KR100988626B1 - Light pipe and illuminating device comprising the same - Google Patents

Abstract

The present invention relates to a light pipe and a lighting device having the same. The light pipe and the lighting apparatus having the same according to the present invention include an optical film rolled to have a hollow including a plurality of prisms and extending in the longitudinal direction of the prism, and a support member surrounding the optical film. The prism side of either prism has a maximum surface roughness of 600 nm to 1.5 μm. Thereby, the light can be uniformly emitted to a long distance by using the diffraction of the light to make the luminance uniform.

Prism, Surface Roughness, Optical Film, Lighting

Description

 Light pipe and illuminating device comprising the same

The present invention relates to a light pipe and a lighting apparatus having the same, and more particularly, to a light pipe including an optical film having a surface roughness of a prism within a predetermined range and a lighting apparatus having the same.

Background Art Lighting devices using light pipes that can transmit light at a relatively small transmission loss over long distances are known in the art. Light pipes, also called light conduits, light guides or light tubes, are used to effectively distribute decorative or functional light over a relatively large area.

Light pipes are used for the purpose of illuminating any area, as well as the use of point illumination for illuminating a particular point. Light traveling inside the light pipe can be distributed to the outside to illuminate specific areas or to maximize decorative effects.

However, it is difficult to properly control the transmission of light inside the light pipe and the emission of light to the outside, making it difficult to obtain uniform luminance along the longitudinal direction of the light pipe.

Therefore, there is a need for a light pipe having a structure that can easily manufacture a light pipe and that can transmit and emit light to a long distance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a light pipe using a light pipe having a uniform brightness along the longitudinal direction of the light pipe and a lighting device having the same.

According to an aspect of the present invention, there is provided a light pipe including a plurality of prisms, the optical film rolled to have a hollow extending in the longitudinal direction of the prism, and a support member surrounding the optical film. The prism side of any one of the prism of is characterized in that it has a maximum surface roughness of 600nm to 1.5㎛.

The lighting apparatus according to the present invention for achieving the above object comprises a light source unit and a light pipe for transmitting and distributing light from the light source unit, the light pipe includes a plurality of prisms and extend along the longitudinal direction of the prism An optical film rolled to have a hollow, and a supporting member surrounding the optical film, wherein the prism side of any one of the plurality of prisms has a maximum surface roughness of 600 nm to 1.5 μm.

According to the present invention, the surface roughness of the prism of the optical film has a predetermined range, whereby uniform light is emitted throughout the light pipe, and at the same time excellent light transmittance.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

1 is a cross-sectional view of a portion of an optical film to illustrate the transmission and reflection of light in a light pipe in connection with the present invention, and FIG. 2 illustrates the transmission and reflection of light in a light pipe in connection with the present invention. It is a perspective view which shows a part of optical film for that. However, for ease of understanding, the structured outer surface is shown as the upper side and the structured outer surface is shown as the lower side.

First, referring to FIGS. 1 and 2, light from a light source (not shown) is incident and refracted by an unstructured inner surface of the optical film as shown by an arrow (one point), and total reflection at both sides of the structured outer prism (2 and 3 points), whereby the outwardly directed light is refracted at the inner surface (4 points) and input back into the interior. When the total reflection process is repeated, light proceeds substantially along the longitudinal direction of the light pipe. In the air inside the light pipe, almost no light loss occurs. Thus, light can be transmitted through the light pipe at almost short distance as well as at a short distance.

3 is a partial cutaway perspective view of a lighting apparatus according to an embodiment of the present invention.

Referring to the drawings, the lighting device 300 according to the present embodiment may include a light source unit 310, a light pipe 320, and may further include a reflective cap 330.

The light source unit 310 is a module that generates light and inputs it to the light pipe 320, and may include at least one lamp (not shown) that generates light. Light generated by the light source unit 310 is input to the light pipe 320 and output to the outside.

The light pipe 320 receives light from the light source unit 310 and transmits and distributes the light to output the light to the outside. The light pipe 320 may include an optical film 322 and a support member 324 to evenly distribute the light generated by the light source unit 310 by reflecting or refracting the light.

The optical film 322 includes a surface structured by a plurality of prisms and the like, and is used by being rolled to have a hollow extending along the longitudinal direction (y direction) of the prism. The optical film 322 may transmit light to an area spaced apart from the light source 310 by reflecting or refracting the light generated by the light source 310.

