JP2000221327A - Optical pipe using plastic sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the optical pipe which has a simple structure and can efficiently distribute light to large area. SOLUTION: The optical pipe 4 has a waveguide 6 which receives Light at its one end and distributes the light along its length. The waveguide 6 has a combination of a mirror reflecting surface and a diffuse reflecting surface which are so arranged that part of the light is passed along the optical pipe mainly by mirror reflection and the rest is emitted out of the optical pipe 4 mainly by diffuse reflection. Those reflecting surfaces are substantially in parallel to the length axis of the optical pipe. More than one waveguide can be used to control light distribution characteristics of the optical pipe. Those waveguides can be formed of inexpensive plastic sheet substances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light pipe used for distributing light from a light source.
More particularly, the present invention relates to a cost-effective and efficient light pipe constructed from plastic sheet material.

[0002]

BACKGROUND OF THE INVENTION Light pipes are conduits typically composed of an optical material having an air-surface interface that provides total internal reflection (TIR) that distributes light from a light source over a large area. One example of such a light pipe is described in Lone A. Whitehead, “Prism Light Guide with Surfaces on Eight Faces (Prism L
right Guide Having Surface
No. 4,260,220, entitled "Which arein Octature". Minnesota Mining and Manufacturing Company (3M) produces a commercially available optical material called an optical lighting film (OLF) useful for constructing light pipes. O
One example of LF is described in U.S. Pat. No. 4,906,070.

One problem with conventional light pipes is that the optical material is comprised of microreplicated prisms, perforated silver-coated plastic, or a composite dielectric coating on a transparent surface. These approaches are relatively complex and costly. Another problem with conventional light pipes is that some of the materials described above are relatively inefficient in distributing light from the light source into the environment to be illuminated. For example, optical materials that provide TIR are designed to confine light within the material. Trapped light undergoes multiple internal reflections before exiting.
Each internal reflection causes some loss of light and its cumulative effect can be significant. Light distribution uniformity can also be a problem for prismatic films. Using such a material to distribute light introduces irregularities into the material to allow light to escape. It is difficult to control light leakage and the light output of light distributed over a large area varies significantly.

[0004] EP-A-0 889 285 describes a light distribution tube which does not use a prismatic film or TIR to distribute the light. Instead, the light tube uses a geometrically complex three-dimensional light redirecting structure inside it, and most of the light incident on the redirecting structure is a light beam and a redirecting structure. At the intersection between the two. 4
Light sources having a beam divergence half angle less than degrees are most preferred.

[0005] A light hose (LITE) manufactured by Space Cannon Illumination, Inc., Fuvine, Italy.
A product called HOSE) is also known. This light hose was officially used by Europe in the fall of 1998 and
It was officially used in the United States in the spring of 999. The light hose consists of an extruded milky acrylic tube used in connection with a light source having a three degree light beam. The tubes range in size from 100 to 500 mm and the wall thickness ranges from 3 to 8 mm. A narrow light beam is used to provide a long light projection through the tube. The primary application of this light hose is for theater lighting, for example for building contouring for dramatic effects.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and solves the above-mentioned drawbacks of the prior art and provides a simple structure for efficiently distributing light over a large area. It is an object to provide a light pipe having the same. It is another object of the present invention to provide a light pipe with high uniformity in light distribution.

[0007]

According to one aspect of the present invention, a light pipe has a conduit configured to receive light at one end and distribute the light along its length.
The conduit is arranged to pass a portion of the light along the light pipe primarily with specular or specular reflection and to emit a portion of the light from the light pipe primarily with diffuse or diffuse reflection. A combination of reflective and diffuse reflective surfaces is used.
These reflecting surfaces are substantially parallel to the longitudinal axis of the light pipe. For example, the conduit is a transparent plastic tube having an internal surface that provides total internal reflection and an opaque material disposed along the length of the tube and covering a portion of the periphery of the tube. And the opaque material provides diffuse reflection. The opaque material can be disposed on the interior surface of the tube and can provide a combination of specular reflection for small beam angles of light and diffuse reflection for large beam angles of light. On the other hand, the opaque material can be disposed on the outer surface of the tube, and the tube material and the opaque material together form a specular reflection for a small beam angle of light and a large beam of light. Provides a combination of diffuse reflection to angle. For example, the conduit can be composed of extruded plastic or plastic sheet material molded to form a tube.

In accordance with another aspect of the present invention, a light pipe has a plurality of conduits configured to receive light at one end and distribute the light along the length of the light pipe. These conduits are offset from each other by their respective gaps and allow a portion of the light to pass along the light pipe primarily with specular reflection and emit a portion of the light out of the light pipe primarily with diffuse reflection. And a combination of specular and diffuse reflecting surfaces arranged to provide the same. In some instances, the number of these conduits varies along the length of the light pipe. In other examples, the length of at least one of the conduits is different from the length of another of the conduits. As mentioned above, each of these conduits can be composed of extruded plastic or plastic sheet material molded to form a tube. In most cases, except for the outermost conduit, each of these conduits has a clear plastic with a glossy finish on both its inner and outer surfaces. In some examples, the outermost conduit has a clear plastic that has a glossy finish on its interior surface and a diffuse finish on its exterior surface. The light pipe may further comprise an opaque material disposed along the length of the outermost conduit and covering a portion of the periphery of the outermost conduit. The opaque material can be disposed on the inner surface of the outermost conduit and can provide a combination of specular reflection for small beam angles of light and diffuse reflection for large beam angles of light. On the other hand, the opaque material can be disposed on the outer surface of the outermost conduit, and the conduit material and the opaque material together form a specular reflection and a light reflection for a small beam angle of light. Provides a combination of diffuse reflection for large beam angles.

