GB2545592A

GB2545592A - LED Tube Lamp

Info

Publication number: GB2545592A
Application number: GB1704608.7A
Authority: GB
Inventors: Jiang Tao; Yang Xiaosu; Li Liqin; Zhang Yueqiang
Original assignee: Jiaxing Super Lighting Electric Appliance Co Ltd
Current assignee: Jiaxing Super Lighting Electric Appliance Co Ltd
Priority date: 2014-09-28
Filing date: 2015-09-25
Publication date: 2017-06-21
Anticipated expiration: 2035-09-25
Also published as: HK1247980B; GB201516993D0; GB201704608D0; GB2545366A; CN105465640A; CN105465640B; GB2549435B; AU2015230858B2; GB2549435A; GB2545366B; GB2545592B; GB201711722D0; HK1222444A1; GB2531425A; GB201704611D0; GB2531425B

Abstract

An LED tube lamp comprises a tube having two end caps (3, Fig. 2) each having two pins (301, Fig. 2) and a LED light bar 2 comprising a bendable circuit board disposed inside the tube and mounted to an inner surface of the tube. The light bar 2 has a plurality of LED light sources (202, Fig. 2) mounted in a row therealong. The light bar is connected to a power supply 5 and is mounted to an inner surface of the tube and has a freely extending end portion 21 which is an integral portion of the bendable circuit board and which is bent away from the tube. The light bar 2 has a first bond pad b at one end that is electrically connected to a second bond pad a on the power supply 5. The bond pads may comprise solder. The power supply 5 may be connected to a circuit board assembly (251, 253, Fig. 36). The bendable circuit board in a fully extended state may be longer than the tube.

Description

LED TUBE LAMP

FIELD OF THE INVENTION

The present invention relates to illumination devices, and more particularly to an LED tube lamp and components thereof.

BACKGROUND OF THE INVENTION

Today LED lighting technology is rapidly replacing traditional incandescent and fluorescent lights. Even in tube lamp applications, instead of being filled with inert gas and mercury as found in fluorescent tube lamps, LED tube lamps are mercury-free. Thus, it is not surprising that LED tube lamps are becoming a highly desired illumination option among different available lighting systems used in homes and workplaces, which used to be dominated by traditional lighting options such as compact fluorescent light bulbs (CFLs) and fluorescent tube lamps. Benefits of LED tube lamps include improved durability and longevity, and far less energy consumption; therefore, when taking into account all factors, they would be considered as a cost effective lighting option.

There are several types of LED tube lamps that are currently available on the market today. Many of the conventional LED tube lamps have a housing that uses material such as an aluminum alloy combined with a plastic cover, or is made of an all-plastic tube construction. The lighting sources usually adopt multiple rows of assembled individual chip LEDs (single LED per chip) being welded on circuit boards, and the circuit boards are secured to the heat dissipating housing. Because this type of aluminum alloy housing is a conductive material, it is prone to result in electrical shock accidents to users. In addition, the light transmittance of the plastic cover or the plastic tube diminish over time due to aging, thereby reducing the overall lighting or luminous efficiency of the conventional LED tube lamp. Furthermore, grainy visual appearance and other derived problems reduce the luminous efficiency, thereby reducing the overall effectiveness of the use of the LED tube lamp. The LED light sources are typically a plurality of spatially arranged LED chips. With respect to each LED chip, due to its intrinsic illumination property, if there was no or insufficient further optical processing, the entire tube lamp would exhibit a grainy or non-uniform illumination effect; as a result, a grainy effect would be produced on the viewer or user, thereby negatively affecting the visual aesthetics thereof. In other words, the overall illumination distribution uniformity of the light output by the LED light sources without having additional optical processing techniques or structures for modifying the illumination path and uniformity would not be sufficient to satisfy the quality and aesthetic requirements of average consumers.

Referring to US patent publication no. 2014226320, as an illustrative example of a conventional LED tube lamp, the two ends of the tube are not curved down to allow the end caps at the connecting region with the body of the tube (including a lens, which typically is made of glass or clear plastic) requiring to have a transition region. During shipping or transport of the LED tube lamp, the shipping packaging support/bracket only makes direct contact with the end caps, thus rendering the end caps as being the only load/stress points, which can easily lead to breakage at the transition region with the glass lens.

With regard to the conventional technology directed to glass tubes of the LED tube lamps, one or more LED chips on board are mounted inside the glass tube lamp by means of adhesive. The end caps are made of a plastic material, and are also secured to the glass tube using adhesive, and at the same time the end cap is electrically connected to the power supply inside the tube lamp and the LED chips on board. This type of LED tube lamp assembly technique resolves the issue relating to electrical shocks caused by the housing and poor luminous transmittance issues. But this type of conventional tube lamp configured with the plastic end caps requires a tedious process for performing adhesive bonding attachment because the adhesive bonding process requires a significant amount of time to perform, leading to production bottlenecks or difficulties. In addition, manual operations or labor are required to perform such an adhesive bonding process, thereby making it difficult to optimize manufacturing using automation. In addition, sometimes the end cap and the glass tube come apart from one another when the adhesive does not sufficiently bond the two together. Thus, the detachment of the end cap and the glass tube can be a problem yet to be solved.

In addition, the glass tube is a fragile breakable part. Thus, when the glass tube is partially broken in certain portions thereof, contact with the internal LED chips on board when illuminated can cause electric shock incidents. Referring to Chinese patent publication no. 102518972, which discloses the connection structure of the lamp caps and the glass tube, as shown in FIG. 1 of the aforementioned Chinese patent reference, it can be seen that the lamp end cap protrudes outward at the joining location with the glass tube, which is commonly done in the conventional market place. According to conducted studies, during the shipping process of the LED tube lamps, the shipping packaging support/bracket only makes contact with the lamp end caps. This means that the end caps are the only load/stress points, which can result in breakage at the transition coupling regions at the ends of the glass tube.

In addition, with regard to the secure mounting method of the lamp end caps and the glass tube, regardless of whether using hot melt adhesive or silicone adhesive, it is hard to prevent the buildup of excess (overflown) leftover adhesive residues, which causes light blockage as well as an unpleasant aesthetic appearance. In addition, a large amount of manpower is required for cleaning off the excessive adhesive buildup, creating a further production bottleneck and inefficiency. As shown also from Figs 3 and 4 of the aforementioned Chinese patent application, the LED lighting elements and the power supply module are required to be electrically connected via a wire bonding technique, and this can also be a problem or issue during shipping due to the concern of breakage.

Based on the above, it can be appreciated that an LED tube lamp fabricated according to the conventional assembly and fabrication methods in mass production and shipping process can experience various quality issues and there is a need for improvement. US patent publication no. 20100103673 discloses an end cap substitute for sealing and inserting into the housing. However, based on various experimentation, upon exerting a force on the glass housing, breakages can easily occur, which lead to product defect and quality issues. Meanwhile, grainy visual appearances are also often found in the aforementioned conventional LED tube lamp. US patent publication no. 2007001709 discloses a lighting device which includes a light-guiding rod and a light emitting unit. The light-emitting unit includes a transparent light-guiding plate, at least one light-emitting diode, a mounting substrate, and a plurality of conductive bumps. The transparent light-guiding plate is disposed in the housing. In one embodiment, the mounting substrate is a flexible opaque substrate and is compliantly mounted on the inner surface of the housing. The mounting substrate has a wiring surface on which electric traces are formed and a reflecting layer provided on portions of the surface not covered by the traces. US patent publication no. 2005162850 discloses a flexible lighting device which includes an elongate flexible tube with a translucent tube shell and opposed tube ends and a flexible circuit board set in the tube so that it extends between the tube ends. The flexible circuit board has opposed interior and exterior surfaces. Electrical circuitry is mounted to the circuit board and connected to an external input source and an output source of electrical power. In one embodiment, the device has inwardly directed LEDs on the circuit board directed into the tube. It is an object of the present invention to at least mitigate the above mentioned problems.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided an LED tube lamp, comprising: a tube; a bendable circuit sheet disposed inside the tube, the bendable circuit sheet comprising a wiring layer; a plurality of LED light sources mounted in a row along the bendable circuit sheet and connected to the wiring layer; wherein the bendable circuit sheet is mounted to an inner surface of the tube; and wherein the bendable circuit sheet further comprises a freely extending end portion which is an integral portion of the bendable circuit sheet.

The row of LED light sources may extend along the longitudinal axis of the tube. The bendable circuit sheet may further comprise a dielectric layer disposed on one side of the wiring layer such that the dielectric layer is separated from the LED light sources by the wiring layer. At least a majority of the dielectric layer may be fixed to an inner surface of the tube.

The bendable circuit sheet may further comprise a soldering portion at or around the end portion of the bendable circuit sheet, and the soldering portion may comprise at least one soldering pad for electrically connecting the bendable circuit sheet to an electrical power supply by soldering to provide electrical power to the plurality of LED light sources. The soldering portion may comprise two spaced apart soldering pads. A structure may be formed through each soldering pad and the bendable circuit sheet and the shape of the structure may be chosen to urge solder into a desired shape during soldering. The structure may be an aperture which extends through the soldering pad and the bendable circuit sheet. The aperture may have a diameter of 1mm to 2 mm. The soldering pad of the bendable circuit sheet may be formed with a solder ball above the aperture after soldering is completed, and a diameter of the solder ball may be larger than the diameter of the aperture. A distance between the aperture and an edge of the bendable circuit sheet may be 1 mm or less. The structure may be a notch formed through the soldering pad and the bendable circuit sheet at an edge of the bendable circuit sheet. The soldering pad of the bendable circuit sheet may be formed with a solder ball above the notch after soldering is completed, and a diameter of the solder ball may be larger than a diameter of the notch.

An aperture may be formed in the bendable circuit sheet between the two spaced apart soldering pads to prevent from short circuit between the soldering pads. An alignment hole may be further configured and disposed near the soldering pads to allow a soldering machine to automatically locate the soldering pads.

The LED tube lamp may further comprises a power supply having a printed circuit board disposed with soldering pads corresponding to the soldering pads of the soldering portion of the bendable circuit sheet, and the soldering pads of the soldering portion of the bendable circuit sheet may be electrically connected to the soldering pads of the printed circuit board of the power supply, respectively to provide electrical connection between the power supply and the LED light sources. The soldering pads of the soldering portion of the bendable circuit sheet and the soldering pads of the printed circuit board of the power supply may point toward same direction when soldering. Alternatively, the soldering pads of the soldering portion of the bendable circuit sheet and the soldering pads of the printed circuit board of the power supply may point toward opposite directions when soldering.

More than two soldering pads may be disposed on the bendable circuit sheet and arranged in one row or two rows.

The LED tube lamp may further comprise one or more reflective layers to reflect light from the plurality of LED light sources. One reflective layer may comprise a surface of the bendable circuit sheet. At least one reflective layer may comprise a reflective film layer disposed on an inner surface of the tube and occupy a portion of an area of the inner surface of the tube. The reflective film layer may have an opening corresponding to the bendable circuit sheet and the bendable circuit sheet may be disposed in the opening of the reflective film layer.

The opening of the reflective film layer may be bigger than the bendable circuit sheet to accommodate the bendable circuit sheet. The bendable circuit sheet may be disposed on the reflective film layer. Alternatively, the bendable circuit sheet may be disposed to one side of the reflective film layer. One or more reflective film layers may extend away from one side of the bendable circuit sheet along the inner surface of the tube. One or more reflective film layers may extend away from opposite sides respectively of the bendable circuit sheet along the inner surface of the tube. One or more reflective film layers may extend away from opposite sides respectively of the bendable circuit sheet a distance such that substantially the same area of the inner surface of the tube is covered by the one or more reflective film layers from either side of the bendable circuit sheet. A ratio of a length of at least one reflective film layer along the inner surface of the tube and a length of the tube may be 0.3 to 0.5. A reflectance of one or more reflective layers may exceed 85%. The average thickness of one or more reflective film layers may be between 140pm and 350pm.

The bendable circuit sheet may further comprise a first circuit protection layer disposed on an outermost layer of the wiring layer. The first circuit protection layer may comprise a material to enhance the reflective properties of the reflective layer of the bendable circuit sheet. The bendable circuit sheet may further comprises a second circuit protection layer disposed on an outermost side of the dielectric layer.

The bendable circuit sheet may comprise a plurality of wiring layers and a plurality of dielectric layers that are sequentially stacked in a staggered manner, the LED light sources may be disposed on the uppermost wiring layer of the plurality of wiring layers, and the LED light sources may be electrically connected to the uppermost wiring layer of the plurality of wiring layers.

Two ends of the bendable circuit sheet may be detached from an inner surface of the tube. The bendable circuit sheet may be sufficiently long such that, in a fully extended state, two ends of the bendable circuit sheet extend beyond two ends of the tube, respectively, and the freely extending end portions may be curled up, coiled or deformed in shape to be fittingly accommodated inside the tube.

The tube may include a main region, a plurality of rear end regions and a transition region connecting the main region and the at least one of the rear end regions, at least one of the rear end regions may be fittingly sleeved with an end cap, and an outer width of at least one of the rear end regions may be less than an outer width of the main region, and one end of the bendable circuit sheet may pass through the transition region to be electrically connected to a power supply.

The bendable circuit sheet may be directly soldered to a power supply. The bendable circuit sheet may be sufficiently flexible to substantially conform to an inner surface of the tube. A circumferential length of the bendable circuit sheet along an inner circumferential surface of the tube and a circumferential length of the inner circumferential surface of the tube may be at a ratio of 0.2 to 0.5, and preferably 0.3 to 0.5.

The tube may comprise a diffusion film layer so that the light emitted from the plurality of LED light sources is transmitted through the diffusion film layer and the tube. The diffusion film layer may be a diffusion coating layer coating above the LED light sources.

The diffusion film layer may be a diffusion coating layer covering above the LED light sources. The diffusion film layer may be a diffusion coating layer coating above the inner circumferential surface of the tube. The diffusion film layer may be a diffusion coating layer covering above the inner circumferential surface of the tube. The diffusion film layer may be a diffusion sheet covering the LED light sources without contacting with the LED light sources. The LED tube lamp may further comprise a diffusion layer associated with at least one LED light source and arranged such that light emitted from the LED light source passes through the diffusion layer to more uniformly distribute the emitted light. The diffusion layer may be arranged to electrically isolate one or more LED light sources. The diffusion layer may be arranged to cover one or more exposed parts of an LED light source.

The LED tube lamp may further comprise an end cap, an end of the tube may be attached to the end cap, a power supply may be disposed in the end cap and the bendable circuit sheet may be electrically connected to the power supply.

The plurality of LED light sources may be configured to direct light in substantially the same direction. The transition region may have a length of 1 mm to 4 mm. The tube may be configured such that upon breaking of the tube, the broken tube does not maintain a straight tube configuration so that the LED tube lamp is structurally rendered unusable

According to an embodiment of an aspect of the invention, there is provided a LED tube lamp having an LED light bar, in which the LED light bar is in form of a bendable circuit sheet.

Embodiments of the present invention can provide an LED tube lamp that includes a plurality of LED light sources, a LED light bar, a tube, at least one end cap and at least one power supply.

In an embodiment of the present invention, the LED light bar is disposed inside the tube, the LED light sources are mounted on the LED light bar, and the LED light sources and the power supply are electrically connected by the LED light bar.

In an embodiment of the present invention, two end caps are provided, in which each end cap is equipped with one power supply. The sizes of the two end caps are different in some embodiments, and the size of one end cap is 30%-80% of the size of the other end cap in some other embodiments.

Embodiments of the present invention provide the chip LEDs / chip LED modules mounted and fixed on the inside wall of the glass tube by a bonding adhesive, in which the chip LEDs / chip LED modules serve as the LED light sources.

According to an embodiment of an aspect of the invention, the tube can be a plastic tube, or, in alternative embodiments, the tube is a glass tube. In a preferred embodiment, the tube can be a transparent glass tube, or a glass tube with coated adhesive film on the inner walls thereof.

In an embodiment of the present invention the LED light bar may be in the form of a bendable circuit sheet including a wiring layer and a dielectric layer. The LED light sources may be disposed on the wiring layer and may be electrically connected to the power supply by the wiring layer therebetween. The wiring layer and the dielectric layer may be stackingly arranged. The dielectric layer may be disposed on a surface of the wiring layer which is away from the LED light sources, and may be fixed to an inner circumferential surface of the tube.

