JPH11142652A - Light emission unit and illuminator using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To exchange a light source without opening a boxy body and to easily form a relatively large-sized illumination surface uniformly light emitting by providing a light incident end on its one end and a light outgoing end on its the other end of an optical fiber of a light emission body and providing at least one optical fiber and a light leakage means on a linear light emission body in the light transmission space of the boxy body. SOLUTION: This illuminator is provided with the light emission body consisting of the optical fiber 2 arranged in the light transmission space 10 and the light leakage means light leaking the light supplied to the optical fiber 2 from the side surface of the optical fiber 2 to the light transmission space 10. This illuminator contains a light uniformizing means so as to obtain nearly uniform luminance over a whole area of a light emission surface 11 by the light leaked from the light emission body. The optical fiber 2 is provided with the light incident end 21 placed on one end of the optical fiber 2 and communicated with the outside of the boxy body 1 and the light outgoing end placed on the other end of the optical fiber 2 and communicated with the outside of the boxy body 1. The light leakage means is arranged on a part of the peripheral surface of the optical fiber 2 nearly along the longitudinal direction of the optical fiber 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internally illuminated display for displaying road signs, advertisements, etc., and a relatively large-sized display which is arranged on an indoor or outdoor plane such as a ceiling, floor or wall of a building. The present invention relates to a light-emitting unit suitable for use in applications such as a planar lighting device, and a lighting device including a plurality of the light-emitting units.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 5-224 discloses a planar light emitting body which emits uniform light from the entire light emitting surface.
No. 020, JP-A-7-5326 and the like.

[0003] The planar illuminants disclosed in these publications generally have the following structure. 1: a box having a light guide space and at least one light-emitting surface; 2: a light source arranged in the light guide space of the box and emitting light into the light guide space; Light-equalizing means for obtaining uniform brightness over substantially the entire light-emitting surface when the light emitted into the light space is emitted from the light-emitting surface to the outside of the box. Body.

The above-mentioned box is usually a rectangular parallelepiped, and is configured such that at least one of the side surfaces having the largest area is a light emitting surface. The light emitting light source is usually a linear light source such as a fluorescent tube or a cold cathode tube, and emits light uniformly over the entire peripheral surface and the length direction.

When a linear light source is used, the linear light source is disposed substantially parallel to the light emitting surface. The arrangement position is usually near the parallel side plate facing the light emitting surface or near one side plate of the four orthogonal side plates perpendicular to the light emitting surface.
Also, in order to make the luminance on the light emitting surface uniform, usually,
It is arranged parallel to one straight side plate. For example, when it is arranged near the orthogonal side plate, it is arranged so as to be parallel to both the orthogonal side plate and the light emitting surface. The number of linear light sources is usually one, but a plurality of linear light sources may be arranged. Further, as a straight side plate located beside the linear light source, a reflector having a U-shaped cross section is usually used.

[0006] Generally, the brightness on the light emitting surface is brightest in a place near the light source, and becomes darker as the distance from the light source increases. Therefore, it is necessary to use light uniforming means in order to obtain uniform brightness over the entire light emitting surface.

The light homogenizing means is, in the planar light emitting device disclosed in the above-mentioned publication, constituted by a laminate comprising a prism film and a white translucent diffused light transmitting sheet. It is arranged so as to reach the light emitting surface after passing through the laminate. The prism film is usually formed of a transparent resin, and has a prism surface in which a plurality of micro prisms are parallel to each other. As such a prism film, for example, “TRAF-II” manufactured by 3M Corporation is used.

[0008]

The planar light emitting device using the linear light source described above has a light emitting surface that emits light uniformly, and is particularly useful as a light guide plate for a backlight that illuminates and visualizes a liquid crystal from behind. is there. Each of these planar light emitters includes a light source therein, and light source management needs to be performed for each light emitter. For example, even when a large illuminator is configured by combining a plurality of planar illuminators, there is a light source for each illuminant unit, and a light source (fluorescent tube or cold cathode tube) whose life has expired is Each requires replacement individually.

When replacing a fluorescent tube or a cold cathode tube,
It is necessary to open and disassemble the box, but it is necessary to avoid opening the box as much as possible in order to prevent entry of foreign matter such as dust. This is because the inclusion of foreign matter stains the inner surface of the box, and reduces the emission luminance and the uniformity of the luminance.

It has been proposed to use an optical fiber as a light source for the planar light emitter. However, a light source is supplied from a light source outside the box to the optical fiber, and light is extracted from the tip of the optical fiber in the conductor space. Shaped light emitters are also designed individually and independently.

[0011] All conventional planar light emitters are designed to emit light independently, and are not designed with the concept of using a plurality of light emitter units in combination.

That is, an object of the present invention is to provide a light-emitting unit which functions as a planar light-emitting body, in which a light source can be replaced without opening a box, and a plurality of units are combined to cover an entire indoor or outdoor plane of a building. Even when the arranged planar lighting devices are configured, it is possible to save the trouble of replacing the light source of each unit, and to easily form a lighting device having a relatively large lighting surface that emits light uniformly. And a light emitting unit.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a housing in which at least one light emitting surface (11) and the light emitting surface (11) are limited to form a light guide space (10). A box (1) consisting of (100);

At least one optical fiber (2) arranged in the light guiding space (10) of the box (1) and the light supplied to the optical fiber (2) is guided from the side of the optical fiber (2). A luminous body (20) including a light leaking means (4) for leaking light into a light space (10); and a light emitting body (20) that is present on the light guide space (10) side of the light emitting surface (11). When the light leaked to the light guide space (10) is emitted from the light emitting surface (11) to the outside of the box, the emitted light has substantially uniform brightness over the entire area of the light emitting surface (11). In the light emitting unit including the light uniformizing means (3), the optical fiber (2) of the light emitting body (20) is located at one end of the optical fiber (2) and communicates with the outside of the box (1). At the input end (21) and the other end of the optical fiber (2) A location and the box (1) outside communicating with the light emitting end and (22), the light leakage means (4)
Provides a light-emitting unit, wherein the light-emitting unit is arranged on a part of a peripheral surface of the optical fiber (2) of the light-emitting body and substantially along a length direction of the optical fiber (2).

