KR100775839B1 - A hollow light pipe - Google Patents

Abstract

The present invention relates to a hollow light pipe, in particular having a linear prism arrangement having a hollow outer pipe, a flat outer surface inserted into the hollow outer pipe and a plurality of triangular grooves extending in the longitudinal direction. It relates to a hollow inner pipe including a hollow inner pipe including an inner surface and a film disposed between the outer pipe and the inner pipe, the film disposed so that the surface formed with a reflective pattern on the surface in contact with the outer pipe facing. In the case of using the hollow light pipe according to the present invention, light can be transmitted uniformly and remotely as compared to the hollow light pipes conventionally used.

Light pipe

Description

Hollow Light Pipe {A HOLLOW LIGHT PIPE}

1 is a perspective view of a light pipe according to the present invention.

2 is a cross-sectional view of a light pipe according to the present invention.

3 is a traveling path of light incident into the light pipe of the present invention.

4 is an explanatory diagram for explaining the principle of total reflection.

5 is a traveling path of light incident on the film in the light pipe.

* Explanation of reference numerals

1: hollow light pipe 2: outer pipe

3: inner pipe 4: film

The present invention relates to a light pipe that transmits light uniformly to a far distance with relatively little loss by using total internal reflection, and more specifically, a hollow outer pipe; A hollow inner pipe including an inner surface having a linear prism arrangement having a flat outer surface and a plurality of triangular grooves extending in a longitudinal direction, inserted into the hollow outer pipe; It is provided between the outer pipe and the inner pipe, and relates to a hollow light pipe, characterized in that made of a film disposed to face the surface formed with a reflective pattern on the surface in contact with the outer pipe.

A light pipe is a pipe that transmits light so that light from a light source can be used as a bright and uniform wide area light without glare. Light from the light source travels through the pipe, which is characterized by uniformly exiting the outside of the pipe using specially treated reflection technology. Therefore, the light pipe having the above characteristics is used for buildings, bridges, road safety guides, and the like, and is also used for decorative lighting for landscapes and large signage.

As a general light pipe, light pipe structures comprising semi-solid or solid optical fibers for transmitting light are known from US Pat. Nos. 4,466,697 and 4,422,719. Such a structure includes a reflective sleeve that surrounds the fiber that transmits the light, which is difficult to transmit enough light for use in lighting because of its size, which is bulky and bulky material. It is inefficient in terms of weight and cost as required.

U.S. Patent No. 4,260,220 discloses a light pipe comprising a rigid polymer sheet of transparent material, which relates to a prism light pipe having an octagonal surface having a structured one side and a smooth other side. will be. The problem is that the acceptable light range is limited to a relatively small range of angles.

Recently used light pipes are typically manufactured using an optical lighting film (OLF). Typical optical writing films are made of a relatively thin sheet-like transparent material, for example acrylic or polycarbonate, with a linear prism arrangement embossed on one side or vice versa. Suitable optical writing films for making light pipes are known from US Pat. Nos. 4,906,070 and 5,056,892. In order for the light to be transmitted evenly over a long distance, it is necessary to include as much light inside the pipe as possible due to total internal reflection. However, in the case of having such a structure, there is a limit in that a large amount of light is contained in the light pipe, and for this reason, there is a certain limit even when light is transmitted at a long distance.

The present invention provides the most efficient and economical way of transmitting light uniformly and remotely using reflection or refraction of light.

The present invention has been made to solve the conventional problems as described above, when using the present invention, it is possible to reduce the cost and to transmit light uniformly over a distance compared to the conventional light pipe manufacturing. In addition, the present invention is easier to manufacture because the pattern is formed on the outer surface of the film, the reflection portion is located on the outside of the pipe structured in the prism shape can be maximized the total reflection effect by the prism.