Furthermore, the bendable circuit sheet may extend along a longitudinal and a circumferential direction of the tube, and the length of the bendable circuit sheet may extend along the circumferential direction of the tube. Preferably, a ratio of the circumferential length of the LED light bar to the circumferential length of the inner circumferential surface of the tube is 0.2 to 0.5, and more preferably 0.3 to 0.5.

Moreover, the bendable circuit sheet can further include a circuit protection layer disposed on an outermost layer of the wiring layer of the bendable circuit sheet. The circuit protection layer may comprise one layer disposed on an outermost surface of the wiring layer or two layers respectively disposed on outermost surfaces of the wiring layer and the dielectric layer of the bendable circuit sheet.

In embodiments of the present invention, the bendable circuit sheet can be electrically connected to the power supply by wire bonding or by soldering, and two ends of the bendable circuit sheet may not be fixed to an inner circumferential surface of the tube, i.e. there are two freely extending end portions at the two ends thereof, respectively.

According to an embodiment of an aspect of the invention, the tube may include a main region, a transition region, and a plurality of rear end regions, wherein a diameter of each of the rear end regions is less than a diameter of the main region, and each of the rear end regions of the tube is fittingly sleeved with the end cap. The transition region may be formed between the main region and each of the rear end regions.

The transition region may be arc-shaped at both ends, one arc thereof near the main region is curved towards inside of the glass tube, and the other arc thereof near the rear end region is curved toward outside of glass tube, and outer surfaces of the transition regions are in compression and inner surfaces of the transition regions are in tension near the rear end region, and outer surfaces of the transition regions are in tension and inner surfaces of the transition regions are in compression near the main region. The normal vector of the arcshaped surface at the end of the transition region near the main region points towards outside of the tube, and the normal vector of the arc-shaped surface at the end of the transition region near the rear end region points towards inside of the tube. In some embodiments, the radius of curvature, R1, of the arc between the transition region and the main region is smaller than the radius of curvature, R2, of the arc between the transition region and the rear end region. The ratio range of R1 : R2 is from 1 : 1.5 to 1 : 10. Furthermore, there is no gap between the main region of the tube and the end cap. The included angle between the transition region and the main region and the included angle between the transition region and the rear end region are larger than 90 degrees.

In an embodiment of the present invention, the bendable circuit sheet may pass through the transition region and be electrically connected to the power supply. In embodiments of the present invention, each of the transition regions may have a length of 1 mm to 4 mm but other lengths are also possible for the transition region.

In an embodiment of the present invention, the LED tube lamp may further comprise a diffusion film layer and a reflective film layer, in which the diffusion film layer is disposed above the LED light sources, and the light emitting from the LED light sources passes through the diffusion film layer and the tube. On the other hand, the reflective film layer may be disposed on an inner circumferential surface of the tube, and the bendable circuit sheet may be disposed on the reflective film layer or one side of the reflective film layer. A ratio of a length of the reflective film layer fixed on an inner surface of the tube extending along the circumferential direction of the tube to a circumferential length of the tube may be 0.3 to 0.5.

In a preferred embodiment, the diffusion film layer is made of a diffusion coating comprising at least one of calcium carbonate, halogen calcium phosphate and aluminum oxide, a thickening agent, and a ceramic activated carbon.

In an embodiment of the present invention, the diffusion film layer is an optical diffusion coating coated on an inner wall or an outer wall of the tube.

In another embodiment of the present invention, the diffusion film layer is an optical diffusion coating coated directly on a surface of the LED light sources.

In another embodiment of the present invention, the diffusion film layer is an optical diffuser covering above the LED light sources without making direct contact therewith.

In an embodiment of the present invention, a reflective film layer is disposed on the inner circumferential surface of the tube, and occupies a portion of the inner circumferential surface of the tube along the circumferential direction of the tube. The LED light sources can be fixedly attached to the inner circumferential surface of the tube, while the reflective film layer can contact one end or two ends of the LED light sources when extending along the circumferential direction of the tube. The LED light sources can also be disposed above the reflective film layer or adjacent to one side of the reflective film layer.

In embodiments of the present invention, the reflective film layer may be disposed on the inner circumferential surface of the tube, and the LED light bar including the LED light sources may be disposed on the reflective film layer or one side of the reflective film layer.

In another embodiment of the present invention, the reflective film layer can be divided into two distinct sections of a substantially equal area and the LED light sources may be disposed in between the two distinct sections of the reflective film layer.

In yet another embodiment of the present invention, the LED light sources may be disposed on the inner circumferential surface of the tube, the reflective film layer may have a plurality of openings configured and arranged to correspondingly accommodate the LED light sources, and the LED light sources may be disposed in the openings of the reflective film layer, respectively.

Preferably, the thickness of the diffusion film layer ranges from 20 pm to 30 pm.

Preferably, the light transmittance of the diffusion film layer ranges from 85% to 96%.

In yet another embodiment of the present invention, the light transmittance of the diffusion film layer ranges from 92 % to 94% while the thickness of the diffusion film layer ranges from 200 pm to 300 pm.

In another embodiment of the LED tube lamp, the LED light bar is a bendable circuit sheet and includes a plurality of wiring layers and a plurality of dielectric layers. The dielectric layers and the wiring layers are sequentially and staggeringly stacked, respectively. The LED light sources are disposed on an uppermost layer of the wiring layers, and are electrically connected to the power support by the uppermost layer of the wiring layers.

The present invention may provide a hot melt adhesive to bond together the end cap and the tube, thus allowing for realization of manufacturing automation for LED tube lamps.

In an embodiment of the present invention, the power supply for the LED tube lamp may be in the form of a single unit, or two individual units. The power supply may be purchased readily from the marketplace because it is of conventional design.

In an embodiment of the present invention, the LED light bar may be adhesively mounted and secured on the inner wall of the tube, thereby having an illumination angle of at least 330 degrees.

According to an embodiment of an aspect of the invention, an LED tube lamp is provided having a substantially uniform exterior diameter from end to end thereof. Each end of the tube comprises one or more narrowly curved end regions for engaging with a corresponding end cap. The end caps enclose the narrowly curved end regions of the glass tube, and the outer diameter of the end caps is substantially equal to the outer diameter of the tube thereby forming the LED tube lamp of substantially uniform exterior diameter from end to end thereof.

An embodiment of the present invention can provide an LED tube lamp that includes a plurality of chip LEDs, an LED light bar, a tube, at least two end caps, an insulation adhesive, an optical adhesive, a hot melt adhesive, a bonding adhesive, and at least one power supply.

[0038] In an embodiment of the present invention, the LED light bar has a female plug and contains LED light sources in form of chip LEDs. Each end cap is formed with a plurality of hollow conductive pins on one surface, and includes a power supply installed therein. The power supply having a male plug at one end, and metal pins at the other end. The male plug of the power supply is fittingly inserted into the female plug of the LED light bar. The metal pins at the other end of the power supply are respectively inserted into the hollow conductive pins, thereby enabling an electrical connection. The power supply can be of one singular unit only disposed in one end cap or of two units respectively located in two end caps. In an embodiment in which the tube of the LED tube lamp has a singular narrowly curved end region at one end and the power supply is of one singular unit, the power supply is preferred to be disposed in the end adjacent to the corresponding singular narrowly curved end region of the tube.

In an embodiment of the present invention, the insulation adhesive may be coated and encapsulated over the LED light bar, while an optical adhesive may be coated and encapsulated over the surfaces of the LED light source (LED chip). Thus, all the LED chips are electrically insulated from the outside, so that the risk of electric shock is reduced even when the tube is partially broken into pieces. The end caps are secured to the tube by using a hot melt adhesive, and thus the assembling of the LED tube lamp can be completed.

In an embodiment of the present invention, the glass tube may be narrowly curved at the opening regions or end regions of the glass lamp, and have a narrower diameter at the respective ends. The hot melt adhesive may be used to secure the end caps to the narrowly curved end regions of the tube, i.e. the end caps are attached to the “transition region”. The hot melt adhesive is prevented from spillover or forming a flash region. A difference between the outer diameter of the end cap and the outer diameter of the glass tube may have an average tolerance of up to +/- 0.2 mm, and a maximum tolerance up to +/- 1 mm. Due to the substantial aligning of the center line of the end cap and the center line of the glass tube combined with the fact that the outer diameter of the end cap and the outer diameter of the glass tube (excluding the two narrowly curved end regions) are substantially equal, the entire LED tube lamp (assembly) has the appearance of an integrated planar flat surface. As a result, during shipping or transport of the LED tube lamp, the shipping packaging support or bracket makes direct contact not only with the end caps, but also with the entire LED tube lamp, including the glass tube; thus the entire span or length of the LED tube lamp serves or functions as multiple load/stress points, which thereby distribute the load/stress more evenly over a wider surface, and reduces the risk of breakage of the glass tube.

In an embodiment of an aspect of the present invention, a LED tube lamp may have a magnetic metal member disposed between an end cap and an end of a tube.

In an embodiment of an aspect of the present invention, the end cap is configured to be attached over an end of the tube. The end cap may comprise an electrically insulating tubular part, sleeving over the end of the tube, and a magnetic object disposed between an inner circumferential surface of the electrically insulating tubular part of the end cap and the end of the tube.

Embodiments of the present invention provide that the magnetic object can be a magnetic metal member fixedly disposed on an inner circumferential surface of the electrically insulating tubular part. At least a portion of the magnetic metal member may be disposed between the inner circumferential surface of the electrically insulating tubular part and the end of the tube.

In embodiments of the present invention, the magnetic metal member and the end of the tube may be adhesively bonded, such as by a hot melt adhesive.

In an embodiment of the present invention, the electrically insulating tubular part further comprises a plurality of protruding portions formed on the inner circumferential direction of the electrically insulating tubular part to be extending inwardly thereof, the protruding portion is disposed between an outer circumferential surface of the magnetic metal member and the inner circumferential surface of the electrically insulating tubular part, thereby forming a gap or space therebetween. A thickness of the protruding portion is less than that of the supporting portion.

In another embodiment of the present invention, an electrically insulating tubular part may sleeve over the end of the tube, an inner circumferential surface of the electrically insulating tubular part may have a plurality of protruding portions extending inwardly in a radial direction, and a magnetic metal member may be fixedly disposed in the end cap. The protruding portions of the electrically insulating tubular part may be disposed between an outer circumferential surface of the magnetic metal member and an inner circumferential surface of the electrically insulating tubular part, wherein the magnetic metal member is at least partially disposed between an inside surface of the protruding portions of the electrically insulating tubular part and the end of the tube. A plurality of gaps between the outer circumferential surface of the magnetic metal member and the inner circumferential surface of the electrically insulating tubular part are formed due to the protruding portions, and the protruding portions may be equally and spatially arranged along the inner circumferential surface of the electrically insulating tubular part. The gaps and the protruding portions may be have a staggered arrangement.

An embodiment of an aspect of the present invention may provide a LED tube lamp having a tube and an end cap, in which the end cap includes an electrically insulating tubular part and a thermal conductive ring. The electrically insulating tubular part has a first tubular part and a second tubular part, the first tubular part is connected to the second tubular part along an axial direction of the tube. An outer diameter of the second tubular part is less than an outer diameter of the first tubular part, and the thermal conductive ring sleeving over the second tubular part is fixedly arranged on an outer circumferential surface of the electrically insulating tubular part, whereby an outer surface of the thermal conductive ring and an outer circumferential surface of the first tubular part are substantially flush with each other. The thermally conductive ring can be a metal ring.

In an embodiment of the present invention, the thermally conductive ring may be adhesively bonded to the tube by hot melt adhesive. In addition, the thermally conductive ring may be fixedly arranged on a circumferential surface of the electrically insulating tubular part. An inner surface of the second tubular part, the inner surface of the thermal conductive ring, the outer surface of the rear end region and the outer surface of the transition region may together form an accommodation space in which the hot melt adhesive is disposed in the accommodation space, such as only partially filing thereof. A portion of the hot melt adhesive may be disposed between the inner surface of the second tubular part and the outer surface of the rear end region. Upon filling and curing (solidification) of the hot melt adhesive, the thermally conductive ring may be bonded to an outer surface of the tube by the hot melt adhesive therebetween at a first location. Upon filling and curing (solidification) of the hot melt adhesive, the second tubular part may be bonded to the rear end region of the tube by the hot melt adhesive therebetween at a second location. Due to the difference in height between the outer surface of the rear end region and the outer surface of the main region of the tube and the presence and location of the thermally conductive ring in relation to the transition region and the main region of the tube, overflow or spillover of the hot melt adhesive to the main region of the tube can be avoided, forsaking or avoiding having to perform manual adhesive wipe off or clean off, thus improving LED tube lamp production efficiency.

In another embodiment, an end of the second tubular part located away from the first tubular part may include a plurality of notches. The notches may be spatially arranged along a circumferential direction of the second tubular part.

Embodiments of the present invention provide a LED tube lamp having a plurality of LED lead frames in which a plurality of LED light sources such as LED chips are disposed therein, respectively. The LED chips are mounted and fixed on the LED lead frames by a bonding adhesive, respectively. Each LED chip preferably has a rectangular shape, such as a strip, with a ratio of a length thereof to a width thereof ranging from 2:1 to 10:1, preferably at a ratio ranging from 2.5:1 to 5:1, and further preferably at a ratio ranging from 3:1 to 4.5:1.

In an embodiment of the present invention, the LED lead frame has two first sidewalls, two second sidewalls and a recess. Each LED chip is disposed in the recess. A height of the first sidewall may be lower than a height of the second sidewall.

In an embodiment, the first sidewalls of the LED lead frame are arranged along a length direction of the tube, and the second sidewalls of the LED lead frame are arranged along a width direction of the tube.

In another embodiment, each of the first sidewalls of the LED lead frame extends along the width direction of the tube, and each of the second sidewalls of the LED lead frame extends along the length direction of the tube.

In an embodiment of the present invention, the LED light sources are mounted within the LED lead frames, respectively, and then together are mounted on the LED light bar. The LED light sources and the power supply are electrically connected by the LED light bar.

In an embodiment, an inner surface of the first sidewall is a sloped flat surface that is facing in a direction outside of the recess.

There may be provided an LED light source, which includes an LED chip and an LED lead frame. The LED lead frame may include a recess, a first sidewall and a second sidewall. The LED chip is disposed in the recess. A height of the first sidewall may be lower than a height of the second sidewall.

In another embodiment, an inner surface of the first sidewall is a sloped curved surface that is facing in a direction outside of the recess.

In an embodiment, the first sidewall of the LED lead frame is configured to have an included angle between the bottom surface of the recess and the inner surface of the first sidewall which ranges from 105 degrees to 165 degrees.

In a preferred embodiment, the included angle between the bottom surface of the recess and the inner surface of the first sidewall can be between 120 degrees and 150 degrees.

In various embodiments, the LED tube lamp has the LED light sources therein arranged in one or more rows, and each row of the LED light sources extends along a length direction of the tube.

In an embodiment, the LED lead frames of the LED light sources have all of the second sidewalls thereof disposed in one straight line along the length direction of the tube.

In another embodiment, the LED light sources are arranged and disposed in more than one rows, and these rows of the LED light sources are arranged along the length direction of the tube.

The LED lead frames of the LED light sources may be disposed in the outermost two rows along the width direction of the tube, and the LED lead frames of the LED light sources may have all of the second sidewalls thereof disposed in one straight line along the length direction of the tube, respectively. The second sidewalls disposed on a same side of the same row may be collinear to one another. The LED lead frames disposed in the outermost two rows may have two first sidewalls configured along the length direction and two second sidewalls configured along the width direction, so that the second sidewalls located at the outermost two rows can block the user’s eye from directly seeing the LED light sources, thereby achieving a reduction of visual graininess which is an undesirable effect.

When a tube with a rigid light bar, as opposed to a flexible light bar, has been ruptured, the entire tube still maintains a straight tube configuration, and the user may be under a false impression that the LED tube lamp remains usable and fully functional. As a result, electric shock can occur upon handling or installation thereof.

One benefit of the LED tube lamp fabricated in accordance with the embodiments of present invention is that as compared to having rigid aluminum plate or FR4 board as the LED light bar, because of added flexibility and bendability of the bendable circuit sheet for the LED light bar according to embodiments of the present invention, the problems faced by the aluminum plate, FR4 board, and conventional 3-layered flexible board having inadequate flexibility and bendability, are thereby solved. Due to the adoption of the flexible substrate / bendable circuit sheet for the LED light bar in some embodiments of the present invention, the bendable circuit sheet (the LED light bar) prevents a ruptured or broken tube being able to maintain a straight pipe or tube configuration so as to better inform the user that the LED tube lamp is deemed unusable so as to avoid potential electric shock accidents from occurring.