[0015]

In the light emitting unit of the present invention, since the light emitting body includes an optical fiber, a light source for supplying light to the optical fiber can be arranged outside the box, and a light source whose life has expired without opening the box can be used. Can be exchanged.

The light-emitting unit of the present invention has the following i)
And ii). That is,

I) The optical fiber of the luminous body has a light incident end located at one end of the optical fiber and communicating with the outside of the box, and a light emitting end located at the other end of the optical fiber and communicating with the outside of the box. And ii) the linear illuminator disposed in the light guiding space of the box is a light leakage that leaks at least one optical fiber and light supplied to the optical fiber from the side of the optical fiber into the light guiding space. And the light leakage means is disposed on a part of the peripheral surface of the optical fiber of the light emitter substantially along the length direction of the fiber.

According to the above configuration i), even when a relatively large flat illuminating device arranged on the entire indoor or outdoor plane such as the wall of a building is constructed, the light source of each unit is replaced. You can save time and effort. The plurality of light emitting units are at least one of the light emitting units.
The light emitting end of one unit and the light incident end of the other unit can be connected to each other so that light can be transmitted between one optical fiber and at least one optical fiber of an adjacent light emitting unit. It is possible to make a plurality of units emit light with one external light source. At this time, one of the plurality of light-emitting units functions as a light-receiving and light-emitting unit to which light is directly supplied from the light source, and the optical fibers of the light-emitting units other than the light-receiving and light-emitting unit transmit the light from the adjacent light-emitting unit. The arrangement is such that light is supplied via optical fibers connected as possible.

In general, most of the light incident from one end (incident end) of an optical fiber does not leak to the outside and passes through as it is without hitting the inner peripheral surface of the fiber. After passing through the inside, it reaches the other end (exit end) and then goes out. The "light leakage means" in the configuration of ii) partially obstructs the total reflection as described above, and enables light leakage from the fiber side surface (peripheral surface). For example, when the light leakage means is a light diffusion reflection film adhered to the outer peripheral surface of the optical fiber, of the light incident from the incident end of the optical fiber, the light reaching the portion where the diffuse reflection film adheres (the inner peripheral surface of the optical fiber). Most diffusely reflect there. The diffusely reflected light is
The light proceeds toward the inner peripheral surface of the optical fiber facing the portion where the diffuse reflection film is in close contact, passes through the inner peripheral surface of the optical fiber, and leaks light to the outside. Light reflected only on the inner peripheral surface of the fiber where the light diffusion reflection film (light leakage means) is not arranged can reach the light emitting end without repeating light being totally reflected. That is, the larger the area (close contact area) of the light diffusion reflection film in the entire optical fiber, the greater the amount of light leaking.

Since the light leakage means is disposed on only a part of the outer peripheral surface of the optical fiber and substantially along the longitudinal direction of the optical fiber, the light leakage from the optical fiber uniformly occurs in the longitudinal direction, and the light emitting device including such an optical fiber Functions as a linear light source similar to a fluorescent tube or a cold cathode tube. Therefore, just by replacing a conventional linear light source such as a fluorescent tube with a luminous body including the above-described optical fiber, a luminous unit having a luminous surface that uniformly emits light can be configured, similarly to the conventional planar luminous body. A plurality of such units can be effectively combined to form a lighting device having a relatively large lighting surface that emits light uniformly.

When a relatively large illuminating device is formed by combining a plurality of units, a part of the light supplied to the optical fiber of the luminous body leaks, but most of the remaining light is emitted from the emitting end to the outside of the fiber. Optimizing the light leakage means so as to exit (to the optical fiber of the next unit). For example, when the light leakage means is a diffuse reflection film, the amount of light leakage can be easily controlled by adjusting the width dimension, the diffusion performance, and the arrangement method (for example, discontinuously provided in a dot shape) of the diffusion reflection film.

On the other hand, it is preferable that the light emitting unit includes an optical fiber for light transmission without light leakage means (that is, an optical transmitter) in addition to the optical fiber acting as a light emitter. By arranging the optical transmitter, light can be supplied to a unit far away from the light source without substantially lowering the transmission efficiency on the way, and it is extremely easy to make the light emission luminance uniform in all units.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Light Emitting Unit) One preferred embodiment of a light emitting unit of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view of a light emitting unit according to the present invention, in which a part of the inside is exposed. FIG. 2 shows A-
FIG. 3 is a cross-sectional view taken along line A ′, and FIG.
It is a cut surface cut along a line.

The box (1) comprises a top plate (5) and a housing (100), and the space formed by both is a light guide space (10). The box body (1) includes a top plate (5) forming a light emitting surface, and a bottom plate (103) disposed at a predetermined distance from the top plate (5) and substantially parallel to the top plate (5).
And two fiber support plates (101 a, 101 b) substantially perpendicular to the top plate (5) and provided with insertion holes for fixedly supporting the optical fiber (2);
01a, 101b) and two side plates (104a, 104b) arranged along a direction substantially perpendicular to the light guide space (10). is there. Thus, the housing (100) comprises a bottom plate (103) and two fiber support plates (101a, 1a).
01b) and two side plates (104a, 104b), and the top plate (5) is a prism film (30).
And a colorless and transparent support plate (51) and a diffused light transmitting sheet (31). The inventive aspect (11) particularly shows the surface of the top plate (5).

The inner surface of the box (1) (ie, the inner surface of the light guide space) is preferably coated with a highly reflective material. Thereby, the luminance of the light emitting surface is easily improved. As such a reflecting material, for example, a metal foil, a metal deposition coating, or the like can be used. In addition, from the viewpoint of preventing a decrease in reflectance due to corrosion of the reflective surface, when a metal is not desired to be used as a reflective material, a dielectric reflective film in which two types of organic polymer thin films having different refractive indices are alternately laminated as a reflective material. Alternatively, a coating containing a white pigment and a polymer can be used.

In the light guide space (10), at least one optical fiber (2) and light supplied to the optical fiber (2) are leaked into the light guide space (10) from the side surface of the optical fiber (2). A light emitting body (20) comprising a light leaking means (4) that emits light. The luminous body (20) is preferably arranged at a position near one side plate (104a). The light leaking means (4) is disposed on a part of the outer peripheral surface of the optical fiber (2) along the longitudinal direction of the optical fiber, and may be referred to as a light diffuse reflection film (hereinafter, also referred to as a "diffuse reflection film"). It is. The details of the diffuse reflection film will be described later.

