KR20100103016A - Tubular diffusive cover for led illumination and led illuminating lamp comprising the same - Google Patents

Abstract

PURPOSE: A tubular diffusive unit for a light emitting diode(LED) lamp and the LED lamp including the same are provided to obtain an anti-static function by forming a functional layer on the external side or the internal side of the diffusing unit. CONSTITUTION: A tubular diffusive unit for an LED lamp includes 0.1 to 10 parts by weight of a light-diffusive agent. The light-diffusive agent with 0.5 to 3.5um of an average diameter is included in a thermoplastic resin. The diffusive unit includes 53 to 84% of the light diffusing rate and 210 to 440Lux of the illuminance. The average diameter of the light-diffusive agent is between 1 and 3um. The refractive index is between 1.2 and 1.6.

Description

TUBULAR DIFFUSIVE COVER FOR LED ILLUMINATION AND LED ILLUMINATING LAMP COMPRISING THE SAME}

The present invention relates to a tubular diffusing member for LED lighting, including a light diffusing agent having a specified average particle diameter and content, and showing an excellent light diffusing rate and illuminance, and an LED lamp having the same.

Recently, attention has been paid to light emitting diodes (hereinafter, abbreviated as "LED elements") including semiconductor elements as light sources of various lighting devices. These LED devices have advantages such as low heat generation and long life compared to conventional lighting such as incandescent lamps, and thus have recently been utilized in various fields as lightings for displays, general lighting devices and automotive headlights. have.

On the other hand, LED lighting may be used as a light that sometimes shows a point light source image for aesthetics, but generally aims to show the light of the surface light source image.

At this time, since the amount of light that can be generated in the LED device must be limited, the surface light source image is composed using dozens or hundreds of LED devices, or if the light is diffused to the diffusion member through which the light emitted from the LED device is transmitted. There is a method of constructing a light source image. The use of tens or hundreds of LED elements can provide a sufficient amount of light, but the cost is not competitive. Therefore, there is a demand for a method capable of efficiently diffusing light emitted from the LED device.

In order to solve this problem, conventionally, a light diffuser including a light diffusing agent and a light guide plate integrally formed with a light guide plate are disclosed. However, the lamp has a light diffusion rate and illuminance as the light emitted from the LED device passes through the light guide plate and the light diffusion plate, and the manufacturing process is cumbersome because the light guide plate and the light diffusion plate are separately manufactured and combined.

In addition, conventionally disclosed molded articles made of a resin composition using inorganic particles having different average particle diameters as light diffusing agents. However, since the resin composition aggregates particles having different particle diameters during extrusion molding, light scatters when the light penetrates or diffuses the molded article, and thus the light diffusion rate is not excellent. In addition, the light diffusing agent is difficult to be dispersed in the resin because the particle size is different from each other.

Disclosure of Invention An object of the present invention is to provide a diffusion member for LED lighting that satisfies both excellent light diffusion rate and illuminance simultaneously, including a light diffusing agent having a specified refractive index and an average particle diameter.

In addition, another object of the present invention to provide an LED lamp having the diffusion member.

A tubular diffusing member for LED lighting comprising 0.1 to 10 parts by weight of a light diffusing agent having an average particle diameter of 0.5 to 3.5 μm in a thermoplastic resin, and has a light diffusing ratio of 53 to 84% and an illuminance of 210 to 440 Lux.

In addition, the present invention provides an LED lamp having the diffusion member.

Contrary to the conventional high light diffusion rate, the illuminance is lowered, the diffusion member of the present invention is formed in a tubular shape, and includes a light diffusing agent having a specified refractive index and an average particle diameter, thereby satisfying excellent illuminance and light diffusion rate. Therefore, the diffusion member diffuses the light to the surface light source image such that the light emitted from the LED element is not visible to the naked eye, and provides bright light. In addition, the LED lamp is provided with a functional layer on the outside or the inside of the diffusion member can be satisfied at the same time excellent illuminance and light diffusion rate while providing functionality such as antistatic.