Another benefit of an LED tube lamp fabricated in accordance with embodiments of present invention is that the bendable circuit sheet (of the LED light bar) having a freely extending end portion can be manipulated and deformed into a desired shape to facilitate connection of the bendable circuit sheet to the output terminal of the power supply via a soldering connection. The freely extending end portion can be coiled so as to be fittingly accommodated inside the tube. A solder bonding technique may be used whereby a soldering pad associated with the power supply is provided on a different surface to a soldering pad on one of the surfaces of the bendable circuit sheet to which is mounted the LED light sources. A downward tension is exerted on the power supply soldering pad by the bendable circuit sheet at the connection end of the power supply and the bendable circuit sheet. Thus, a bendable circuit sheet with a bond pad having through holes would form a stronger and more secure electrical connection between the bendable circuit sheet and the power supply.

Another benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that the bendable circuit sheet allows for forming solder joints between the flexible substrate and the power supply. The bendable circuit sheet can be used to pass through the transition region and be solder bonded to the output terminal of the power supply for providing electrical coupling to the power supply, so as to avoid the usage of bonding wires, and improve the reliability.

Another benefit of an LED tube lamp fabricated in accordance with an embodiment of the present invention is that the tube having the diffusion film layer coated and bonded to the inner wall thereof allows the light outputted or emitted from the LED light sources to be more uniformly transmitted through the diffusion film layer and then through the tube. In other words, the diffusion film layer provides an improved, more uniform illumination distribution of the light outputted by the LED light sources so as to avoid the formation of dark regions seen inside the illuminated or lit up tube.

Another benefit of an LED tube lamp fabricated in accordance with an embodiment of the present invention is that the application of the diffusion film layer made of optical diffusion coating material to an outer surface of the rear end region along with the hot melt adhesive generates increased friction resistance between the end cap and the tube due to the presence of the optical diffusion coating (when compared to that of an example that is without any optical diffusion coating), which is beneficial for preventing accidental detachment of the end cap from the tube. In addition, using this optical diffusion coating material for forming the diffusion film layer, a superior light transmittance ratio of about 85%-96% can be achieved.

Another benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that the diffusion film layer can also provide electrical isolation for reducing risk of electric shock to a user upon breakage of the tube. Meanwhile, in some embodiments, the particle size of the reflective material such as strontium phosphate or barium sulfate will be much larger than the particle size of the calcium carbonate. Therefore, selecting just a small amount of reflective material in the optical diffusion coating can effectively increase the diffusion effect of light.

Another benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that the reflective film layer when viewed by a person looking at the tube from the side serves to block the LED light sources, so that the person does not directly see the LED light sources, thereby reducing the visual graininess effect. Meanwhile, light emitted from the LED light sources is reflected by the reflective film layer and therefore the divergence angle of the LED tube lamp can be controlled via the disposition of the reflective film layer so that more light is emitted toward parts of the tube which are not coated with the reflective film, thereby increasing the energy efficiency of the LED tube lamp whilst providing the same level of illumination performance. Preferably, reflectance at more than 95% can also be achievable.

Another benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that the glass tube containing an adhesive film layer can allow the broken glass pieces to adhere together even upon breakage of the tube, without forming shattered openings, thereby preventing accidental electric shock caused by physical contact between a person and the internal electrical conducting elements residing inside the glass tube. At the same time, through having the adhesive film layer of the type of material composition which also includes light diffusing and light transmitting properties, it is possible to achieve more evenly distributed LED tube illumination, and higher light transmittance.

In an embodiment, the glass tube is coated with the adhesive film layer on its inside wall surface. The adhesive film layer is made primarily of calcium carbonate, along with a thickening agent, ceramic activated carbon, and deionized water, which are mixed and combined together to be evenly coated on the side wall surface of the glass tube, with average thickness of 20~30 micrometers, which can lead to about 85%-96% light transmittance ratio. Finally, the deionized water is evaporated, so as to leave behind the calcium carbonate, the thickening agent, and the ceramic activated carbon.

One benefit of an LED tube lamp fabricated in accordance with an embodiment of the present invention is that the magnetic metal member is out of sight when viewed by a user of the LED tube lamp, thus the flush surface of the end cap can be more aesthetically pleasing.

Another benefit of an LED tube lamp fabricated in accordance with an embodiment of the present invention is that actual curing (solidification) of the hot melt adhesive by an energized induction coil may be performed more uniformly and done more precisely. Thus the bonding of the end cap, the magnetic metal member, and the tube may be more secure and lasting.

Another benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that, due to the difference in height between the outer surface of the rear end region and the outer surface of the main region of the tube and the presence and location of the magnetic metal member in relation to the transition region and the main region of the tube, overflow or spillover of the hot melt adhesive to the main region of the tube can be totally avoided, thereby forsaking or avoiding having to perform manual adhesive wipe off or clean off, and thus improving LED tube lamp production efficiency.

Another benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that, due to the substantial aligning of the center line of the end cap and the center line of the glass tube, the outer diameter of the end cap and of tube are substantially equal, so that the entire LED tube lamp (assembly) appears to have an integrated planar flat surface.

As a result, during shipping or transport of the LED tube lamp, the shipping packaging support or bracket would not just only make direct contact with the end caps, but also the entire LED tube lamp, including the glass tube; thus the entire span or length of the LED tube lamp serves or functions as having multiple load/stress points, which thereby distributes the load/stress more evenly over a wider surface area, and can reduce the risk for breakage of the glass tube.

One benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that when the user is viewing along the width direction toward the tube, the second sidewall can block the line of sight of the user to the LED light source, thus reducing unappealing grainy spots. In addition, the sloped first sidewall also enhances light extraction from the LED light source.

Another benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that, by having the LED lead frames with the height of the first sidewall being lower than that of the second sidewall, more light emitted from the LED chips can be effectively transmitted along a length direction out of the recesses of the LED lead frames, while lesser light can be transmitted along a width direction out of the recesses thereof.

Meanwhile, yet another benefit of an LED tube lamp fabricated in accordance with embodiments of the present invention is that the LED lead frames serve to protect the LED chips from potential damages.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: FIG. 1 is a perspective view of an LED tube lamp according to an embodiment of the present invention; FIG. 2 is an exploded view of a disassembled LED tube lamp according to an embodiment of the present invention; FIG. 3 is a cross-sectional partial view of one end region of a tube of the LED tube lamp according to an embodiment of the present invention; FIG. 4 is a frontal perspective schematic view of an end cap of the LED tube lamp according to an embodiment of the present invention; FIG. 5 is a bottom perspective view of the end cap of the LED tube lamp according to an embodiment of the present invention, showing the inside structure thereof; FIG. 6 is a side perspective view of a power supply of the LED tube lamp according to an embodiment of the present invention; FIG. 7 is a cross-sectional partial view of a connecting or coupling region of the end cap and the tube according to an embodiment of the present invention; FIG. 8 is perspective illustrative schematic partial view of an all-plastic end cap (containing a magnetic metal member and hot melt adhesive) and the tube being bonded together by an induction coil heat curing (solidification) process according to another embodiment of the present invention; FIG. 9 is a partial perspective sectional view of the all-plastic end cap (containing a magnetic metal member and hot melt adhesive) of FIG. 8 showing internal structure thereof; FIG. 10 is a sectional partial view of the connecting region of the tube showing a connecting structure between the LED light bar and the power supply according to an embodiment of the present invention; FIG. 11 is a cross-sectional view of a two-layered flexible substrate of the LED tube lamp of an embodiment of the present invention; FIG. 12 is an end cross-sectional view of the tube of the LED tube lamp having two reflective film layers respectively disposed on two sides of the LED light bar as taken along an axial direction of the tube, according to one embodiment of present invention; FIG. 13 is an end cross-sectional view of the tube of the LED tube lamp having a reflective film layer disposed under the LED light bar as taken along an axial direction of the tube, according to another embodiment of present invention; FIG. 14 is an end cross-sectional view of the tube of the LED tube lamp having two reflective film layers respectively disposed on two sides of the LED light sources as taken along an axial direction of the tube, according to yet another embodiment of present invention; FIG. 15 is a perspective view of an LED lead frame for the LED light sources of the LED tube lamp of an embodiment of the present invention; FIG. 16 is an exploded partial perspective view of the electrically insulating tubular part of the end cap according to another embodiment of the present invention, showing a supporting portion and a protruding portion disposed on the inner surface thereof; FIG. 17 is a cross-sectional view of the electrically insulating tubular part and the magnetic metal member of the end cap of FIG. 16 taken along a line X-X; FIG. 18 is a top sectional view of the end cap shown in FIG. 16, showing the electrically insulating tubular part and the tube extending along a radial axis of the tube according to an embodiment of the present invention; FIG. 19 is a schematic diagram showing the structure of the magnetic metal member including at least one hole, upon flattening out the magnetic metal member to be extending in a horizontal plane according to an embodiment of the present invention; FIG. 20 is a schematic diagram showing the structure of the magnetic metal member including at least one embossed structure, upon flattening out the magnetic metal member to be extending in a horizontal plane according to an embodiment of the present invention; FIG. 21 is a top cross-sectional view of the end cap according to another embodiment of the present invention, showing an electrically insulating tubular part in an elliptical or oval shape extending along a radial axis of the tube which also has a corresponding elliptical or oval shape; FIG. 22 is an end cross-sectional view of the tube of the LED tube lamp having a reflective film layer disposed on one side of the LED light bar as taken along axial direction of the tube, according to another embodiment of the present invention; FIG. 23 is an end cross-sectional view of the tube of the LED tube lamp having a reflective film layer disposed under and beside one side of the LED light bar as taken along an axial direction of the tube, according to yet another embodiment of present invention; FIG. 24 is a top view of two soldering pads of a bendable circuit sheet of the LED tube lamp of one embodiment of the present invention; FIG. 25 is a top view of three soldering pads of the bendable circuit sheet of the LED tube lamp of one embodiment of the present invention; FIG. 26 is a top view of three soldering pads of the bendable circuit sheet of the LED tube lamp of another embodiment of the present invention; FIG. 27 is a top view of four soldering pads of the bendable circuit sheet of the LED tube lamp of one embodiment of the present invention; FIG. 28 is a top view of four soldering pads of the bendable circuit sheet of the LED tube lamp of another embodiment of the present invention; FIG. 29 is a top view of two soldering pads formed with through holes of the bendable circuit sheet of the LED tube lamp of one embodiment of the present invention; FIG. 30 is an enlarged cross-sectional view showing a soldering bonding between the printed circuit board of the power supply and the soldering pads of the bendable circuit sheet of FIG. 29; FIG. 31 is an enlarged cross-sectional view showing another soldering bonding between the printed circuit board of the power supply and the soldering pads of the bendable circuit sheet of FIG. 29, with the through holes being closer to the edge of the bendable circuit sheet; FIG. 32 is a top view of two soldering pads respectively formed with notches of the bendable circuit sheet of the LED tube lamp of another embodiment of the present invention; FIG. 33 is an enlarged cross-sectional view showing a soldering bonding between the printed circuit board of the power supply and the soldering pads of the bendable circuit sheet taken along dissection line A-A’ of FIG. 32; FIG. 34 is a perspective view of two soldering pads of the bendable circuit sheet of the LED tube lamp of one embodiment of the present invention; FIG. 35 is a perspective view of a thermo-compression head used for solder bonding the bendable circuit sheet to the printed circuit board of the power supply; FIG. 36 is a perspective view of a bendable circuit sheet according to another embodiment of the present invention electrically connected to the printed circuit board of the power supply; FIG. 37 is a perspective view of the bendable circuit sheet according to another embodiment of the present invention electrically connected to the printed circuit board of the power supply in a different configuration from that shown in FIG. 36; FIG. 38 shows an enlarged partial cross-sectional view of the tube shown in FIG. 7 at the transition region thereof; FIG. 39 shows the bendable circuit sheet and the printed circuit board of the power supply arranged between the thermos-compression head and a carrier of a soldering vehicle prior to solder bonding step; FIG. 40 shows the soldering vehicle used for soldering bonding the bendable circuit sheet and the printed circuit board of the power supply according to embodiments of present invention; and FIG. 41 shows the bendable circuit sheet and the printed circuit board of the power supply correctively arranged between the thermos-compression head and the carrier of the soldering vehicle after the soldering bonding step according to an embodiment of present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will now be described more specifically, by way of example, with reference to the following embodiments and accompanying drawings. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.

According to an embodiment of present invention, an LED tube lamp is shown in FIGs. 1 and 2, in which the LED tube lamp includes at least a tube 1, an LED light bar 2, and two end caps 3. The LED light bar 2 is disposed inside the tube 1 when assembled. The two end caps 3 are disposed at the two ends of the tube, respectively. The two end caps have different sizes in some embodiments. In some embodiments the size of one end cap is 30%-80% of the size of the other end cap. The tube 1 can be made of plastic or glass.

In the present embodiment, the tube 1 is made of tempered glass. The method for strengthening or tempering of the glass tube can be done by a chemical tempering method or a physical tempering method for further processing on the glass tube 1. For example, the chemical tempering method is to use other alkali metal ions to exchange with the Na ions or K ions. Other alkali metal ions and the sodium (Na) ions or potassium (K) ions on the glass surface are exchanged, in which an ion exchange layer is formed on the glass surface. When cooled to room temperature, the glass is then under tension on the inside, while under compression on the outside thereof, so as to achieve the purpose of increased strength. The following glass tempering methods may be used: high temperature type ion exchange method, the low temperature type ion exchange method, dealkalization, surface crystallization, sodium silicate strengthening method. The high-temperature ion exchange method includes the following steps.

First, glass containing sodium oxide (Na20) or potassium oxide (K2O) in the temperature range of the softening point and glass transition point are inserted into molten salt of lithium, so that the Na ions in the glass are exchanged for Li ions in the molten salt. Later, the glass is cooled to room temperature. Since the surface layer containing Li ions has a different expansion coefficient with respect to the inner layer containing Na ions or K ions, the surface produces residual stress and is reinforced. Meanwhile, the glass containing AL2O3, T1O2 and other components, by performing ion exchange, can produce glass crystals of extremely low coefficient of expansion. The crystallized glass surface after cooling produces a significant amount of pressure, up to 700MPa, which can enhance the strength of glass.

The low-temperature ion exchange method includes the following steps: First, a monovalent cation (e.g., K ions) undergoes ion exchange with the alkali ions (e.g. Na ion) on the surface layer at a temperature range that is lower than the strain point temperature, so as to allow the K ions to penetrate the surface. For example, for manufacturing a Na2<D + CaO + S1O2 system glass, the glass can be impregnated for ten hours at more than four hundred degrees in the molten salt. The low temperature ion exchange method can easily obtain glass of higher strength, and the processing method is simple, does not damage the transparent nature of the glass surface, and not undergo shape distortion.

Dealkalization includes treating glass using a platinum (Pt) catalyst along with sulfurous acid gas and water in a high temperature atmosphere. The Na+ ions are migrated out and bleed from the glass surface to be reacted with the Pt catalyst, so that the surface layer becomes a S1O2 enriched layer, which results in a low expansion glass and produces compressive stress upon cooling.

The surface crystallization method and the high temperature type ion exchange method are different, but only the surface layer is treated by heat treatment to form low expansion coefficient microcrystals on the glass surface, thus reinforcing the glass.

The sodium silicate glass strengthening method is a tempering method using sodium silicate (water glass) in water solution at 100 degrees Celsius and several atmospheres of pressure treatment, where a stronger/higher strength glass surface that is harder to scratch is thereby produced.

The above glass tempering methods described including physical tempering methods and chemical tempering methods, in which various combinations of different tempering methods can also be combined together.

