Light-emitting apparatus and light-emitting apparatus system

A light-emitting apparatus includes: a first light guide which includes a first photoreceptor, a second photoreceptor, and a leak, the first light guide guiding light radiated by a radiation apparatus and received by the first photoreceptor and the second photoreceptor, the leak allowing leakage light to be leaked out, the leakage light being part of the light; a converter which converts a wavelength of the leakage light leaked out of the first light guide; a second light guide which is disposed along the first light guide, the second light guide guiding the light radiated by the radiation apparatus and received by a third photoreceptor to the second photoreceptor; and a protector which is tubular and in which the first light guide and the second light guide are disposed such that the first photoreceptor and the third photoreceptor are disposed at a same open end.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of Japanese Patent Application Number 2016-148989 filed on Jul. 28, 2016, the entire content of which is hereby incorporated by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a light-emitting apparatus which linearly emits light using laser light as a light source, and a light-emitting apparatus system.

2. Description of the Related Art

Conventionally, there has been a light-emitting apparatus which includes a leak that allows part of light guided into a light guide such as a optical fiber to be leaked out, and which causes a phosphor around the light guide to linearly emit visible light based on the leaked light.

For example, Patent Literature (PTL) 1 (Japanese Unexamined Patent Application Publication No. H5-27121) discloses a technique for achieving surface emission by splitting, by a beam splitter, laser light, into two beams, and causing the two beams of the split laser light to enter the respective both ends of a light guide circularly placed.

Moreover, Patent Literature (PTL) 2 (Japanese Unexamined Patent Application Publication No. 2006-3598) discloses a technique for reducing luminance unevenness of light emission in an extending direction of a light guide, by disposing a radiation apparatus which radiates laser light at each of the both ends of the light guide, and causing the both ends of the light guide to radiate laser light.

SUMMARY

Unfortunately, when a light guide is bent into an elongated U-shape and light is linearly emitted by causing laser light to enter the both ends of the light guide, the both ends of the light guide which emit the strongest light become one end of the whole, and the central part of the light guide which emits the weakest light becomes another end of the whole. In this case, it is not possible to reduce luminance unevenness.

On the other hand, when radiation apparatuses are disposed at the both ends of the light guide, it is necessary to dispose, along the light guide, an electric wire for supplying power to the radiation apparatuses. In this case, the two radiation apparatuses make routing of the light guide difficult.

The present disclosure has an object to provide a light-emitting apparatus and a light-emitting apparatus system which not only ensure luminance evenness but also make routing of a light guide easy when light is linearly emitted using the light guide.

A light-emitting apparatus according to one aspect of the present disclosure is a light-emitting apparatus connected to a radiation apparatus which radiates laser light, the light-emitting apparatus including: a first light guide which includes a first photoreceptor at one end, a second photoreceptor another end, and a leak, the first light guide guiding light radiated by the radiation apparatus and received by the first photoreceptor and the second photoreceptor, the leak allowing leakage light to be leaked out in a direction crossing a light-guiding direction, the leakage light being part of the light; a converter which is disposed along the first light guide and converts a wavelength of the leakage light leaked out of the first light guide; a second light guide which is disposed along the first light guide, includes a third photoreceptor, and does not include the leak, the second light guide guiding the light radiated by the radiation apparatus and received by the third photoreceptor to the second photoreceptor; and a protector which is tubular and in which the first light guide and the second light guide are disposed such that the first photoreceptor and the third photoreceptor are disposed at a same open end.

According to the present disclosure, when linear light is emitted using a light guide, it is possible to ensure luminance evenness and improve routability.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a light-emitting apparatus according to an embodiment of the present disclosure will be described with reference to the drawings. It is to be noted that embodiments and variations to be described below each show a specific example of the present disclosure. The numerical values, shapes, materials, structural elements, the arrangement and connection the structural elements, etc. indicated in the following embodiments and variations are mere examples, and therefore do not intend to limit the present disclosure. Furthermore, among the structural elements in the following embodiments and variations, structural elements not recited in any of the independent claims which indicate the broadest concept of the present; disclosure are described as optional structural elements.

It is also to be noted that the figures are schematic diagrams and are not necessarily precise illustrations. Additionally, the same structural elements are assigned the same reference signs in the figures, and descriptions thereof may be omitted.

FIG. 1is a diagram illustrating, partially in a cross section, the configuration of a light-emitting apparatus according to Embodiment 1.

FIG. 2is a cross-sectional view illustrating a state where the light-emitting apparatus according to Embodiment 1 is cut along a plane perpendicular to an extending direction of a first light guide.