The present invention relates to an LED lighting diffuser and an LED lighting lamp having the same, including a light diffusing agent having a specified average particle diameter and content, which exhibits excellent diffusion rate and illuminance to diffuse light into a surface light source image and provide bright light.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is a tubular diffusion member (hereinafter, referred to as a 'diffusion member') for LED lighting including a thermoplastic resin and a light diffusing agent, characterized in that it satisfies the light diffusion rate of 53 to 84% and the illuminance of 210 to 440 Lux at the same time. Since the tubular diffuser is formed on the front surface to surround the LED element, there is less light loss than the case of the plate, and the light is evenly reflected on the entire diffuser, thereby improving the illuminance and light diffusivity of the diffuser. Can be. That is, in the case of the light diffusion rate, the light diffusion rate of the diffusion member itself is also excellent, but may be better depending on the shape of the diffusion member.

In addition, the diffusion member may further include additives such as an antistatic agent, an ultraviolet absorber, a light stabilizer, and an antioxidant.

Hereinafter, each component contained in the diffusion member of this invention is demonstrated in detail.

Thermoplastic resins can be used all of the conventional resins used in the art, in particular, excellent in transparency or translucency, light transmittance, durability, thermal stability, etc., for example, acrylic resin, styrene-acrylic copolymer resin, Resin selected from styrene resin, styrene-acrylonitrile resin, polycarbonate resin, and olefin resin can be used individually or 2 types or more.

As said acrylic resin, Methacrylic acid alkyl ester, such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, and 2-ethylhexyl methacrylate; Alkyl acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate; Methacrylic acid cycloalkyl esters such as cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate and dicyclopentanyl methacrylate; Acrylic acid cycloalkyl esters such as cyclohexyl acrylate and 2-methylcyclohexyl acrylate; Methacrylic acid aryl esters such as phenyl methacrylate and benzyl methacrylate; And any homopolymer or copolymer thereof selected from acrylic acid aryl esters such as phenyl acrylate and benzyl acrylate.

As the styrene-acrylic copolymer resin, one or two or more selected from methacrylic acid alkyl ester, acrylic acid alkyl ester, methacrylic acid cycloalkyl ester, acrylic acid cycloalkyl ester, methacrylic acid aryl ester and acrylic acid aryl ester and styrene and one or two or more copolymers selected from α-methylstyrene, m-methylstyrene, p-methylstyrene, and p-methoxystyrene.

Examples of the styrene resins include any one homopolymer or a copolymer thereof selected from styrene, α-methyl styrene, m-methyl styrene, p-methyl styrene, and p-methoxy styrene.

As the styrene-acrylonitrile copolymer resin, one or two or more selected from styrene, α-methyl styrene, m-methyl styrene, p-methyl styrene and p-methoxy styrene and an acrylonitrile monomer Coalescence is mentioned.

The polycarbonate resin may be a linear and branched aromatic polycarbonate homopolymer, a polyester copolymer or a mixture of one or more thereof prepared by reacting dihydroxy phenol with phosgene or by reaction of dihydroxy phenol with a carbonate precursor. A group consisting of:

The olefin resin may include one or two or more copolymers selected from polyethylene, polypropylene, and polyisobutylene.

It is preferable that the light diffusing agent exhibits an excellent light diffusing effect, thereby improving illuminance and having a wide light distribution. The light diffusing agent may use all conventional light diffusing agents used in the art, and in particular, organic particles, inorganic particles or hollow particles may be used alone or in combination. Specifically, for example, silicon-based, acrylic-based, styrene-based, methyl methacrylate-styrene copolymers, polycarbonate-based, olefin-based crosslinked or uncrosslinked fine particles, silica, talc, calcium carbonate, barium sulfate, titanium dioxide (TiO ₂ ), One or two or more types selected from glass can be used in combination, and they are silicone type and acrylic type preferably.

The refractive index of the light diffusing agent is 1.2 to 1.6, preferably 1.3 to 1.5. If the refractive index is less than 1.2 or more than 1.6, sufficient light diffusing function cannot be given.

In addition, the difference in specific gravity between the light diffusing agent and the thermoplastic resin is preferably 1 or less. At this time, if the difference in specific gravity exceeds 1, it is difficult to form a diffusion member in which the diffusion agent is uniformly mixed.