In the illustrated embodiment as shown in FIG. 3, the tube 1 includes a main region 102, a plurality of rear end regions 101, and a plurality of transition regions 103. The tube 1 is fabricated by undergoing a glass shaping process so as to form one or more narrowly curved end regions at one or more ends thereof, in which each narrowly curved end region includes one rear end region 101 and one transition region 103, from a cylindrical raw tube. At the same time, the glass shaping process coincides to be substantially concurrently or is the same as a glass toughening or tempering treatment process. In other words, while the tube 1 is toughened or tempered, the narrowly curved end regions as shown in FIG. 3 are also shaped alongside at the same time. Each transition region 103 is located between an end of the main region 102 and one rear end region 101. The rear end region 101 is connected to one end of the transition region 103, and the other end of the transition region 103 is connected to one end of the main region 102.

In the illustrated embodiment, the number of the rear end regions 101 and the number of the transition regions 103 are two, respectively. The transition region 103 is curved or arcshaped at both ends thereof under cross-sectional view, that is to say, the curved ends of the transition regions 103 are seen along the axial direction of the lamp tube 1.

The transition region is arc-shaped at both ends. One arc thereof near the main region is curved towards the inside of the glass tube, and the other arc thereof near the rear end region is curved toward the outside of the glass tube. Outer surfaces of the transition regions are in compression and inner surfaces of the transition regions are in tension near the rear end region, and outer surfaces of the transition regions are in tension and inner surfaces of the transition regions are in compression near the main region. The normal vector of the arcshaped surface at the end of the transition region near the main region points towards the outside of the tube, and the normal vector of the arc-shaped surface at the end of the transition region near the rear end region points towards the inside of the tube. In some embodiments, the radius of curvature, R1, of the arc between the transition region and the main region is smaller than the radius of curvature, R2, of the arc between the transition region and the rear end region. The ratio range of R1:R2 is from 1:1.5 to 1:10. Furthermore, there is no gap between the main region of the tube and the end cap. The included angle between the transition region and the main region and the included angle between the transition region and the rear end region are larger than 90 degrees.

As illustrated in FIGs. 7 and 9, one end cap 3 sleeves over the rear end region 101. The outer diameter of the rear end region 101 is less than the outer diameter of the main region 102. A cross section view of the rear end region 101 shows a flat surface, which is parallel with the main region 102. After undergoing a glass toughening or tempering treatment process, the rear end regions 101 of the tube 1 are formed to be a plurality of toughened glass structural portions. The end cap 3 sleeves over the rear end region 101 (which is a toughened glass structural portion). The outer diameter of the end cap 3 is the same as the outer diameter of the main region 102 of the tube 1.

Referring to FIGs. 4 and 5, each end cap 3 includes a plurality of hollow conductive pins 301, an electrically insulating tubular part 302 and a thermally conductive ring 303. The thermally conductive ring 303 can be a metal ring that is tubular in shape. The thermally conductive ring 303 sleeves over the electrically insulating tubular part 302. The hollow conductive pins 301 are disposed on the electrically insulating tubular part 302. As shown in FIG. 7, one end of the thermally conductive ring 303 extends away from the electrically insulating tubular part 302 of the end cap 3 and towards one end of the tube 1, and is bonded and adhered to the end of the tube 1 using a hot melt adhesive 6. As illustrated, the hot melt adhesive 6 forms a pool and then solidifies to fittingly join together the rear end region 101 and a portion of the transition region 103 of the tube 1 to a portion of the thermally conductive ring 303 and a portion of the electrically insulating tubular part 302 of the end cap 3. As a result, the end cap 3 is then joined to one end of the tube 1 using the hot melt adhesive 6.

The thermally conductive ring 303 of the end cap 3 extends to the transition region 103 of the tube 1. The outer diameter of the thermally conductive ring 303 is substantially the same as the outer diameter of the main region 102 of the tube 1, and the outer diameter of the thermally conductive ring 303 is also substantially the same as the outer diameter of the electrically insulating tubular part 302. The electrically insulating tubular part 302 facing toward the tube 1 and the transition region 103 has a gap therebetween. As a result, the LED tube lamp has a substantially uniform exterior diameter from end to end thereof. Because of the substantially uniform exterior diameter of the LED tube lamp, the LED tube lamp has uniformly distributed stress point locations covering the entire span of the LED tube lamp (in contrast with conventional LED tube lamps which have different diameters between the end caps 3 and the tube 1, and often utilizes packaging that only contacts the end caps 3 (of larger diameter), but not the tube 1 of reduced diameter). In addition, no gap is formed between the end cap 3 and the main region 102. Therefore, the packaging design configured for shipping of the tube 1 of the described embodiment of present invention can include more evenly distributed contact stress points at many more locations covering the entire span of the LED tube lamp, up to contacting along the entire outer surface of the LED tube lamp 1.

In the present embodiment, the outer diameter of the end caps 3 are substantially the same as the outer diameter of the main region 102, and the tolerance for the outer diameter measurements thereof are preferred to be within +/- 0.2 millimeter (mm), and should not exceed +/- 1.0 millimeter(mm). The difference between an outer diameter of the rear end region 101 and the outer diameter of the main region 102 can be 1 mm to 10 mm for typical product applications. Meanwhile, for preferred embodiments, the difference between the outer diameter of the rear end region 101 and the outer diameter of the main region 102 can be 2 mm to 7 mm. The length of the transition region 103 along the axial direction of the tube 1 is between 1 mm to 4 mm. Upon experimentation, it was found that when the length of the transition region 103 along the axial direction of the tube 1 is either less than 1 mm or more than 4 mm, problems would arise due to insufficient strength or reduction in light illumination surface of the tube. In an alternative embodiment, the transition region 103 can be without curve or arc in shape.

Upon adopting the T8 standard lamp format as an example, the outer diameter of the rear end region 101 is configured between 20.9 mm to 23 mm. Meanwhile, if the outer diameter of the rear end region 101 is less than 20.9 mm, the inner diameter of the rear end region 101 would be too small, thus preventing the power supply to be fittingly inserted into the tube 1. The outer diameter of the main region 102 is preferably configured to be between 25 mm to 28 mm.

Referring to FIG. 2, the LED light bar 2 of the embodiment of the present invention has a plurality of LED light sources 202 mounted thereon. An end cap 3 has a power supply 5 installed therein. The LED light sources 202 and the power supply 5 are electrically connected by the LED light bar 2. The power supply 5 may be in the form of a single individual unit (i.e., all of the power supply components are integrated into one module unit), and installed in one end cap 3. Alternatively, the power supply 5 may be divided into two separate units (i.e. all of the power supply components are divided into two parts) which are installed at the two end caps 3, respectively. The number of units of the power supply 5 corresponds to the number of the ends of the tube 1 which have undergone a glass tempering and strengthening process. In addition, the location of the power supply also corresponds to the location of the tube 1 which has undergone glass tempering.

The power supply can be fabricated by encapsulation molding by using a high thermal conductivity silica gel (with thermal conductivity >0.7w / m · k), or fabricated in the form of exposed power supply electronic components that are packaged by a conventional heat shrink sleeve placed into the end cap 3.

Referring to FIG. 2 and FIGs. 4-6, the power supply 5 includes a male plug 51 and a metal pin 52. The male plug 51 and the metal pin 52 are located at opposite ends of the power supply 5. The LED light bar 2 is configured with a female plug 201 at an end thereof. The end cap 3 is configured with a hollow conductive pin 301 used for coupling with an external power source. The male plugs 51 of the power supply 5 are fittingly engaged into the female plug 201 of the LED light bar 2, while the metal pins 52 of the power supply 5 are fittingly engaged into the hollow conductive pins 301 of the end cap 3. Upon inserting the metal pin 52 into the hollow conductive pin 301, a punching action is provided against the hollow conductive pin 31 using an external punching tool to create a slight amount of shape deformation of the hollow conductive pin 301, thereby securing and fixing the metal pin 52 of the power supply 5.

Upon being energized or powered on, the electrical current passes through the hollow conductive pin 301, the metal pin 52, the male plug 51, and the female plug 201, to reach the LED light bar 2, and through the LED light bar 2 to reach the LED light sources 202. In other embodiments, the male plug 51 and the female plug 52 may not be employed, and conventional wire bonding techniques can be adopted instead. In an alternative embodiment, the power supply 5 can be mounted on a printed circuit board (not shown), and the connection technique using the male plug 51 and the female plug 201 or alternatively, the wire bonding technique can be utilized to electrically connect the LED light bar 2 to the power supply 5. Meanwhile, the device structure of the power supply 5 is not limited to that shown in FIG. 6.

Referring to FIGs. 4-5 and FIGs. 7-9, the end cap 3 sleeves over the tube 1. To be more specific, the end cap 3 sleeves over the rear end region 101 and extends toward the transition region 103 so as to partially overlap the transition region 103. In the present embodiment, the thermally conductive ring 303 of the end cap 3 is extended to reach the transition region 103 of the tube 1, so that by means of the intimate or direct physical contact between the thermally conductive ring 303 and the transition region 103, the thermally conductive ring 303 and the tube 1, via adhesive bonding using the hot melt adhesive 6, prevent any spillover or overflow of any hot melt adhesive 6 from the end cap 3 which might otherwise remain hanging onto a surface of the main region 102. Meanwhile, an end of the electrically insulating tubular part 302 facing the tube 1 is not extended to reach the transition region 103. That is to say, the end of the electrically insulating tubular part 302 facing the tube 1 and the transition region 103 has a gap therebetween. In addition, the electrically insulating tubular part 302 is made of a material that is not a good electrical conductor, but is not limited to being plastic or ceramic materials.

The hot melt adhesive 6 (includes “welding mud powder”) may include one or more of phenolic resin 2127#, shellac, rosin, calcium carbonate powder, zinc oxide, and ethanol, etc. The tube 1 at the rear end region 101 and the transition region 103 (as shown in FIG. 7) is coated by the hot melt adhesive, which when it has undergone heating, would be greatly expanded, so as to allow tighter and closer contact between the end cap 3 and the tube 1, thus allowing for realization of manufacturing automation for LED tube lamp. Furthermore, the hot melt adhesive 6 would not be subject to decreased reliability when operating under elevated temperature conditions by the power supply and other heat generating components. In addition, the hot melt adhesive 6 can prevent the deterioration of bond strength over time between the tube 1 and the end cap 3, thereby improving long term reliability.

Specifically, the hot melt adhesive 6 is filled in between an inner surface portion of the extending portion of the thermally conductive ring 303 and the outer circumferential surface of the tube 1 at the rear end region 101 and the transition region 103 (location is shown in a broken/dashed line identified as “B” in FIG. 7, also referred to as “a first location”). The coating thickness of the hot melt adhesive 6 can be 0.2 mm to 0.5 mm.

After curing, the hot melt adhesive 6 expands and contacts with the tube 1, thus fixing the end cap 3 to the tube 1. Thus, upon filling and curing (solidification) of the hot melt adhesive 6, the thermally conductive ring 303 is caused to be bonded or fixedly arranged to an outer (circumferential) surface of the tube 1 by the hot melt adhesive 6 therebetween at the dashed line “B” in FIG. 7, which can also be referred to as the first location herein. Due to the difference in height between the outer circumferential surface of the rear end region 101 and the outer circumferential surface of the main region 102, thus avoid overflow or spillover of the hot melt adhesive 6 to the main region 102 of the tube 1, forsaking or avoiding having to perform manual adhesive wipe off or clean off, thus improving LED tube lamp production efficiency.

Meanwhile, likewise for the embodiment shown in FIG. 9, a magnetic metal member 9 is fixedly arranged or disposed on an inner circumferential surface of the electrically insulating tubular part 302, and bonded to an outer circumferential surface of the tube 1 using the hot melt adhesive 6, in which the hot melt adhesive 6 does not spill over through the gap between the end cap and one of the transition regions 103 during the filling process of the hot melt adhesive 6. During the fabrication process of the LED tube lamp, a heat generating equipment is used to heat up the thermally conductive ring 303, and also heat up the hot melt adhesive 6, to thereby melt and expand the adhesive to securely attach and bond the end cap 3 to the tube 1.

In the present embodiment, the electrically insulating tubular part 302 of the end cap 3 includes a first tubular part 302a and a second tubular part 302b. The first tubular part 302a and the second tubular part 302b are connected along an axis of extension of the electrically insulating tubular part 302 or an axial direction of the tube 1. The outer diameter of the second tubular part 302b is less than the outer diameter of the first tubular part 302a. The outer diameter difference between the first tubular part 302a and the second tubular part 302b is between 0.15 mm to 0.30 mm. The thermally conductive ring 303 is fixedly configured over and surrounding the outer circumferential surface of the second tubular part 302b. The outer surface of the thermal conductive ring 303 is coplanar or substantially flush with respect to the outer circumferential surface of the first tubular part 302a, in other words, the thermal conductive ring 303 and the first tubular part 302a have substantially uniform exterior diameters from end to end. As a result, the end cap 3 achieves an outer appearance of smooth and substantially uniform tubular structure.

In the present embodiment, a ratio of the length of the thermal conductive ring 303 along the axial direction of the end cap 3 with respect to the axial length of the electrically insulating tubular part 302 ranges from 1: 2.5 to 1: 5. In the present embodiment, the inner surface of the second tubular part 302b and the inner surface of the thermally conductive ring 303, the outer surface of the rear end region 101 and the outer surface of the transition region 103 together form an accommodation space. In order to ensure bonding longevity using the hot melt adhesive, in the present embodiment, the second tubular part 302b is at least partially disposed around the tube 1, the hot melt adhesive 6 being at least partially filled in an overlapped region (shown by a broken/dashed line identified as “A” in FIG. 7, also referred herein as “a second location”) between the inner surface of the second tubular part 302b and the outer surface of the rear end region 101 of the tube 1, in which the second tubular part 302b and the rear end region 101 of the tube 1 are bonded by the hot melt adhesive 6 disposed therebetween.

During manufacturing of the LED tube lamp, when the hot melt adhesive 6 is coated and applied between the thermally conductive ring 303 and the rear end region 101, it may be appropriate to increase the amount of hot melt adhesive used, such that in the subsequent heating process, the hot melt adhesive can be caused to expand and flow in between the second tubular part 302b and the rear end region 101, to thereby adhesively bond the second tubular part 302b and the rear end region 101. However, in the present embodiment, the hot melt adhesive 6 does not need to completely fill the entire accommodation space (as shown in the illustrated embodiment of FIG. 7), in which a gap is reserved or formed between the thermally conductive ring 303 and the second tubular part 302b. Thus, the hot melt adhesive 6 can be only partially filing the accommodation space.

During fabrication of the LED tube lamp, the rear end region 101 of the tube 1 is inserted into one end of the end cap 3. The axial length of the portion of the rear end region 101 of the tube 1 which had been inserted into the end cap 3 accounts for one-third (1/3) to two-thirds (2/3) of the total length of the thermally conductive ring 303 in an axial direction thereof. One benefit is that, the hollow conductive pins 301 and the thermally conductive ring 303 have sufficient creepage distance therebetween, and thus it is not easy to form a short circuit leading to dangerous electric shock to individuals. On the other hand, due to the electrically insulating effect of the electrically insulating tubular part 302, the creepage distance between the hollow conductive pin 301 and the thermally conductive ring 303 is increased, and thus less people are likely to be subject to an electric shock caused by operating and testing under high voltage conditions.

In this embodiment, the electrically insulating tube 302, in its general state, is not a good conductor of electricity and/or is not used for conducting purposes, but it is not limited to being made of plastics, ceramics and other electrically-insulating materials. Furthermore, for the hot melt adhesive 6 disposed in the inner surface of the second tubular part 302b, due to the presence of the second tubular part 302b interposed between the hot melt adhesive 6 and the thermally conductive ring 303, the heat conducted from the thermally conductive ring 303 to the hot melt adhesive 6 may be reduced. Thus, referring to FIG. 5, in this embodiment, the end of the second tubular part 302b facing the tube 1 (i.e., away from the first tubular part 302a) is provided with a plurality of notches 302c, configured for increasing the contact area of the thermal conductive ring 303 and the hot melt adhesive 6, in order to be more conducive to providing rapid heat conduction from the thermally conductive ring 303 to the hot melt adhesive 6, so as to accelerate the curing (solidification) of the hot melt adhesive 6. The notches 302c are spatially arranged along a circumferential direction of the second tubular part 302b. Meanwhile, if a user touches the thermally conductive ring 303, due to the insulating properties of the hot melt adhesive 6 located between the thermally conductive ring 303 and the tube 1, no electrical shock is likely to be produced by touching a damaged portion of the tube 1.

