Patent Application
20240230038
The present disclosure relates to illumination devices, and more particularly to an LED tube lamp and its components including the light sources, electronic components, and end caps.
LED lighting technology is rapidly developing to replace traditional incandescent and fluorescent lightings. LED tube lamps are mercury-free in comparison with fluorescent tube lamps that need to be filled with inert gas and mercury. 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 typically be considered as a cost-effective lighting option.
Typical LED tube lamps have a lamp tube, a circuit board disposed inside the lamp tube with light sources being mounted on the circuit board, and end caps accompanying a power supply provided at two ends of the lamp tube with the electricity from the power supply transmitting to the light sources through the circuit board. However, existing LED tube lamps have certain drawbacks.
First, the typical circuit board is rigid and allows the entire lamp tube to maintain a straight tube configuration when the lamp tube is partially ruptured or broken, and this gives the user a false impression that the LED tube lamp remains usable and is likely to cause the user to be electrically shocked upon handling or installation of the LED tube lamp.
Second, the rigid circuit board is typically electrically connected with the end caps by way of wire bonding, in which the wires may be easily damaged and even broken due to any move during manufacturing, transportation, and usage of the LED tube lamp and therefore may disable the LED tube lamp.
Third, the existing LED tube lamps are bad in heat dissipation, especially have problem in dissipating heat resulting from the power supply components inside the end caps. The heat resulting from the power supply components may cause a high temperature around end cap and therefore reduces life span of the adhesive and simultaneously disables the adhesion between the lamp tube and the end caps.
In addition, an LED light source is a point light source. Light rays emitted from the LED light source are highly concentrated and are hard to be evenly distributed. Accordingly, the present disclosure and its embodiments are herein provided.
It's specially noted that the present disclosure may actually include one or more inventions claimed currently or not yet claimed, and for avoiding confusion due to unnecessarily distinguishing between those possible inventions at the stage of preparing the specification, the possible plurality of inventions herein may be collectively referred to as “the (present) invention” herein.
Various embodiments are summarized in this section, and are described with respect to the “present invention,” which terminology is used to describe certain presently disclosed embodiments, whether claimed or not, and is not necessarily an exhaustive description of all possible embodiments, but rather is merely a summary of certain embodiments. Certain of the embodiments described below as various aspects of the “present invention” can be combined in different manners to form an LED tube lamp or a portion thereof.
The present invention provides a novel LED tube lamp and aspects thereof.
The present invention provides an LED tube lamp. According to one embodiment, the LED tube lamp includes a glass lamp tube, two end caps, an adhesive, a power supply, a diffusion film, a plurality of LED light sources and an LED light strip. The glass lamp tube includes a main body region and two rear end regions. Each of the two rear end regions is coupled to a respective end of the main body region. Each of the end caps is sleeving with a respective rear end region. Each of the end cap includes a lateral wall and an end wall. The lateral wall is substantially coaxial with the glass lamp and the end wall is substantially perpendicular to an axial direction of the glass lamp tube. The adhesive is disposed between each of the lateral wall and each of the rear end regions. The LED light strip comprises a mounting region adhered to an inner circumferential surface of the glass lamp tube and a connecting region electrically connecting to the mounting region. The plurality of LED light sources are mounted on the mounting region. The power supply includes a circuit board separating from the LED light strip and electrically connecting to the connecting region. The diffusion film is covering on an outer surface of the glass lamp tube. The glass lamp tube and the end cap are secured by an adhesive. The connecting region, one of the rear end regions, the adhesive and one of the lateral wall are stacked sequentially in a radial direction of the glass lamp tube.