In the case where the surface to be structured is a prism, the surface roughness of the side of the prism, in particular the peak to vally (PV) of the side of the prism, is preferably 600 nm to 1.5 μm. If the maximum surface roughness (PV) is smaller than 600 nm, the diffuse reflection effect is reduced, making it difficult to emit uniform light through the optical film 322, whereas when the maximum surface roughness (PV) is larger than 1.5 µm, the light transmittance is Can be degraded.

A detailed description of the surface roughness of the prism of the optical film 322 will be described later with reference to FIGS. 5 and 6.

The reflective cap 330 is attached to one end of the light pipe 320 to reflect light transmitted and distributed by the light pipe 320. The reflective cap 330 is preferably attached to one end of the light pipe 320 that is not connected to the light source unit 310, that is, to the opposite side of the light source unit 310, and provides light to the inside connected to the light pipe 320. The reflector may reflect the light transmitted by the light pipe 320 to the inside of the light pipe 320. By confining the light in the light pipe 320 using the reflective cap 330, the brightness of the light output from the lighting device 300 can be increased.

FIG. 4 is a cross-sectional view illustrating a cross section along AA ′ of the lighting apparatus shown in FIG. 3.

Referring to the drawings, the lighting device 300 according to the present embodiment, the light source unit 310 including the housing 316, the light source 312, the reflector 314, the optical film 322, the support member. The light pipe 320 may include a 324, and may further include a reflective cap 330 including a cap 332 and a reflector 334.

The light source unit 310 stores a light source 312 that outputs light, a reflector 314 that reflects the light output by the light source 312, and guides the light pipe 320 to the light pipe 320, and the light source 312 and the reflector 314. It may include a housing 316 to.

The light source 312 is a lamp for generating light, and may use various types of lamps according to an environment in which the light pipe 320 is disposed. For example, a halogen lamp, a light emitting diode, a metal halide lamp, a plasma lighting source, or the like may be used as the light source 312.

The reflector 314 may be disposed behind the light source 312 and may include a metal material such as aluminum or silver having excellent reflectance on the surface. The structure of the reflector 314 is not particularly limited, but is preferably determined corresponding to the length of the lighting device 300, and may be formed as an aspheric reflector. For example, the reflectance can be increased by forming the reflector 314 into a non-caliber reflector and forming a film containing a metal material such as aluminum or silver on the surface of the reflector 314 corresponding to the light source 312. .

The housing 316 may include a space for accommodating the light source 312 and the reflector 314 therein, and may protect the light source 312 and the reflector 314 from an external impact or foreign matter. In order to protect the light source 312 and the reflector 314, the housing 316 is preferably formed of a material having excellent strength, heat dissipation characteristics, and workability.

The light pipe 320 is optically connected to the light source unit 310, and receives and transmits and distributes the light generated by the light source unit 310. The light pipe 320 may include an optical film 322 that includes a structured surface that reflects or refracts light, and a support member 324 that surrounds the optical film 322. The optical film 322 is rolled to have a hollow 380. The optical film 322 may have a surface corresponding to the support member 324, and transmit and distribute the light output from the light source unit 310 so that the light is evenly output from the light pipe 320.

The reflective cap 330 may include a cap 332 attached to one end of the light pipe 320 and a reflector 334 disposed in the cap 332 to reflect light transmitted by the light pipe 320. The reflector 334 may include a coating film including a metal material having a high reflectance such as aluminum or silver so as to efficiently reflect light transmitted by the light pipe 320. The reflector 334 may have a planar or spherical shape, and when formed in a spherical shape, it is preferable that the reflector 334 is a concave mirror having a curvature of 0.001 or less.

FIG. 5 is a cross-sectional view showing an example of a B-B 'cross section of the light pipe shown in FIG.

Referring to FIG. 5, the light pipe 320 according to the present embodiment may include an optical film 322 including a plurality of prisms, and a support member 324 surrounding the optical film 322.

That is, the optical film 322 may include a first surface 322a structured by a plurality of prisms and a second surface 322b facing the first surface 322a. In particular, the prism may extend in the longitudinal direction of the light pipe 320 and may have an isosceles triangle, equilateral triangle, or trapezoid shape. Meanwhile, the prism of the optical film 322 may be disposed outside. That is, the first surface 322a of the optical film 322, specifically, apex of each of the plurality of prisms 322p may be disposed to face the support member 324. In addition, the optical film 322 is rolled to have a hollow 380. Although shown in the figure as being roundly rolled, the present invention is not limited thereto and may be rolled into various shapes such as polygons.

