lamp

Abstract

A lamp (10) comprising a printed circuit board (100) which comprises a substrate (110) extending in a first direction x. A high voltage track (120) and a plurality of conductive regions (130) are provided on the substrate. The high voltage track extends in the first direction, and the plurality of conductive regions are provided in a row extending in the first direction. Each conductive region comprises three subregions (131, 132, (133) arranged along the first direction, with a center subregion (133) having a greater distance D3 from the high voltage track than a distance D1, D2 between the high voltage track and each of the first and second subregions.

Description

[0001] Lamp

[0002] FIELD OF THE INVENTION

[0003] The invention relates to the field of printed circuit boards, PCBs, for lamps and in particular, to PCBs for tubular lamps.

[0004] BACKGROUND OF THE INVENTION

[0005] The end of life of an LED can cause a PCB on which the LED is provided to become carbonized, as the supply of current to a broken LED causes an increase in the temperature of the PCB at the location of the broken LED. A carbonized PCB has a much lower resistance.

[0006] In a glass tubular LED luminaire, this may result in arcing that extends along a high voltage track of the PCB, creating a high temperature that causes the glass of the luminaire to crack. In some cases, this can lead to customer complaint due to possibility of part of the luminaire breaking off and falling from its fitting, and potentially injuring someone standing below the luminaire.

[0007] EP 2593709B1 discloses a lighting device comprising a light transmissive light outlet unit, and light emitting diodes generating light which is emitted through the light outlet unit.

[0008] US 20140218905A1 discloses a light-emitting module includes a rectangular substrate, at least two light-emitting circuits and inter-module connection part. The lightemitting circuit connects plural light-emitting elements in a longitudinal direction of the substrate.

[0009] CN 205956869U discloses a flexible light strip.

[0010] US 20180320832A1 discloses a light engine for a tube lamp has a substrate defining a longitudinal direction, having at least three conductive traces extending in the longitudinal direction.

[0011] SUMMARY OF THE INVENTION

[0012] The invention is defined by the claims. According to examples in accordance with an aspect of the invention, there is provided a lamp comprising a printed circuit board, PCB, and a plurality of LEDs provided on the printed circuit board, wherein the printed circuit board comprises: a substrate extending in a first direction; a high voltage track provided on the substrate and extending in the first direction; and a plurality of conductive regions provided in a row extending in the first direction on the substrate, wherein each conductive region comprises a first subregion, a second subregion, and a third subregion provided between the first and second subregions in the first direction, wherein, for each conductive region: a length of the third subregion in the first direction is less than a length of the conductive region in the first direction; and a distance between the high voltage track and the third subregion is greater than a distance between the high voltage track and each of the first and second subregions. The plurality of LEDs are orientated such that electrodes of the LEDs are aligned along the first direction such that the plurality of LEDs are connected to one another via the plurality of conductive regions.

[0013] The increased distance between the conductive region and the high voltage track at the third subregion reduces a likelihood that, when used in a lamp, and in particular a tubular lamp, arcing near a failing LED on the PCB will spread to neighboring LEDs and along the entire PCB. The increased distance therefore reduces a likelihood that the temperature of the tubular lamp will become hot enough to cause damage to other parts of a tubular luminaire comprising the tubular lamp.

[0014] When used in a tubular lamp, LEDs may be connected to the first and second subregions of the conductive regions with its electrodes aligned along the first direction as the extending row of the conductive regions. The shorter distance between the high voltage track and the first and second subregions enables to first and second subregions to have a greater width, increasing the conductive area of the first and second subregions and thus improving the thermal performance of the tubular lamp.

[0015] In some examples, the length of the third subregion in the first direction is less than half of the length of the conductive region in the first direction.

[0016] In some examples, the length of each third subregion in the first direction is at least 5 times a recommended creepage distance for the printed circuit board.

[0017] The inventors have found that an insulating space having a length of at least 5 times the recommended creepage distance of 1 mm per 1000 V provides an increased likelihood that arcing will be prevented at the third subregion. The reason is that, when the PCB is carbonized at the arcing area, the wider remaining area with no copper provides a sufficient distance to prevent creepage. In some examples, the length of each third subregion in the first direction is at least 2 mm. 2 mm is 5 times the recommended creepage distance for a 400 V tubular LED lamp.