According to yet another aspect of the invention, a light distribution system provides a light beam having a total beam angle of less than 30 degrees, and receives at one end a light beam from the light source and its length. A light pipe that distributes light along the light pipe, the light pipe passing a part of the light along the light pipe mainly by specular reflection and a part of the light to the outside of the light pipe mainly by diffuse reflection. Has a combination of a specular reflection surface and a diffuse reflection surface arranged to emit light. Preferably, the light source provides a light beam having a total beam angle of less than 20 degrees. For example, the light source can be sunlight. The light distribution system may further include an end cap covering an end of the light pipe distal to the light source, the end cap directing light back through the light pipe. It has a reflective surface positioned and shaped for redirection. In some examples, the light pipe has first and second substantially concentric conduits, and the distribution system further includes a first conduit for supporting the first conduit. A mounting device and a second mounting device for supporting the second conduit and receiving and supporting the first mounting device and the first conduit in the second conduit. Preferably, the first and second mounting devices hold the first and second conduits out of contact with each other.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In the following description, for the purpose of illustrating the present invention, not limiting it to specific structures, interfaces, techniques, etc., in order to provide a thorough understanding of the present invention. Describes specific details. However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known structures, devices, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

The TIR pipe is capable of efficiently confining beams up to a total beam angle of 54 to 56 °. However, in order for light to escape from the TIR pipe, it must be scattered beyond this angle. TI
In contrast to R pipes, the light pipes of the present invention do not confine light within the pipe material. The present invention uses a light source with a smaller beam angle. With the exception of the specular component (eg, a small angle, almost parallel beam), all other beams are likely to escape from the light pipe of the present invention at each bounce, as described below in connection with FIGS. have. As described above, TI
The R-pipe uses an extractor or irregularity in the OLF material that is intended to scatter some of the incident light out of the confinement cone angle. However, in contrast to the present invention, a significant portion of the light remains within the cone angle and must undergo multiple interactions with the extractor to exit the pipe. Thus, TIR pipes are typically characterized by more bounce off the pipe per unit length, and the efficiency loss per bounce is the same or greater than the present invention. Thus, the present invention is more efficient for light sources with smaller beam angles. This is because the number of bounces before the light escapes is relatively low and the loss per bounce is lower.

Compared to the light tube described in EP-A-0 889 285, the present invention provides a simpler configuration. The present invention uses a reflective surface that is substantially parallel to the longitudinal axis of the light tube. In other words, the present invention does not use a complicated internal structure. The light tube described in EP '285 avoids the use of prismatic films, but requires a geometrically complex three-dimensional light redirecting structure. . This construction is a tapered extractor,
It extends along a substantial portion of the tube and is for a progressively larger area of the tube cross section at a greater distance from the light source. Although not explicitly stated,
The principle of operation seems to use a long floodlight with a single reflection from the light redirecting structure to extract light from the tube. Thus, the light pipe of the '285 publication requires a light beam that is significantly narrower than that of the present invention. In any case, the '285 publication does not describe or suggest the principles of operation and simple construction of the present invention.

The invention is based on the application of the following principle for distributing light. First, for narrow angles of incidence, glossy plastics provide a good specular surface. In particular, glossy plastics show brilliant reflections due to the high efficiency of Fresnel reflections at shallow angles. Second, for shallow angles of incidence,
Many common opaque materials exhibit a combination of specular and diffuse reflection. According to the present invention, there is provided an optical device that combines these principles, is low-cost, efficient, and uniformly distributes light from an appropriate bright light source.

FIG. 1 is a schematic sectional view of a transparent material exhibiting specular reflection. The light beam B ₁ enters the substance 1 at an incident angle θ ₁ . Part B _S of the beam is specularly reflected and part B _T of the beam is transmitted (refraction is ignored in this figure). The relative magnitude of B _S and B _T depends on the properties of the substance 1 and the incident angle θ ₁ . The effects shown in FIG. 1 are also present in the most common inexpensive plastic sheet materials including, but not limited to, polycarbonate, acrylic, PET, PETG. FIG. 2 is a schematic cross-sectional view of an opaque material that exhibits both specular and diffuse reflection. The light beam B ₂ is incident on the substance 2 at an incident angle θ ₂ . Part B _S of the beam is specularly reflected and part B _D of the beam is diffusely reflected. As described above, the relative size of B _S and B _D depends on the characteristics of the substance 2 and the incident angle θ ₂ . The effects shown in FIG. 2 are not limited to these, but include white vinyl tape, flooring tape, PV
It is present to a varying extent in a wide range of inexpensive and commonly available materials, including C, and other appliques.

FIG. 3 is a graph showing the relationship between the reflectance and the incident angle for an exemplary transparent material exhibiting specular reflection. As can be seen from FIG. 3, Fresnel reflections can be very efficient when the incident light is at a shallow angle of incidence near the material surface. FIG. 3 shows the relationship between the reflectance and the angle of incidence for a dielectric surface having a refractive index of about 1.58.

FIG. 4 is a schematic sectional view of a light pipe according to the first embodiment of the present invention. The light pipe 4 has a transparent plastic conduit 6 with a relatively low refractive index. To distribute the light uniformly and effectively over the light pipe, some of the light must be passed along the pipe and some light must be allowed to exit the light pipe. No. According to the present invention, a material having both a specular reflection component and a diffuse reflection component is disposed along the length of the pipe. As shown in FIG.
Are disposed on the inner surface of the conduit 6. The material 8 provides both specular and diffuse reflection components. In an application example, the light source 10 supplies a light beam into the light pipe 4. This light beam has a relatively small total beam angle of less than about 30 °. For example, for a plastic having a refractive index of about 1.5, a light beam having a relatively narrow total beam angle of less than about 15-20 ° is preferred. A smaller beam angle of light produces a smaller number of bounces for a given length and aspect ratio of the light pipe, thereby improving light distribution efficiency.

It is possible to arrange a reflective end cap or mirror at the end of the light pipe 4 opposite the light source 10. Preferably, the mirror is tilted at an angle, thereby improving light distribution and / or efficiency (eg, about ± 10 degrees). Alternatively, the mirror may have a curved surface to redirect light back into the light pipe. The light pipe 4 further includes the light source 1
It is also possible to seal with a transparent plastic plate or lens at the end closest to zero. The plate or lens can have an anti-reflective coating.