In the illustrated embodiment, the light emitting surface (1
1) is a surface of the top plate (5), and the top plate (5) includes a prism film (30), a colorless and transparent support plate (51),
It is a laminate comprising a diffused light transmitting sheet (31). In addition, the top plate (5) also functions as a light uniformizing means (3), and the prism film (30) and the diffused light transmitting sheet (31) effectively work to substantially make the light uniform. It works effectively. The support plate (51) is used to improve the mechanical strength of the top plate (5) as a whole, but the laminate composed of the prism film (30) and the diffused light transmitting sheet (31) has a sufficient thickness. Or if it has mechanical strength, it is not necessary to use the support plate (51).

On the other hand, in the illustrated embodiment, the exposing means (4)
Are arranged so as to be emitted (leaked) from the fiber (2) toward the opposite side plate (104b). The side plates (104a, 104b) are curved in a direction perpendicular to the length direction of the fiber (2), and have a curved surface that is convex toward the outside of the box. Further, the inner surfaces of both side plates are mirror-finished. With such a configuration,
It is possible to prevent a decrease in luminance at a position farthest from the light emitting body (20), that is, at the light emitting surface (11) near the side plate (104b).

The optical fiber (2) is located at one end of the optical fiber (2) and a light incident end (21) communicating with the outside of the box (1), and the optical fiber (2) is located at the other end of the optical fiber (2). 1) It has a light emitting end (22) communicating with the outside. The light incident end (21) is an entrance for guiding light from outside the unit (for example, a light source) to the inside of the optical fiber (2). Part of the light guided into the fiber leaks into the light guiding space of the unit due to the action of the light leaking means (4), and most of the remaining light goes out of the unit from the light emitting end (22). At this time, if the light emitting end (22) and the light incident end of the optical fiber of another light emitting unit arranged adjacent to each other are brought into close contact with each other, light can be transmitted between both optical fibers.

As a method of adhering the fibers, a method of bonding with a transparent resin or a transparent adhesive having substantially the same refractive index as the optical fiber is preferable. When the optical fiber is made of plastic, a method of fusing by heating or ultrasonic waves can be used. For example, when the optical fiber is an acrylic resin, it can be bonded with an acrylic adhesive or thermally fused at a temperature in the range of 100 to 250 ° C. Further, when the optical fiber is made of plastic, it is possible to sufficiently connect the fibers so that optical transmission is possible between the fibers simply by pressing the ends of the fibers.

Further, as shown in FIG. 14, a box-shaped fiber supporting plate (1) is provided so that such a connection can be easily made.
01a, 101b) is preferably provided with a fiber support (12) having an insertion hole (102a, 102b) into which the fiber (2) is inserted. (Here, the insertion hole 102b is shown. However, it is a through hole provided in the fiber supporting portion 101b in the same manner as the insertion hole 102a.) For example, the light incident end (21) is located inside (from the light guide space (10)) the fiber support plate (101a).
The fiber (2) is fixed to the fiber support (12) while being depressed along the length of the insertion hole (102a) toward the side (side). Thereby, the insertion hole (102a)
A receiving portion is formed therein, into which a portion near the light emitting end of the optical fiber of the light emitting unit arranged adjacently can be fitted. On the other hand, the portion near the light emitting end (22) of the optical fiber (2), on the other hand, protrudes outward from the fiber support plate (101b) along the length direction of the insertion hole.
The fiber (2) is fixed to the fiber support. Thereby, this protruding portion of the fiber (2) is fitted into the receiving portion in the vicinity of the light incident end of the optical fiber of the adjacent unit, and the optical fibers of the two adjacent units are placed between them. Connect so that optical transmission is possible. As shown in FIG. 15, the fiber support portion (12) can be omitted if the thickness of the fiber support plate (101a, 101b) is sufficiently large, and the fiber support portion (12) is inserted into the insertion hole provided directly in the fiber support plate. Such a receiving portion can also be formed. The length of the insertion hole (dimension along the length direction of the fiber) is usually in the range of 5 to 50 mm.
The length of the fiber receiving portion provided in the insertion hole is usually in the range of 2 to 40 mm.

A method of fixing an optical fiber in an insertion hole of a fiber support portion or a fiber support plate is as follows.
(I) a method of bonding with a transparent resin or a transparent adhesive having substantially the same refractive index as the optical fiber; (II) an optical fiber and a fiber support (or a fiber support plate)
When both are made of plastic, a method of fusing by heating or ultrasonic waves. (III) As shown in FIG. 10, a clad material (6a, 6
A method utilizing b) can be used. In the case of the method shown in FIG. 10, the light incident end (21a) of the optical fiber (2a) of one unit is arranged so as to be recessed into the insertion hole along the thickness direction of the support plate (101a), and the cladding covering the fiber is disposed. The ends of the material (6a) are aligned with the outer surface of the support plate (101a). The light emitting end (22b) of the optical fiber (2b) of the other unit is arranged so as to protrude outward from the insertion hole along the thickness direction of the support plate (101b), and the clad material (6b) covering the fiber Of the support plate (10
Align with the outer surface of 1a). The connection between the fibers of the two units (2a, 2b) is performed by inserting the optical fiber (2b) of the other unit into the portion of the clad material (6a) without the optical fiber (2a), and using the connection method as described above. Do it. At this time, it is preferable to fix the clad material in the insertion hole of the fiber support plate with an adhesive or the like.

(Box) Each component of the box (1) is usually made of plastic such as acrylic, polycarbonate, ABS, polyester, polyolefin, polyvinyl chloride; metal such as stainless steel and aluminum; glass; wood; Formed from However, the component forming the light emitting surface (11) needs to be light transmissive. In addition, in order to color the light from the light emitting surface, a component forming the light emitting surface (top plate, etc.)
Can also be colored. For example, as described above, when the top plate includes a transparent support plate, the support plate can be formed from a colored light transmissive material.

The box body (1) can be produced, for example, by separately preparing each part and joining them together by an adhesive means.