The present invention is a hollow outer pipe; A hollow inner pipe including an inner surface having a linear prism arrangement having a flat outer surface and a plurality of triangular grooves extending in a longitudinal direction, inserted into the hollow outer pipe; It relates to a hollow light pipe provided between the outer pipe and the inner pipe and made of a film disposed to face the surface formed with a reflective pattern on the surface in contact with the outer pipe. Here, the inner angle of the triangular prism formed in the inner pipe is 90 degrees. The reflective pattern has a structure that emits light to the outside by laser processing, printing laminating, hologram processing or scratching in the circumferential direction of the light pipe, and the size of the pattern becomes wider as it moves away from the light source. The spacing becomes narrower as the distance from the light source increases.

The scattering film may be attached to the inner surface of the outer pipe at predetermined intervals in the circumferential direction, and it is preferable to use the scattering film treated with the scattering material at a higher density as it moves away from the light source. The further away from the light source on the outer surface of the outer pipe, the more directly the scattering material can be processed.

The light pipe may be made of one or more polymeric materials selected from the group consisting of polycarbonate, polymethylmethacrylate, acrylic, polypropylene, polystyrene and polyvinyl chloride, in particular, the outer pipe is made of polycarbonate, Preferably, the inner pipe is made of acrylic.

The film used in the present invention can be used as one or more polarizing films drawn in the same direction as the longitudinal direction of the light pipe.

As mentioned above, the hollow light pipe according to the present invention, unlike the conventional light pipe, the inner surface is arranged so that the surface formed with a reflective pattern on the surface in contact with the inner pipe and the outer pipe structured in the shape of a triangular prism By using the film, the total reflection effect of the prism is increased to uniformly transmit the light at a long distance. This is because the inner pipe layer, the film layer and the outer pipe layer form a multilayer, so that the total reflection of light increases. In addition, since the reflector is located outside the pipe structured in a prism shape, the total reflection effect by the prism is maximized. When the pattern is added to the outer surface of the film than when the pattern is added to the inner surface, it is advantageous to send out the light.

Hereinafter, a light pipe according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals refer to like elements throughout. This is presented to understand the content of the present invention, and the scope of the present invention should not be construed as being limited to these examples.

1 is a perspective view of one embodiment of a hollow light pipe 1 according to the invention, and FIG. 2 is a sectional view according to the invention. The hollow light pipe 1 has an inner inner prism array having a hollow outer pipe 2, a flat outer surface inserted into the hollow outer pipe, and a plurality of triangular grooves extending in the longitudinal direction. It consists of a hollow inner pipe 3 comprising a side and a film 4 comprising a reflective pattern. The present invention is different from the conventional invention, the inner surface of the inner pipe is structured along the longitudinal direction of the pipe in a prism shape, and disposed between the inner pipe and the outer pipe so that the surface formed with a reflective pattern on the surface in contact with the outer pipe facing. Film is inserted.

In one embodiment, the hollow outer pipe 2 uses a private pipe and the hollow inner pipe 3 has a linear prism arrangement having a flat outer surface and a plurality of triangular grooves extending in the longitudinal direction. A pipe having sides is used, which can be made by extrusion of the light pipe. In the case of using a reflector having a pattern formed on a private pipe, a structured pipe as described above is used because a hologram may occur. In addition, in order to uniformly transmit the incident light to a long distance, it should be provided with a reflector for reflecting a certain amount of light, in the present invention is inserted into the film provided with a reflective pattern between the inner pipe and the outer pipe for this role. This is because the total reflection effect by the prism is maximized when the reflector is located outside the pipe having a triangular prism shape. At this time, the reflective pattern of the film is preferably directed to the surface in contact with the outer pipe. When a reflective pattern is added to a surface in contact with the inner pipe, light is emitted to the outside of the pipe, so that light may be transmitted remotely. If the pattern is processed directly on the inner pipe, the total reflection effect is low, the process is difficult and expensive. In addition, by using a film provided with a reflective pattern to form a multi-layer structure to increase the total reflection area it is possible to transmit the light more remote.