[0018] In some examples, the length of each third subregion in the first direction is at least 3 mm. The inventors have found that an insulating space of at least 3 mm further increases the likelihood that arcing will be prevented at the third subregion.

[0019] In some examples, the distance between the high voltage track and each third subregion is at least 5 times the recommended creepage distance for the printed circuit board.

[0020] The inventors have found that an insulating space having a width of at least 5 times the recommended creepage distance of 1 mm per 1000 V provides an increased likelihood that arcing will be prevented at the third subregion.

[0021] In some examples, the distance between the high voltage track and each third subregion is at least 2 mm.

[0022] In some examples, the distance between the high voltage track and each third subregion is at least 3 mm.

[0023] In some examples, the printed circuit board further comprises a DC return track provided on the substrate and extending in the first direction. This allows more than one string of LEDs to be provided on the PCB.

[0024] In some examples, the DC return track is provided on an opposite side of the plurality of conductive regions to the high voltage track; and at least the conductive regions provided adjacent to the DC return track each further comprise a fourth subregion and a fifth subregion provided between the second and fourth subregions in the first direction, wherein, for each conductive region comprising fourth and fifth subregions, a distance between the DC return track and the fifth subregion is greater than a distance between the DC return track and each of the second and fourth subregions.

[0025] In other words, an increased insulating space is additionally provided between the DC return track and each conductive region. This reduces a likelihood that arcing near a failing LED on the PCB will extend along the PCB between the conductive regions and the DC return track.

[0026] In some examples, the distance between the DC return track and each fifth subregion is at least 5 times the recommended creepage distance for the printed circuit board. In some examples, the distance between the DC return track and each fifth subregion is at least Preferably, the distance between the DC return track and each fifth subregion is at least 3 mm.

[0027] In some examples, the DC return track is provided on a same side of the plurality of conductive regions as the high voltage track.

[0028] This allows the use of conductive regions having three (rather than five) subregions. When the PCB with the DC return track on the same side of the conductive regions as the high voltage track is used in a tubular lamp, one or more jumpers may be used to connect the LEDs of the tubular lamp to the DC return track.

[0029] In some examples, the printed circuit board further comprises an AC power track provided on the substrate and extending in the first direction.

[0030] The AC power track may be provided on the same side of the conductive regions as the high voltage track or on the opposite side of the conductive regions to the high voltage track. In some examples, when the AC power track is provided on the opposite side of the conductive regions to the high voltage track, each conductive region may further comprise a fourth subregion and a fifth subregion provided between the second and fourth subregions in the first direction, wherein, for each conductive region, a distance between the AC power track and the fifth subregion is greater than a distance between the AC power track and each of the second and fourth subregions.

[0031] There is also proposed a tubular lamp, comprising: the printed circuit board described above; and a plurality of LEDs provided on the printed circuit board, wherein the plurality of LEDs are orientated such that electrodes of the LEDs are aligned along the first direction such that the plurality of LEDs are connected to one another via the plurality of conductive regions.

[0032] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment s) described hereinafter.

[0033] BRIEF DESCRIPTION OF THE DRAWINGS

[0034] For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

[0035] Figure 1 illustrates an exploded view of a tubular lamp, according to an embodiment of the invention;

[0036] Figure 2 illustrates an exploded view of a tubular lamp, according to another embodiment of the invention; Figure 3 illustrates an exploded view of a tubular lamp, according to another embodiment of the invention;

[0037] Figure 4 illustrates an exploded view of a tubular lamp, according to another embodiment of the invention;

[0038] Figure 5 illustrates an exploded view of a tubular lamp, according to another embodiment of the invention;

[0039] Figure 6 illustrates an exploded view of a tubular lamp, according to another embodiment of the invention; and

[0040] Figure 7 illustrates an exploded view of a tubular lamp, according to another embodiment of the invention; and

[0041] Figure 8 illustrates an exploded view of a tubular lamp, according to another embodiment of the invention.

[0042] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The invention will be described with reference to the Figures.

[0044] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the apparatus, systems and methods, are intended for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects, and advantages of the apparatus, systems and methods of the present invention will become better understood from the following description, appended claims, and accompanying drawings. It should be understood that the Figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the Figures to indicate the same or similar parts.