FIG. 5 is a schematic diagram showing a light beam incident on the reflecting material 8. Light beam 12 incident on reflective material 8
Produces a specular reflection component 14, which remains at a relatively narrow angle of incidence and passes along the light pipe. Since the reflections originate from the first surface, the light beam need not pass through the material with each reflection, resulting in lower losses per bounce. The light beam 12 incident on the material 8 also produces a diffuse reflection component 16 at a relatively large angle of incidence exiting the light pipe 4. The light has only a small number of bounces inside the light pipe 4 and the loss in the pipe material is low and the use of relatively thin plastic sheets with low loss in the sheet is possible. Light is very efficiently distributed. Suitable light pipe materials are advantageous because they are inexpensive and readily available. For example, many types of common adhesive tapes have both specular and diffuse reflection components on their non-stick surface. The relative magnitude of each component varies as a function of the angle of incidence. In other words, when the tape is viewed straight from above (i.e., a high angle of incidence), the tape appears to have a dull finish, and when the tape is viewed from the side (i.e., a shallow angle of incidence), the The tape appears to have a glossy finish. Exemplary tapes include 3M # 471 and McMaster® manufactured by Minnesota Manufacturing and Mining Company.
There are # 6029T118 manufactured by Cars, both of which are common white vinyl tapes. It should be understood that these particular tapes are exemplary and not limiting. In general, any highly white or reflective material with similar properties can be used.

[0019] As a further advantage, reasonable conduit materials are inexpensive and readily available. For example, conduit 6
Can be composed of 0.5 mm (0.020 inch) thick transparent polycarbonate. Different grades of plastic can be used depending on the target environment for the light pipe (eg, UV resistant materials may be desirable for outdoor use). Other suitable materials include PET, PETG, and acrylic. Such plastics can be ordered in various lengths and widths. The conduit 6 is formed, for example, by laying out a desired length of plastic having a width corresponding to the desired circumference of the pipe.
Material 8 is applied on the desired surface of the plastic. The plastic can then be rolled to form a cylinder and the ends of the plastic can be taped in at the seams. The ends can overlap or abut. The seam can be sealed by adhesive or other methods such as ultrasonic welding. On the other hand, it is not necessary to seal the seam at all if other means for maintaining the light pipe arrangement are provided. Other methods of forming the conduit will be apparent to those skilled in the art.

Suitable light sources include any high intensity light source capable of generating a light beam having a desired beam angle. For example, a spotlight typically can generate a relatively small beam angle. Other suitable light sources include "high frequency inductive lamps and power oscillators (High Frequency) with appropriate optics to produce the desired beam angles.
y InductiveLamp and Power
Oscillator) described in PCT Publication No. WO 99/36940. Another suitable light source is a "lamp containing sulfur (La
mp Included Sulfur), a microwave-driven sulfur or selenium lamp of the type generally described in US Pat. No. 5,404,076. Preferably, such a lamp is configured with a reflective microwave cavity as shown in FIG. 14 of U.S. Pat. No. 5,903,091, with appropriate optics for generating the desired beam angle. Is done. A preferred microwave aperture lamp is "High Brightness Microwave Lamp."
ve Lamp) "in co-pending application Ser. No. 60 / 133,885.

FIG. 6 is a schematic sectional view of a light pipe according to a second embodiment of the present invention. According to a second embodiment of the present invention, light is distributed through a light pipe using a plurality of layers of plastic material. Light source 20 provides a light beam having a relatively narrow beam angle into one end of light pipe 24. The light pipe 24 is an inner pipe 26
And an outer pipe 28. A reflective material 30 is disposed on the inner surface of the outer pipe 28. The reflecting material 30 has both a specular reflection component and a diffuse reflection component as described above. Preferably, the reflective material 30 extends along substantially the entire length of the light pipe 24.

A gap 32 is provided between the inner pipe 26 and the outer pipe 28. The purpose of this gap is
Improves the ability to confine light within the light pipes (due to the double glint between the pipes) and what may occur if the inner pipe 26 was in contact with the outer pipe 28 This is to provide a suitable air-to-pipe interface to avoid certain light losses. Preferably, the gap is about 1-2 mm wide,
The size of the gap is not critical. Appropriate spacer elements (not shown) are used to maintain the air gap along the length of the light pipe. For example, the air gap can be provided by a plurality of transparent plastic rings spaced along the length of the light pipe 24 and positioned between the inner and outer pipes. On the other hand, a void can be provided by winding a nylon wire or the like around the inner pipe 26.
Furthermore, as an alternative, it is possible to form ribs or raised portions in the plastic sheet to provide an appropriate gap.

FIG. 7 shows a schematic cross section of the light pipe taken along line 7-7 in FIG. As shown in FIG. 7, the inner pipe 26 and the outer pipe 28 are substantially concentric. The reflective material 30 follows the inner surface of the outer pipe 28 and covers an angle of the inner surface of the pipe 28. The angular portion of the reflective material can be varied to provide a desired light output. Some of the light incident on the reflective material 30 is scattered by the Fresnel reflection effect into a beam that is not well confined. These beams are scattered from the reflective material 30 in a direction mainly orthogonal to the plane of the tape surface. For example, as shown in FIG. 7, when the reflective substance is arranged in the upper semicircle of the cross section of the light pipe 24, the scattered light from the reflective substance 30 is mainly due to the lower semicircle of the light pipe 24. In the direction shown.