Reflective films may be provided on the inner surface of the outer pipe to allow light to be reflected or emitted directly to the outside through the inner wall of the light pipe, which may be laser processed, printed laminating, holographic or scratched in the circumferential direction of the light pipe. And a pattern of structures that emit light to the outside. This pattern transmits light evenly from the light source to the last end. It is preferable that the pattern has a structure in which its size becomes wider as it moves away from the light source, or becomes narrower as the distance between the patterns moves away from the light source. This is because light in a portion closer to the light source is less reflected by the pattern and goes out, and light in a portion far from the light source is reflected by a pattern of a wide area so that a lot of light is reflected.

The film may use a polarizer film, because when using a polarizing film drawn in the same direction as the longitudinal direction structured in the hollow light pipe, light may be transmitted more remotely. For reference, a polarizing film is a core optical film used in a thin film liquid crystal display device (TFT LCD) such as a notebook PC and a desktop PC monitor, and is a 310 μm-thick composite film having a polarizing function that passes only a predetermined direction of light. In the case of using such a polarizing film, only light in one direction is transmitted to prevent diffuse reflection, thereby reducing eye fatigue.

The inner surface of the inner light pipe has a linear prism array having a plurality of triangular grooves extending in the longitudinal direction, wherein an inner angle of each of the triangular prismatic shapes is 90 °, and a height of each of the structured triangular prism shapes is It is preferable that it is 0.05-0.25 mm, and it is most preferable that it is 0.1-0.2 mm. Experiments have demonstrated that the incident light is most included in the light pipe in the above numerical range. If the height of the prism shape is 0.25 mm or more, since the prism phenomenon does not occur, the light cannot be trapped inside by total reflection. In addition, when the height is less than 0.05mm, scattering occurs in the inner surface of one prism-shaped insert, which impedes transmission of light at a long distance. Thus, the most advantageous effect occurs within the above numerical range.

The light transmission and reflection principle of the light pipe will be described with reference to the present invention.

Referring to FIG. 3, when the light source enters the inner light pipe as shown by the arrow, the light is totally reflected at the structured inner surface and the light travels along the inner surface of the hollow light pipe in the longitudinal direction. In addition, the light incident on the film through the air layer again creates total reflection, and total reflection occurs between the film and the outer pipe. Since the light pipe of this invention forms a multilayered structure, the area | region in which total reflection occurs is large compared with the conventional light pipe. In the case of using a private light pipe, about 30% of the incident light is totally reflected inside. When the total reflection process is repeated, the incident light can be transmitted at a long distance with little transmission loss. This is caused by the following principle.

4 shows the principle of total reflection in glass with a critical angle of 42 degrees. First, if you look at the equilateral triangle glass of part B, the light incident into the glass at a 90 ° angle with the glass surface reaches another surface of the triangle, that is, the lower surface of the triangle, so the angle formed by the lower surface and its normal is 60 °. According to the principle of total reflection, the direction is changed as in ①-1 and emitted to the outside. In the equilateral triangular glass of the C and C 'portions, the light incident into the glass at an angle of 90 ° to the glass surface is emitted as ②-1 in the C triangle and as ②-2 in the C' triangle. This optical path difference is dependent on the lower distance d between the two triangles, so the larger d is advantageous for the far-field propagation of light.

5 illustrates a light transmission process in a light pipe in which an optical writing film is installed. 5A shows that only total reflection occurs inside the light pipe in which the optical writing film is installed. FIG. 5B illustrates a process in which the light passing through is transmitted to the outside as the transmission angle of the light is changed by touching the reflective film attached inside the optical lighting film, and FIG. 5C illustrates the size of the reflective film attached inside the optical lighting film. The adjustment shows the process by which the light in progress is transmitted uniformly and uniformly to the outside.