[0045] The invention provides a printed circuit board comprising a substrate extending in a first direction. A high voltage track and a plurality of conductive regions are provided on the substrate. The high voltage track extends in the first direction, and the plurality of conductive regions are provided in a row extending in the first direction. Each conductive region comprises three subregions arranged along the first direction, with a center subregion having a greater distance from the high voltage track.

[0046] Embodiments are at least partly based on the realization that an increased distance between the high voltage track and a section of the conductive region reduces a likelihood that, if arcing occurs at one location on the printed circuit board, the arcing will extend along the length of the PCB.

[0047] Illustrative embodiments may, for example, be employed in tubular luminaires. Figure 1 illustrates an exploded view of a tubular lamp 10, according to an embodiment of the invention. The tubular lamp 10 comprises a printed circuit board (PCB) 100 and a plurality of LEDs 15 provided on the PCB. The PCB 100 is, itself, an embodiment of the invention.

[0048] The PCB 100 comprises a substrate 110, extending in a first direction x, a high voltage track 120, and a plurality of conductive regions 130. The substrate may be made of an organic material, such as an epoxy resin.

[0049] The high voltage track 120 is provided on the substrate 110 and extends in the first direction x along the PCB 100. A positive terminal 140 is provided at one end of the high voltage track. A negative terminal 150 is provided at the same end of the PCB as the positive terminal.

[0050] The plurality of conductive regions 130 are provided in a row extending in the first direction x on the substrate 110. Each conductive region comprises a first subregion 131, a second subregion 132, and a third subregion 133 provided between the first and second subregions in the first direction x, such that the length Ls of the third subregion in the first direction x is less than the length LR of the conductive region in the first direction. In some examples, the length Ls of the third subregion in the first direction x may be less than half of the length LR of the conductive region in the first direction.

[0051] Each conductive region 130 is configured such that a distance D3 between the high voltage track 120 and the third subregion 133 is greater than a distance Di between the high voltage track and the first subregion 131, and greater than a distance D2 between the high voltage track and the second subregion 132. The increased distance D3 reduces a likelihood that arcing due to a failed LED will spread along the length of the PCB 100.

[0052] In other words, the distance D3 between the high voltage track 120 and the third subregion 133 of a conductive region 130 provides an insulting space between the high voltage track and the third subregion, the insulating space having a length Ls (in the first direction x) and a width D3 (in a second direction y, perpendicular to the first direction). In some examples, this insulating space is filled with air. In some examples, the insulating space may be at least partially filled with another insulating material; for instance, an insulating coating applied to the PCB.

[0053] The increased distance D3 between each third subregion 133 and the high voltage track 120 is achieved in Figure 1 by providing a third subregion that has a smaller width in the second direction y (perpendicular to the first direction x) than the first and second subregions 131, 132. In this way, the increased distance D3 is provided without increasing the overall width of the conductive regions 130.

[0054] The distance Di between the high voltage track 120 and the first subregion 131 of each conductive region 130 and the distance D2 between the high voltage track and each second subregion 132 may each be at least equal to a recommended creepage distance. A creepage distance between the high voltage track and a subregion of the conductive region is a distance along the surface of the PCB between the high voltage track and the subregion. The recommended creepage distance is a distance sufficient to electrically isolate each subregion from the high voltage track during normal use of the tubular lamp.

[0055] For instance, a tubular LED lamp typically has a high voltage of about 400 V; the recommended creepage distance is therefore 0.4 mm (based on a recommended creepage distance of 1 mm per 1000 V). The distances Di and D2 may therefore be at least 0.4 mm. In some examples, a buffer distance may be added to the recommended creepage distance; for instance, the distances Di and D2 may be at least 0.5 mm.

[0056] In Figure 1, the distance Di between the high voltage track 120 and the first subregion 131 of each conductive region 130 is equal to the distance D2 between the high voltage track and each second subregion 132. However, the skilled person will readily appreciate that, in some cases, the distances Di and D2 may be different to one another.

[0057] As stated above, the distance D3 between the high voltage track 120 and the third subregion 133 of each conductive region is greater than the distances Di and D2. The distance D3 is sufficient to reduce a likelihood of arcing between the third subregion and the high voltage track, if a part of the PCB close to the third subregion becomes carbonized due to the expiry / failure of an LED 15.