The present invention provides an LED tube lamp. According to one embodiment, the LED tube lamp includes a glass lamp tube, two end caps, an adhesive, a power supply, a diffusion layer, a plurality of LED light sources and an LED light strip. The glass lamp tube includes a main body region and two rear end regions. Each of the two rear end regions is coupled to a respective end of the main body region. Each of the end caps is sleeving with a respective rear end region. Each of the end cap includes a lateral wall and an end wall. The lateral wall is substantially coaxial with the glass lamp and the end wall is substantially perpendicular to an axial direction of the glass lamp tube. The adhesive is disposed between each of the lateral wall and each of the rear end regions. The LED light strip comprises a mounting region adhered to an inner circumferential surface of the glass lamp tube and a connecting region electrically connecting to the mounting region. The plurality of LED light sources are mounted on the mounting region. The power supply includes a circuit board separating from the LED light strip and electrically connecting to the connecting region. The diffusion layer is covering on an inner circumferential surface of the glass lamp tube. The glass lamp tube and the end cap are secured by an adhesive. The connecting region, one of the rear end regions, the adhesive and one of the lateral wall are stacked sequentially in a radial direction of the glass lamp tube.
In some embodiments, each of the two end caps comprises two conductive pins and at least one opening, the two conductive pins and the opening are arranged on the end wall.
In some embodiments, the LED tube lamp further comprises a reflective film covering a portion of the inner circumferential surface of the glass lamp tube.
In some embodiments, the reflective film is disposed on two opposite sides of the LED light sources.
In some embodiments, the LED light strip and the reflective film are stacked on each other in the radial direction of the glass lamp tube and are adhered to the inner circumferential surface of the glass lamp tube.
In some embodiments, at least one of the two end caps comprises a socket, and the circuit board of the power supply are inserted into the socket.
In some embodiments, an outer diameter of each of the lateral wall is substantially the same as the outer diameter of the main body region.
In some embodiments, the outer diameter of each of the two rear end regions is less than the outer diameter of the main body region.
In some embodiments, the mounting region is attached to the inner circumferential surface of the main body and the connecting region is detached from the inner circumferential surface of the glass lamp tube to form a freely extending end portion.
In some embodiments, the circuit board of the power supply comprises a first soldering pad and the freely extending end portion comprises a second soldering pad, the first soldering pad is soldered with the second soldering pad by a soldering material.
In some embodiments, a portion of the inner circumferential surface of the glass lamp tube not covered by the reflective film is covered by the diffusion layer.
The present disclosure provides a novel LED tube lamp based on the glass-made lamp tube to solve the above-mentioned problems. The present disclosure will now be described in the following embodiments with reference to the drawings. The following descriptions of various embodiments of this invention are presented herein for the purpose of illustration and giving examples only. It is not intended to be exhaustive or to be limited to the precise form disclosed. These example embodiments are just that—examples —and many implementations and variations are possible that do not require the details provided herein. It should also be emphasized that the disclosure provides details of alternative examples, but such a listing of alternatives is not exhaustive. Furthermore, any consistency of detail between various examples should not be interpreted as requiring such detail—it is impracticable to list every possible variation for every feature described herein. The language of the claims should be referenced in determining the requirements of the invention.
“Terms such as “about” or “approximately” may reflect sizes, orientations, or layouts that vary only in a small relative manner, and/or in a way that does not significantly alter the operation, functionality, or structure of certain elements. For example, a range from “about 0.1 to about 1” may encompass a range such as a 0% to 5% deviation around 0.1 and a 0% to 5% deviation around 1, especially if such deviation maintains the same effect as the listed range.”
“Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and/or the present application, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.”
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In the above-mentioned embodiments, the shape of opening 304 is not limited to be a circle. The openings 304 can be designed to be in a shape of arc as shown in
In the above-mentioned embodiments, the openings 304 disposed on the surface of the end cap 3 may help to dissipate heat resulting from the power supply 5 by passing through the end cap 3 such that the reliability of the LED tube lamp could be improved. While in some embodiments, the openings 304 disposed on the surface of the end cap 3 may not pass through the end cap 3 for heat dissipation. In those embodiments using highly thermal conductive silicone gel to secure the glass lamp tube 1 and the end caps 3, the openings 304 may also accelerate the solidification process of the melted highly thermal conductive gel.