The shape of the box is not limited to that shown in FIG. 1 as long as the effects of the present invention are not impaired. For example, only the side plate (104a) located in the vicinity of the illuminant is a curved plate as described above, and the side plate (104a) located away from the illuminant.
b) may be a flat plate (FIG. 4) or a plate having a substantially rectangular parallelepiped shape. Further, the top plate (5) forming the light emitting surface (11) may be a parallelogram such as a rhombus or a trapezoid. Also, instead of the top plate (5), the side plate (104b) or the bottom plate (10
3) can form a light emitting surface. In such a case,
A prism film, a diffused light transmitting sheet, and the like as light uniforming means are arranged close to or close to the side plate (104b) or the bottom plate (103). Further, any two or all of the top plate (5), the side plate (104b), and the bottom plate (103) may have a light emitting surface.

The thickness of the parts constituting the box (1) is appropriately determined according to the material and role of each part. For example, the top plate (5) and the bottom plate (103) have a relatively large area, and are always exposed when the light emitting surface is formed. Therefore, the top plate (5) and the bottom plate (103) should be as thick as possible to increase the mechanical strength. desirable. However, if the thickness is too large, the unit cannot be reduced in weight, which may cause inconvenience in handling and may cause a decrease in luminance of the light emitting surface. From such a viewpoint, the thickness of these parts is usually in the range of 0.5 to 30 mm, preferably 1 to 30 mm.
It is in the range of ２０20 mm. Fiber support plate (101
a, 101b) also depends on the number and weight of the optical fibers to be supported, but requires sufficient mechanical strength as in the case of the top plate and the bottom plate. Range from 1 to 20 mm. In the case where the fiber receiving portion is formed in the insertion hole provided directly in the fiber support plate as described above, it is preferable that the thickness is larger. The side plate does not require much higher mechanical strength than other parts, and therefore can be made as thin as possible. From such a viewpoint, it is usually 0.1 to 30 mm, preferably 0.1 to 30 mm.
The range is 5 to 20 mm.

On the other hand, the height of the box (the distance between the outer surface of the top plate and the outer surface of the bottom plate) is appropriately determined by the diameter, arrangement, and number of optical fibers disposed inside. It is desirable to be thinner in terms of weight reduction. Therefore, it is usually in the range of 2 to 30 cm, preferably 3 to 20 cm, particularly preferably 5 to 15 cm. In addition, the light emitting surface (1
The plane dimension of 1) is usually 20 cm × 20 cm to 200 cm × 200 c, taking the case where the light emitting surface is square as an example.
m, preferably 25cmX25cm-100cmX100
cm. If it is too large, it is difficult to reduce the weight,
On the other hand, if it is too small, a large number of units are required when assembling a relatively large-sized lighting device, and the efficiency of work may be reduced. When the light emitting surface is other than a square, the area is in the range of the above product (400 to 40,000).
cm ² ).

(Light Equalizing Means) In the embodiment of FIG. 1, a light transmissive laminate comprising a prism film (30) and a diffused light transmitting sheet (31) is the light equalizing means. The prism surface of the prism film (30) is arranged toward the light guide space, and the plurality of micro prisms are arranged in parallel with the optical fiber (light emitter). The surface opposite to the prism surface is a smooth surface. In the illustrated embodiment, the prism film (30) is disposed substantially parallel to the light emitting surface. However, as shown in FIG. 5, as the prism film (30) moves away from the light emitting body (2a), the prism film (30) moves away from the light emitting surface. It can also be arranged curved. Such an arrangement is advantageous, for example, when the distance between the two side plates (104a, 104b) is long, to prevent a decrease in luminance of the light emitting surface at a position away from the light emitting body.

The apex angle of the micro prism of the prism film is usually in the range of 65 to 115 degrees. As such a prism film, “TRAF” manufactured by 3M Corporation,
Products such as "TRAF-II", "OLF" and "BEF" can be used.

The shape of the prism is not limited to a triangular cross section as shown in the figure, but a prism having a semicircular or arcuate cross section or a triangular shape with a rounded apex may be used. it can. Further, the plurality of prisms on the prism surface may include those having different shapes and / or different sizes. Further, the prism surface may be arranged facing the diffused light transmitting sheet, or a plurality of prism films may be arranged in combination.

The diffused light transmitting sheet (31) is, for example,
It is a plastic film or glass (ground glass) having a roughened surface, or a film made of a resin in which inorganic pigments or polymer particles are dispersed. Diffused light transmission sheet (3
The light transmittance of 1) is usually 10 to 70%, preferably 20%.
〜60%. If the light transmittance is too high, the brightness of the light emitting surface may not be uniform, and if it is too low, the brightness may be reduced.

The light uniformizing means may include, for example, a diffuse reflection sheet disposed on the surface of the bottom plate (light guide space side) in addition to the combination of the prism film (30) and the diffused light transmitting sheet (31). , A prism film, a plurality of dot-shaped diffuse reflection projections formed on the bottom plate surface, and the like. It can also include a nonwoven fabric disposed in the light guide space (10). Furthermore, it is also possible to use only a nonwoven fabric and omit the laminate of the prism film and the diffused light transmitting sheet. In this case, the horizontal plane area of the nonwoven fabric is preferably substantially equal to the light emitting surface.

(Light Emitting Element) The light emitting element (20) includes an optical fiber (2) and light leakage means (4).

The optical fiber (2) is made of a material having a level of transparency capable of transmitting light incident inside from one end in the longitudinal direction of the fiber toward the other end, for example, a refractive index of 1.3 to 2.0. It is formed from a range of zero materials. Such a material is, for example, quartz glass, optical glass, plastic, or the like.

The optical fiber (2) is an optical fiber comprising a solid core formed of the above transparent material; a liquid-encapsulated fiber in which a liquid having a relatively high refractive index such as silicone gel is enclosed in a flexible plastic tube; Can be used. In the case of a solid core, it is usually coated with a clad material to prevent the core from being soiled. The cladding material is
It is formed from a transparent material having a refractive index less than that of the core.

The plastic used as the material of the optical fiber can be formed from a light-transmitting polymer such as acrylic polymer, polymethylpentene, ethylene-vinyl acetate copolymer, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer. , The refractive index of plastic is usually 1.3 to 1.9,
The total light transmittance is usually 80% or more. Also, the polymer can be cross-linked to provide sufficient mechanical strength against deflection of the optical fiber itself.

Next, a method for producing a solid core type optical fiber will be described using an acrylic fiber as an example.