[0058] For instance, the distance D3 may be at least 5 times the recommended creepage distance, e.g. at least 2 mm for a recommended creepage distance of 0.4 mm. Preferably, the distance D3 is at least 7.5 times the recommended creepage distance, e.g. at least 3 mm for a recommended creepage distance of 0.4 mm.

[0059] Similarly, the length Ls of each third subregion 133 in the first direction x should be sufficiently large to reduce a likelihood of arcing between the first subregion 131 and the second subregion of each conductive region 130.

[0060] For instance, the length Ls may be at least 5 times the recommended creepage distance, e.g. at least 2 mm for a recommended creepage distance of 0.4 mm. Preferably, the length Ls is at least 7.5 times the recommended creepage distance, e.g. at least 3 mm for a recommended creepage distance of 0.4 mm. In some examples, the length Ls and the distance D3 may each be as large as the size of the conductive region allows, while still providing a sufficient width of the third subregion 133 for conductive purposes and a sufficient length of the first and second subregions 131, 132 for themal purposes. For instance, the third subregion may have a width of at least 0.4 mm in the second direction y. The first and second subregions may each have a length of at least 1.5 mm in the first direction x. Preferably, one or both of the first and second subregions have a length of at least 1.8 mm in the first direction x.

[0061] The plurality of LEDs 15 are connected to one another via the plurality of conductive regions 130. In particular, each conductive region provides an electrical connection between two LEDs of the plurality of LEDs, with a first LED partially provided on the first subregion 131 and a second LED partially provided on the second subregion 132.

[0062] In other words, each LED 15, with the exception of the first and last LEDs in the row of LEDs, is in electrical contact with two conductive regions 130: at the first subregion 131 of one conductive region and at the second subregion 132 of an adjacent conductive region. The LED closest to the terminals 140, 150 (i.e. at a proximal end of the row of LEDs) is in electrical contact with one conductive region 130 and a separate first conductive portion, which is connected to the negative terminal 150. The LED furthest from the terminals (i.e. at a distal end of the row of LEDs) is in electrical contact with one conductive region 130 and a separate second conductive portion 170, which is connected to the high voltage track 120.

[0063] The tubular lamp 10 shown in Figure 1 is a singled-ended lamp with 6 LEDs connected in series. However, the skilled person will readily appreciate that any number of LEDs may be used, and that the PCB 100 may be adapted to accommodate a desired number of LEDs, by adjusting the length of the PCB and the number of conductive regions 130 as required. The skilled person will further appreciate that the PCB may be adapted for a double- ended lamp and / or to provide more than one string of LEDs. Figures 2 to 7 provide some examples of alternative arrangements; further examples will be apparent to the skilled person.

[0064] Figure 2 illustrates an exploded view of a tubular lamp 20, according to another embodiment of the invention. The tubular lamp 20 comprises a printed circuit board (PCB) 200 and a plurality of LEDs 25 provided on the PCB. The PCB 200 is, itself, an embodiment of the invention.

[0065] The tubular lamp 20 is similar to the tubular lamp 10 illustrated in Figure 1, but the printed circuit board 200 further comprises an AC track 280. This allows the tubular lamp 20 to be used in lighting installations in which the tubular lamp is connected to a mains input at both ends. In particular, the AC track may be connected to the mains input at the end of the AC track furthest from the terminals 240, 250, and to an LED driver at the end of the AC track closest to the terminals.

[0066] The AC track 280 is provided on the substrate 210, on an opposite side of the plurality of conductive regions 230 to the high voltage track 220, and extends along the PCB 200 in the first direction x.

[0067] As in Figure 1, each conductive region 230 comprises a third subregion 233, provided between a first subregion 231 and a second subregion 232, with a greater distance D3 between the high voltage track 220 and the third subregion than the distance Di, D2 between the high voltage track and each of the first and second subregions.

[0068] The distance D4 between each conductive region 230 and the AC track 280 in Figure 2 is constant along the length LR of the conductive region. The distance D4 may be at least the recommended creepage distance. In some examples, a buffer distance may be added to the recommended creepage distance; for instance, the distance D4 may be at least 0.5 mm for a recommended creepage distance of 0.4 mm. Preferably, the distance D4 is at least 0.7 mm.