Generally, the transmission capacity of a light pipe according to the present invention is proportional to the outer diameter of the light pipe. Larger diameter pipes have less internal bounce of light and the rate of light leakage depends on the number of bounces. In the case of a multi-layer transparent plastic boundary (e.g., two or more concentric plastic pipes), a light pipe according to the present invention distributes light over a distance greater than about 50 pipe diameters. For example, for a 38 cm (15 inch) diameter pipe, this can be achieved while maintaining high uniformity (better than about 25% over most of the pipe).
Supports over 9 meters (60 feet).
Typically, more layers are provided near the light source and / or near the mirrored end cap (see FIG. 11). According to the present invention, the uniformity and distribution of light along the light pipe depends on the number of layers, the length of each layer, and the finishing of each side of each layer (ie,
(Diffusive or glossy). 8 to 11 are schematic diagrams showing another configuration of the light pipe according to the second embodiment of the present invention. 8 to 11
, The number of layers varies along the type distance. By varying the number of concentric plastic pipes as a function of the distance along the pipe, the light pipe according to the invention controls the rate at which light is allowed to escape from the light pipe. In FIG. 11, a section 34 of diffusing material is provided near both the light source and the mirrored end cap to reduce the appearance of bright spots at both ends of the light pipe.

According to another aspect of the invention, the plastic sheet is such that the resulting structure has both specular and diffuse reflection components when viewed through the plastic sheet from the opposite side. It is possible to obtain a desired reflection characteristic by applying various substances to the surface of the substrate. FIG. 12 is a schematic sectional view showing another configuration of the light pipe according to the present invention. The light pipe 44 has a plurality of concentric conduits 46,48. In FIG. 12, a reflective material 50 is disposed on the outer surface of the outermost conduit 48. For example, the reflective material 50 can have a white tape. FIG. 13 is a schematic diagram illustrating the light beam 52 incident on the inner surface of the conduit 48. FIG.
As can be seen in 3, the inner surface of the outermost conduit 48 provides a specular component 54 for shallow angles of incidence, and the reflective material 50 on the outer surface The generated diffuse reflection component 56 is given. Thus, under this aspect of the invention, the reflective material 5
0 does not need to provide a specular reflection component. Other examples of reflective material 50 include, for example, outermost conduit 48
Tyvek ™ or other diffusely reflective material secured in an appropriate manner to the outer surface of the outermost conduit 48.

FIG. 14 is a schematic diagram of the light output pattern for a light pipe according to the present invention using a plastic sheet with a gloss finish on both sides. The light pipe 60 has a plastic conduit 61 carrying a reflective material 62 on an inner surface 63. Reflective material 62 covers about 180 ° of interior surface 63 of conduit 61, thereby defining a light output window of about 180 ° on the opposite side of pipe 60 with respect to reflective material 62. Inner surface 6 of conduit 61
Both 3 and exterior surface 64 have a glossy finish. Thus, the light scattered by the reflective material 62 exits the pipe 60 in a pattern approximately indicated by the dotted line 65.

By using a generally available matte finish, such as a satin or velvet finish, on the outermost surface of the outermost plastic conduit, the light escaping from the pipe will reduce the gloss of the plastic sheet. It is further diffused by the unfinished sides. FIG. 15 is a schematic illustration of a light output pattern for a light pipe according to the present invention using a plastic sheet having a gloss finish on the inside and a diffusion finish on the outside. The light pipe 66 has a plastic conduit 67 carrying a reflective material 68 on an inner surface 69. Reflective material 68 covers about 180 ° of interior surface 69 of conduit 67. Inner surface 68 has a glossy finish and provides a specular reflection for passing shallow angles of light along pipe 66. The outer surface 70 of the conduit 66 has a matte finish and further diffuses light exiting the pipe 66.
Therefore, the light scattered by the reflecting material 68 is represented by a dotted line 71.
Exits from the pipe 66 in a pattern approximately indicated by

When a plurality of concentric conduits are used to transport light along a light pipe, typically only the outer surface of the outermost conduit has a matte finish, velvet finish, or other diffuser finish. It is desired to have a sexual finish. Exceptions to this general rule may apply in the area of the light pipe closest to the light source and the mirror-type end cap, and beams that are not within an angle that are efficiently transported by the Fresnel reflection effect are more diffuse. To reduce the glare when looking directly at these beams (which otherwise would escape from the light pipe with concentrated spatial and angular cones). Notwithstanding the general rules above, the present invention may be useful for any particular application, so that gloss and / or diffusive It is intended to use a surface.

FIG. 16 shows a schematic diagram of the light output from yet another embodiment of a light pipe according to the present invention. The light pipe 72 is similar to the light pipe described in connection with FIG. 12 and has an outer conduit 48 on which the reflective material 50 is disposed. The light pipe 72 further comprises
The outermost conduit 48 has an additional silver or aluminum coated reflector or reflector 73 over approximately 270 ° and a diffuser tape 74 is provided over the output window defined by the reflector 73. As shown in FIG. 16, a relatively directional output substantially indicated by a dotted line 75 is obtained.

FIG. 17 shows a flat bottom 76 made of a diffusing material and a silver / aluminum coated reflector 77.
1 illustrates an exemplary embodiment of a hemispherically shaped light pipe having a top consisting of: 18 to 20 show respective sectional views for different light pipe configurations according to the invention.

FIG. 21 is a schematic view of a first plastic sheet in a preliminary preparation stage for forming a light pipe according to the present invention. FIG. 22 is a schematic view of a second plastic sheet in a preliminary preparation stage for forming a light pipe according to the present invention. FIG. 23 is a cross-sectional view of a first preferred embodiment for a light pipe according to the present invention.

Referring to FIGS. 21 to 23, the first exemplary embodiment of the present invention is configured as follows. The 2.4 m (8 ft) section of light pipe 80 includes a preformed transparent plastic rigid jacket 82 having an outer diameter of about 15 cm (6 inches). Plastic polycarbonate sheet 8 about 47 cm (18.4 inches) wide and 2.4 m (8 feet) long
4 (0.5 mm / 0.02 inch thick) has a glossy finish on one side and a matte finish on the other side, which is a white color that extends along the length of the sheet. Several slightly overlapping strips of vinyl tape are provided, on each side of the glossy side of the sheet, about 18 cm (7 inches) of reflective material.
A wide strip 86 is provided. As a result, the sheet 84
A clear strip 88 of about 4.8 inches (11 cm) is left in the middle of the. The sheet 84 is rolled with the tape 86 inside and held within a diameter of less than 15 cm (6 inches) and inserted into a rigid jacket 82. The seat 84 is then released and opened to the outer jacket 82. The two strips 86 abut or slightly overlap each other to provide an approximately 270 ° reflective surface, and the transparent strip 88 defines a 90 ° light transmissive window.