First, an acrylic monomer (mixture), which is a raw material for an optical fiber, is filled in a tube extending in the longitudinal direction and having an opening at at least one end, and the reaction of the mixture filled in the tube is performed at the other end of the tube. The mixture is heated progressively at a temperature equal to or higher than the reaction temperature, such that progressively occurs from the side toward the open end. That is, the heating position is moved from the other end toward the opening end. During the reaction, the reaction is performed while pressurizing the mixture with a pressurized gas that comes into contact with the mixture. After the heating up to the opening end is completed, it is preferable to further heat the entire tube for several hours in order to complete the reaction.

The acrylic monomer as a raw material of the optical fiber includes, for example, (i) a (meth) acrylate having a homopolymer having a Tg higher than 0 ° C. (for example, n-butyl methacrylate, methyl methacrylate, methyl acrylate, 2-hydroxyethyl methacrylate, n-propyl methacrylate, phenyl methacrylate, etc.)
(Ii) Tg of the homopolymer is less than 0 ° C. (meth)
Acrylates (eg, 2-ethylhexyl methacrylate, ethyl acrylate, tridecyl methacrylate, dodecyl methacrylate, etc.) or a mixture of (i) and (ii) can be used. In the case of a mixture, the mixing weight ratio (H: L) of the (meth) acrylate (H) of (i) and the (meth) acrylate (L) of (ii) is usually 15:85 to 60:40. Range. In addition, a polyfunctional monomer such as diallyl phthalate, triethylene glycol di (meth) acrylate, or diethylene glycol bisallyl carbonate may be added to the above mixture as a crosslinking agent.

The acrylic optical fiber formed as described above can be a uniform polymer from one end to the other end in the longitudinal direction of the optical fiber, and has good optical transmission performance and
It has a sufficient mechanical strength against bending of the optical fiber itself, and is particularly suitable for connecting a plurality of light emitting units and assembling a relatively large lighting device.

The tube used in the above production method is as follows:
A fluoropolymer such as a tetrafluoroethylene-hexafluoropropylene copolymer (FEP) is preferred. In this case, after the reaction is completed, it can be used as a protective material (cladding material) for the optical fiber without removing it from the optical fiber. Incidentally, with respect to such a method for producing a flexible optical fiber, see JP-A-63-19 / 1988.
No. 604 and the like.

The cross section of the optical fiber in the width direction is not limited as long as the effects of the present invention are not impaired, as long as the optical fiber can maintain its flexibility, such as a circle, an ellipse, a semicircle, or an arc having an area larger than the semicircle. Anything is fine. The diameter of the optical fiber is usually 8 when the cross section in the width direction is circular.
４０40 mm, preferably 10-30 mm.

On the other hand, as the light leakage means, [I] a diffuse reflection film adhered to the outer peripheral surface of the optical fiber (solid core); [II] a diffuse reflection portion formed by roughening the outer peripheral surface of the optical fiber [III] On the outer peripheral surface of the optical fiber, one formed of a plurality of linear scratches provided along a direction perpendicular to the length direction of the fiber can be used.

As the diffuse reflection film, [a] a resin film containing diffuse reflection particles dispersed therein; [b] a diffuse light transmissive or diffuse reflection (opaque) base material, and the base material on the fiber peripheral surface An adhesive film composed of a transparent adhesive to be brought into close contact, and [c] an adhesive film composed of a transparent adhesive and having an adhesive layer having an uneven adhesive surface can be used.

The diffuse reflective particles are, for example, 1.5 to
It is a white inorganic powder having a refractive index in the range of 3.0.
Barium sulfate (refractive index:
1.51), magnesia (refractive index: 1.8), titania (refractive index: 2.6) and the like are preferable. The resin forming the diffuse reflection film is preferably a transparent resin having a higher refractive index than the material of the optical fiber and having a refractive index different from that of the diffuse reflection particles. As such a resin, an acrylic resin, a silicone resin, a polystyrene resin, a polyolefin resin, and the like are preferable. The mixing ratio of the resin and the diffuse reflection particles is usually 5 to 10 parts by weight of the resin with respect to 100 parts by weight of the particles.
000 parts by weight. Further, a color pigment may be contained in the diffuse reflection film, and white light supplied to the fiber may be leaked as colored light.

The diffuse reflection film can be easily formed from a coating film of a dispersion containing the resin and the diffuse reflection particles. For example, it can be formed by a method such as directly applying the dispersion to the outer peripheral surface of the fiber, or transferring the coating film formed on the temporary base material to the outer peripheral surface of the fiber. When using the transfer method, if the resin contains an adhesive,
Transfer can be performed easily.

For preparing the dispersion, a dispersion apparatus such as a sand mill, a kneader, a roll mill, and a planetary mixer can be used. For forming a coating film, a coating device such as a roll coater, a knife coater, a bar coater, and a die coater can be used.

The thickness of the diffuse reflection film is usually from 1 to 2,000.
μm, preferably 5 to 1,000 μm, particularly preferably 10 μm.
８００800 μm. If the thickness is too small, the amount of light leaked from the fiber may decrease, and the luminance of the light emitting surface may decrease. Conversely, if the thickness is too large, the flexibility may decrease and the reflective film may be damaged.

The width (dimension in the direction perpendicular to the length direction) of the diffuse reflection film depends on the amount of light to be leaked by the unit, but is usually in the range of 1 to 35 mm. The diffuse reflection film is
It is composed of one or a plurality of striped films arranged along the length of the fiber. Further, the diffuse reflection film can be provided continuously or discontinuously in the length direction. When provided discontinuously, the length of the diffuse reflection film divided into a plurality of pieces can be made different in the length direction, and a large number of (plural) thin pieces having substantially the same length in the length direction and long in the width direction can be provided. It is also possible to form a "equally spaced bar code" in which stripes are arranged at substantially equal intervals. Further, it can also be obtained by a diffuse reflection film formed by printing in a halftone dot (dot) shape.

The light reflected by the diffuse reflection film is most strongly reflected toward the inner peripheral surface of the fiber facing the diffuse reflection film, and most of the light leaks and is used for light emission of the unit. On the other hand, a light-transmitting diffuse reflection film can also be used, and in this case, a component of light that passes through the diffusion reflection film and leaks light can also be used. However, in order to enhance the directivity of light and to facilitate the design of the unit such as the type and arrangement of the light uniforming means and the dimensions of the light guide space, the light transmittance of the diffuse reflection film is lower (for example, 30%). The following is preferable.