[0069] The distance D4 between the AC track 280 and the conductive region 230 is therefore less than the distance D3 between the high voltage track and the third subregion 233 of the conductive region. When the PCB 200 is fitted in a tubular luminaire, a driver of the luminaire is likely to fail due to arcing between the conductive regions and the AC track, thus terminating the arcing.

[0070] The likelihood of arcing in a PCB having an AC track on an opposite side of the conductive regions to the high voltage track may be further reduced by providing an increased insulating space between the AC track and each conductive region, as described with respect to Figure 8 below.

[0071] Figure 3 illustrates an exploded view of a tubular lamp 30, according to another embodiment of the invention. The tubular lamp 30 comprises a printed circuit board (PCB) 300 and a plurality of LEDs 35 provided on the PCB. The PCB 300 is, itself, an embodiment of the invention.

[0072] The tubular lamp 30 is similar to the tubular lamp 20 illustrated in Figure 2, but in Figure 3, the AC track 380 is provided on a same side of the conductive regions 330 as the high voltage track 320.

[0073] Figure 4 illustrates an exploded view of a tubular lamp 40, according to another embodiment of the invention. The tubular lamp 40 comprises a printed circuit board (PCB) 400 and a plurality of LEDs 45 provided on the PCB. The PCB 400 is, itself, an embodiment of the invention. The tubular lamp 40 is similar to the tubular lamps 10, 20 and 30 of Figures 1 to 3, but the plurality of LEDs 45 are connected in two strings: a first string 45a, and a second string 45b. The LEDs within each string are connected to one another in series, and the first string is connected in parallel to the second string.

[0074] In order to enable the first string 45a and the second string 45b to be connected to each other in parallel, the PCB 400 further comprises a DC return track 490, provided on the substrate 410, on an opposite side of the plurality of conductive regions to the high voltage track 420, and extending in the first direction x, from the negative terminal 450 along the length of the second string to a first conductive portion 460a at a proximal end of the first string (i.e. closest to the terminals). A first conductive portion 460b at a proximal end of the second string (i.e. closest to the terminals) is also connected to the DC return track 490. The first and second strings 45a, 45b are respectively connected to the high voltage track by second conductive portions 470a and 470b.

[0075] Since the DC return track 490 is provided alongside the conductive regions for the second string of LEDs 45b, the conductive regions 430b for the second string are structured to reduce a likelihood of arcing between the conductive regions and the DC return track extending along the PCB 400.

[0076] In particular, each conductive region 430b for the second string further comprises a fourth subregion 434 and a fifth subregion 435. The fifth subregion 435 is provided between the second subregion 432 and fourth subregion in the first direction x. A distance Ds between the fifth subregion and the DC return track 490 is greater than a distance De between the fourth subregion and the DC return track, and greater than a distance D? between the second subregion and the DC return track.

[0077] The distance Ds between the high voltage track 420 and the fifth subregion of each conductive region may be at least 5 times the recommended creepage distance (preferably, at least 7.5 times the creepage distance). For instance, for a 400 V tubular lamp, the distance Ds may be at least 2 mm (preferably, at least 3 mm).

[0078] The distance De between the fourth subregion and the DC return track and the distance D? between the second subregion and the DC return track may each be at least equal to the recommended creepage distance. For instance, for a 400 V tubular lamp, the distances De and D? may be at least 0.4 mm (preferably, at least 0.5 mm).

[0079] Similarly to the third subregion of each conductive portion, each fifth subregion 435 has a length Ls2 in the first direction x that is sufficient to reduce a likelihood of arcing between the second subregion 432 and the fourth subregion 434. The length Ls2 may be at least 5 times the creepage distance (preferably, at least 7.5 times the creepage distance). For instance, for a 400 V tubular lamp, the length Ls2 may be at least 2 mm (preferably, at least 3 mm).

[0080] As the DC return track 490 does not run alongside the conductive regions for the first string of LEDs 45a, the conductive regions for the first string have the same structure as those used in the PCBs of Figures 1 to 3, i.e. with three subregions, the center subregion having a greater distance from the high voltage track 420.

[0081] Figure 5 illustrates an exploded view of a tubular lamp 50, according to another embodiment of the invention. The tubular lamp 50 comprises a printed circuit board (PCB) 500 and a plurality of LEDs 55 provided on the PCB, connected in a first string 55a and second string 55b. The PCB 500 is, itself, an embodiment of the invention.