The support member 324 may be made by coating, extrusion, injection, molding or roll processing. For example, after the resin is formed into a film by coating, extruding, injection, molding or roll processing, the resin is rolled into a cylindrical shape to form the support member 324, or the resin is extruded through extrusion. The support member 324 may be made by drawing out a cylindrical shape. In addition to the support member 324 can be made in various ways.

The support member 324 is disposed outside the optical film 322 to surround the optical film 322 to protect the optical film 322 from dust that may be introduced from the outside or impact that may be applied from the outside.

It is preferable that the optical film 322 contains the thermoplastic resin material which is excellent in the light transmittance and excellent in impact resistance, heat resistance, etc. For example, the optical film 322 may include polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), or the like. In particular, the polycarbonate is high in strength, not easily broken, and easily deformed, and has high visible light transmittance, making it suitable as a material of the optical film 322.

On the other hand, the support member 324 may be composed of at least one polymeric material selected from the group consisting of polycarbonate (PC), polymethyl methacrylate (PMMA), acrylic, polypropylene, polystyrene and polyvinyl chloride. .

On the other hand, in the context of the present invention, the more uniform the surface of the prism of the optical film 322, the less the diffuse reflection effect, the more difficult it is to emit uniform light through the light pipe 320, the more uneven the surface of the prism, The light transmittance may be lowered.

Therefore, in the present invention, the surface roughness of the prism is used to describe the uniformity of the surface of the prism. Specifically, the surface roughness of the prism means the surface roughness of the side surface 322s of the prism. Of the surface roughnesses of the side surfaces 322s of the prism, peak to vally (PV) means the difference between the peak (maximum) and the valleys (minimum values) of the prism side surfaces.

Table 1 below shows experimental results for the brightness and light transmittance of the optical film 322 according to the maximum surface roughness PV of the side surface 322s of the prism 322p.

Surface roughness (PV) Surface luminance of light source (cd / ㎡) Light pipe termination luminance (cd / ㎡) Light transmittance 500 nm 6000 5000 ◎ 600 nm 5950 5430 ○ 700 nm 5900 5450 ○ 800 nm 5860 5460 ○ 900 nm 5830 5490 ○ 1㎛ 5790 5500 ○ 1.1 μm 5760 5500 ○ 1.2 μm 5740 5510 ○ 1.3 μm 5720 5510 ○ 1.4 μm 5710 5515 ○ 1.5 μm 5700 5520 ○ 1.6 μm 5690 5520 ×

As shown in Table 1, when the maximum surface roughness (PV) is smaller than 600 nm, the diffuse reflection effect is inferior, so that the difference between the surface luminance of the light source unit and the light pipe terminal luminance is remarkably large, and is uniform throughout the entire surface of the light pipe 320. It becomes difficult to emit light.

On the other hand, when the maximum surface roughness PV is larger than 1.5 micrometers as shown in Table 1, surface roughness will become large too much and the light transmittance of the light pipe 320 whole including the optical film 322 will fall.

Accordingly, the maximum surface roughness PV of the prism 322p of the optical film 322 is preferably in the range of 600 nm to 1.5 μm. Within this range, the light pipe 320 including the optical film 322 can efficiently transmit light to the end of the light pipe 320, and the light transmittance is also good.

On the other hand, it is also possible to describe using the root mean square (RMS) surface roughness as the surface roughness of the side surface 322s of the prism 322p. RMS surface roughness may be defined as in the following equation.

Here, RMS denotes the RMS surface roughness of the prism side 322s, L denotes the length of the prism side 322s, and z denotes the surface centerline 322c of the prism side 322s and the actual prism surface 322s. Indicates distance.

That is, the RMS surface roughness is calculated by dividing the value obtained by integrating the squared distance from the surface center line 322c of the prism side surface 322s of the optical film 322 by the length L of the side surface of the prism 322p, and again calculating the square root. Can be defined as one value.

Table 2 below shows the experimental results for the brightness and light transmittance of the optical film 322 according to the RMS surface roughness of the prism side surface 322s.