Further, as long as the effects of the present invention are not impaired, the diffuse reflection film may contain various additives in addition to the above-mentioned materials. The additives include a cross-linking agent, an ultraviolet absorber, a heat stabilizer, a surfactant, a plasticizer, an antioxidant, a fungicide, a coloring agent, a luminous material, a tackifier, and the like. As the coloring material, fluorescent dyes and pigments can be used in addition to ordinary pigments and dyes.

(Illumination Device) By combining a plurality of light emitting units of the present invention, an illumination device having a relatively large illumination surface can be formed. Such an illuminating device can be used, for example, as an illuminating device for an internally illuminated display that displays a road sign, an advertisement, and the like. In this case, a light-transmissive display sheet having a display of a sign, an advertisement, or the like can be arranged on the surface of the illumination surface (light-emitting surface) so that the display can be visually recognized even at night. In addition, a transparent or translucent prism-type retroreflective sheet can be used as the light-transmitting display sheet.

Further, the present invention can also be used as a flat lighting device having a relatively large lighting surface arranged on an indoor plane or an outdoor plane such as a ceiling, floor, or wall of a building. In this case, for example, a lighting device as shown in FIG. 6 or FIG. 8 (details will be described later) is bonded to the indoor plane or the outdoor plane and the bottom plate of the light emitting unit using an adhesive means or the like. It is arranged so that the light emitting surface (illumination surface) can be seen by an observer. The external light source connected to each unit is preferably arranged so as not to be seen by an observer. In addition, since the lighting device of the present invention can form a large-area lighting surface by combining a plurality of light-emitting units, a large-sized lighting device that covers the entire indoor or outdoor plane can be formed.

The lighting device as described above can be easily formed by, for example, combining an external light source with a lighting body composed of a plurality of light emitting units of the present invention as follows. For example, a plurality of light emitting units are arranged at a place where an illuminating body is to be installed in accordance with a predetermined arrangement method, and an external light source is provided so that light is supplied into the fiber from a light incident end of an optical fiber with the light receiving / light emitting unit. Connect. For example, as shown in FIG.
A transmission path (203) including an optical fiber is disposed between the external light source (200) and the light input end (201) of the optical fiber of the light emitting unit. The light input end of the optical fiber is connected to each other so that light can be transmitted between the two fibers, and the light from the light source is supplied to the optical fiber of the light receiving / light emitting unit via the transmission path. FIG. 7 will be described later.

As a light source, a high-intensity lamp such as a xenon lamp, a halogen lamp, and a flash lamp can be used.
The power consumption of the lamp is usually 10 to 500 W. The lamp is usually arranged in a container, and a reflector for the lamp is provided in the container. The light supplied by the light source may be not only white light but also colored light. For example, light emitted from a lamp can be supplied to a light receiving / light emitting unit as colored light through a color filter.

As a method of arranging the light emitting units, for example, a method as shown in FIG. 6 can be employed. FIG. 6B is a plan view of a method of arranging the light emitting units, and FIG. 6A schematically shows only the optical fiber portion. The illustrated light emitting unit has a substantially rectangular parallelepiped box, and three light guides arranged near the one side plate and substantially parallel to the side plate in the light guide space of the box as shown in FIG. 10-b. An optical fiber. The first unit (1a) includes three optical fibers, of which only one has the light leakage means (4a). That is, the optical fiber on which the light leakage means (4a) is arranged constitutes a light emitting body, and the remaining two constitute an optical transmission body. The second unit (1b) includes two optical fibers, and only one of the optical fibers has the light leakage means (4).
b) is arranged. That is, the optical fiber on which the light leakage means (4b) is arranged constitutes a light emitter, and the other one constitutes an optical transmitter. In addition, the first unit (1
The two fibers of the optical transmission body of a) and the two optical fibers of the second unit (1b) are connected to the first unit (1).
In order that light transmission from a) to the second unit (1b) is possible,
A light emitting end of a transmission optical fiber of the first unit;
The light input ends of the two fibers of the unit are connected to each other. The third unit (1c) includes only one optical fiber, and the light leakage means (4c) is arranged on the fiber. That is, the third unit (1c) does not include the optical transmitter. The optical fiber of the second unit (1b) and the optical fiber of the luminous body of the third unit (1c) are capable of transmitting light from the second unit (1b) to the third unit (1c). The light emitting end of the light transmitting optical fiber of the second unit and the light incident end of the light emitting optical fiber of the third unit are connected to each other.

In other words, the first unit (1a) functions as a light-receiving and light-emitting unit, and is adjacent to the other light-emitting units (1b, 1c) on the side closer to the external light source (200). Light is supplied via an optical fiber (optical transmission body) of the arranged light emitting unit which is connected so as to enable optical transmission.

The plurality of light-emitting units arranged as described above are arranged such that the light-emitting surfaces (11) of the respective units are located on substantially the same plane, and the illumination surface composed of an aggregate of the light-emitting surfaces is arranged. The lighting device according to the present invention can be configured by configuring an illuminating body formed so as to have the illuminating body and connecting the illuminating body and an external light source that supplies light to the illuminating body. In addition to the case of using an illuminator consisting of three units as described above,
As shown in FIG. 8, nine light-emitting units can be combined with one light source to form a large-sized lighting device having a larger-sized lighting surface. Also, as in the third unit in the embodiment shown in FIG. 6, in the last unit in which there is no adjacent next unit to supply light, the light emitting oblique end of the optical fiber is covered with a reflecting member,
It is preferable to prevent light from leaking out from the light emitting bevel.
This makes it easy to effectively use the light supplied to the last unit farthest from the light source for light emission of the unit. Such a reflecting member can be formed from the above-mentioned reflecting material.

In the illuminating body composed of the three units, the light emitting units each including a different number of optical fibers are used. However, all the units may include the same number (three) of fibers. it can. In this case, in each unit, only one of the three optical fibers is used as a light emitter. In each unit, optical fibers arranged at different positions are used as light emitter units. In each unit, the light emitting end of the fiber of the illuminant need not be connected to the light incident end of any fiber of the next adjacent unit. Therefore, it is preferable to arrange a reflection member at the light emitting end of the light emitting fiber in order to increase the light emission luminance of the light emitting body.