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The glass lamp tube 1 is covered by a heat shrink sleeve 19. The thickness of the heat shrink sleeve 19 may range from 20 μm to 200 μm. The heat shrink sleeve 19 is substantially transparent with respect to the wavelength of light from the LED light sources 202 such that only a slight part of the lights transmitting through the glass lamp tube is absorbed by the heat shrink sleeve 19. The heat shrink sleeve 19 may be made of PFA (perfluoroalkoxy) or PTFE (poly tetra fluoro ethylene). Since the thickness of the heat shrink sleeve 19 is only 20 μm to 200 μm, the light absorbed by the heat shrink sleeve 19 is negligible. At least a part of the inner surface of the glass lamp tube 1 is formed with a rough surface and the roughness of the inner surface is higher than that of the outer surface, such that the light from the LED light sources 202 can be uniformly spread when transmitting through the glass lamp tube 1. In some embodiments, the roughness of the inner surface of the glass lamp tube 1 may range from 0.1 μm to 40 μm.
The glass lamp tube 1 and the end cap 3 are secured by a highly thermal conductive silicone gel disposed between an inner surface of the end cap 3 and outer surfaces of the glass lamp tube 1. In some embodiments, the highly thermal conductive silicone gel has a thermal conductivity not less than 0.7 w/mk. In some embodiments, the thermal conductivity of the highly thermal conductive silicone gel is not less than 2 w/mk. In some embodiments, the highly thermal conducive silicone gel is of high viscosity, and the end cap 3 and the end of the glass lamp tube 1 could be secured by using the highly thermal conductive silicone gel and therefore qualified in a torque test of 1.5 to 5 newton-meters (Nt-m) and/or in a bending test of 5 to 10 newton-meters (Nt-m). The highly thermal conductive silicone gel has excellent weatherability and can prevent moisture from entering inside of the glass lamp tube 1, which improves the durability and reliability of the LED tube lamp.
In some embodiments, the inner surface of the glass lamp tube 1 is coated with an anti-reflection layer with a thickness of one quarter of the wavelength range of light coming from the LED light sources 202. With the anti-reflection layer, more light from the LED light sources 202 can transmit through the glass lamp tube 1. In some embodiments, the refractive index of the anti-reflection layer is a square root of the refractive index of the glass lamp tube 1 with a tolerance of +20%.
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The diffusion film 13 may be in form of an optical diffusion coating, which is composed of any one of calcium carbonate, halogen calcium phosphate and aluminum oxide, or any combination thereof. When the optical diffusion coating is made from a calcium carbonate with suitable solution, an excellent light diffusion effect and transmittance to exceed 90% can be obtained.
In some embodiments, the composition of the diffusion film 13 in form of the optical diffusion coating may include calcium carbonate, strontium phosphate, thickener, and a ceramic activated carbon. Specifically, such an optical diffusion coating on the inner circumferential surface of the glass lamp tube 1 has an average thickness ranging from about 20 to about 30 μm. A light transmittance of the diffusion film 13 using this optical diffusion coating may be about 90%. Generally speaking, the light transmittance of the diffusion film 13 may range from 85% to 96%. In addition, this diffusion film 13 can also provide electrical isolation for reducing risk of electric shock to a user upon breakage of the glass lamp tube 1. Furthermore, the diffusion film 13 provides an improved illumination distribution uniformity of the light outputted by the LED light sources 202 such that the light can illuminate the back of the light sources 202 and the side edges of the bendable circuit sheet 205 so as to avoid the formation of dark regions inside the glass lamp tube 1 and improve the illumination comfort. In another possible embodiment, the light transmittance of the diffusion film can be 92% to 94% while the thickness ranges from about 200 to about 300 μm.
In another embodiment, the optical diffusion coating can also be made of a mixture including calcium carbonate-based substance, some reflective substances like strontium phosphate or barium sulfate, a thickening agent, ceramic activated carbon, and deionized water. The mixture is coated on the inner circumferential surface of the glass lamp tube 1 and may have an average thickness ranging from about 20 to about 30 μm. In view of the diffusion phenomena in microscopic terms, light is reflected by particles. The particle size of the reflective substance such as strontium phosphate or barium sulfate will be much larger than the particle size of the calcium carbonate. Therefore, adding a small amount of reflective substance in the optical diffusion coating can effectively increase the diffusion effect of light.