RMS surface roughness Surface luminance of light source (cd / ㎡) Light pipe termination luminance (cd / ㎡) Light transmittance 30 nm 5950 5120 ◎ 32nm 5900 5180 ◎ 33 nm 5880 5460 ○ 35 nm 5870 5460 ○ 40 nm 5865 5465 ○ 50 nm 5860 5468 ○ 70 nm 5750 5470 ○ 100 nm 5720 5475 ○ 120 nm 5715 5478 ○ 150 nm 5700 5490 ○ 170 nm 5690 5500 ○ 200 nm 5670 5510 ○ 210 nm 5660 5515 ×

As shown in Table 2, when the RMS surface roughness is less than 33 nm, the diffuse reflection effect is inferior, so that the difference between the surface luminance of the light source and the light pipe end luminance is significantly increased, and uniform light is emitted through the entire surface of the light pipe 320. It is difficult to do.

On the other hand, as shown in Table 2, when the RMS surface roughness is larger than 200 nm, the surface roughness becomes too large, and the light transmittance of the entire light pipe 320 including the optical film 322 is lowered.

Accordingly, the RMS surface roughness of the prism of the optical film 322 is preferably in the range of 33 nm to 200 nm. Within this range, the light pipe 320 including the optical film 322 can efficiently transmit light to the end of the light pipe 320, and the light transmittance is also good.

FIG. 6 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

Referring to the drawings, the cross-sectional view of the light pipe 620 of FIG. 6 is almost similar to the cross-sectional view of the light pipe 320 of FIG. 5. The description of the supporting member 624 and the optical film 622 of FIG. 6 is the same as described with reference to FIG. 5. However, the first surface 622a structured by the prism of the optical film 622 and the first surface 622a of the second surface 622b facing the first surface 622a are directed inwardly. There is a difference. That is, the prism of the optical film 622 may be directed inwardly opposite to FIG. 5. In other words, an apex of each of the plurality of prisms 622p of the optical film 622 may be disposed to face the hollow 680.

Meanwhile, as described above in FIG. 5, the maximum surface roughness PV of the side surface 622s of the prism 622p of the optical film 622 is preferably 600 nm to 1.5 μm. Further, the RMS surface roughness of the side surfaces 622s of the prism 622p of the optical film 622 is preferably 33 nm to 200 nm.

As a result, the light pipe can efficiently transmit light to the end of the light pipe, and the light transmittance is also improved.

FIG. 7 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

Referring to the drawings, the cross-sectional view of the light pipe 720 of FIG. 7 is almost similar to the cross-sectional view of the light pipe 320 of FIG. 5. The description of the optical film 722 having the support member 724 of FIG. 7, the first face 722a structured with a prism, and the second face 722b opposite the first face 722a is described in FIG. 5. Same as described.

However, there is a difference between the optical film 722 and the support member 724 in that it further includes a reflective film 730 for reflecting light from the light source unit. By providing the reflective film 730, it is possible to uniformly emit light in a predetermined direction through the entire light pipe.

FIG. 8 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

Referring to the drawings, the cross-sectional view of the light pipe 820 of FIG. 8 is almost similar to the cross-sectional view of the light pipe 720 of FIG. 7. An optical film 822 having a support member 824 in FIG. 8, a first face 822a structured with a prism, a second face 822b opposite the first face 822a, and a reflective film 830. Description of the same as described in FIG.

However, there is a difference between the optical film 822 and the support member 824 in that it further includes an emission film 835 for emitting light from the light source. Preferably, the emission film 835 is disposed below the reflective film 830. By the emitting film 835, light is efficiently emitted to the outside in the light pipe.

9 is a plan view of the lighting apparatus having the light pipe of FIG. 8.

Referring to the drawings, the lighting device 900 of FIG. 9 is almost similar to the lighting device 300 of FIG. 4. The lighting apparatus 900 of FIG. 9 may include a light source unit 910 and a light pipe 320, and may further include a reflective cap 930. On the other hand, the light pipe 320 may further include an emission film 935, as shown in the drawing, the further away from the light source unit 910, the larger the size of the emission film 935 is preferable. In the drawing, the light source unit 910 is disposed at one end of the light pipe 920, but is not limited thereto, and may be disposed at both ends of the light pipe 920. At this time, the emission film 935 may be formed in a rhombus shape that is larger in size as it moves away from the light source.