The number of optical fibers arranged in one unit is not limited to three. FIG. 10 is a diagram schematically showing only the arrangement of the optical fibers of the unit. FIG.
, Two, three, four, six, or other numbers are also possible. The number of optical fibers used as the light emitter is not limited to one, and two or more optical fibers can be used as long as the effects of the present invention are not impaired.

Further, the location of the optical fiber in the light emitting unit is not only in the vicinity of the side plate as described above, but also in FIG.
As shown in (1), it can be arranged close to the bottom plate. In the illustrated example, the optical fibers are arranged in the width direction (2
(In the direction connecting the two side plates) substantially parallel to the side plates. In this case, as a light uniformizing means, in addition to a laminate including a prism film (30) and a diffused light transmitting sheet (31) disposed on a top plate, a reflecting plate (or a prism film) as shown in FIG. It is preferable to arrange along one side plate.

On the other hand, each unit may be configured to include an optical fiber that serves both as a light emitter and an optical transmitter. For example, as shown in FIG. 9, a plurality of luminous body units (three in the illustrated example) are arranged along the length of the fiber as in the above case. At this time, in the first unit (1a) functioning as both a light receiving and light emitting unit, the width of the light leaking means (4a) is narrowest, and in the third unit (1c) farthest from the light source, the light leaking means (4c) is used.
Is the widest, and the second unit (1b) includes an optical fiber having light leakage means (4b) with a width dimension between them. As a result, in the optical fiber of the first unit, the amount of light transmitted to the second unit is larger than the amount of light leaking into the light guide space, and the second and third units emit light of each unit. Is supplied with the required amount of light. Further, since only the remaining light amount consumed by the light emission of the first and second units reaches the third unit, most of the light reaching the optical fiber is leaked, and the third unit farthest from the light source is sufficient. The width of the light leakage means can be made as wide as possible so as to emit light with a high luminance. In such a configuration, the volume of the optical fiber occupying the light guiding space can be made as small as possible, so that the height of the box (the distance between the top plate and the bottom plate) is made as small as possible, and the light emitting unit of the thin type is formed. Can be formed.

Further, as shown in FIG. 7, one light emitting unit may have a plurality of (three in the illustrated example) light emitting optical fibers. In a light emitting unit having a light emitting surface (11) having a large area as shown in FIG. 7-a, three optical fibers are provided as shown in a schematic view of the XX ′ section (FIG. 7-b). There is a light leaking means (4a, 4b, 4c) attached to each, and each light leaking means is configured to cover a different length area. The light leakage means may be partially overlapped. With such a configuration, when the length of the box body (dimension along the length direction of the fiber) is relatively long, the luminance difference between the side near the light entrance end and the side near the light exit end is small. Is less likely to occur, and the luminance of the entire light emitting surface can be made uniform.

[0075]

The present invention will be described in more detail with reference to examples.
It should not be understood that the present invention is limited to these examples.

First, three light emitting units of the type shown in FIGS. 1 to 3 were formed from the following components. However, the first
The unit (light-receiving and light-emitting unit) has three optical fibers (1 for light emission and 2 for light transmission), the second unit has two optical fibers (1 for light emission and 1 for light transmission), and the third unit has Contains only one optical fiber for light emission, and the arrangement of the light emitters of each unit is the same as the illuminator shown in FIG.

Box: The bottom plate and the two fiber support plates were formed from a 10 mm thick wooden plate. Further, the two side plates were arranged at predetermined positions by bending a dielectric reflection film having a reflectance of about 90% into a U-shaped cross section as shown in the figure. These parts were joined to each other via an adhesive to form a box portion (housing) excluding the top plate. Further, the dielectric reflection film was disposed so as to cover the entire inner surface of the bottom plate. On the other hand, a prism film “TRAF-I” manufactured by 3M Co., Ltd.
I ", a top plate composed of a transparent tempered glass having a thickness of about 5 mm and a white translucent acrylic plate having a thickness of about 0.5 mm was separately prepared. After the light-emitting body and the light transmission body (details will be described later) were arranged inside the housing, the top plate was bonded to the fiber support plate and the side plate using an adhesive. The width of the fiber support plate (the distance between the top plate and the bottom plate)
Is about 80 mm, and the plane size of the top plate (light emitting surface) is 3 mm.
It was 0 cm × 30 cm. The distance between the peripheral surface of the optical fiber (cladding material) disposed closest to the bottom plate and the bottom plate was about 10 mm. In the case of a unit including a plurality of fibers, they were arranged so that the distance between the peripheral surfaces of the fibers (cladding material) was about 5 mm.

Optical fiber: butyl acrylate 30
100 parts by weight of a monomer component consisting of 70 parts by weight of 2-ethylhexyl methacrylate and 1 part by weight of triethylene glycol dimethacrylate as a crosslinking monomer.
From the monomer mixture added in parts by weight, it was produced by the above-mentioned production method (a method disclosed in JP-A-63-19604, in which a monomer filled in a tube was thermally polymerized from one end to the other end in a progressive manner). Solid optical fiber.
The diameter of the cross section (circle) is 12.7 mm, and the refractive index is 1.48.
Met. In addition, this optical fiber was able to efficiently transmit the light incident from one end to the other end with almost no emission from the outer peripheral surface.

Light-emitting body: First, 100 parts by weight of titanium dioxide as diffuse reflection particles and a dispersible polyurethane as a light-transmitting polymer ("Part No .: UR-8" manufactured by Toyobo Co., Ltd.)
700 ", an aromatic polyurethane having a sodium sulfonate group as a hydrophilic functional group in the molecule) 10 parts by weight,
A pre-dispersion was prepared from a mixture comprising a solvent (methyl ethyl ketone) using a sand mill. Next, a paint prepared by mixing the pre-dispersion and 300 parts by weight of an acrylic pressure-sensitive adhesive was applied on a release film and dried to form a transfer-type pressure-sensitive adhesive film for forming a diffuse reflection film. The pressure-sensitive adhesive is an acrylic copolymer obtained by polymerizing a monomer mixture containing isooctyl acrylate as a main component, and the release film has a thickness of 50 μm.
An ET film having one surface subjected to a silicone release treatment was used. In the coating operation, a knife coater was used.
After slitting the pressure-sensitive adhesive film into a tape shape having a width of 7 mm, the coated surface was pressure-bonded along the length direction to the outer peripheral surface of an optical fiber for a light emitting body, the release film was removed, and the diffuse reflection film was transferred. The thickness of the diffuse reflection film was about 300 μm, and had a sufficient concealing property. Finally, the inside diameter is about 1
The optical fiber was covered with a 2.7 mm FEP clad to form a luminous body.