In addition, the light diffusing agent has an average particle diameter of 0.5 to 3.5 ㎛, preferably 1 to 3 ㎛ in terms of obtaining sufficient light diffusing properties, the particle diameter may vary depending on the optical properties. If the average particle diameter of the light diffusing agent is less than 0.5 μm, light passing through the diffusing member is not diffused due to the straightness. When using the average particle diameter of 0.5 to 3.5 μm, light passing through the diffusing member is diffused to 180 °. Good light distribution characteristics are exhibited. In addition, in the case where the average particle diameter is more than 3.5 mu m, the diffusion rate itself is high, but a large amount of addition is required, which is not economical. When the light is not diffused sufficiently, the point light source image as shown in (a) of FIG. 1 is shown. When the light is diffused by optimizing an appropriate amount of additives, while protecting the image of the surface light source, a high illuminance value (Lux) is secured. A surface light source image as shown in FIG. 1 (b) is shown.

In addition, the content of the light diffusing agent is 0.1 to 10 parts by weight, preferably 0.1 to 7 parts by weight based on 100 parts by weight of the thermoplastic resin. In this case, when the content is less than 0.1 part by weight, the incident light may not be sufficiently diffused. If the content is more than 10 parts by weight, the transmittance of the light may be lowered and high luminance may not be exhibited.

Such a light diffusing agent is not present in a high concentration in a portion of the diffusion member, but is present throughout the diffusion member.

The diffusion member may further include an additive consisting of an antistatic agent, an ultraviolet absorber, a light stabilizer, and an antioxidant alone or in combination of two or more thereof.

The additive may be used, but it is preferable to add the additive to improve the functionality of the diffusion member.

The content of the additive may be included in an amount of 0.1 to 25 parts by weight, preferably 0.1 to 6 parts by weight, based on 100 parts by weight of the thermoplastic resin.

1A is a view of a diffusion member using a light diffusing agent having a small average particle diameter, and FIG. 1B is a view of a diffusion member according to a preferred embodiment of the present invention.

FIG. 1A illustrates light passing through a diffusion member including a light diffusion agent having an average particle diameter of less than 0.5 μm, and FIG. 1B illustrates a diffusion member including a light diffusion agent having a refractive index of 1.2 to 1.6 and an average particle diameter of 0.5 to 3.5 μm. It shows the light passing through.

As shown in FIG. 1, the diffusion member of FIG. 1A does not diffuse light emitted from the LED device to represent light of a point light source image. In addition, the diffusion member of FIG. 1B diffuses the light to the extent that it is not visible to the naked eye to represent the light of the surface light source image.

2 is a perspective view of a diffusion member according to a preferred embodiment of the present invention.

As shown in Figure 2, the diffusion member 100 of the present invention is provided with a heat sink 10 in the rear.

The diffusion member 100 is provided in front of the LED element 21 to diffuse the light emitted from the LED element 21.

The diffusion member 100 is not limited to the shape, and may be any conventional shape as long as it is not a flat type such as a semi-circle, a ridge, a dent, or the like.

In order to manufacture the diffusion member 100, all conventional methods used in the art may be used, and a single extrusion method or a double extrusion method is preferable.

Here, the single-layer extrusion method includes the step of injecting the resin composition for the diffusion member by melt-kneading and cooling, thereby producing a diffusion member having a single layer cross section. In addition, the double extrusion method includes a step of injecting, respectively kneading, kneading, kneading, spreading, and spreading the resin composition for the diffusion member and the resin composition for the functional, and further comprising a multi-functional layer on the outside or the inside of the diffusion member. Can be.

The resin composition for the diffusion member and the resin composition for the function are used as a resin composition having strong bonding strength to each other, and the same resin composition or different resin compositions may be used. In addition, additives such as an antistatic agent, an antioxidant, and a heat stabilizer can be added to the functional resin composition to impart functionality to the LED lamp.

The thickness of the diffusion member 100 and the member composed of the functional layer and the diffusion member 100 is generally 0.5 to 2.0 mm in consideration of workability such as strength and handleability, and preferably 1.0 to 1.5 mm. .

The diffusion member 100 of the present invention is excellent in the light diffusion rate and illuminance, so that the light emitted from the LED element 21 is diffused to the extent that it is not visible to the naked eye, and provides bright light.