10 is a perspective view of a lighting apparatus according to an embodiment of the present invention.

Referring to the drawings, the lighting apparatus of FIG. 10 is similar to the lighting apparatus of FIG. 3, except that the protrusion 1040 is formed on the surface of the support member of the light pipe 1020. Other descriptions of the light source unit 1010, the light pipe 1020, and the reflective cap 1030 of FIG. 10 will be omitted with reference to FIG. 3.

Since a plurality of protrusions 1040 are formed on the surface of the support member of the light pipe 1020, uniform light may be emitted through the entire light pipe 1020. On the other hand, the protrusion 1040 may be formed integrally with the support member of the light pipe 1020.

Meanwhile, unlike the drawing, a plurality of grooves may be formed on the surface of the support member of the light pipe 1020. In this case, the groove may be integrally formed with the supporting member of the light pipe 1020.

11 is a perspective view showing a lighting apparatus according to an embodiment of the present invention.

Referring to the drawings, the lighting apparatus of FIG. 11 is similar to the lighting apparatus of FIG. 3, except that protrusions 1040 and grooves 1050 are formed on the surface of the support member of the light pipe 1020. There is. Other light source units 1010, light pipes 1020, and reflective caps 1030 will be described with reference to FIG. 3.

Since protrusions 1040 and grooves 1050 are formed on the surface of the support member of the light pipe 1020, uniform light may be emitted through the entire light pipe 1020. On the other hand, the protrusion 1040 and the groove 1050 may be formed integrally with the support member of the light pipe 1020.

FIG. 12 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

Referring to the drawings, the cross sectional view of the light pipe 1020 of FIG. 12 is substantially similar to the cross sectional view of the light pipe 320 of FIG. 5. The description of the optical film 1022 having the support member 1024 of FIG. 12, the first face 1022a structured by a prism and the second face 1022b opposite the first face 1022a is described in FIG. 5. Same as described.

However, there is a difference in that at least one of the protrusion 1040 and the groove 1050 is formed on at least one of an inner surface and an outer surface of the support member 1024. The protrusions 1040 and the grooves 1050 may be surface treated to be formed on the surface of the support member 1024 through injection, extrusion, molding, roll processing, thermosetting or UV curing.

For example, by pressing a roll or plate in which the protrusion 1040 and / or the groove 1050 are engraved onto one surface of the support member 1024, the surface of the support member 1024 may be pressed. The support member 1024 having the protrusion 1040 and / or the groove 1050 may be formed.

Alternatively, after the resin is injected into the flat mold having the protrusions 1040 and / or the grooves 1050, the resin is cured to support the protrusions 1040 and / or the grooves 1050. You can make a member. In addition, the protrusion 1040 and / or the groove 1050 may be formed on the surface of the support member 1024 in various ways.

Since the protrusions 1040 and the grooves 1050 are formed on at least one of the inner and outer surfaces of the support member 1024, uniform light is emitted through the entire light pipe regardless of the position of the light source. This is because light is scattered or totally reflected by the protrusions 1040 and the grooves 1050.

FIG. 13 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

Referring to the drawings, the cross-sectional view of the light pipe 1120 is almost similar to the cross-sectional view of the light pipe 320 of FIG. Description of the optical film 1122 having the supporting member 1124 of FIG. 13, the first surface 1122a structured by a prism, and the second surface 1122b opposite to the first surface 1122a is illustrated in FIG. 5. Same as described.

However, there is a difference that a diffusion layer 1160 including the diffusion particles 1140 and a light-transmitting material 1150 is further formed on at least one of an inner surface and an outer surface of the support member 1124. Herein, the light-transmitting material 1150 may be a resin. That is, after coating a mixture of the diffusion particles 1140 and the resin (1150) to the support member 1124, the resin (resin, 1150) can be cured by UV curing or thermosetting, to form a diffusion layer 1160. have. In the drawing, the diffusion layer 1160 is formed on the outer surface of the support member 1124.

The diffusion particles 1140 may include any one of silica series. In particular, the diffusion particles 1140 may be beads, and the beads may include at least one of silica, polymethylmethacrylate (PMMA), and polystyrene.

The resin 1150 is transparent, has excellent mechanical properties, and has a balance of heat resistance, cold resistance, and electrical properties, such as polyethylene, polypropylene, polycarbonate, polyester and acrylic It may include one.