About 46 cm (about 18.1 inches) wide and 2.
8 m (8 ft) long plastic polycarbonate sheet with glossy finish on both sides (0.5 mm /
0.02 inch thick) separate plastic sheet 94
Are provided with a strip 96 of neoprene across the width of sheet 94 spaced about 18 inches (45 cm). Neprene 96 is about 1.5 mm (1/16 inch) thick and is adhered to the sheet with clear RTV108 silicone. After drying, the sheet 94 is rolled with the neoprene 96 outside and held at a diameter of less than 15 cm (6 inches). The sheet 94 is then inserted into the pipe section 80 and released to open against the previously inserted sheet 84. Neoprene 96 provides an air gap between the two plastic sheet layers 84,94.

[0034]Performance data for the first form  Assembling and connecting these three sections 80
To form a light pipe 24 feet long. Rigid
Racket 82 abuts and tapes at seam
You. The small length of the inner layers 84 and 94 is a rigid jacket
Can extend beyond the end of the socket 82 and
Can be interleaved with the inner layer of the next section
It is possible. The light pipe is suspended from the ceiling and
Commercially available from High End Systems, Austin, Kissas
Cyber Light (CYBERLIGHT)
Illuminate with a (trademark) spotlight. The spotlight
Is about 7,000-8, in the form of a collimated beam
Provides 500 lumens of light, about 15 ° to 28
It is possible to adjust between a total beam angle of °. Reflection
Cap on the light pipe opposite the spotlight
Mounted on the end. Reflective portion of the end cap
Are inclined about 10 ° from the vertical.

Exemplary normalized performance data for a full beam angle light source of about 15 ° measured about 30 inches away from the pipe is as follows:

[0036]

[Table 1]

FIGS. 25 and 26 are graphs comparing the light output of the above-described light pipe with that of the conventional TIR light pipe. Conventional TIR light pipes use OLF for light distribution.
Is a 25 cm (10 inch) diameter pipe. Conventional TIR light pipes are commercially available from Fusion Lighting, Inc. of Rockville, Maryland, a Light Drive (Light Dri).
ve) Illuminated by a ™ 1000 light source. The light source is provided with a reflector for directing light into the light pipe. Note that the conventional TIR system described above is considered to have good performance in terms of light distribution and uniformity. However, as shown in FIGS. 25 and 26, the light pipe of the present invention distributes light with greater uniformity over longer pipes. Also, because the beam angle is relatively narrow, the light output is less intense in a section of the light pipe adjacent to the light source. In the case of a conventional TIR system, a significant amount of light output tends to be concentrated near the light source, as can be seen from FIG. It may produce the desired glare or glare.

FIG. 24 is a schematic sectional view showing a second preferred embodiment of the light pipe according to the present invention. FIG.
Referring to -22 and 24, an exemplary second embodiment of the present invention is configured as follows. The six foot section of the light pipe 100 has a rounded outer sleeve 102 having a diameter of about 15 cm (6 inches). About 47cm
A plastic polycarbonate sheet 84 (0.4 mm) that is 18 inches (18.4 inches) wide and 6 feet long and has a glossy finish on one side and a matte finish on the other side.
/0.02 inch thick) on each side of the satin finish side of the sheet about 18 cm (7 inches) of reflective material
A highly reflective Mylar that extends along the length of the sheet to provide a strip 86 of width.
It is prepared with the strip comprising r). For example, it is possible to use several overlapping strips of transparent double-sided tape to secure mylar to sheet 84. This allows
Approximately 11 cm (4.8 inches) along the middle of sheet 84
Transparent strip 88 is left. One side of the sheet 84 is inserted into the channel 105a of the mounting device 107 extruded with the strip 86 outside. The sheet 84 is then secured to one side of the mounting device by tape or other suitable method. The sheet 84 is then rolled with the strip 86 outside and the free end of the sheet 84 is inserted into the release channel 105b. The sheet 84 is then secured to the opposite side of the mounting device 107 by tape or other suitable method, thereby forming the outer sleeve 102. These two strips 86
Provides a reflective surface of about 270 ° and a transparent strip 8
8 to provide a 90 ° light transmission window. Depending on the material used for the mounting device, a strip of reflective material 104 may be disposed on the interior surface of mounting device 107 to provide the desired light reflection properties (eg, any of diffuse and / or specular reflection). Combinations).

Approximately 46 cm (18.1 inches) wide and 1.8
Another plastic sheet 94 consisting of a plastic polycarbonate sheet (0.5 mm / 0.02 inch thick) having a glossy finish on one side and a matte finish on the other side, having a length of 6 m (6 feet), is provided on the matte finish side. It is provided with three strips of transparent foam tape 96 from 3M across the width of the sheet. One strip is approximately centered and the other two strips are about 15 cm (6 inches) from each end
Place them apart. The tape 96 is about 1.5mm / 1 /
16 inches) thick. Sheet 94 is rolled with tape 96 outward and held to a diameter of less than 15 cm (6 inches). For example, one or both sides of the rolled sheet 94 can be fixed with masking tape. The sheet 94 is then inserted into the pipe section 100 and released (eg, removing the masking tape),
The outer sleeve 102 is spread. Tape 96 provides a gap between the two layers of plastic sheets 84,94.