At this time, the light diffusion rate of the diffusion member 100 is 53 to 84%, preferably 53 to 71%. In addition, the roughness is 210 to 440 Lux, preferably 300 to 370 Lux. The total light transmittance is 45 to 64%, preferably 50 to 60%.

The heat sink 10 is provided at the rear of the LED element 21, all of the conventional heat sinks used in the art may be used, and specific examples may be a metal or resin such as aluminum.

LED lamp of the present invention is characterized in that the diffusion member is provided.

In the present invention, since the LED lamp is well known to those skilled in the art of the present invention, a detailed description of each configuration is omitted.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

In the following Examples and Comparative Examples, "%" and "parts" indicating contents are by weight unless otherwise specified.

Example 1

In order to manufacture the resin composition (A) for the diffusion member, 100 parts of styrene (HRM40, oriental styrene) which is a thermoplastic resin, 2 parts of acrylic particles having an average particle diameter of 3 µm and a refractive index of 1.5 as a light diffusing agent, 1 part of an ultraviolet absorber, and an optical eye One part of the tablets was mixed.

A single-layer diffusion member was manufactured by single-extrusion of the resin composition (A) for diffusion member prepared above in a mold formed in a semicircle at 200 to 260 ° C. At this time, the thickness of the diffusion member is 1.2 mm.

Example 2

In the same manner as in Example 1, a resin composition (A) for diffusion members was prepared.

In order to manufacture the functional resin composition (B), 100 parts of thermoplastic resin PMMA (MX-1000, Soken Chemical) and 2 parts of heat stabilizers were mixed.

The resin composition for diffusion members (A) and the functional resin composition (B) manufactured in a semi-circular mold were double-extruded at 200 to 260 ° C. to prepare a spread member and a strength improving layer. At this time, the functional layer is formed outside or inside the diffusion member. The thickness of the diffusion member is 1.15 mm and the thickness of the functional layer is 0.05 mm.

Example 3

A diffusion part was prepared in the same manner as in Example 1 except for using one part of the light diffusing agent.

Comparative Example 1

A diffusion member was manufactured in the same manner as in Example 1, without using a light diffusing agent.

Comparative Example 2

A diffusion member was prepared by mixing 100 parts of thermoplastic resin, 2 parts of PMMA having an average particle diameter of 5 to 6 µm and a refractive index of 1.49 as a light diffusing agent.

Comparative Example 3

A diffusion member was manufactured in the same manner as in Example 1, using 11 parts of a light diffusing agent.

Comparative Example 4

A diffusion member was manufactured in the same manner as in Example 1, using a light diffusing agent having an average particle diameter of 0.3 μm.

Comparative Example 5

The diffusion member was manufactured in the same manner as in Example 1, using a light diffusing agent having an average particle diameter of 20 μm.

Test Example

The physical properties of the diffusion members prepared in Examples and Comparative Examples were measured by the following method, and the results are shown in Table 1 below.

(1) Total light transmittance (%)

Each of the prepared samples were processed by 60x60mm 5 each and stored for 24 hours at constant temperature and humidity (25 ℃, 50% Rh) and then measured using a haze meter (HRM-150, Murakami).

 (2) Light diffusion rate (%)

The light diffusivity is calculated by inputting the transmittance measured by passing light at 5 °, 20 °, and 70 ° to a sample made of a variable angle photometer (GC 5000L).

(3) Lux

Measure illuminance using an illuminometer (LUX METER 51001, Yokogawa).

(4) image improvement

After mounting the LED module in the manufactured diffusion member, the image of the light source was visually observed and evaluated based on the following criteria.

○: surface light source is realized without any point light source.

(Triangle | delta): Some point light source exists.

X: Many point light sources exist.