Halogen calcium phosphate or aluminum oxide can also serve as the main material for forming the diffusion film 13. The particle size of the calcium carbonate may be about 2 to 4 μm, while the particle size of the halogen calcium phosphate and aluminum oxide may be about 4 to 6 μm and 1 to 2 μm, respectively. When the light transmittance is required to be 85% to 92%, the required average thickness for the optical diffusion coating mainly having the calcium carbonate may be about 20 to about 30 μm, while the required average thickness for the optical diffusion coating mainly having the halogen calcium phosphate may be about 25 to about 35 μm, the required average thickness for the optical diffusion coating mainly having the aluminum oxide may be about 10 to about 15 μm. However, when the required light transmittance is up to 92% and even higher, the optical diffusion coating mainly having the calcium carbonate, the halogen calcium phosphate, or the aluminum oxide must be thinner.
The main material and the corresponding thickness of the optical diffusion coating can be decided according to the place for which the glass lamp tube 1 is used and the light transmittance required. It is to be noted that the higher the light transmittance of the diffusion film 13 is required, the more apparent the grainy visual of the light sources is.
In some embodiments, the inner peripheral surface or the outer circumferential surface of the glass lamp tube 1 may be further covered or coated with an adhesive film (not shown) to isolate the inside from the outside of the glass lamp tube 1. In this embodiment, the adhesive film is coated on the inner peripheral surface of the glass lamp tube 1. The material for the coated adhesive film includes methyl vinyl silicone oil, hydro silicone oil, xylene, and calcium carbonate, wherein xylene is used as an auxiliary material. The xylene will be volatilized and removed when the coated adhesive film on the inner surface of the glass lamp tube 1 solidifies or hardens. The xylene is mainly used to adjust the capability of adhesion and therefore to control the thickness of the coated adhesive film.
In some embodiments, the thickness of the coated adhesive film may be between about 100 and about 140 micrometers (μm). The adhesive film having a thickness being less than 100 micrometers may not have sufficient shatterproof capability for the glass lamp tube 1, and the glass lamp tube 1 is thus prone to crack or shatter. The adhesive film having a thickness being larger than 140 micrometers may reduce the light transmittance and also increase material cost. The thickness of the coated adhesive film may be between about 10 and about 800 micrometers (μm) when the shatterproof capability and the light transmittance are not strictly demanded.
In some embodiments, the LED tube lamp according to the embodiment of the present invention can include an optical adhesive sheet. Various kinds of the optical adhesive sheet can be combined to constitute various embodiments of the present invention. The optical adhesive sheet, which is a clear or transparent material, is applied or coated on the surface of the LED light source 202 in order to ensure optimal light transmittance. After being applied to the LED light sources 202, the optical adhesive sheet may have a granular, strip-like, or sheet-like shape. The performance of the optical adhesive sheet depends on its refractive index and thickness. The refractive index of the optical adhesive sheet is in some embodiments between 1.22 and 1.6. In some embodiments, it is better for the optical adhesive sheet to have a refractive index being a square root of the refractive index of the housing or casing of the LED light source 202, or the square root of the refractive index of the housing or casing of the LED light source 202 plus or minus 15%, to contribute better light transmittance. The housing/casing of the LED light sources 202 is a structure to accommodate and carry the LED dies (or chips) such as a LED lead frame. The refractive index of the optical adhesive sheet may range from 1.225 to 1.253. In some embodiments, the thickness of the optical adhesive sheet may range from 1.1 mm to 1.3 mm. The optical adhesive sheet having a thickness less than 1.1 mm may not be able to cover the LED light sources 202, while the optical adhesive sheet having a thickness more than 1.3 mm may reduce light transmittance and increases material cost.