These five sections 100 are assembled and connected together to form a 30 foot long light pipe. An additional layer of two diffusive materials, one about 120 cm (4 feet) long and the other about 90 cm (3 feet) long, was positioned in the first section near the light source to create a bright spot. Avoid appearing.
These outer sleeves 102 abut and can be taped or otherwise joined together at a seam. A small length of the inner layers 84, 94 can extend beyond the ends of the outer sleeve 102 and be interleaved with the inner layers of the next section. The light pipe is illuminated by a high intensity metal halide lamp suspended from the ceiling and placed in an elliptical reflector. A suitable lamp is model number V
Osram / Sylva of Danvers, Mass. As IPR 4000/32.
Nia) is commercially available. This lamp is about 12 °
About 20,000 lumens in the form of a focused beam with a total beam angle of A reflective end cap is attached to the end of the light pipe opposite the spotlight. A concave reflector is positioned on the end cap to avoid the appearance of a high brightness spot at the end of the light pipe opposite the light source.

[0041]Mounting and coupling mechanism  Place the light pipe of the present invention near the ceiling or in the area to be illuminated.
Hang it to any other desired position or take it
Any of a number of conventional mounting and coupling mechanisms to attach
It is obvious to a person skilled in the art that
You. Similarly, light pipes using a number of conventional coupling devices
Multiple sections can be joined together
It is.

FIGS. 27 and 28 are perspective views of a mounting device according to one aspect of the present invention, which provides up to three layers of conduit without the need for spacer elements.
Referring to FIG. 27, the first mounting device 120 is typically made of extruded plastic having a length corresponding to the desired length of the light pipe section. The mounting device 120 has a strut portion 122, which is substantially perpendicular to the opposing fins 124a and 124b. Fins 124a and 124b can be curved to have a radius corresponding to the desired radius of the conduit. Referring to FIG. 28, the second mounting device 1
30 is also made of extruded plastic,
Typically, it has a length corresponding to the desired length of the light pipe section. Body part 132 of mounting device 130
Defines a channel 134 that is adapted to receive the post 122 of the first mounting device 120. The main body 130 further includes a plurality of mounting holes 135a, 135b,
135c, 135d, which allow the mounting device 130 to be directly attached to the ceiling (eg, holes 135a, 135a, 135d).
By bolting through 135b) or U
It can be used to secure tracks in shape (eg, by pinning through holes 135c, 135d). Holes 135a, 135b can be internally countersunk to provide clearance for the bolt head and to avoid interference with struts 122. Similarly, holes 135c and 135d are provided between the pin and the support 12
2 should be positioned so as to avoid interference between them. The mounting device 130 further includes a plurality of fins 136.
a, 136b and 138a, 138b, which are curved to have respective radii corresponding to the desired radius of the conduit.

In the application, the first mounting device 120 is used to provide one layer of conduit. The conduit has a length corresponding to the length of the mounting device 120 and is formed from a plastic sheet having a desired width selected to provide the desired overall circumference (with fins 124a, 124b) of the conduit. It is formed. One of the long ends of the sheet is fixed to one fin 124a or 124b of the mounting device 120. For example, the ends can be secured by tape, adhesive, ultrasonic welding, or other conventional means. The sheet is then rolled and the other end is secured to the other fin.

Similarly, mounting device 130 can be used to provide one or two layers of conduit. The first layer can be secured to the fins 136a, 136b, taking care not to cover the channel 134. For example, the sheet can be adhered to the inner surface 136c of the fins 136a, 136b. On the other hand, the sheet can be fixed in a channel 136d formed between two sets of fins. The second layer can be secured to the outer surfaces of the fins 138a, 138b.

Advantageously, the fins in each of the first and second mounting devices 120, 130 provide up to three layers of conduit and the need to provide additional spacer elements between the layers. Remove or reduce. If additional layers are desired, they can be provided with a spacer element as described elsewhere herein and can be added to the conduit supported by the first mounting device 120. It is possible to unfold it.

FIG. 29 is a schematic diagram of a coupling device 140 according to the present invention. FIG. 30 is a schematic cross-sectional view of the coupling device 140 taken along line 30-30 in FIG. Coupling device 140 is generally configured as a plastic ring having a pair of opposed channels 142a and 142b disposed parallel to the longitudinal axis of the light pipe and disposed about a circumference. In some applications, the outermost layer of the light pipe section is inserted into the channel 142a or 142b and secured by tape, glue, ultrasonic welding, or other conventional means. Advantageously, the coupling device 140 helps the light pipe to maintain its shape. The mating end of the next light pipe section is inserted and secured into the release channel to join the plurality of light pipe sections together. When used with a mounting device as described herein, the outermost conduit section is configured to extend slightly beyond the end of the mounting device. On the other hand, the coupling device 140 can be configured as a semi-circular ring with the angular section corresponding to the angular section occupied by the mounting device removed.

FIG. 31 shows an end cap 16 according to the present invention.
0 is a schematic sectional view of FIG. The end cap 160 is parallel to the longitudinal axis of the light pipe and has a channel 1 around its circumference.
62 are defined. Channel 162 is configured to receive a layer (eg, an outermost layer) of the light pipe. The inner surface 164 of the end cap is preferably highly reflective and configured to redirect light incident on the end cap in the opposite direction along the light pipe. Preferably, surface 164 is beveled or shaped to improve light distribution and / or efficiency of the light pipe. For example, the end cap can have a mirror that is tilted about 10 ° toward the diffuser to reflect light in the opposite direction along the pipe and scatter redirected light from the light pipe. is there. The mirror may be integral with the end cap 160 or may be a separate part.

FIG. 32 shows a schematic cross-sectional view of a second end cap 170 according to another aspect of the present invention. The end cap 170 has a mirror 172 with a curved surface 174. Preferably, the curved surface is configured to improve light distribution and / or efficiency of the light pipe. For example, if certain areas of the light pipe are poorly illuminated, the curved surface 174 will focus light incident on the end plate at the diffuser near areas requiring additional light output. That is, it is possible to adopt a mode of focusing. Mirror 172 may be integral with end cap 170 or may be a separate part.