The thermally conductive ring 303 can be made of various heat conducting materials. The thermally conductive ring 303 of the present embodiment is a metal sheet, such as aluminum alloy. The second tubular part 302b is sleeved with the thermally conductive ring 303 being tubular or ring shaped. The electrically insulating tubular part 302 may be made of electrically insulating material, but would have low thermal conductivity so as to prevent the heat reaching the power supply components located inside the end cap 3, which would negatively affect performance of the power supply components. In this embodiment, the electrically insulating tubular part 302 is a plastic tube. In other embodiments, the thermally conductive ring 303 may also be formed by a plurality of metal plates arranged along a plurality of second tubular part 302b in either a circumferentially-spaced or a not circumferentially-spaced arrangement. In other embodiments, the end cap may take on or have other structures.

Referring to FIGs. 8-9, the end cap 3 according to another embodiment includes a magnetic object being of a magnetic metal member 9 and an electrically insulating tubular part 302, rather than a thermally conductive ring. The magnetic metal member 9 is fixedly arranged on the inner circumferential surface of the electrically insulating tubular part 302, and has overlapping portions with respect to the tube 1 in the radial direction. The hot melt adhesive 6 is coated on the inner circumferential surface of the magnetic metal member 9 (the surface of the magnetic metal tube member 9 facing the tube 1), and bonding with the outer circumferential surface of the tube 1. In order to increase the adhesion area, and to improve the stability of the adhesion, the hot melt adhesive 6 can cover the entire inner circumferential surface of the magnetic metal member 9.

When manufacturing the LED tube lamp of another embodiment, the electrically insulating tubular part 302 is inserted in an induction coil 11, so that the induction coil 11 and the magnetic metal member 9 are disposed opposite (or adjacent) to one another along the radially extending direction of the electrically insulating tubular part 302. A method for bonding the end cap 3 and the tube 1 with the magnetic metal member 9 according to another embodiment includes the following steps. The induction coil 11 is energized. After the induction coil 11 is energized, the induction coil 11 forms an electromagnetic field, and the electromagnetic field upon contacting the magnetic metal member 9 then induces an electrical current, so that the magnetic metal member 9 becomes heated. Then, the heat from the magnetic metal member 9 is transferred to the hot melt adhesive 6, thus curing (solidification) the hot melt adhesive 6 so as to bond the end cap 3 with the tube 1. The induction coil 11 and the electrically insulating tubular part 302 are coaxially aligned, so that the energy transfer is more uniform. In this embodiment, a deviation value between the axes of the induction coil 11 and the electrically insulating tubular part 302 is not more than 0.05mm. When the bonding process is complete, the induction coil 11 is removed from the tube 1. Upon completion of the fabrication process of the tube 1, the induction coil 11 remains stationary at the same location, and the tube 1 is detached away from the induction coil 11. In an alternative embodiment, the tube 1 can remain stationary while the induction coil 11 is detached away from the tube 1.

In the present embodiment, a heat curing equipment (not shown) can have a plurality of induction coils (not shown), that is to say, a plurality of tubes (not shown) can be placed in a default location, so that the plurality of induction coils of the heat curing equipment can be movably configured and positioned into appropriate heat curing configuration similar to that as shown in FIG. 8. After heat curing is completed, the plurality of induction coils can be detached away from the lamp tubes. It is worth mentioning that the induction coil 11, as shown in FIG. 8, can also use a top and a bottom semicircular jig to form a shape and structure similar to the induction coil 11 as shown, without necessarily having to use the same illustrated-ring shaped coil structure, in order to achieve the same effect.

The electrically insulating tubular part 302 is further divided into two portions, namely a first tubular part 302d and a second tubular part 302e. In order to provide better support of the magnetic metal member 9, an inner diameter of the first tubular part 302d at the inner circumferential surface of the electrically insulating tubular part 302, for supporting the magnetic metal member 9, is larger than the inside diameter of the second tubular part 302e, and a stepped structure is formed by the electrically insulating tubular part 302 and the second tubular part 302e, where an end of the magnetic metal member 9 as viewed in an axial direction is abutted against the stepped structure. An inside diameter of the magnetic metal member 9 is larger than an outer diameter of the end (which is the rear end region 101) of the tube 1. Upon installation of the magnetic metal member 9, the entire inner circumferential surface of the end cap 3 is maintained flush. Additionally, the magnetic metal member 9 may be of various shapes, e.g., a sheet-like or tubular-like structure being circumferentially arranged or the like, where the magnetic metal member 9 is coaxially arranged with the electrically insulating tubular part 302.

In other embodiments, the manufacturing process for bonding the end cap 3 and the tube 1 together can be achieved without the magnetic metal member 9. For example, a magnetic substance such as iron powder, nickel powder or iron-nickel powder may be directly mixed in the hot melt adhesive 6, or that highly magnetic powder material can replace a portion of the calcium carbonate powder, to a ratio of about 1:3 ~ 1:1 in volume between the highly magnetic powder material and the calcium carbonate powder. As a result, the end cap 3 when attached to the tube 1 using the hot melt adhesive 6 can pass the quality testing (including destructive testing) of the end cap, so as to comply with the torque test quality standard and the bending moment quality standard at the same time. Typically, bending moment quality standard for the tube lamp is required to be larger than 5 N- m. In addition, the torque test quality standard is required to be larger than 1.5 N m (Newton-meter). In the present embodiment, the hot melt adhesive 6 is blended with a predetermined highly magnetic powder material composition to endure 5 N m ~ 10 N m for bending moment test results, and 1.5 N m ~ 5 N m for torque test results. When manufacturing the LED tube lamp of the embodiment, the hot melt adhesive 6 is contained between the inner circumferential surface of the electrically insulating tubular part 302 of the end cap 3 and the end of the tube 1. After the induction coil 11 is energized, the induction coil 11 forms an electromagnetic field, and the charged particles of the magnetic substance become heated. Then, the heat generated from the charged particles of the magnetic substance is transferred to the hot melt adhesive 6, thus curing or solidifying the hot melt adhesive 6 so as to bond the end cap 3 with the tube 1.

In other embodiments, the end cap 3 can also be made of all-metal, in which case it is necessary to further provide an electrically insulating member beneath the hollow conductive pins as a safety feature for accommodating high voltage usage.

In other embodiments, the magnetic metal member 9 can have at least one opening 91 as shown in FIG. 19, in which the openings 91 can be circular, but not limited to being circular in shape, such as, for example, oval, square, star shaped, etc., as long as being possible to reduce the contact area between the magnetic metal member 9 and the inner circumferential surface of the electrically insulating tubular part 302, but while maintaining the function of melting and curing or solidifying the hot melt adhesive 6. Preferably, the openings 91 occupy 10% to 50% of the area of the magnetic metal member 9. The opening 91 can be arranged circumferentially around the magnetic metal member 9 in an equidistantly spaced or not equally spaced manner.

In other embodiments, the magnetic metal member 9 has an indentation/embossed structure 93 as shown in FIG. 20, in which the embossed structure 93 is formed to be protruding from the inner circumferential surface of the magnetic metal member 9 toward the outer circumferential surface of the magnetic metal member 9, or vice versa, so long as the contact area between the inner circumferential surface of the electrically insulating tubular part 302 and the outer circumferential surface of the magnetic metal member 9 is reduced, but can sustain the function of melting and curing or solidifying the hot melt adhesive 6.

In other embodiments, the magnetic metal member 9 is a non-circular ring, such as, but not limited to, an oval ring as shown in FIG. 21. When the tube 1 and the end cap 3 are both circular, the minor axis of the oval ring shape is slightly larger than the outer diameter of the end region of the tube 1, so long as the contact area of the inner circumferential surface of the electrically insulating tubular part 302 and the outer circumferential surface of the magnetic metal member 9 is reduced, but can still achieve or maintain the function of melting and curing or solidifying the hot melt adhesive 6. When the tube 1 and the end cap 3 are circular, non-circular rings can reduce the contact area between the magnetic metal member 9 and the inner circumferential surface of the electrically insulating tubular part, but still can maintain the function of melting and curing or solidifying hot melt adhesive 6. In other words, the inner circumferential surface of the electrically insulating tubular part 302 includes a supporting portion 313, which supports the (non-circular shaped) magnetic metal member 9, so that the contact area between the magnetic metal member 9 and the inner circumferential surface of the electrically insulating tubular part 302 is reduced, but can still achieve the melting and curing or solidifying of the hot melt adhesive 6.

In other embodiments, the inner circumferential surface of the electrically insulating tubular part 302 has a plurality of supporting portions 313 and a plurality of protruding portions 310, as shown in FIGs.16-18, in which the thickness of the protruding portion 310 is smaller than the thickness of the supporting portion 313. A stepped structure is formed at an upper edge of the supporting portion 313, in which the magnetic metal member 9 is abutted against the upper edges of the supporting portions 313, so that the magnetic metal member 9 can then be securely or firmly mounted within the electrically insulating tubular part 302. At least a portion of the protruding portion 310 is positioned between the inner circumferential surface of the electrically insulating tubular part 302 and the magnetic metal member 9. The arrangement or configuration of the protruding portions 310 may be arranged in a ring configuration in the circumferential direction along the inner circumferential surface of the electrically insulating tubular part 302 at equidistantly spaced or non-equidistantly spaced distances, the contact area of the inner circumferential surface of the electrically insulating tubular part 302 and the outer circumferential surface of the magnetic metal member 9 is reduced, but can achieve or maintain the function of melting and curing or solidifying the hot melt adhesive 6. The protruding thickness of the supporting portion 313 toward the interior of the electrically insulating tubular part 302 is between 1 mm to 2 mm. The thickness of the protruding portion 310 of the electrically insulating tubular part 302 that is disposed on the inner circumferential surface of the electrically insulating tubular part 302 is less than the thickness of the supporting portion 313, and the thickness of the protruding portion 310 is between 0.2 mm to 1 mm.

Referring again to FIG. 2, the LED tube lamp according to an embodiment of the present invention also includes an adhesive film 4, an electrical insulation adhesive film 7, and an optical adhesive film 8.

The LED light bar 2 is bonded onto the inner circumferential surface of the tube 1 by using the adhesive film 4. In the illustrated embodiment, the adhesive film 4 may be silicone adhesive, but is not limited thereto. The electrical insulation adhesive film 7 is coated on the surface of the LED light bar 2 facing the LED light sources 202, so that the LED light bar 2 is not exposed, thus electrically insulating the LED light bar 2 and the outside environment.

During application of the electrical insulation film 7, a plurality of through holes 71 are reserved and set aside corresponding to the positions/locations of the LED light sources 202. The LED light sources 202 are mounted in the through holes 71. The material composition of the electrical insulation adhesive film 7 comprises vinyl silicone, hydrogen polysiloxane and aluminum oxide. The electrical insulation adhesive film 7 has a thickness range of 100 pm to 140 pm (micrometers). If less than 100 pm in thickness, the electrical insulation adhesive film 7 will not achieve sufficient electrically insulating effect, but if more than 140 pm in thickness, the excessive electrical insulation adhesive will result in material waste.

An optical adhesive film 8 is applied or coated on the surface of the LED light source 202. The optical adhesive film 8 is a clear or transparent material, in order to ensure optimal light transmission rate. After providing coating application to the LED light sources 202, the shape or structure of the optical adhesive film 8 may be in the form of a particulate gel or granular, a strip or a sheet. A preferred range for the refractive index of the optical adhesive film 8 is between 1.22 and 1.6. Another embodiment of the optical adhesive film 8 can have a refractive index value that is equal to a square root of the refractive index of the housing or casing of the LED light source 202, or equal to plus or minus 15% of the square root of the refractive index of the housing or casing of the LED light source 202, so as to achieve better light transmittance. The housing/casing of the LED light sources 202 is a housing structure to accommodate and carry the LED dies (or chips) such as a LED lead frame 202b as shown in FIG. 15. The refractive index range of the optical adhesive film 8 in this embodiment ranges from 1.225 to 1.253. The thickness of the optical adhesive film 8 can be in the range of 1.1 mm to 1.3 mm.

When assembling the LED light sources to the LED light bar, the optical adhesive film 8 is applied on the LED light sources 202; then the electrical insulation adhesive film 7 is coated on one side of the LED light bar 2. Then the LED light sources 202 are fixed or mounted on the LED light bar 2. Then another side of the LED light bar 2 which is opposite to the side of which the LED light sources 202 are mounted thereon, is bonded and affixed using the adhesive film 4 to the inner circumferential surface of the tube 1. Later, the end cap 3 is fixed to the end portion of the tube 1, while the LED light sources 202 and the power supply 5 are electrically connected by the LED light bar 2.

Alternatively, as shown in FIG. 10, the LED light bar 2 can be used to pass through the transition region 103 for providing electrical coupling to the power supply 5, or traditional wire bonding methods can be adopted to provide the electrical coupling as well. A finished LED tube lamp is then fabricated upon the attachment or joining of the end caps 3 to the tube 1 as shown in FIG. 7 (with the structures shown in FIGs 4-5), or as shown in FIG. 8 (with the structure of FIG. 9).

In the described embodiment, the LED light bar 2 is fixed by the adhesive film 4 to an inner circumferential surface of the tube 1, so that the LED light sources 202 are mounted in the inner circumferential surface of the tube 1, which can increase the illumination angle of the LED light sources 202, thereby expanding the viewing angle, so that an excess of 330 degrees viewing angle is possible to achieve. Through the utilization of applying the electrical insulation adhesive film 7 on the LED light bar 2 and applying of the optical adhesive film 8 on the LED light sources, the electrical insulation of the LED light bar 2 is provided, so that even when the tube 1 is broken, electrical shock does not occur, thereby improving safety.

Furthermore, the LED light bar 2 may be a flexible substrate, an aluminum plate or strip, or a FR4 board, in an alternative embodiment. Since the tube 1 of the embodiment is a glass tube, if the LED light bar 2 comprises a rigid aluminum plate or FR4 board, when the tube has been ruptured, e.g., broken into two parts, the entire tube is still able to maintain a straight pipe or tube configuration, then the user may be under a false impression the LED tube lamp can remain usable and fully functional, and it is easy to cause electric shock upon handling or installation thereof. Because of added flexibility and bendability of the flexible substrate for the LED light bar 2, the problem faced by the aluminum plate, FR4 board, or conventional 3-layered flexible board having inadequate flexibility and bendability, are thereby solved. Due to the adoption of the flexible substrate / bendable circuit sheet for the LED light bar 2, the LED light bar 2 does not allow a ruptured or broken tube to maintain a straight pipe or tube configuration so as to better inform the user that the LED tube lamp is rendered unusable and thereby avoid potential electric shock accidents from occurring.

The following is a description of further aspects of the flexible substrate / bendable circuit sheet used as the LED light bar 2.

The power supply 5 can be an integral unit configured with power supply electronic components mounted on a printed circuit board. The printed circuit board at an input terminal thereof can have a metal pin 52 to be connected to the end cap 3, and at an output terminal thereof can have a male plug 51, an electrical metal connection hole or a soldering pad depending upon the specific connection configuration of the LED light bar 2 (in the form of a bendable circuit sheet). The output terminals of the bendable circuit sheet (LED light bar) and the power supply can be electrically connected by means of wire bonding technique or interconnect coupling technique via the male plug 51 of the power supply 5 inserting into the female plug 201 of the LED light bar 2. The output terminals of the bendable circuit sheet (LED light bar 2) and the power supply 5 can be electrically connected by means of wire bonding technique or interconnect coupling technique via the male plug 51 of the power supply 5 inserting into the female plug 201 of the LED light bar 2. When using the wire bonding technique, an outer layer of the bonding wire can be an electrical insulation sheath covering the bonding wire for providing electrical insulation and protection. Furthermore, the output terminals of the bendable circuit sheet (the LED light bar 2) and the power supply 5 can be electrically connected by other means or techniques such as rivet contacts, solder paste bonding, soldering, cable tie. The method for securing the LED light bar 2 is the same as before, whereby one side of the flexible substrate is bonded to the inner circumferential surface of the tube 1 by using the adhesive film 4, and the two ends of the flexible substrate / bendable circuit sheet can be either bonded (fixed) or not bonded to the inner circumferential surface of the tube 1. If the two ends of the flexible substrate arranged along an axial direction of the tube 1 are not bonded or fixed to the inner circumferential surface of the tube 1, and also if the wire bonding is used, the bonding wires are prone to be broken apart due to sporadic motions caused by subsequent transport activities as well as being free to move at the two ends of the flexible substrate / bendable circuit sheet. Therefore, a better option may be by soldering for forming solder joints between the flexible substrate and the power supply.