In process of assembling the LED light sources to the LED light strip 2, the optical adhesive sheet is firstly applied on the LED light sources 202; then an insulation adhesive sheet is coated on one side of the LED light strip 2; then the LED light sources 202 are fixed or mounted on the LED light strip 2; the other side of the LED light strip 2 being opposite to the side of mounting the LED light sources 202 is bonded and affixed to the inner surface of the lamp tube 1 by an adhesive sheet; finally, the end cap 3 is fixed to the end portion of the lamp tube 1, and the LED light sources 202 and the power supply 5 are electrically connected by the LED light strip 2.
In one embodiment, each of the LED light sources 202 may be provided with a LED lead frame having a recess, and an LED chip disposed in the recess. The recess may be one or more than one in amount. The recess may be filled with phosphor covering the LED chip to convert emitted light therefrom into a desired light color. Compared with a conventional LED chip being a substantial square, the LED chip in this embodiment is in some embodiments rectangular with the dimension of the length side to the width side at a ratio ranges generally from about 2:1 to about 10:1, in some embodiments from about 2.5:1 to about 5:1, and in some more desirable embodiments from 3:1 to 4.5:1. Moreover, the LED chip is in some embodiments arranged with its length direction extending along the length direction of the glass lamp tube 1 to increase the average current density of the LED chip and improve the overall illumination field shape of the glass lamp tube 1. The glass lamp tube 1 may have a number of LED light sources 202 arranged into one or more rows, and each row of the LED light source 202 is arranged along the length direction (Y-direction) of the glass lamp tube 1.
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The hot melt adhesive 6 is a composite including a so-called commonly known as “welding mud powder”, and in some embodiments includes one or more of phenolic resin 2127#, shellac, rosin, calcium carbonate powder, zinc oxide, and ethanol. Rosin is a thickening agent with a feature of being dissolved in ethanol but not dissolved in water. In one embodiment, a hot melt adhesive 6 having rosin could be expanded to change its physical status to become solidified when being heated to high temperature in addition to the intrinsic viscosity. Therefore, the end cap 3 and the lamp tube 1 can be adhered closely by using the hot melt adhesive to accomplish automatic manufacture for the LED tube lamps. In one embodiment, the hot melt adhesive 6 may be expansive and flowing and finally solidified after cooling. In this embodiment, the volume of the hot melt adhesive 6 expands to about 1.3 times the original size when heated from room temperature to about 200 to 250 degrees Celsius. The hot melt adhesive 6 is not limited to the materials recited herein. Alternatively, a material for the hot melt adhesive 6 to be solidified immediately when heated to a predetermined temperature can be used. The hot melt adhesive 6 provided in each embodiments of the present invention is durable with respect to high temperature inside the end caps 3 due to the heat resulted from the power supply. Therefore, the lamp tube 1 and the end caps 3 could be secured to each other without decreasing the reliability of the LED tube lamp.
Furthermore, there is formed an accommodation space between the inner surface of the thermal conductive member 303 and the outer surface of the lamp tube 1 to accommodate the hot melt adhesive 6, as indicated by the dotted line B in
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In one embodiment, for the sake of securing adhesion between the end cap 3 and the lamp tube 1, the second tubular part 302b is at least partially disposed around the lamp tube 1, and the accommodation space further includes a space encompassed by the inner surface of the second tubular part 302b and the outer surface of the rear end region 101 of the lamp tube 1. The hot melt adhesive 6 is at least partially filled in an overlapped region (shown by a dotted line “A” in
The hot melt adhesive 6 is not required to completely fill the entire accommodation space as shown in
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In addition, in some embodiments, the length of the LED light strip 2 is greater than that of the sum of the rear end region 101, the main body region 102, and the transition region 103 of the lamp tube 1 along the axial direction of the LED tube lamp. The freely extending end portions 21 of the LED light strip 2 extends beyond the rear end region 101 towards inside of the end cap 3 while the LED light strip 2 is properly positioned in the lamp tube 1.