As illustrated in these figures, light-emitting apparatus100according to Embodiment 1 illuminates a predetermined space in, for example, a building, a mobile body, an outdoor place, or the like, is used as an indicator lamp, a neon sign, or the like, and is connected to radiation apparatus200which radiates laser light. In Embodiment 1, light-emitting apparatus100includes first light guide101, second light guide102, converter103, protector105, and return104.

Radiation apparatus200generates laser light to be radiated to converter103. In Embodiment 1, radiation apparatus200includes at least one laser element201(four laser elements201in Embodiment 1) which emits laser light of a short wavelength selected from a blue-violet to blue (430 nm to 490 nm) range such that converter103radiates visible light of a long wavelength. Although laser element201is not limited to a particular type, an element which oscillates laser using a semiconductor can be given as an example. Each laser element201of radiation apparatus200is connected in series to one power supply (not shown), and all laser elements201can be stopped from oscillating at once by disconnecting tie power supply or cutting off a power supply line. Laser elements201of radiation apparatus200are collectively housed in one housing. In addition, radiation apparatus200includes waveguide body202such that laser light radiated by a half of laser elements201reaches first photoreceptor111of first light guide101, and laser light radiated by the other half of laser elements201reaches third photoreceptor121of second light guide102.

It is to be noted that radiation apparatus200may include a beam splitter which splits laser light radiated by one laser element201into two beams of laser light, and may emit the two beams of laser light split by the beam splitter to first photoreceptor111of first light guide101and third photoreceptor121of second light guide102, respectively.

FIG. 3is a cross-sectional view illustrating a cross section of a first light guide and a converter when cut perpendicular to a light-guiding direction of laser light.

FIG. 4is a cross-sectional view illustrating a cross section of the first light guide and the converter when cut along the light-guiding direction of laser light.

First light guide101is capable of guiding laser light radiated by radiation apparatus200along a linear path, and includes first photoreceptor111at one end and second photoreceptor112at another end. In addition, first light guide101guides the received laser light and includes leak113which allows part of the guided laser light to be leaked out in a direction crossing the light-guiding direction.

In Embodiment 1, first light guide101is what is called an optical fiber which is flexible (has flexibility), and includes core114and cladding115. A higher refractive index is set for core114than for cladding115, which allows first light guide101to keep laser light inside core114by total reflection, and guide the laser light highly efficiently. Core114and cladding115are made from a material which is highly transmissive of laser light, such as quartz glass and a plastic material like an acryl resin.

Leak113is a component or structure which allows part of laser light guided by first light guide101and passing inside core114to be leaked out in a direction crossing the light guiding direction.

In Embodiment 1, leak13includes minute beads dispersed inside core114. The beads have a surface which scatters laser light, and part of the laser light scattered by leak113travels in a direction different from the light-guiding direction, and passes through cladding115to leak out of first light guide101.

It is to be noted that leak113is not limited to the beads dispersed inside core114, and may be another component or structure. For example, leak113may be cavities (air bubbles) dispersed inside core114. In addition, leak113may be a portion provided in part of cladding115and having a refractive index different from that of cladding115to avoid total reflection of laser light passing inside core114.

Converter103is disposed along first light guide101and converts a wavelength of laser light which leak113allows to be leaked out of first light guide101in a direction crossing the light-guiding direction. In Embodiment 1, converter103is what is called a remote phosphor including dispersed phosphor particles which emits fluorescence when excited by laser light leaked out of first light guide101. Specifically, converter103can be exemplified as a component in which phosphor particles are dispersed inside a transparent base material. Moreover, a base material of converter103is made of resin etc. which is transparent to laser light and light radiated by phosphors, and bends following a change in the form of first light guide101.

Although it is sufficient that converter103includes at least one type of phosphor, in Embodiment 1, converter103includes multiple types of phosphors. More specifically, in order to radiate light of a desired color such as white light using, as excitation light, the laser light of the short wavelength received from radiation apparatus200, converter103includes, in an appropriate ratio, multiple types of phosphors which emit beams of light of a wavelength longer than that of the laser light and of colors such as red, yellow, and green. As stated above, the beams of light having the desired colors can be radiated by the mixing of the beams of light of different wavelengths radiated by the multiple types of the phosphors excited by the laser light of the short wavelength. Here, the term “ratio” includes a ratio in which at least one number is 0.

Although a method for disposing converter103along first light guide101is not particularly limited, for example, converter103may be attached to first light guide101by applying a liquid base material (resin) containing phosphors onto the outer circumferential surface of first light guide101, or converter103having a sheet shape or cylindrical shape may be laminated onto first light guide101.

It is to be noted that phosphors may be included in cladding115of first light guide101, and caused to serve as converter103and leak113.