Referring to FIG. 10, the LED light bar 2 in the form of the bendable circuit sheet can be used to pass through the transition region 103 and bonded by soldering to the output terminal of the power supply 5 for providing electrical coupling to the power supply 5, thereby avoiding the use of wire bonding, and improving the reliability thereof. In the illustrated embodiment, two ends of the LED light bar 2 are not fixed to an inner circumferential surface of the tube and are free to be manipulated. In this arrangement, the flexible substrate does not need to have the female plug 201, and the output terminal of the power supply 5 does not need to have the male plug 51.

The output terminal of the power supply 5 can have one or more output terminal pads / soldering pads "a”, and leaving behind an amount of tin solder on the output terminal pads “a”, so that the thickness of the tin solder on the pads “a” are sufficient for later forming a solder joint. Likewise, the ends of the bendable circuit sheet can also have a plurality of soldering pads “b”, so that the soldering pads “a” from the output terminal of the power supply 5 are soldered to the soldering pads “b” of the bendable circuit sheet. The surface on the soldering pad “b” of the bendable circuit sheet (the LED light bar 2) can be referred to as a front surface, and the other surface on the opposite side thereof can be called a back surface (and likewise, the surface on which the soldering pads “a” are located on the output terminal of the power supply 5 can also be referred to as a front surface), and the LED light bar 2 / bendable circuit sheet and the power supply 2 can be connected at their respective front surfaces thereof, so as to ensure stability. However, during the soldering process, a thermo-compression head 41 as shown in FIG. 35 needs to be pressed against a back surface of the bendable circuit sheet 2, and the application of heat curing across the bendable circuit sheet 2 to reach the solder disposed on the other side of the bendable circuit sheet 2 would not be as reliable and effective. Therefore, an alternative embodiment is provided in which holes in the soldering pad of the bendable circuit sheet 2 facilitating direct heating using the thermo-compression head 41 by applying heat on the front side of the bendable circuit sheet 2 to solder bond to the soldering pad “a” of the power supply 5 located on the front surface.

As shown in FIG. 24, in this embodiment, the soldering pads “b” of the bendable circuit sheet 2 are two separate pads for electrically connecting with an anode and a cathode of the bendable circuit sheet 2, respectively. The size or dimension of the soldering pads “b” is about 3.5 x 2 mm2. The printed circuit board of the power supply 5 also has corresponding soldering pads “a”. A space is left for the solder above the soldering pads “b” for the automated solder bonding equipment, in which the thickness of the solder can be 0.1 mm to 0.7 mm, with preferred thickness being 0.3 mm to 0.5 mm, and 0.4 mm being the optimal thickness thereof.

An electrically insulating hole “c” is formed and disposed between two soldering pads “b”, for the sake of preventing accidental electrical short caused by adjacent solidifying solder portions from separate soldering pads that have inadvertently joined together. In addition, an alignment hole “d” can be configured and disposed behind the electrically insulating hole “c”, which can be used for allowing the automated solder bonding equipment to accurately determine the correct location of the soldering pads “b” (as shown in FIG. 24). The bendable circuit sheet 2 has at least one soldering pad “b”, for electrically connecting to the positive and negative electrodes of the LED light sources 202, respectively.

In other embodiments, for the sake of achieving scalability and compatibility, the number or quantity of the soldering pads “b” can be more than two, for example, three, four, or more than four. When there is just one soldering pad “b”, the two ends of the bendable circuit sheet are respectively connected to the power supply to form a return circuit. In this case, an electronic component replacement technique can be used, such as, i.e. replacing capacitor by inductor. As illustrated in FIGs. 25 to 28, when the number of soldering pads “b” are three, the third soldering pad “b” can be used for ground pad, and when the number of the soldering pads “b” are four, the fourth pad can be used for a signal input terminal.

Correspondingly, the power supply soldering pads “a” and the bendable circuit sheet soldering pads “b” are equal in number. When the number of soldering pads “b” is at least three, the soldering pads “b” (which are essentially bonding pads) can be arranged in a row or two rows, in accordance with the dimensions of the actual occupying area, so as to prevent them from being too close and causing an electrical short circuit.

In other embodiments, the soldering pad “b” can be a single bonding pad. The lesser the number of the soldering pads, the easier the fabrication process becomes. On the other hand, with a greater number of soldering pads, the bendable circuit sheet 2 and the output terminal of the power supply 5 have a stronger and more secured electrical connection therebetween.

In other embodiments, with reference to FIGs 29 to 31, an inner portion of the soldering pad “b” can have a plurality of through holes “e”, and the soldering pad “a” can be soldered to the soldering pad “b” so that upon soldering, the tin solder can penetrate through the through holes “e” of the soldering pad “b”. The through hole “e” can have a diameter of 1 mm to 2mm, with preferred diameter being 1.2 mm to 1.8 mm, and optimal diameter being 1.5 mm. If the through hole “e” is too small, the melted solder cannot pass through it during soldering bonding.

Upon exiting the through holes “e”, the tin solder accumulates at and surrounds the outer periphery of the opening of the through holes “e” so that upon cooling, a plurality of solder balls “g”, with diameter larger than the diameter of the through holes “e”, are formed. The solder balls “g” possess a similar function to nails or rivets, so that apart from having the solder tin to secure the soldering pad “a” and the soldering pad “b”, the solder balls “g” further act to strengthen the electrical connection of the two pads “a”, “b”.

In other embodiment as shown in FIGs. 30 to 33, when a distance of the through hole “e” of the soldering pad “b” away from the edge of the bendable circuit sheet 2 is less than or equal to 1mm (^1 mm), the soldered tin would pass through the through-hole “e” and accumulate at periphery of the through-hole “e” Meanwhile, excess amount of the tin solder may also undergo reflux or reflow downward to be solidified together with the solder on the soldering pad “a”, as shown in FIG. 31 in particular, and the resulting illustrated solder bonding structure has added electrical connection reliability. Furthermore, an alternative to having the through-hole “e” in the soldering pad “b” would be having a notch “f” as shown in FIGs. 32 and 33. The soldered tin can pass through the notch “f” to bond together the soldering pad “b” and the soldering pad “a”, and the excess amount of the tin solder may more easily undergo reflux or reflow downward to be solidified together with the solder on the soldering pad “a”, as well as accumulating around the periphery of the notch T as shown in FIG. 33 in particular. The resulting illustrated solder bonding structure has added electrical connection reliability.

In the present embodiment, the notch “f” of the soldering pads are disposed at the periphery and side edge thereof, that is to say, when the soldering pad “b” possesses the notch “f”, the soldering pad “a” and the soldering pad “b” are securely electrically connected via the tin solder extending and filling through the notch “f”, and the excess tin solder would accumulate around the periphery of the openings of the notch “f”, so that upon cooling, the solder balls “g” with diameter larger than the diameter of the notch “f” are formed. In the present embodiment, due to the notch structure of the soldering pad “b”, the tin solder has the function similar to C-shaped nails. Regardless of whether of forming the through holes “e” or the notch “f” of the soldering pads “b” before the solder bonding process or during the solder bonding process using the thermo-compression head 41 directly, the same through holes or notch structure of present embodiment can be formed.

The (soldering) thermo-compression head 41 and a contacting surface of the tin solder can be a flat, concaved, or convex surface, the convex surface can be a long strip shape or of a grid shape. The contacting surface of the tin solder does not completely cover the through holes “e” of the soldering pads “b”, so as to ensure that the tin solder can penetrate through the through holes “e”. When the tin solder has accumulated around the periphery of the opening of the through holes “e”, the concaved surface can provide a receiving space for the solder ball. In other embodiments, the bendable circuit sheet 2 has the alignment hole “d”, which can be used to ensure precise positioning of the soldering pad “a” with respect to the soldering pad “b” during soldering bonding.

In the above embodiment, most of the bendable circuit sheet 2 is attached and secured to the inner circumferential surface of the tube 1. However, the two ends of the bendable circuit sheet 2 are not secured or fixed to the inner circumferential surface of the tube 1, which thereby form a freely extending end portion 21, respectively. Upon assembly of the LED tube lamp, the freely extending end portion 21 along with the soldered connection between the output terminal of the power supply 5 and itself would be coiled, curled up or deformed to be fittingly accommodating inside the tube 1, so that the freely extending end portions 21 of the bendable circuit sheet 2 are deformed in shape due to being contracted or curled to fit or accommodate inside the tube 1.

Using the abovementioned bendable circuit sheet 2 of having the through holes “e” in the soldering pads “b” thereof, the soldering pad “a” of the power supply 5 share the same surface with one of the surfaces of the bendable circuit sheet 2 that is mounted with the LED light source 202. In other words, the soldering pad of the bendable circuit sheet and the soldering pad of the printed circuit board of the power supply point toward same direction when soldering. When the freely extending end portions 21 of the bendable circuit sheet 2 are deformed due to contraction or curling up, a lateral tension is exerted on the power supply 5 at the connection end of the power supply 5 and the bendable circuit sheet 2. In contrast to the solder bonding technique of having the output terminal pad “a” of the power supply 5 being of different surface to one of the surfaces of the bendable circuit sheet 2 that is mounted with the LED light source 202 thereon, i.e. the soldering pad of the bendable circuit sheet and the soldering pad of the printed circuit board of the power supply point toward opposite directions when soldering, a downward tension is exerted on the power supply 5 at the connection end of the power supply 5 and the bendable circuit sheet 2, so that the bendable circuit sheet 2, with the through-hole configured soldering pads “b”, form a stronger and more secure electrical connection between the bendable circuit sheet 2 and the power supply 5.

In the present embodiment, the soldering pad “b” of the bendable circuit sheet 2 is disposed on the other side thereof which has the light sources 202 mounted thereon. The soldering pads “b” of the bendable circuit sheet 2 are securely solder-bonded to the corresponding output terminal pads “a”, respectively. During assembly of the LED tube lamp, the freely extending end portion 21 of the bendable circuit sheet 2 that is contracted to be deformed in shape toward the inside of the lamp tube 1, and is located at the same side as that of the bendable circuit sheet 2 with the light sources 202 mounted thereon. The through holes “e” can be fabricated before or during the soldering process. If done during the soldering process, the thermo-compression head 41 can be used to directly form the through holes “e”.

As shown in FIG. 35, the thermo-compression head 41 includes a thermo-compression bonding surface 411, at least one guide channel 412, a shaping channel 413, and a pressing surface 414. The thermo-compression bonding surface 411 is to make direct contact with the tin solder, for providing the compression force and heating source during solder bonding, and the shape of the thermo-compression bonding surface 411 can be flat, concaved, or convex. The concaved shape can be elongated strip or grid-like structure. The concaved-shaped thermo-compression bonding surface 411 would not completely cover the through-holes of the soldering pad. In the thermo-compression head 41 of the illustrated embodiment, a plurality of guide channels 412 that are arc-shaped concave sections are located at the lower portion of the thermo-compression bonding surface 411, which are used for guiding the flow of the melted tin solder from the thermo-compression bonding surface 411 to the through-holes “e” or the notches “f” of the soldering pads “b”, the guide channels 412 also provides the function of flow or backflow blocking, so that when the melted soldered tin is being accumulated on the surface of the soldering pad “b”, the shaping channel 413 being of a deeper concaved section than the adjacently-located guide channel 412, so as to provide a reserved cavity for allowing the tin solder to solidify upon cooling to become solder ball structure. The pressing surface 414 at the sides of the shaping channel 413 is a surface that is lower than the thermo-compression bonding surface 411, and the difference in height between the pressing surface 414 and the thermo-compression bonding surface 411 is configured to accommodate the overall height of the bendable circuit sheet 2 being pressed over the printed circuit board of the power supply 5 during the solder bonding process.

The tin solder has a preferred thickness of 0.3 mm to 0.5 mm for successfully and securely bonding the bendable circuit sheet 2 to the power supply 5. FIG. 39 shows an illustrative example of tin solder ball thicknesses being significantly different above two adjacent soldering pads “b”, with the bendable circuit sheet 2 and the printed circuit board of the power supply 5 arranged between the thermo-compression head 41 and the carrier prior to solder bonding step. As a result of such uneven heights of the tin solder, the thermocompression head 41 would not be able to melt the two tin solder balls evenly, that is to say, the taller solder ball is melted prior to the shorter solder ball, which results in inadequate solder bonding strength or integrity of the soldering pad having the shorter solder ball directly above thereof.

In the illustrated embodiment, the thermo-compression head 41 is configured to be adjustably rotatable so that, upon feedback of the contact force amounts exerted by the contacting of the two solder balls to the corresponding two soldering pads, the thermocompression head 41 can adjust its roll angle accordingly to even out or balance the contact force amounts.

In the illustrated embodiment shown in FIG. 41, a different approach is adopted, in which the thermo-compression head 41 remain stationary while the bendable circuit sheet 2 is rotated by a carrier 61 of a soldering vehicle 60 as shown in FIG. 40. The soldering vehicle 60 includes a carrier 61, a carrier frame 62, a rotating cam 63, and two spring pieces 64. The carrier 61 is used for holding the bendable circuit sheet 2 and the power supply 5. The carrier frame 62 is configured to carry the carrier 61. The carrier 61 includes the rotating cam 63, which serves the purpose of rotating the carrier 61 in roll direction thereof, and the two spring pieces 64 which function as force balancing mechanism to assist in maintaining balance in force exertion. The bendable circuit sheet 2 together with the power supply 5 can be mounted on the carrier 61 of the soldering vehicle 60.

As shown in FIG. 41, by rotating the carrier 61 via the rotating cam 63 thereof, tin solder balls of significantly different thicknesses above two adjacent soldering pads can be properly accommodated for achieving balanced contact with the soldering pad so as to improve solder bonding strength or integrity. The usage of a drive motor for actuating the rotation of the carrier 61 instead of using the rotating cam 63 and the two spring pieces 64 can also be adopted in an alternative embodiment, in which case the carrier frame 62 is not needed.

If the two ends of the bendable circuit sheet are to be securely fixed to the inner surface of the tube 1, the female plug 201 is mounted on the bendable circuit sheet, and the male plug 51 of the power supply 5 is inserted into the female plug 201, in that order, so as to establish electrical connection therebetween. Direct current (DC) signals are carried on the wiring layer 2a of the bendable circuit sheet, unlike the 3-layered conventional flexible substrates for carrying high frequency signals using a dielectric layer. One of the advantages of using the bendable circuit sheet as shown in illustrated embodiment of FIG. 10 over a conventional rigid LED light bar is that damages or breakages occurring during the wire bonding of the LED light bar and the power supply of the tube (for conventional rigid LED light bar) is prevented by solder bonding of the bendable circuit sheet and then coiled back into the tube to arrive at the proper position inside the tube.

Referring to the illustrated embodiment of FIG. 11, the LED light bar 2 is a bendable circuit sheet which includes a wiring layer 2a and a dielectric layer 2b that are arranged in a stacked manner. The LED light source 202 is disposed on a surface of the wiring layer 2a away from the dielectric layer 2b. In other words, the dielectric layer 2b is disposed on a surface of the conductive wiring layer 2a that is away from the LED light sources 202. The wiring layer 2a is electrically connected to the power supply 5. Meanwhile, the adhesive sheet 4 is disposed on a surface of the dielectric layer 2b away from the wiring layer 2a to bond and to fix the dielectric layer 2b to the inner circumferential surface of the tube 1. The wiring layer 2a can be a metal layer serving as a power supply layer, or can be bonding wires such as copper wire.

In an alternative embodiment, the LED light bar 2 further includes a circuit protection layer (not shown). In another alternative embodiment, the dielectric layer can be omitted, in which the wiring layer is directly bonded to the inner circumferential surface of the tube. The circuit protection layer can be an ink material, possessing functions such as solder resist and optical reflectance. Whether the wiring layer 2a has a one-layered, or two-layered structure, the circuit protective layer can be adopted. The circuit protection layer can be disposed on the side/surface of the LED light bar 2, such as the same surface of the wiring layer which has the LED light source 202 disposed thereon.