The above-mentioned features of the present invention can be accomplished in any combination to improve the LED tube lamp, and the above embodiments are described by way of example only. The present invention is not herein limited, and many variations are possible without departing from the spirit of the present invention and the scope as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201410734425.5 | Dec 2014 | CN | national |
| 201510075925.7 | Feb 2015 | CN | national |
| 201510136796.8 | Mar 2015 | CN | national |
| 201510259151.3 | May 2015 | CN | national |
| 201510324394.0 | Jun 2015 | CN | national |
| 201510338027.6 | Jun 2015 | CN | national |
| 201510373492.3 | Jun 2015 | CN | national |
| 201510448220.5 | Jul 2015 | CN | national |
| 201510482944.1 | Aug 2015 | CN | national |
| 201510483475.5 | Aug 2015 | CN | national |
| 201510499512.1 | Aug 2015 | CN | national |
| 201510555543.4 | Sep 2015 | CN | national |
| 201510557717.0 | Sep 2015 | CN | national |
| 201510595173.7 | Sep 2015 | CN | national |
| 201510645134.3 | Oct 2015 | CN | national |
| 201510716899.1 | Oct 2015 | CN | national |
| 201510726365.7 | Oct 2015 | CN | national |
| 201510868263.9 | Dec 2015 | CN | national |
This application is a continuation application of U.S. patent application Ser. No. 17/076,831, filed on 2020 Oct. 22, which is a continuation application of U.S. patent application Ser. No. 16/719,861, filed on 2019 Dec. 18, which is a continuation application of U.S. patent application Ser. No. 16/051,826, filed on 2018 Aug. 1, which is a continuation-in-part (CIP) application claiming benefit of non-provisional application Ser. No. 15/087,092, filed on 2016 Mar. 31, which is a continuation-in-part (CIP) application claiming benefit of PCT Application No. PCT/CN2015/096502, filed on 2015 Dec. 5; and non-provisional application Ser. No. 15/437,084, filed on 2017 Feb. 20, which is a continuation application claiming benefit of non-provisional application Ser. No. 15/056,106, filed on 2016 Feb. 29, claiming benefit of PCT Application No. PCT/CN2015/096502, filed on 2015 Dec. 5 This application claims priority to Chinese Patent Applications No. CN 201410734425.5 filed on 2014 Dec. 5; CN 201510075925.7 filed on 2015 Feb. 12; CN 201510136796.8 filed on 2015 Mar. 27; CN 201510259151.3 filed on 2015 May 19; CN 201510324394.0 filed on 2015 Jun. 12; CN 201510338027.6 filed on 2015 Jun. 17; CN 201510373492.3 filed on 2015 Jun. 26; CN 201510448220.5 filed on 2015 Jul. 27; CN 201510482944.1 filed on 2015 Aug. 7; CN 201510483475.5 filed on 2015 Aug. 8; CN 201510499512.1 filed on 2015 Aug. 14; CN 201510555543.4 filed on 2015 Sep. 2; CN 201510557717.0 filed on 2015 Sep. 6; CN 201510595173.7 filed on 2015 Sep. 18; CN 201510645134.3 filed on 2015 Oct. 8; CN 201510716899.1 filed on 2015 Oct. 29 CN 201510726365.7 filed on 2015 Oct. 30, and CN 201510868263.9 filed on 2015 Dec. 2, the disclosures of which are incorporated herein in their entirety by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17076831 | Oct 2020 | US |
| Child | 18426351 | US | |
| Parent | 16719861 | Dec 2019 | US |
| Child | 17076831 | US | |
| Parent | 16051826 | Aug 2018 | US |
| Child | 16719861 | US | |
| Parent | 15056106 | Feb 2016 | US |
| Child | 15437084 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15437084 | Feb 2017 | US |
| Child | 16051826 | US | |
| Parent | PCT/CN2015/096502 | Dec 2015 | WO |
| Child | 15056106 | US | |
| Parent | 15087092 | Mar 2016 | US |
| Child | 16051826 | US | |
| Parent | PCT/CN2015/096502 | Dec 2015 | WO |
| Child | 15087092 | US |