[0049]Small light pipe  A further advantage of the light pipe of the present invention is that it utilizes the principles of the present invention.
It is possible to construct very small diameter pipes.
That is. Prism film is very small
It is impossible to round to a great diameter. The advantages of the present invention are:
The material used can be extruded to a very small diameter or
Can be rounded to a very small diameter
And

A light pipe having substantially the same dimensions as a typical fluorescent lamp is constructed as follows. Two cylindrical tubes are formed from extruded plastic and have a thickness of about 1.2
Cut to m (4 feet) length. One tube has an outer diameter that is slightly smaller than the inner diameter of the other tube. For example, the outer tube can have an extruded Lexan ™ having an outer diameter of 38 mm (1.5 inches) and a thickness of about 2-3 mm (1/8 inch). The inner tube can have extruded Lexan ™ having an outer diameter of 31 mm (1.25 inches) and a thickness of 2 to 3 mm (1/8 inch). Instead of an extruded tube, it is also possible to roll a suitable thin plastic sheet to form a conduit.

The smaller diameter tubes are inserted into the larger diameter tubes and the tubes are separated through suitable spacer means to provide a void. For example, relatively thick (eg, 0.5-1.0 mm) foam tape can be used at two or more points along the inner tube. Alternatively, a channel may be provided in the end cap to receive each tube and position the plurality of tubes coaxially and in a non-contacting manner without spacers.

The outer tube has a glossy inner surface and a diffused (eg, satin or velvet) outer surface. The inner tube has a glossy inner surface and an outer surface. Highly reflective Mylar
(Trademark) half of the outer surface of the outer tube (ie 180 °)
And secured thereto by transparent double-sided tape or other suitable means.

The small light pipe is illuminated, for example, with a lamp as described in PCT Publication No. WO 99/36940, 4.4.2, with appropriate optics to provide a tight beam angle of light. For example, a suitable optical system is shown in FIGS. FIG. 33 is a schematic diagram of a lens system suitable for use with the miniature light pipe of the present invention. FIG. 34 is a schematic cross-sectional view of the lens system taken along line 34-34 in FIG. The lens system 200 includes a first lens 204 held in place by a holding ring 206, and second and third lenses 20 fixed by a holding ring 212.
8, 210 is provided with a lens folder 202. Exemplary first lens 204 is part number J45
-303 as Edmond Industrial Optics, Burlington, NJ, USA
s) A 12 mm coated plano-convex lens commercially available from the company. Exemplary second and third lenses 20
8, 210 are both part number J45-1
50 and J32-895 are 45 mm coated plano-convex lenses available from Edmund Industrial Optics of Burlington, NJ, USA. The lens system focuses a total beam angle of about 140 ° of light from the lamp aperture to a total beam angle of about 22 ° of light into the miniature light pipe. The second and third lens pairs can be replaced by a single double convex lens. As will be appreciated by those skilled in the art, a wide range of optical equipment can be used to provide the desired tight beam angle of light.

[0054]Hybrid lighting  According to another aspect of the invention, a light source for a light pipe of the invention is provided.
It can be the sun. Sun is a place seen from the earth
In this case, it is a 7 ° light source. Therefore, the light pipe of the present invention
Can be used in sunlight, artificial light, or hybrid lighting systems.
And can be used beneficially with these two combinations
It is possible.

A simple, readily available tape and plastic that can be constructed using simple techniques,
A low cost, efficient light pipe has been described. The light pipe according to the present invention can be applied over a wide range of markets and dimensions not previously considered for conventional TIR light pipes or other light pipe applications.

Although the specific embodiments of the present invention have been described in detail above, the present invention is not limited to these specific examples, and various modifications can be made without departing from the technical scope of the present invention. Of course is possible. For example, while the embodiments described above primarily use a curved cross-section of a light pipe, this is merely an example of a achievable cross-section and other cross-sectional shapes may be useful in other applications. Of course, it is possible to use. For example, a rectangular shape is beneficial in applications that retrofit to a conventional suspended ceiling with a metal grid grid pattern, such as one configured to accept a standard 2x2 or 2x4 fluorescent fixture. May be important. The shape of the bottom surface, along with its finish, can also be applied to control the divergence of the beam.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a transparent material showing specular reflection.

FIG. 2 is a schematic cross-sectional view of an opaque material showing both specular reflection and diffuse reflection.

FIG. 3 is a graph showing the relationship between the reflectance and the incident angle for an exemplary transparent material exhibiting specular reflection.

FIG. 4 is a schematic sectional view showing a light pipe according to a first embodiment of the present invention.

FIG. 5 is a schematic diagram showing a light beam incident on a diffuse reflection material.

FIG. 6 is a schematic sectional view of a light pipe according to a second embodiment of the present invention.

7 is a schematic cross-sectional view of the light pipe taken along line 7-7 in FIG.

FIG. 8 is a schematic diagram showing another configuration of the light pipe according to the second embodiment of the present invention.

FIG. 9 is a schematic diagram showing another configuration of the light pipe according to the second embodiment of the present invention.

FIG. 10 is a schematic diagram showing another configuration of the light pipe according to the second embodiment of the present invention.

FIG. 11 is a schematic diagram showing another configuration of the light pipe according to the second embodiment of the present invention.

FIG. 12 is a schematic sectional view showing another configuration of the light pipe according to the present invention.

FIG. 13 is a schematic diagram showing a light beam incident on an inner surface of a light pipe.

FIG. 14 is a schematic diagram showing the light output pattern for a light pipe according to the present invention using a plastic sheet having a glossy finish on both sides.

FIG. 15 is a schematic diagram showing the light output pattern for a light pipe according to the invention using a plastic sheet with a glossy inside and a matte finish on the outside.

FIG. 16 is a schematic cross-sectional view illustrating light output from yet another embodiment of a light pipe according to the present invention.

FIG. 17 is a schematic cross-sectional view of a light pipe having a hemispherical shape according to the present invention.

FIG. 18 is a schematic sectional view showing another shape of the light pipe according to the present invention.

FIG. 19 is a schematic sectional view showing another shape of the light pipe according to the present invention.

FIG. 20 is a schematic sectional view showing another shape of the light pipe according to the present invention.

FIG. 21 is a schematic diagram showing a first plastic sheet in a preparation stage for forming a light pipe according to the present invention.