It should be noted that, in the present embodiment, the bendable circuit sheet is a onelayered structure made of just one layer of the wiring layer 2a, or a two-layered structure (made of one layer of the wiring layer 2a and one layer of the dielectric layer 2b), and thus would be more bendable or flexible to curl than the conventional three-layered flexible substrate. As a result, the bendable circuit sheet (the LED light bar 2) of the present embodiment can be installed in a tube that is of a customized shape or non-linear shape, and the bendable circuit sheet can be mounted touching the sidewall of the tube. The bendable circuit sheet mounted closely to the tube wall is one preferred configuration, and the fewer number of layers thereof, the better the heat dissipation effect, and the lower the material cost. Of course, the bendable circuit sheet is not limited to being a one-layered or twolayered structure only; in other embodiments, the bendable circuit sheet can include multiple layers of the wiring layers 2a and multiple layers of the dielectric layers 2b, in which the dielectric layers 2b and the wiring layers 2a are sequentially stacked in a staggered manner, respectively, to be disposed on the surface of the one wiring layer 2a that is opposite from the surface of the one wiring layer 2a which has the LED light source 202 disposed thereon.

The LED light source 202 is disposed on the uppermost layer of the wiring layers 2a, and is electrically connected to the power supply 5 through the (uppermost) wiring layer 2a. Furthermore, the inner circumferential surface of the lamp tube 1 or the outer circumferential surface thereof is covered with an adhesive film (not shown), for the sake of isolating the inner content from outside content of the lamp tube 1 after the lamp tube 1 has been ruptured. The present embodiment has the adhesive film coated on the inner circumferential surface of the lamp tube 1.

In an alternative embodiment as shown in FIGs 36 and 37, the solder bonded bendable circuit sheet 2 and the power supply 5 can be replaced by a circuit board assembly 25. The circuit board assembly 25 includes a longer circuit board 251 and a shorter circuit board 253 that are adhered together. The longer circuit board 251 and the shorter circuit board 253 can be securely fixed by adhesive. The longer circuit board 251 can be a flexible circuit board or the bendable circuit sheet 2. The shorter circuit board 253 can be a rigid board, have a length of 15 mm to 40 mm, with preferred length of 19 mm to 36 mm. The longer circuit board 251 can have a length of 800 mm to 2800 mm, with preferred length being 1200 mm to 2400 mm.

The lengths of the shorter circuit board 253 and the longer circuit board 251 can also be changed to adapt to various different LED tube lamp dimensions. As shown in FIG. 36, the electronic components mounted on the shorter circuit board 253 are electrically connected to the longer circuit board 251 via a conductive wiring layer at a same side as that of the electronic components. As shown in FIG. 37, the electronic components are mounted on the shorter circuit board 253 and the electronic components and the conductive wiring layer of the longer circuit board 251 are at opposite sides of the shorter board 253. The circuit board assembly 25 does not require solder bonding between the bendable circuit sheet 2 to the power supply 5, but instead, the longer circuit board 251 and the shorter circuit board 253 are adhesively secured, followed by electrically connecting the electronic components on the shorter circuit board 253 to the longer circuit board 251 by using the conductive circuit layer to the longer circuit board 251.

In a preferred embodiment, the tube 1 can be a glass tube with a coated adhesive film on the inner wall thereof (not shown). The coated adhesive film also serves to isolate and segregate the inside and the outside contents of the tube 1 upon being ruptured thereof. The coated adhesive film material includes methyl vinyl silicone oil, hydro silicone oil, Xylene, and calcium carbonate.

Xylene is used as an auxiliary material. Upon solidifying or hardening of the coated adhesive film when coated on the inner surface of the tube 1, the xylene will be volatilized and removed. The xylene is mainly used for the purpose of adjusting the degree of adhesion or adhesiveness, which can then adjust the thickness of the bonding adhesive. In the present embodiment, the thickness of the coated adhesive film can be between 10 to 800 micrometers (pm), and the preferred thickness of the coated adhesive film can be between 100 to 140 micrometers (pm). This is because the bonding adhesive thickness being less than 100 micrometers does not have sufficient shatterproof capability for the glass tube and, thus, the glass tube is prone to crack or shatter. At above 140 micrometers of bonding adhesive thickness the light transmittance rate would reduce and also increase material cost. An allowable ratio range for vinyl silicone oil + hydrosilicone oil is (19.8-20.2): (20.2-20.6), but exceeding this allowable ratio range would negatively affect the adhesiveness or bonding strength. The allowable ratio range for the xylene and calcium carbonate is (2-6):(2-6), and if lesser than the lowest ratio, the light transmittance of the tube will be increased, but grainy spots would be produced or result from illumination of the LED tube, negatively affecting illumination quality and effect.

If the LED light bar 2 is configured to be a flexible substrate, no coated adhesive film is thereby required.

To improve the illumination efficiency of the LED tube lamp, the tube 1 has been modified according to an embodiment of the present invention by having a diffusion film layer 13 coated and bonded to the inner wall thereof as shown in FIG. 12, so that the light outputted or emitted from the LED light sources 202 is transmitted through the diffusion film layer 13 and then through the tube 1. The diffusion film layer 13 allows for improved illumination distribution uniformity of the light outputted by the LED light sources 202. The diffusion film layer 13 can be coated onto different locations, such as onto the inner wall or outer wall of the tube 1 or onto the diffusion coating layer (not shown) at the surface of each LED light source 202, or coated onto a separate membrane cover covering the LED light source 202. The diffusion film layer 13 in the illustrated embodiment of FIG. 12 is a diffusion film that is not in contact with the LED light source 202 (but covering above or over to enshroud the LED light sources underneath thereof). The diffusion film layer 13 can be an optical diffusion film or sheet, usually made of polystyrene (PS), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), and/or polycarbonate (PC), in one composite material composition thereof.

In an alternative embodiment, the diffusion film layer can be an optical diffusion coating, which has a material composition to include at least one of calcium carbonate, halogen calcium phosphate and aluminum oxide, which possesses excellent light diffusion and transmittance to exceed 90%. Further, the application of the diffusion film layer made of an optical diffusion coating material to an outer surface of the rear end region 101 along with the hot melt adhesive 6 would produce or generate increased friction resistance between the end cap and the tube due to the presence of the optical diffusion coating (when compared to that of an example that is without any optical diffusion coating), which is beneficial for preventing accidental detachment of the end cap from the tube. Composition of the diffusion film layer made by the optical diffusion coating for the alternative embodiment includes calcium carbonate (e.g., CMS-5000, white powder), thickening agents, and a ceramic activated carbon (e.g., ceramic activated carbon SW-C, which is a colorless liquid).

Specifically, the average thickness of the diffusion film layer or the optical diffusion coating falls between 20 ~ 30 pm after being coated on the inner circumferential surface of the glass tube, where finally the deionized water will be evaporated, leaving behind the calcium carbonate, ceramic activated carbon and the thickener. Using this optical diffusion coating material for forming the diffusion film layer 13, a light transmittance of the diffusion film layer 13 of about 90% can be achieved.

Generally speaking, the light transmittance ratio of the diffusion film layer 13 ranges from 85% to 96%. Furthermore, in another possible embodiment, the light transmittance ratio of the diffusion film layer can be 92%-94% while the thickness range is 200-300 pm which can have another effect. In addition, this diffusion film layer 13 can also provide electrical isolation for reducing risk of electric shock to a user upon breakage of the tube. Furthermore, the diffusion film layer 13 provides an improved illumination distribution uniformity of the light outputted by the LED light sources 202 so as to avoid the formation of dark regions seen inside the illuminated or lit up tube 1.

In other embodiments, the optical diffusion coating can also be made of strontium phosphate (or a mixture of calcium carbonate and strontium phosphate) along with a thickening agent, ceramic activated carbon and deionized water, and the coating thickness can be same as that of present embodiment. In another preferred embodiment, the optical diffusion coating material may be calcium carbonate-based material with a small amount of reflective material (such as strontium phosphate or barium sulfate), the thickener, deionizes water and carbon activated ceramic to be coated onto the inner circumferential surface of the glass tube with the average thickness of the optical diffusion coating falls between 20 ~ 30 pm. Then, finally the deionized water will be evaporated, leaving behind the calcium carbonate, the reflective material, ceramic activated carbon and the thickener.

The diffusion phenomena in microscopic terms, light is reflected by particles. The particle size of the reflective material such as strontium phosphate or barium sulfate will be much larger than the particle size of the calcium carbonate. Therefore, selecting a small amount of reflective material in the optical diffusion coating can effectively increase the diffusion effect of light. In other embodiments, halogen calcium phosphate or aluminum oxide can also serve as the main material for forming the diffusion film layer 13. The diameter of the calcium carbonate particles is 2 pm ~ 4pm, and the diameter of the particles of halogen calcium phosphate and aluminum oxide are about 4 pm ~ 6 pm and 1 pm ~ 2 pm, respectively.

For satisfying transmittance of 85 % ~ 92%, when using calcium carbonate, the diffusion film layer 13 would have an average thickness of 20 pm ~ 30 pm, meanwhile when using halogen calcium phosphate, the diffusion film layer 13 would have an average thickness of 25 pm ~ 35 pm, whereas when using aluminum oxide, the diffusion film layer 13 would have an average thickness of 10 pm ~ 15 pm. For satisfying transmittance rate above 92%, the diffusion film layer 13 should be thinner in thickness. In other words, the diffusion film layer thickness can be further adjusted according to desired light transmittance requirement.

In the present embodiment, the diffusion film layer 13 may be formed by two methods, including: (1) a pressure coating method: first after the entire lamp tube is erected upright, a diffusion coating equipment using an exerted pressure fills the inside of the lamp tube with a diffusion coating solution; later the pressure is reduced to normal ambient pressure; due to the diffusion coating solution containing a thickening agent to increase the viscosity of the diffusion coating material such as calcium carbonate when attaching and bonding to the inner circumferential surface of the lamp tube, after the excess diffusion coating solution is recovered back to the diffusion coating equipment, air drying step is performed to convert the diffusion coating solution to the (dry) diffusion film layer formed on the inner circumferential surface of the lamp tube. (2) spray coating method: using a diffusion coating solution spraying equipment, the entire inner circumferential surface of the lamp tube is sprayed with a diffusion coating solution, while the lamp tube can be tilted at an angle or rotated in order to increase the uniformity of the diffusion coating attached to the inner circumferential surface of the lamp tube; finally, air drying is performed to convert the diffusion coating solution to the (dry) diffusion film layer evenly formed on the inner circumferential surface of the lamp tube.

Furthermore, as shown in FIG. 12, the inner circumferential surface of the tube 1 is also provided or bonded with a reflective film layer 12. The reflective film layer 12 is provided around the LED light sources 202, and occupies a portion of an area of the inner circumferential surface of the tube 1 arranged along the circumferential direction thereof. As shown in FIG. 12, the reflective film layer 12 is disposed at two sides of the LED light sources 202 extending along a circumferential direction of the tube. The reflective film layer 12, when viewed by a person looking at the tube from the side (in the X-direction shown in FIG. 12), serves to block the LED light sources 202, so that the person does not directly see the LED light sources 202, thereby reducing the visual graininess effect. On the other hand, the reflective film 12 reflects light emitted from the LED light sources 202, and can be utilized to control the divergence angle of the LED tube lamp, so that more light is emitted in a direction towards part of the tube without the reflective film coating, such that the LED tube lamp has a higher energy efficiency whilst providing the same level of illumination performance.

The reflection film layer 12 is provided on the inner circumferential surface of the tube 1, and has a opening 12a on the reflective film layer 12 which is configured corresponding to the locations of the LED light bar 2. The sizes of the opening 12a is the same or slightly larger than the size of the LED light bar 2. During assembly, the LED light sources 202 are mounted on the LED light bar 2 (or flexible substrate) provided on the inner surface of the tube 1, and then the reflective film layer 12 is adhered to the inner surface of the tube, so that the opening 12a of the reflective film layer 12 is matched to the corresponding LED light bar 2 in a one-to-one relationship, and the LED light sources 202 are exposed to the outside of the reflective film layer 12.

In the present embodiment, the reflectance of the reflective film layer 12 is at least greater than 85%. Better reflectance of 90% can also be achieved. Meanwhile, more preferably reflectance at more than 95% reflectance can also be achievable, in order to obtain more reflectance.

The reflective film layer 12 extends circumferentially along the length of the tube 1 occupying about 30% to 50% of the inner surface area of the tube 1. In other words, extending along a circumferential direction of the tube 1, a circumferential length of the reflective film layer 12 along the inner circumferential surface of the tube 1 and a circumferential length of the tube 1 has a ratio of 0.3 to 0.5.

In the illustrated embodiment of FIG. 12, the reflective film layer 12 is disposed substantially in the middle along a circumferential direction of the tube 1, so that the two distinct portions or sections of the reflective film layer 12 disposed on the two sides of the LED light bar 2 are substantially equal in area. The reflective film layer 12 material may be made of PET or by selectively adding some reflective materials such as strontium phosphate or barium sulfate, with a thickness of 140pm to 350pm, or of 150pm to 220pm for a more preferred embodiment.

In other embodiments, the reflective film layer 12 may be provided in other forms, for example, along the circumferential direction of the tube 1 on one or both sides of the LED light source 202, while occupying the same 30% to 50% of the inner surface area of the tube 1.

Alternatively, as shown in FIG. 13, the reflective film layer 12 can be without any openings, so that the reflective film layer 12 is directly adhered or mounted to the inner surface of the tube 1 as that of illustrated embodiment, and followed by mounting or fixing the LED light bar 2, with the LED light sources 202 already being mounted thereon, on the reflective film layer 12. In another embodiment, just the reflection film layer 12 may be provided without a diffusion film layer 13 being present, as shown in FIG. 14.

In another embodiment, the reflective film layer 12 and the LED light bar 2 are in contact with one another on one side thereof as shown in FIG. 22. In addition, a diffusion film layer 13 is disposed above the LED light bar 2. Referring to FIG. 23, the LED light bar 2 (with the LED light sources 202 mounted thereon) is directly disposed on the reflective film layer 12, and the LED light bar 2 is disposed at an end region of the reflective layer 12 (without having any diffusion layer) of the LED tube lamp of yet another embodiment of the present invention.

In other embodiments, the width of the LED light bar 2 (along the circumferential direction of the tube) can be widened to occupy a circumference area of the inner circumferential surface of the tube 1 at a ratio ranging from 0.2 to 0.5, and preferably ranging from 0.3 to 0.5, in which the widened portion of the LED light bar 2 can provide a reflective effect similar to the reflective film. As described in the above embodiment, the LED light bar 2 may be coated with a circuit protection layer, the circuit protection layer may be an ink material, providing an increased reflective function, with a widened flexible substrate using the LED light sources as a starting point to be circumferentially extending, so that the light is more concentrated. In the present embodiment, the circuit protection layer is coated on just the top side of the LED light bar 2 (in other words, being disposed on an outermost layer of the LED light bar 2 (or bendable circuit sheet).

In the embodiment shown in FIGs. 12-14, the inner circumferential surface of the glass tube, can be coated entirely or partially with an optical diffusion coating (parts that have the reflective film would not be coated by the optical diffusion coating). The optical diffusion coating is preferably applied to the outer surface at the end region of the tube 1, so that the end cap 3 and the tube 1 can be bonded more firmly.

Referring to FIG. 15, the LED light source 202 may be further modified to include a LED lead frame 202b having a recess 202a, and an LED chip 18 disposed in the recess 202a. Specifically, the traditional dimension of the LED chip 18 is in a square shape of the length side to the width side at a ratio about 1:1. In an embodiment of the present invention, the LED chip 18 can be rectangular in shape as a strip with the dimension of the length side to the width side at a ratio ranging from 2:1 to 10:1, preferably at a ratio ranging from 2.5:1 to 5:1, and further preferably at a ratio ranging from 3:1 to 4.5:1. As a result, the length direction of the LED die (or chip) 18 can be arranged or aligned along the length direction of the tube 1, so that average current density of the LED chip 18 and overall illumination quality are further improved. The recess 202a is filled with phosphor, the phosphor coating covering the LED chip 18 to convert emitted light to the desired color of light.

In one tube 1, there are a multiple number of LED light sources 202, which are arranged into one or more rows, and each row of the LED light sources 202 is arranged along the axis direction or length direction (Y-direction) of the tube 1. There may be one or more recesses 202a belonging to each LED lead frame 202b. In the illustrated embodiment, each LED lead frame 202b has one recess 202a, and correspondingly, the LED lead frame 202b includes two first sidewalls 15 arranged along a length direction (Y-direction) of the tube 1, and two second sidewalls 16 arranged along a width direction (X-direction) of the tube 1. In the present embodiment, the first sidewall 15 extends along the width direction (X-direction) of the tube 1, the second sidewall 16 extends along the length direction (Y-direction) of the tube 1. The first sidewall 15 is lower in height than the second sidewall 16. The recess 202a is enclosed by the first sidewalls 15 and the second sidewalls 16.

