In addition, the contrast between the black surface of the PCBA 2 and the UV light radiated by the LEDs 3 provides a greater attractive effect on any insects in the vicinity of the lamp 1.

-9While the present invention has been described and illustrated with reference to particular embodiments, it will be appreciated by those of ordinary skill in the art that the invention lends itself to many different variations not specifically illustrated herein. In particular, it will be appreciated that the particular construction and shape of the lamp described above is only one possibility, and various other constructions and shapes could be used in embodiments of the invention.

Claims

1. A lamp for an insect light trap for trapping insects, comprising:

2. A lamp as claimed in claim 1, wherein the conformal coating material is present around the perimeter of the one or more light-emitting diodes.

3. A lamp as claimed in claim 1, wherein the light-emitting surfaces of the one or more LEDs are completely enclosed by the conformal coating material.

4. A lamp as claimed in any preceding claim, wherein the lamp does not comprise a lens covering the one or more light-emitting diodes.

5. A lamp as claimed in any preceding claim, wherein the support comprises a printed circuit board assembly, and the one or more light-emitting diodes are fixed to the printed circuit board assembly.

6. A lamp as claimed in any preceding claim, wherein the support comprises a heat sink.

7. A lamp as claimed in any claim 6, wherein the heat sink is substantially the length of the lamp.

8. A lamp as claimed in claim 6 or 7, wherein the heatsink is formed of aluminium.

9. A lamp as claimed in any preceding claim, wherein the support comprises a thermal tape.

10. A lamp for an insect light trap for trapping insects, comprising:

wherein the surface of the support is black in colour.

11. A lamp as claimed in claim 10, wherein the support comprises a printed circuit board assembly, and the one or more light-emitting diodes are fixed to the printed circuit board assembly.

12. A lamp as claimed in claim 10 or 11, wherein the support comprises a heat sink.

13. A lamp as claimed in claim 12, wherein the heat sink is substantially the length of the lamp.

14. A lamp as claimed in claim 12 or 13, wherein the heatsink is formed of aluminium.

15. A lamp as claimed in any of claims 10 to 14, wherein the support comprises a thermal tape.

16. A lamp as claimed in any of claims 10 to 15, wherein at least a part of the support is coated with a black coating.

17. A lamp as claimed in any of claims 10 to 15, wherein at least a part of the support is impregnated with a black dye.

18. A lamp as claimed in any of claims 10 to 17, wherein the one or more lightemitting diodes are fixed in the support by a conformal coating material.

19. A lamp as claimed in claim 18, wherein the conformal coating material is present around the perimeter of the one or more light-emitting diodes.

20. A lamp as claimed in claim 18, wherein the light-emitting surfaces of the one or more LEDs are completely enclosed by the conformal coating material.

21. A lamp as claimed in any of claims 10 to 20, wherein the lamp does not comprise a lens covering the one or more light-emitting diodes.

22. An insect light trap for trapping insects, comprising:

a housing; and a lamp as claimed in any preceding claim, mounted within the housing.

23. A kit comprising an insect light trap for trapping insects, and a lamp as claimed in any of claims 1 to 21.