Light rays
Transmittance (%) Light Diffusion Rate (%) Lux Image enhancement Street 1.0m 1.5m 2.0m 3.0m Example 1 56 69 369 198 132 77 ○ Example 2 52 71 360 191 125 73 ○ Example 3 64 53 427 231 150 84 ○ Comparative Example 1 90 2 515 284 177 96 X Comparative Example 2 64 47 361 191 125 74 △ Comparative Example 3 45 84 203 106 68 38 ○ Comparative Example 4 66 51 440 235 150 89 X Comparative Example 5 58 64 382 208 131 78 △

As shown in Table 1, the diffusion members of Examples 1 to 3 prepared according to the embodiment of the present invention was confirmed that the total light transmittance, light diffusion rate and illuminance are excellent at the same time. In addition, the roughness was confirmed to be 5 to 20% superior to the comparative example. Examples 1 to 3 confirmed that the light can be diffused to the surface light source image.

Even if the functional layer is additionally provided inside or outside the diffusion member, only the diffusion member of the present invention can satisfy both excellent light diffusion rate, illuminance, and surface light source image.

On the other hand, Comparative Examples 1 to 4 confirmed that the total light transmittance, light diffusion rate and illuminance were not excellent at the same time. Particularly, Comparative Example 1 does not use a diffusing agent, but may have excellent illuminance but low light diffusion rate. In Comparative Example 5, light may be mixed with a point light source and a surface light source image even though the light diffusion rate and illuminance may be excellent. there is a problem.

3 is a light diffusion distribution chart measuring angles of light passing through a diffusion member with a variable photometer. This is for the light diffusion at a total of 180 ° left and right 90 ° with a light exit direction of 0 °, which means that the broader and rounder the light diffusion characteristics are. In particular, the Y axis represents the intensity of light. As shown in FIG. 3, Comparative Example 2 has better light distribution characteristics than Comparative Example 3, but is not satisfactory. Comparative Example 3 is prepared by adding an excess diffusion agent. weak.

On the other hand, it can be seen that Example 1 has a high light diffusion rate and illuminance because the intensity is large while the left and right diffusion widths are wide.

As described above, the diffusion member of the present invention is excellent in light diffusion and diffuses light into a surface light source, and has excellent illuminance, and can be used as various lightings such as LED lighting, signboards, and interior and exterior lighting.

1A is a view of a diffusion member using a light diffusing agent having a small average particle diameter,

1B is a view of a diffusion member according to a preferred embodiment of the present invention,

2 is a perspective view of a diffusion member according to a preferred embodiment of the present invention;

3 is a view showing a light diffusion distribution of a diffusion member according to a preferred embodiment of the present invention.

** Description of the major symbols in the drawings **

10: heatsink 20: LED module

21: LED element 22: substrate

100: diffusion member

Claims (10)

A tubular diffusing member for LED lighting comprising 0.1 to 10 parts by weight of a light diffusing agent having an average particle diameter of 0.5 to 3.5 μm in a thermoplastic resin, wherein the diffusing member has a light diffusivity of 53 to 84% and an illuminance of 210 to 440 Lux. The diffusion member of claim 1, wherein the average particle diameter of the light diffusing agent is 1 to 3 μm. The diffusion member of claim 1, wherein the light diffusing agent has a refractive index of 1.2 to 1.6. The diffusion member of claim 1, wherein the light diffusing agent has a refractive index of about 1.3 to about 1.5. The light diffusing agent according to claim 1, wherein the light diffusing agent is a silicon-based, acrylic-based, styrene-based, methyl methacrylate-styrene copolymer-based, polycarbonate-based, olefin-based crosslinked or uncrosslinked fine particles, silica, talc, calcium carbonate, barium sulfate, titanium dioxide And a diffusion member selected from the group consisting of glass. The diffusion member according to claim 1, wherein the light diffusing agent is one selected from the group consisting of silicon-based and acrylic-based. The diffusion member of claim 1, wherein the thermoplastic resin is at least one member selected from the group consisting of an acrylic resin, a styrene-acrylic copolymer resin, a styrene resin, a styrene-acrylonitrile resin, a polycarbonate resin, and an olefin resin. The diffusion member according to claim 1, wherein at least one additive selected from the group consisting of an antistatic agent, an ultraviolet absorber, a light stabilizer, and an antioxidant is added in an amount of 0.1 to 25 parts by weight based on 100 parts by weight of the thermoplastic resin. The diffusion member of claim 1, wherein the diffusion member represents a surface light source image. An LED lamp having a diffusion member according to any one of claims 1 to 9.

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