Light transmitting body: On the other hand, an optical transmitting body was formed in the same manner as in the case of the above light emitting body except that the diffuse reflection film was not provided. As a light source, a 30 W halogen lamp with a reflecting mirror (“JCR-30W” manufactured by Iwasaki Electric Co., Ltd.) was used. The connection between the light receiving and light emitting unit and the light source is
As shown in FIG. 7, a transmission line formed by using three optical fibers similar to the above-mentioned transmission body, and three fibers of the light-receiving and light-emitting unit are respectively connected to a light emitting end and a light incident end by: They were connected so that light transmission was possible.

Subsequently, the three light emitting units formed as described above were connected to each other by using the method shown in FIG. 12, thereby forming an illuminator. The light emitting oblique end of the optical fiber of the third unit was covered with a reflection member made of the dielectric reflection film.

On the other hand, the light source is connected to the lighting body,
The lighting device of the present invention was formed. The connection between the light-receiving and light-emitting unit and the light source is, as shown in FIG. 7, a transmission path formed by using three optical fibers similar to the transmission body,
The light emitting end and the light incident end were connected so that the three fibers of the light receiving and light emitting unit could transmit light mutually.

[0083]

[Light Emission of Lighting Apparatus] The luminance of each light emitting surface of the lighting apparatus formed as described above was measured using an illuminometer “T-1H (product number)” manufactured by Minolta Co., Ltd. FIG. 13 shows the measurement results. At the time of measurement, the lighting device is arranged with the lighting surface (light emitting surface of each unit) facing upward, the light emitting surface of each unit is divided into nine parts as shown in the figure, and approximately 30 cm upward from the light emitting surface of each divided part. The luminance at a remote position was measured.

As can be seen from the results, according to the present invention, light is uniformly emitted over the entire light emitting surface of each unit.
Further, it is possible to form a lighting device that emits light uniformly over the light emitting surfaces of all units (that is, the entire lighting surface).

[Brief description of the drawings]

FIG. 1 is a perspective view having a partial cross section of a light emitting unit of the present invention.

FIG. 2 is a cross-sectional view of the light emitting unit of FIG. 1 taken along line AA ′.

FIG. 3 is a sectional view of the light emitting unit of FIG. 1 taken along the line BB ′.

FIG. 4 is a diagram showing a housing of the light emitting unit of the present invention in which one of its side plates is flat.

FIG. 5 is a diagram showing a prism film of FIG. 2 that is curved;

FIG. 6 is a lighting device in which three light emitting units are connected, FIG. 6A is a longitudinal sectional view of an optical fiber portion, and FIG. 6B is a plan view.

FIG. 7 is a view of one light emitting unit having a relatively large area, and FIG. 7A is a plan view;
FIG. 7B is a longitudinal sectional view of the optical fiber unit.

FIG. 8 is a schematic diagram when three lighting devices of the type of FIG. 6 are connected from one light source.

FIG. 9 is a diagram in which three light-emitting units are connected and one connected optical fiber is used as a light-emitting body.

FIG. 10 is a cross-sectional view showing an arrangement when a plurality of optical fibers are used.

FIG. 11 is a schematic cross-sectional view when a light emitting surface and an optical fiber are present on opposing surfaces.

FIG. 12 is a cross-sectional view illustrating a connecting portion of a light emitting unit.

FIG. 13 is a light intensity measurement result at a light emitting portion measured in an example.

FIG. 14 is a sectional view showing details of the fiber support section of FIG. 3;

FIG. 15 is a cross-sectional view showing another embodiment of the fiber support section of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Box, 2 ... Optical fiber, 4 ... Light leakage means, 10 ... Light guide space, 11 ... Light emitting surface, 100 ... Housing, 200 ... Light source.

Claims (3)

[Claims] 1. A box (1) comprising at least one light-emitting surface (11) and a housing (100) defining the light-emitting surface (11) to form a light guide space (10); At least one optical fiber (2) disposed in the light guiding space (10) of (1) and the light supplied to the optical fiber (2) is transmitted from the side surface of the optical fiber (2) to the light guiding space (10). A luminous body (20) comprising a light-leaking means (4) for causing light to leak, and a light-guiding space (10) which is present on the light-guiding space (10) side of the light-emitting surface (11) and extends from the luminous body (20). The light that has leaked to
A light uniformizing means (3) for allowing the emitted light to have substantially uniform brightness over the entire area of the light emitting surface (11) when the light is emitted from the light emitting surface (11) to the outside of the box. In the light emitting unit, the optical fiber (2) of the light emitting body (20) is located at one end of the optical fiber (2) and communicates with the outside of the box (1). And a light emitting end (22) communicating with the outside of the box (1), the light leaking means (4) being provided on a part of a peripheral surface of the optical fiber (2) of the light emitting body. (2) A light emitting unit, which is arranged substantially along the length direction. 2. At least one optical fiber having no light leakage means separately from the light-emitting body (20) in the light-guiding space (10) of the box (1) forms an optical transmitter. 2. The light emitting unit according to claim 1, wherein the optical fiber also has a light incident end communicating with the outside of the box and a light emitting end. 3. A light-emitting unit according to claim 1, wherein at least one optical fiber of each light-emitting unit and at least one optical fiber of an adjacent light-emitting unit are capable of transmitting light. And a light emitting end formed by connecting a light emitting end of the unit and a light incident end of the other unit to each other, and an external light source for supplying light to the lighting body. One of the units functions as a light-receiving and light-emitting unit to which light is directly supplied from a light source, and an optical fiber of a light-emitting unit other than the light-receiving and light-emitting unit is connected to an adjacent light-emitting unit so that light can be transmitted. The lighting device is arranged so that light is supplied through the lighting device.