Applying the above principle to the present invention, the light incident inside the light pipe of the present invention is total reflection by the prism by the structured inner surface of the light pipe, and total reflection again in the inner medium of the structured inner pipe After the process, the remaining incident light passes through it and causes total reflection between the inserted film and the air layer and the outer pipe. Therefore, when the inner surface of the inner pipe and the patterned film are used, the medium through which the light passes and the air layer increase. Therefore, the total reflection using the triangular prism and the total reflection inside the medium are used to generate more light. Can be captured, allowing light incident on the light pipe to travel farther. However, in the case of infinitely increasing the number of media by using the multilayer structure, there is a disadvantage in that it is rather disadvantageous to use as lighting, and the problem of cost increases. Therefore, in the case of using the light pipe having the same structure as the present invention, the light pipe can be manufactured most economically, and light can be transmitted uniformly and effectively at a long distance.

The light pipe is preferably used by polycarbonate (PC) or polymethyl methacrylate (PMMA) having excellent light transmittance alone or in duplicate, and in addition to other polymeric materials having relatively high light transmittance, such as acrylic. , Polypropylene, polystyrene, polyvinyl chloride, and the like. The inner pipe is somewhat weak in impact, but uses a high light transmittance, such as acrylic, and the outer pipe is preferably made of polycarbonate resistant to external impact.

A scattering film in which a scattering material is added in the circumferential direction may be added to the inner surface of the outer pipe, and the film serves to spread the light evenly by using particles having good diffusion efficiency. In this case, it is preferable to use a scattering film treated with a scattering material at a higher density as it moves away from the light source. In addition to using a film treated with the scattering material as described above, it is also possible to treat and use the scattering material directly on the outer surface of the outer pipe, and even in this case, the scattering material is treated at a higher density as the distance from the light source increases. desirable.

As the hollow light pipe according to the present invention, the inner surface structured in the shape of a triangular prism and the film having a pattern on the surface in contact with the outer pipe are used to increase the total reflection effect of the prism and to uniformly transmit light at a long distance. Let's do it. This is because the inner pipe layer, the film layer and the outer pipe layer form a multilayer, so that the total layer of light reflection increases. In addition, when the film is added to the pattern in the direction in contact with the outer pipe is used, since the total reflection effect by the prism is maximized, it is much more advantageous to send out the light than when the pattern is added to the inner surface.

Claims (11)

Hollow outer pipes; A hollow inner pipe including an inner surface having a linear prism arrangement having a flat outer surface and a plurality of triangular grooves extending in the longitudinal direction, inserted into the hollow outer pipe; A hollow light pipe provided between the outer pipe and the inner pipe, the film is disposed so that the surface with a reflection pattern is formed on the surface in contact with the outer pipe. The method of claim 1, Hollow light pipe, characterized in that the inner angle of the triangular prism is 90 °. The method of claim 1, The reflective pattern is a hollow light pipe, characterized in that the laser processing, printing laminating, holographic processing or scratching process in the circumferential direction of the light pipe to emit light to the outside. The method of claim 3, wherein Hollow light pipe, characterized in that the size of the pattern is gradually wider away from the light source. The method of claim 3, wherein Hollow light pipe, characterized in that the distance between the patterns become narrower as the distance from the light source. The method of claim 1, And a scattering film is added to the inner surface of the outer pipe at predetermined intervals in the circumferential direction. The method of claim 6, Hollow light pipe, characterized in that the scattering material contained in the film is treated with a higher density gradually away from the light source. The method of claim 1, The hollow light pipe, characterized in that the scattering material is directly processed to a higher density as the distance away from the light source on the outer surface of the outer pipe. The method of claim 1, Wherein said light pipe is made of at least one polymeric material selected from the group consisting of polycarbonate, polymethylmethacrylate, acrylic, polypropylene, polystyrene and polyvinyl chloride. The method of claim 9, And wherein said outer pipe is made of polycarbonate and said inner pipe is made of acrylic. The method of claim 1, And the film is at least one polarizing film drawn in the longitudinal direction of the light pipe.

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