Since the diffusion layer 1160 is formed on at least one of the inner surface and the outer surface of the support member 1124, uniform light is emitted through the entire light pipe regardless of the position of the light source.

Meanwhile, a diffusion sheet including diffusion particles and a light transmissive material may be disposed between the optical film 1122 and the support member 1124. Herein, the light transmissive material may be a resin. That is, the mixture of the diffusion particles and the resin is coated on one or both sides of the base film and then cured the resin (resin) by UV curing or thermosetting, to make a diffusion sheet.

While the above has been shown and described with respect to preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, it is usually in the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

1 is a cross-sectional view of a portion of an optical film to illustrate the transmission and reflection of light in a light pipe in connection with the present invention.

2 is a perspective view of a portion of an optical film to illustrate the transmission and reflection of light in a light pipe in connection with the present invention.

3 is a partial cutaway perspective view of a lighting apparatus according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a cross section along AA ′ of the lighting apparatus shown in FIG. 3.

FIG. 5 is a cross-sectional view showing an example of a B-B 'cross section of the light pipe shown in FIG.

FIG. 6 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

FIG. 7 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

FIG. 8 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

9 is a plan view of the lighting apparatus having the light pipe of FIG. 8.

10 is a perspective view of a lighting apparatus according to an embodiment of the present invention.

11 is a perspective view showing a lighting apparatus according to an embodiment of the present invention.

FIG. 12 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

FIG. 13 is a cross-sectional view showing another example of the B-B 'cross section of the light pipe shown in FIG.

<Explanation of symbols on main parts of the drawings>

310: light source unit 320: light pipe

322: optical film 324: support member

330: reflective cap 730: reflective film

835: release film 1040: projection

1050: home 1140: diffusion particles

1150: light transmitting material 1160: diffusion layer

Claims (19)

An optical film comprising a plurality of prisms, the optical film curled to have a hollow extending in the longitudinal direction of the prism; And And a support member surrounding the optical film. The prism side of any one of the plurality of prisms having a maximum surface roughness of 600nm to 1.5㎛. The method of claim 1, A side of one of the plurality of prisms, the light pipe, characterized in that having a root mean square (RMS) surface roughness value of 33nm to 200nm. The method of claim 1, And wherein each apex of the plurality of prisms faces the support member. The method of claim 1, Each apex of the plurality of prisms facing the hollow. The method of claim 1, The support member, the light pipe, characterized in that it comprises a plurality of protrusions formed integrally with the support member. The method of claim 1, The support member, the light pipe, characterized in that it comprises a plurality of grooves formed integrally with the support member. The method of claim 1, The support member includes a plurality of protrusions and grooves formed integrally with the support member. The method of claim 1, And a diffusion layer comprising a light transmitting material and diffusion particles, the diffusion layer being disposed on at least one of an inner surface and an outer surface of the support member. The method of claim 1, And at least one of a reflecting film and an emitting film disposed between the optical film and the support member. A light source unit; And a light pipe for transmitting and distributing light from the light source unit. The light pipe, An optical film comprising a plurality of prisms, the optical film curled to have a hollow extending in the longitudinal direction of the prism; And And a support member surrounding the optical film. The prism side of any one of the plurality of prisms having a maximum surface roughness of 600nm to 1.5㎛. The method of claim 10, A side of one of the plurality of prisms, the illumination device, characterized in that having a root mean square (RMS) surface roughness value of 33nm to 200nm. The method of claim 10, And an apex of each of the plurality of prisms faces the support member. The method of claim 10, Wherein each vertex of the plurality of prisms faces the hollow. The method of claim 10, The support member, the illumination device, characterized in that it comprises a plurality of projections formed integrally with the support member. The method of claim 10, The support member, the illumination device, characterized in that it comprises a plurality of grooves formed integrally with the support member. The method of claim 10, The support member, the illumination device, characterized in that it comprises a plurality of projections and grooves formed integrally with the support member. The method of claim 10, And a diffusion layer comprising a light transmitting material and diffusion particles, the diffusion layer being disposed on at least one of an inner surface and an outer surface of the support member. The method of claim 10, And at least one of a reflective film and an emission film disposed between the optical film and the support member. The method of claim 18, And the width of the emission film increases as the distance from the light source is increased.

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