[0082] The tubular lamp 50 is similar to the tubular lamp 40 of Figure 4, but the DC return track 590 is provided on the same side of the conductive regions 530 as the high voltage track 520. This means that the additional subregions of the conductive regions for the second string 45b in Figure 4 are not required in the PCB 500 of Figure 5. The conductive regions 530 in Figure 5 each have three subregions, with the center subregion having a greater distance from the high voltage track 520, as described above with respect to Figures 1 to 3.

[0083] In order to connect each string of LEDs 55a, 55b to the DC return track 590, the tubular lamp 50 further comprises a jumper 51 for each string of LEDs. Each jumper is in electrical contact with the DC return track and a first conductive portion at an end of each string of LEDs, passing over the high voltage track 520. This connects the first conductive portion 560a at a proximal end of the first string 55a and the first conductive portion 560b at a proximal end of the second string 55b to the DC return track.

[0084] Figure 6 illustrates an exploded view of a tubular lamp 60, according to another embodiment of the invention. The tubular lamp 60 comprises a printed circuit board (PCB) 600 and a plurality of LEDs 65 provided on the PCB, connected in a first string 65a and second string 65b. The PCB 600 is, itself, an embodiment of the invention.

[0085] The tubular lamp 60 is similar to the tubular lamp 40 of Figure 4, but PCB 600 further comprises an AC track 680, provided on the same side of the conductive regions 630 as the DC return track 690 (i.e. on an opposite side of the conductive regions to the high voltage track 620). The AC track 680 extends along the length of the PCB 600 in the first direction x.

[0086] Figure 7 illustrates an exploded view of a tubular lamp 70, according to another embodiment of the invention. The tubular lamp 70 comprises a printed circuit board (PCB) 700 and a plurality of LEDs 75 provided on the PCB, connected in a first string 75a and second string 75b. The PCB 700 is, itself, an embodiment of the invention.

[0087] The tubular lamp 70 is similar to the tubular lamp 50 of Figure 5, but PCB 700 further comprises an AC track 780, provided on the same side of the conductive regions 730 as the DC return track 790 (i.e. on a same side of the conductive regions to the high voltage track 620). The AC track 780 extends along the length of the PCB 700 in the first direction x.

[0088] Although Figures 4 to 7 each illustrate a tubular lamp with two strings of LEDs, the skilled person will appreciate, any number of strings of LEDs may be connected using the designs illustrated in Figures 4 to 7.

[0089] Figure 8 illustrates an exploded view of a tubular lamp 80, according to another embodiment of the invention. The tubular lamp 80 comprises a printed circuit board 800 and a plurality of LEDs 85 provided on the PCB. The PCB 800 is, itself, an embodiment of the invention.

[0090] The tubular lamp 80 is similar to the tubular lamp 20 of Figure 2, but the conductive regions 830 of PCB 800 comprise five subregions, as described with respect to Figures 4 and 6. The distance between the AC track 880 and the fifth subregion 835, provided between the second subregion 832 and the fourth subregion 834, is greater than the distance between the AC track and each of the second and fourth subregions. This further reduces a likelihood of arcing extending along the length of the PCB between the AC track 880 and the conductive regions 830, compared with the PCB 200 of Figure 2.

[0091] The tubular lamps disclosed herein may be fitted in any suitable tubular luminaire. Other components that may be included in the tubular luminaire, including driving circuitry, a housing, a lens or lenses, and so on, will be readilt apparent to the skilled person.

[0092] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

[0093] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0094] If the term "adapted to" is used in the claims or description, it is noted the term "adapted to" is intended to be equivalent to the term "configured to". If the term "arrangement" is used in the claims or description, it is noted the term "arrangement" is intended to be equivalent to the term "system", and vice versa. Any reference signs in the claims should not be construed as limiting the scope.