In other embodiments, in one row of the LED light sources, it is permissible to have one or more sidewalls of the LED lead frames of the LED light sources to adopt another configuration or manner of extension structures.

When the user is viewing along the X-direction toward the tube, the second sidewall 16 can block the line of sight of the user to the LED light source 202, thus reducing unappealing grainy spots. The first sidewall 15 is formed to be extending along a direction that is substantially parallel with the width direction of the tube 1 and may have a different structure such as zigzag, curved, wavy, and the like. The second sidewall 16 is formed to be extending along a direction that is substantially parallel with the length direction of the tube 1 and may have a different structure such as zigzag, curved, wavy, and the like.

Having the first sidewall 15 being of a lower height than the second sidewall 16 is beneficial for allowing light illumination to be easily dispersed beyond the LED lead frame 202b, and no grainy effect to be produced upon viewing in the Y-direction.

The first sidewall 15 includes an inner surface 15a. The inner surface 15a of the first sidewall 15 is a sloped surface, which promotes better light guiding effect for illumination and facing toward outside of the recess. The inner surface 15a can be a flat or curved surface. The slope of the inner surface 15a is between about 30 degrees to 60 degrees. In other words, the included angle between the bottom surface of the recess 202a and the inner surface 15a is between 120 and 150 degrees. In other embodiments, the slope of the inner surface of the first sidewall can also be about 15 degrees to 75 degrees, that is, the included angle between the bottom surface of the recess 202a and the inner surface of the first sidewall is 105 degrees to 165 degrees. Alternatively, the slope may be a combination of flat and curved surfaces.

In other embodiments, if there are several rows of the LED light sources 202, arranged in a length direction (Y-direction) of the tube 1, as long as the LED lead frames 202b of the LED light sources 202 disposed in the outermost two rows (closest to the tube) along the width direction of the tube 1, have two first sidewalls 15 configured along the length direction (Y-direction) and two second sidewalls 16 configured in one straight line along the width direction (X-direction), so that the second sidewalls 16 disposed on a same side of the same row are collinear to one another. However, the arrangement direction of the LED lead frames 202b of the other LED light sources 202 that are located between the aforementioned LED light sources 202 disposed in the outermost two rows are not limited, for example, for the LED lead frames 202b of the LED light sources 202 located in the middle row (third row), each LED lead frame 202b can include two first sidewalls 15 arranged along in the length direction (Y-direction) of the tube 1, and two second sidewalls 16 arranged along in the width direction (X-direction) of the tube 1, or alternatively, each LED lead frame 202b can include two first sidewalls 15 arranged along in the width direction (X-direction) of the tube 1, and two second sidewalls 16 arranged along in the length direction (Y-direction) of the tube 1, or arranged in a staggered manner. When the user is viewing from the side of the tube along the X-direction, the outermost two rows of the LED lead frames 202b of the LED light sources 202 can block the user’s line of sight for directly seeing the LED light sources 202. As a result, the visual graininess unpleasing effect is reduced.

Similar to the present embodiment, with regard to the two outermost rows of the LED light sources, one or more of the sidewalls of the LED lead frames of the LED light sources may adopt other configurational or distribution arrangements. When multiple LED light sources 202 are distributed or arranged along the length direction of the tube in one row, the LED lead frames 202b of the multiple LED light sources 202 have all of the second sidewalls 16 thereof disposed in one straight line along the width direction of the tube, respectively. That is to say, being at the same side, the second sidewalls 16 form substantially a wall structure to block the user’s line of sight from seeing directly towards the LED light source 202. When the multiple LED light sources 202 are distributed or arranged along the length direction of the tube in multiple rows, the multiple LED light sources 202 are distributed or arranged along the width direction, with regard to the two outermost rows of the LED light sources located along the width direction of the tube, each row of the LED lead frames 202b of the multiple LED light sources 202, in which all of the second sidewalls 16 disposed at the same side are in one straight line along the width direction of the tube, that is to say, being at the same side, as long as the second sidewalls 16 of the LED light sources 202 located at the outermost two rows can block the user’s line of sight for directly seeing the LED light sources 202, the reduction of visual graininess unpleasing effect can thereby be achieved.

Regarding the one or more middle row(s) of the LED light sources 202, the arrangement, configuration or distribution of the sidewalls are not specifically limited to any particular one, and can be the same as or different from the arrangement and distribution of the two outermost rows of the LED light sources, without departing from the spirit and scope of the present disclosure.

In one embodiment, the LED light bar 2 includes a dielectric layer 2b and one conductive wiring layer 2a, in which the dielectric layer 2b and the conductive wiring layer 2a are arranged in a stacked arrangement.

The narrowly curved end regions of the glass tube 1 can reside at two ends, or can be configured at just one end thereof in different embodiments. In an alternative embodiment, the LED tube lamp further includes a diffusion layer (not shown) and a reflective film layer 12, in which the diffusion layer is disposed above the LED light sources 202, and the light emitting from the LED light sources 202 passes through the diffusion layer and the tube 1. Furthermore, the diffusion film layer can be an optical diffusion covering above the LED light sources without directly contacting thereof. In addition, the LED light sources 202 can be bondedly attached to the inner circumferential surface of the tube. In another embodiment, the magnetic metal member 9 can be a magnetic substance that is magnetic without being made of metal. The magnetic substance can be doped into the hot melt adhesive.

In the embodiments of the present invention, the LED light bar 2 is described or mentioned interchangeably with the bendable circuit sheet 2, because in several embodiments, the LED light bar 2 is made of a bendable circuit sheet according to the disclosure of the present invention ( instead of being made of a conventional rigid circuit board). Thus, the bendable circuit sheet 2 and the LED light bar 2 belong to the same element throughout the instant disclosure. In addition, the soldering pad “b” is also described or mentioned interchangeably with the term “bonding pad”, so that the two are the same element.

The LED tube lamps according to various different embodiments of the present invention are described as above. With respect to an entire LED tube lamp, the features including “having the structure-strengthened end region”, “adopting the bendable circuit sheet as the LED light strip”, “coating the adhesive film on the inner surface of the lamp tube”, “coating the diffusion film on the inner surface of the lamp tube”, “covering the diffusion film in form of a sheet above the LED light sources”, “coating the reflective film on the inner surface of the lamp tube”, “the end cap including the thermal conductive member”, “the end cap including the magnetic metal member”, “the LED light source being provided with the lead frame”, and “utilizing the circuit board assembly to connect the LED light strip and the power supply” may be applied in practice singly or integrally such that only one of the features is practiced or a number of the features are simultaneously practiced.

Furthermore, any of the features “having the structure-strengthened end region”, “adopting the bendable circuit sheet as the LED light strip”, “coating the adhesive film on the inner surface of the lamp tube”, “coating the diffusion film on the inner surface of the lamp tube”, “covering the diffusion film in form of a sheet above the LED light sources”, “coating the reflective film on the inner surface of the lamp tube”, “the end cap including the thermal conductive member”, “the end cap including the magnetic metal member”, “the LED light source being provided with the lead frame”, and “utilizing the circuit board assembly to connect the LED light strip and the power supply” includes any related technical points and their variations and any combination thereof as described in the abovementioned embodiments of the present invention.

As an example, the feature “having the structure-strengthened end region” may include “the lamp tube includes a main body region, a plurality of rear end regions, and a transition region connecting the main body region and the rear end regions, wherein the two ends of the transition region are arc-shaped in a cross-section view along the axial direction of the lamp tube; the rear end regions are respectively sleeved with end caps; the outer diameter of at least one of the rear end regions is less than the outer diameter of the main body region; the end caps have same outer diameters as that of the main body region.”

As an example, the feature “adopting the bendable circuit sheet as the LED light strip” may include “the connection between the bendable circuit sheet and the power supply is by way of wire bonding or soldering bonding; the bendable circuit sheet includes a wiring layer and a dielectric layer arranged in a stacked manner; the bendable circuit sheet has a circuit protective layer made of ink to reflect lights and has widened part along the circumferential direction of the lamp tube to function as a reflective film.”

As an example, the feature “coating the diffusion film on the inner surface of the lamp tube” may include “the composition of the diffusion film includes calcium carbonate, halogen calcium phosphate and aluminum oxide, or any combination thereof, and may further include thickener and a ceramic activated carbon; the diffusion film may be a sheet covering the LED light source.”

As an example, the feature “coating the reflective film on the inner surface of the lamp tube” may include “the LED light sources are disposed above the reflective film, within an opening in the reflective film or beside the reflective film.”

As an example, the feature “the end cap including the thermal conductive member” may include “the end cap includes an electrically insulating tube, the hot melt adhesive is partially or completely filled in the accommodation space between the inner surface of the thermal conductive member and the outer surface of the lamp tube.” The feature “the end cap including the magnetic metal member” includes “the magnetic metal member is circular or non-circular, has openings or indentation/embossment to reduce the contact area between the inner peripheral surface of the electrically insulating tube and the outer surface of the magnetic metal member; has supporting portions and protruding portions to support the magnetic metal member or reduce the contact area between the electrically insulating tube and the magnetic metal member.”

As an example, the feature “the LED light source being provided with the lead frame” may include “the lead frame has a recess for receive an LED chip, the recess is enclosed by first sidewalls and second sidewalls with the first sidewalls being lower than the second sidewalls, wherein the first sidewalls are arranged to locate along a length direction of the lamp tube while the second sidewalls are arranged to locate along a width direction of the lamp tube.”

As an example, the feature “utilizing the circuit board assembly to connect the LED light strip and the power supply” may include “the circuit board assembly has a long circuit sheet and a short circuit board that are adhered to each other with the short circuit board being adjacent to the side edge of the long circuit sheet; the short circuit board is provided with a power supply module to form the power supply; the short circuit board is stiffer than the long circuit sheet.”

While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.

The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.

Claims

1. An LED tube light, comprising: a plurality of LED light sources; an end cap; a light tube extending in a first direction along a length of the light tube, and having an end attached to the end cap; a power supply comprising a circuit board and one or more circuit elements, disposed in the end cap; and an LED light bar extending in the first direction, and disposed inside the light tube, the LED light sources being mounted on the LED light bar, the LED light sources and the power supply being electrically connected by the LED light bar; wherein the LED light bar is substantially linearly configured and includes a bendable circuit board, the bendable circuit board is made of one conductive layer and one dielectric layer to form a two-layered structure, the dielectric layer is disposed on a surface of the conductive layer that is away from the LED light sources and the dielectric layer is fixed to an inner circumferential surface of the light tube, the LED light sources are disposed on the conductive layer and are electrically connected to the power supply by the conductive layer therebetween, the bendable circuit board has a first end and a second end opposite each other along the first direction, and at least the first end of the bendable circuit board is bent away from the light tube to form a freely extending end portion, wherein the freely extending end portion is an integral portion of the bendable circuit board and extends to be disposed in the end cap and is directly soldered to the power supply.

2. An LED tube light, comprising: a plurality of LED light sources; an end cap; a light tube extending in a first direction along the length of the light tube, and having an end attached to the end cap; a power supply, disposed in the end cap, the power supply including a circuit board and one or more circuit elements disposed thereon; and an LED light bar extending in the first direction, and disposed inside the light tube; wherein the LED light bar is a bendable circuit board or flexible substrate, the LED light sources are mounted on the LED light bar, and the LED light sources and the power supply are electrically connected by the LED light bar, the bendable circuit board or flexible substrate has a first end and a second end opposite each other along the first direction, and at least the first end of the bendable circuit board or flexible substrate is bent away from the light tube to form a freely extending end portion, wherein the freely extending end portion is an integral portion of the bendable circuit board or flexible substrate, and wherein the freely extending end portion is directly soldered to the circuit board of the power supply.

3. The LED tube light of claim 2, wherein the LED light bar comprises a conductive layer, and the LED light sources are disposed on the conductive layer and are electrically connected to the power supply by the conductive layer therebetween.

4. The LED tube light of claim 3, wherein the LED light bar further comprises a dielectric layer, the dielectric layer is disposed on the conductive layer away from the LED light sources, and is fixed to an inner circumferential surface of the light tube at a portion of the LED light bar other than the freely extending end portion.

5. The LED tube light of claim 2, wherein the LED light bar has one conductive layer being formed of only one metal layer, has only one dielectric layer, and has a circuit protection layer being formed of only one layer disposed on the conductive layer, wherein the dielectric layer is disposed on the conductive layer away from the LED light sources.

6. The LED tube light of any of claims 2 to 5, wherein the LED light bar extends along a circumferential direction of the light tube, wherein a ratio of a circumferential length of the bendable circuit board along an inner circumferential surface of the light tube to a circumferential length of the inner circumferential surface of the light tube is between 0.3 and 0.5.

7. The LED tube light of claim 4, wherein the bendable circuit board further comprises a circuit protection layer being formed of one layer disposed on an outermost surface of the conductive layer of the bendable circuit board.

8. The LED tube light of claim 4, wherein the bendable circuit board further comprises a circuit protection layer being of two layers respectively disposed on outermost layers of the conductive layer and the dielectric layer of the bendable circuit board.

9. The LED tube light of any of claims 2 to 8, wherein a portion of the LED light bar where the LED light sources are disposed is substantially linearly configured, and the first end of the LED light bar is not fixed to an inner circumferential surface of the light tube.

10. The LED tube light of claim 9, wherein the bendable circuit board forms a freely extending end portion at the second end thereof, and each freely extending end portion is curled up, coiled or deformed in shape to be fittingly accommodated inside the light tube.

11. The LED tube light of any of claims 2 to 10, wherein the light tube includes a main region and a plurality of rear end regions, a diameter of each rear end region is less than a diameter of the main region, and the end cap is fittingly sleeved on one of the rear end regions of the light tube.

12. The LED tube light of claim 11, wherein the light tube further includes a transition region between the main region and each of the rear end regions.

13. The LED tube light of claim 12, wherein the bendable circuit board is passed through one of the transition regions to be electrically connected to the power supply.

14. The LED tube light of claim 12 or claim 13, wherein each of the transition regions has a length of 1 mm to 4 mm.

15. The LED tube light of any of claims 2 to 14, further comprising a reflective film layer disposed on an inner circumferential surface of the light tube and occupying a portion of an area of the inner circumferential surface of the light tube.

16. The LED tube light of claim 15, wherein the bendable circuit board is disposed on the reflective film layer.

17. The LED tube light of claim 15, wherein the bendable circuit board is disposed on one side of the reflective film layer.

18. The LED tube light of any of claims 15 to 17, wherein a ratio of a circumferential length of the reflective film layer along the inner circumferential surface of the light tube and a circumferential length of the light tube is 0.3 to 0.5.

19. The LED tube light of claim 2, wherein the bendable circuit board comprises a plurality of conductive layers and a plurality of dielectric layers, the dielectric layers and the conductive layers are sequentially stacked in a staggered manner.

20. An LED tube light, comprising: a plurality of LED light sources; first and second end caps, at least the first end cap having a power supply disposed therein, the power supply including a circuit board and circuit elements disposed thereon; a light tube extending in a first, longitudinal, direction along the length of the light tube, and having a first and second end in the first direction respectively attached to the first and second end caps; and an LED light bar, disposed inside the light tube and extending in the first direction, the LED light sources being mounted on the LED light bar, the LED light sources and the power supply being electrically connected by the LED light bar; wherein the LED light bar is a bendable circuit board or flexible substrate, the bendable circuit board or flexible substrate forms a freely extending end portion at the first and second ends thereof, respectively, wherein each freely extending end portion is an integral portion of the bendable circuit board or flexible substrate and is bent to be separated from the light tube; wherein at least the first end of the bendable circuit board or flexible substrate has two separated pads for electrically connecting to the circuit board of the power supply by soldering.

21. The LED light tube of claim 20, wherein the conductive layer and the dielectric layer form a two-layered structure for the bendable circuit board or flexible substrate, and the dielectric layer is disposed on a surface of the conductive layer that is away from the LED light sources and fixed to an inner circumferential surface of the light tube.

22. The LED tube light of claim 1, wherein the bendable circuit board is soldered to the circuit board of the power supply in the end cap.