It is to be noted that at least one of the concentration of phosphor and the ratio among the multiple types of the phosphors may be gradually or continuously varied.

Moreover, converter103may include a function film for efficiently irradiating the phosphors with laser light, a function film for efficiently radiating emitted visible light, or the like.

Furthermore, converter103may include cover131which protects converter103from scrapes and scratches. Although a method for forming cover131or disposing cover131around converter103is not particularly limited, a thin flexible resin tube may be disposed in close adhesion around converter103. Moreover, cover131may be formed by applying a liquid resin onto converter103and hardening the resin using ultraviolet radiation, heat, etc.

It is to be noted that cover131may include a scattering component or structure which scatters laser light to reduce the coherence of laser light leaked out of first light guide101and converter103.

Like first light guide101, second light guide102is capable of guiding laser light radiated by radiation apparatus200along a linear path, includes third photoreceptor121which receives the laser light, at an end on the side of radiation apparatus200, and allows second photoreceptor121of first light guide101to receive the laser light. Moreover, unlike first light guide101, second light guide102does not deliberately include leak113. Furthermore, second light guide102is disposed along first light guide101. Here, that leak113is deliberately included means artificially providing leak113in a light guide such as disposing beads inside core114as in first light guide101.

In Embodiment 1, like first light guide101, second light guide102is an optical fiber including core114and cladding115. In addition, second light guide102includes curved portion122which is curved by approximately the minimum bend radius, on the opposite side of third photoreceptor121, and the length of second light guide102including curved portion122is greater than that of first light guide101.

Protector105is a flexible tubular component into which first light guide101and second light guide102are inserted such that first photoreceptor111of first light guide101and third photoreceptor121of second light guide102are disposed at the same opening end. Protector105allows second light guide102to be disposed along first light guide101, and first light guide101and second light guide102to appear like one component which linearly emits light. In addition, protector105is capable of protecting first light guide101and second light guide102from a localized pressure or impact from the outside.

Although a material of or a method for producing protector105is not particularly limited, protector105which can be produced by extrusion molding and part or all of which is made of a transparent silicone resin can be given as an example.

In Embodiment 1, protector105includes partition151which partitions a space inside protector105into first chamber154which houses first light to guide101, and second chamber155which houses second light guide102. Moreover, a surrounding wall of protector105on the side of first chamber154is transmissive portion152which is transparent and capable of transmitting light emitted by converter103, and a surrounding wall of protector105on the side of second chamber155is light blocking portion153which blocks light involuntarily leaked out of second light guide102. With this, the light emitted by converter103can be transmitted to the outside of protector105. Furthermore, partition151allows first light guide101to avoid direct contact with second light guide102disposed along first light guide101, and is capable of reducing damage to these light guides and converter103.

Moreover, a surface of partition151at least on the side of first chamber154serves as a reflector which reflects light emitted by converter103toward the outside of protector105. Specifically, partition151is opaque white in color, and serves both as the reflector which reflects the light emitted by converter103, and as the light-blocking portion which blocks the light involuntarily leaked out of second light guide102.

With this, it is possible to distribute, to the surrounding wall on the side of first chamber154, light almost evenly emitted in all directions by converter103in a plane perpendicular to an extending direction of first light guide101. In addition, it is possible to achieve a desired color temperature by preventing light leaked out of second light guide102being mixed.

Furthermore, the surrounding wall of protector105on the side of first chamber154includes a scattering portion which scatters laser light. With this, it is possible to reduce the coherence of laser light involuntarily emitted by a break of first light guide101, and improve safety for the human eye. The scattering portion is not particularly limited, and fine particles may be dispersed in transmissive portion152which is the surrounding wall of protector105on the side of first chamber154or a minute uneven structure may be formed on the external wall surface to scatter laser light.

It is to be noted that examples of a method for producing protector105which includes partition151and of which the surrounding wall is divided into transmissive portion152and light-blocking portion153include coinjection molding which integrally extrudes different types of resins.

Return104is disposed on the side of second photoreceptor112of first light guide101, and turns back laser light guided by second light guide102. In Embodiment 1, return104is a highly rigid component which maintains a curved state of curved portion122resulting from an end opposite third photoreceptor121of second light guide102being curved by approximately the minimum bend radius, and which protects curved portion122from pressure etc. exerted from the outside. Here, the minimum bend radius of second light guide102refers to the minimum bend radius which allows the loss of guided light caused by bending second light guide102to be within an allowable range, and is exemplified as being approximately 10 times the diameter of second light guide102. It is to be noted that the minimum bending radius depends on types or the like of components (e.g., a core and a cladding) included in second light guide102.