Claims

CLAIMS:

1. A lamp (10, 20, 30, 40, 50, 60, 70, 80), comprising: a printed circuit board, PCB (100, 200, 300, 400, 500, 600, 700, 800), and a plurality of LEDs (15, 25, 35, 45, 55, 65, 75, 85) provided on the printed circuit board, wherein the printed circuit board comprises: a substrate (110, 210, 310, 410, 510, 610, 710, 810) extending in a first direction (x); a high voltage track (120, 220, 320, 420, 520, 620, 720,820) provided on the substrate and extending in the first direction; and a plurality of conductive regions (130, 230, 330, 430, 530, 630, 730, 830) provided in a row extending in the first direction on the substrate, wherein each conductive region comprises a first subregion (131, 231, 331, 431, 531, 631, 731, 831), a second subregion (132, 232, 332, 432, 532, 632, 732, 832), and a third subregion (133, 233, 333, 433, 533, 633, 733, 833) provided between the first and second subregions in the first direction, wherein, for each conductive region: a length (Ls) of the third subregion in the first direction is less than a length (LR) of the conductive region in the first direction; and a distance (D3) between the high voltage track and the third subregion is greater than a distance (Di, D2) between the high voltage track and each of the first and second subregions; wherein the plurality of LEDs are orientated such that electrodes of the LEDs are aligned along the first direction such that the plurality of LEDs are connected to one another via the plurality of conductive regions (130, 230, 330, 430, 530, 630, 730, 830).

2. The lamp of claim 1, wherein the length (Ls) of the third subregion (133, 233, 333, 433, 533, 633, 733, 833) in the first direction is less than half of the length (LR) of the conductive region (130, 230, 330, 430, 530, 630, 730, 830) in the first direction.

3. The lamp of claim 1 or 2, wherein the length (Ls) of each third subregion (133, 233, 333, 433, 533, 633, 733, 833) in the first direction (x) is at least 5 times a recommended creepage distance for the printed circuit board.

4. The lamp of claim 3, wherein the length (Ls) of each third subregion (133, 233,333, 433, 533, 633, 733, 833) in the first direction (x) is at least 2 mm.

5. The lamp of claim 4, wherein the length (Ls) of each third subregion (133, 233, 333, 433, 533, 633, 733, 833) in the first direction (x) is at least 3 mm.

6. The lamp of any of claims 1 to 5, wherein the distance (D3) between the high voltage track (120, 220, 320, 420, 520, 620, 720, 820) and each third subregion (133, 233, 333, 433, 533, 633, 733, 833) is at least 5 times the recommended creepage distance for the printed circuit board.

7. The lamp of claim 6, wherein the distance (D3) between the high voltage track (120, 220, 320, 420, 520, 620, 720, 820) and each third subregion (133, 233, 333, 433, 533, 633, 733, 833) is at least 2 mm.

8. The lamp of claim 7, wherein the distance (D3) between the high voltage track (120, 220, 320, 420, 520, 620, 720, 820) and each third subregion (133, 233, 333, 433, 533, 633, 733, 833) is at least 3 mm.

9. The lamp of any of claims 1 to 8, further comprising a DC return track (490, 590, 690, 790) provided on the substrate (410, 510, 610, 710) and extending in the first direction (x).

10. The lamp of claim 9, wherein: the DC return track (490, 690) is provided on an opposite side of the plurality of conductive regions (430b, 630) to the high voltage track (420, 620); and at least the conductive regions provided adjacent to the DC return track each further comprise a fourth subregion (434, 634) and a fifth subregion (435, 635) provided between the second and fourth subregions in the first direction, wherein, for each conductive region comprising fourth and fifth subregions: a distance (D5) between the DC return track and the fifth subregion is greater than a distance (De, D7) between the DC return track and each of the second and fourth subregions.

11. The lamp of claim 10, wherein the distance (D5) between the DC return track (490, 690) and each fifth subregion (435, 635) is at least 5 times the recommended creepage distance for the printed circuit board.

12. The lamp of claim 11, wherein the distance (D5) between the DC return track (490, 690) and each fifth subregion (435, 635) is at least 2 mm.

13. The lamp of claim 9, wherein the DC return track (590, 790) is provided on a same side of the plurality of conductive regions (530, 730) as the high voltage track (520, 720).

14. The lamp of any of claims 1 to 13, further comprising an AC power track (280, 380, 680, 780, 880) provided on the substrate (210, 310, 610, 710, 810) and extending in the first direction (x).

15. The lamp of any of claims 1 to 14, wherein the lamp is a tubular lamp.

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