FIG. 22 is a schematic diagram showing a second plastic sheet in a preparatory stage for forming a light pipe according to the present invention.

FIG. 23 is a schematic sectional view showing a first preferred embodiment of the light pipe according to the present invention.

FIG. 24 is a schematic sectional view showing a second preferred embodiment of the light pipe according to the present invention.

FIG. 25 is a graph comparing the light output of a conventional TIR light pipe with the light output of the light pipe of the present invention.

FIG. 26 is a graph comparing the light output of a conventional TIR light pipe with the light output of the light pipe of the present invention.

FIG. 27 is a cutaway schematic perspective view showing a first light pipe mounting device according to another aspect of the present invention.

FIG. 28 is a cutaway schematic perspective view showing a second light pipe mounting device according to the present invention.

FIG. 29 is a schematic diagram illustrating a light pipe coupling device according to another aspect of the invention.

FIG. 30 is a schematic sectional view of the light pipe coupling device taken along line 30-30 in FIG. 29;

FIG. 31 is a schematic sectional view showing a first light pipe end cap according to the present invention.

FIG. 32 is a schematic sectional view showing a second light pipe end cap according to the present invention.

FIG. 33 is a schematic diagram illustrating a lens system suitable for use with the light pipe of the present invention.

FIG. 34 is a schematic cross-sectional view of the lens system taken along line 34-34 in FIG.

[Explanation of symbols]

 Reference Signs List 4 light pipe 6 conduit 8 reflective material 10 light source

Continued on the front page (72) Inventor Mikair A. Dubinowski United States, Maryland 20886, Gettysburg, Steadwick Road 10022, Apartment 303 (72) Inventor Vincent H. Kuwon United States, Maryland 20877, Gettysburg, Killarney Lane 9901, Apartment 101 (72) Inventor Frank Soise United States, Maryland 21702, Frederick, Fox Run Coat 1385

Claims (21)

[Claims] 1. A light pipe, comprising: a conduit for receiving light at one end and distributing the light along its length, wherein the conduit mainly reflects a portion of the light by specular reflection. A mirror-reflective surface and a diffuse-reflective surface arranged to pass along the pipe and to emit a part of the light mainly to the outside of the light pipe by diffuse reflection, wherein the reflective surface is A light pipe substantially parallel to a longitudinal axis of the light pipe. 2. The tube of claim 1 wherein said conduit is disposed along a length of said tube and a transparent plastic tube having an interior surface providing specular reflection. A light pipe comprising an opaque material partially covering the opaque material, the opaque material providing diffuse reflection. 3. The method of claim 2, wherein the opaque material is disposed on an interior surface of the tube and provides specular reflection for small beam angles of light and diffuse reflection for large beam angles of light. Providing a light pipe. 4. The opaque material of claim 2, wherein said opaque material is disposed on an interior surface of said tube, said tubing material and said opaque material together being mirrored for a small beam angle of light. A light pipe that provides reflection and diffuse reflection for large beam angles of light. 5. The light pipe of claim 1, wherein said conduit comprises an extruded plastic tube. 6. A light pipe according to claim 1, wherein said conduit comprises a plastic sheet material molded to form a tube. 7. A light pipe, comprising: a plurality of conduits receiving light at one end and distributing the light along a length of the light pipe, wherein the plurality of conduits are defined by respective gaps. Arranged so as to be offset from each other and to allow a portion of the light to pass through the light pipe primarily by specular reflection and to emit a portion of the light out of the light pipe primarily by diffuse reflection. A light pipe having a specular reflection surface and a diffuse reflection surface provided. 8. The light pipe of claim 7, wherein the number of said conduits varies along the length of the light pipe. 9. The light pipe of claim 7, wherein the length of at least one of the plurality of conduits is different from the length of another of the plurality of conduits. 10. The light of claim 7, wherein each of the plurality of conduits comprises either an extruded plastic tube or a plastic sheet material molded to form a tube. pipe. 11. The method of claim 7, wherein each of the plurality of conduits, except for the outermost conduit, comprises a clear plastic having a glossy finish on both its inner and outer surfaces. And light pipe. 12. The light pipe of claim 11, wherein said outermost conduit comprises a clear plastic having an interior surface polished and an exterior surface having a diffusion finish. . 13. The opaque material of claim 12, further comprising an opaque material disposed along a length of the outermost conduit and covering a part of a periphery of the outermost conduit. Light pipe. 14. The method of claim 13, wherein the opaque material is disposed on an interior surface of the outermost conduit and provides specular reflection for small beam angles of light and for large beam angles of light. A light pipe characterized by giving diffuse reflection. 15. The method of claim 13, wherein the opaque material is disposed on an outer surface of the outermost conduit,
And the tube material and the opaque material together,
A light pipe characterized by providing specular reflection for a small beam angle of light and diffuse reflection for a large beam angle of light. 16. A light distribution system for providing a light beam having a total beam angle of less than 30 degrees, a light pipe receiving at one end a light beam from the light source and distributing the light along its length. , And
A mirror surface disposed to allow a portion of the light to pass along the light pipe primarily by specular reflection and to emit a portion of the light out of the light pipe primarily by diffuse reflection; A light distribution system having a reflective surface and a diffusely reflective surface. 17. The light source according to claim 16, wherein the light source is 20 light sources.
A light distribution system for providing a light beam having a total beam angle of less than degrees. 18. The light distribution system according to claim 16, wherein the light source supplies sunlight. 19. The light pipe of claim 16, further comprising an end cap covering an end of the light pipe opposite the light source, wherein the end cap reflects light along the light pipe. A light distribution system having a reflective surface. 20. The light pipe of claim 16, wherein the light pipe comprises first and second substantially concentric conduits.
Further, the light distribution system comprises: a first mounting device for supporting the first conduit; supporting the second conduit; and supporting the first mounting device and the first conduit within the second conduit. A light distribution system, comprising: 21. The light distribution system according to claim 20, wherein said first and second mounting devices hold said first and second conduits out of contact with each other.