As described above, light-emitting apparatus100according to the present embodiment makes it possible to easily handle a light-emitting component which linearly emits light, by causing protector105to collectively protect first light guide101, converter103disposed along first light guide101, and second light guide102. Moreover, because one end of light-emitting apparatus100is connected to radiation apparatus200and another end of the same can be freely moved, it is possible to freely dispose light-emitting apparatus100, and cause light-emitting apparatus100to emit linear light in any pattern such as a character. Here, the term linear refers not only to rectilinear but also to curved, meandering, zigzag, annular, etc. Moreover, because laser light is received by each of first photoreceptor111and second photoreceptor112and guided in an opposite direction, light-emitting apparatus100makes it possible to reduce luminance unevenness of the visible light in the extending direction of first light guide101.

Moreover, because return component104protects curved portion122of second light guide102which has relatively inadequate structural strength, it is possible to increase the structural strength of whole light-emitting apparatus100and to dispose light-emitting apparatus100on a floor surface or the like to which pressure is applied from the outside.

Next, another embodiment of light-emitting apparatus100will be described. It is to be noted that the same reference signs are assigned to components (portions) having the same operation, function, shape, mechanism, or structure as in Embodiment 1, and description thereof may be omitted. Moreover, hereinafter, description will center on points different from those of Embodiment 1, and description of the identical matters may be omitted.

FIG. 5is a diagram illustrating, partially in a cross section, the configuration of a light-emitting apparatus according to Embodiment 2.

As illustrated in the figure, light-emitting apparatus100according to Embodiment 2 is connected to radiation apparatus200which radiates laser light, as in Embodiment 1, and includes first light guide101, second light guide102, converter103, and return104. Moreover, light-emitting apparatus100includes protector105.

First light guide101according to Embodiment 2 is the same as the one in Embodiment 1. It is to be noted that in Embodiment 2, converter103is not attached to first light guide101.

Second light guide102according to Embodiment 2 does not include curved portion122and has an end which is opposite third photoreceptor121and connected to return104. Moreover, second light guide102has almost the same length as first light guide101, because second light guide102does not include curved portion122.

As illustrated inFIG. 6, converter103is provided to the surrounding wall of protector105on the side of first chamber154. Specifically, phosphor particles which are excited by laser light leaked out of first light guide101are dispersed in protector105.

Return104includes: reflector141which returns light radiated by second light guide102, to second photoreceptor112of first light guide101, by reflecting the light; and cavity142through which laser light passes.

Reflector141is a mirror capable of reflecting laser light radiated by radiation apparatus200. In Embodiment 2, two reflectors141are separately provided inside return104so as to cause laser light emitted by second light guide102to enter second photoreceptor112by reflecting the laser light twice. Moreover, cavity142is formed in a U-shape inside return104so as not to interfere with the laser light reflected by reflectors141.

Moreover, protector105is bonded to return104at one end of protector105. This makes it possible to protect first light guide101and second light guide102more firmly.

As described above, light-emitting apparatus100according to Embodiment 2 produces the following advantageous effects in addition to or instead of the advantageous effects produced by light-emitting apparatus100according Embodiment 1.

Because return component104including reflector141makes it possible to return laser light emitted by second light guide to second photoreceptor112of first light guide101regardless of the minimum bend radius of second light guide102or the like, it is possible to dispose second light guide102in the proximity of first light guide101.

It is to be noted that the present invention is not limited to the aforementioned embodiments. For example, other embodiments which can be realized by combing any of the structural elements described in the present description or by excluding some of the structural elements may be embodiments of the present invention. Furthermore, variations obtainable through various modifications to the aforementioned embodiments which can be conceived by a person skilled in the art without departing from the essence of the present invention, that is, the meaning of the recitations in the claims are included in the present invention.

For example, although first chamber154and second chamber155into which first light guide101and second light guide102are inserted respectively are illustrated as being large relative to the diameter of these light guides, protector105may hold at least one of first light guide101and second light guide102in close adhesion.

Moreover, although reflector141has been described as being integral with partition151, for example, a tape-like film on which metal is deposited and which has high reflecting properties may be inserted into protector105and be used as reflector141.

Furthermore, instead of causing the surrounding wall of protector105which forms second chamber155to serve as light-blocking portion153, a tubular component which can be inserted into protector105and has light-blocking properties may be used as light-blocking portion153. In this case, the inside of the tubular component forms second chamber155, and a surrounding wall of the tubular component also serves as partition151.

Moreover, irregularities for controlling light distribution may be formed in the outer surface or inner surface of protector105, and a component including irregularities may be separately attached to protector105.