JP2013118054A - Linear lighting apparatus and aggregate linear lighting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear lighting apparatus and an aggregate linear lighting apparatus with light distribution characteristics control, enhancement in luminance, and downsizing as well as weight saving facilitated.SOLUTION: The linear lighting apparatus includes a first light source emitting first laser light, a support body, a first light guide, and a second light guide. The support body has a top face and a first opening. The first light guide, arranged at a top face side of the support body, includes a bottom face, an emission face, and a first slanted face at an acute angle with the bottom face. The second light guide includes a first end face for the first laser light to be guided in, and guides the first laser light. Further, the second light guide is optically coupled with the bottom face of the first light guide so that an optical axis of the first laser light is to cross the first slanted face, and is fitted inside the first opening. The first laser light guided is emitted from the emission face. A cross-section area of the second light guide is smaller than that of the first light guide.

Description

  Embodiments described herein relate generally to a linear illumination device and a collective linear illumination device.

  LED (light emitting diode) is the mainstream of light-emitting devices for solid-state lighting applications. The LED is a discrete light emitting element. Therefore, in order to realize a linear illumination device, it becomes a form of an array light source in which LEDs are arranged. The array light source has a granular light emission due to its nature, and looks unnatural.

  Further, when aiming at uniform light emission as much as possible by reducing the graininess, the number of elements increases because a high-density array is used. If the number of elements is large, the cost increases, and it is necessary to select LED elements having uniform characteristics.

  For example, when applying LED to in-vehicle lighting such as headlamps, fog lamps, and interiors, and general lighting, heat sinks and fins for heat dissipation are required, and reflectors and lenses for controlling light distribution characteristics Etc. are also required. This increases the weight and size of the headlamp unit.

Japanese Patent No. 3434726

  Provided are a linear illumination device and a collective linear illumination device that are easy to control light distribution characteristics, achieve high brightness, and are small and light.

  The linear illumination device according to the embodiment includes a first light source that emits a first laser beam, a support, a first light guide, and a second light guide. The support has an upper surface and is provided with a first opening that reaches the upper surface. The first light guide is disposed on the upper surface side of the support, and includes a bottom surface, an emission surface provided on a side opposite to the bottom surface, and a first inclination that forms an acute angle with the bottom surface. And a surface. The second light guide has a first end surface into which the first laser light is introduced, and guides the first laser light. The second light guide is optically coupled to the bottom surface of the first light guide so that an optical axis of the first laser light intersects the first inclined surface, and the first light guide Provided in the opening. The introduced first laser light is emitted from the emission surface while being guided in the first light guide. The cross-sectional area of the second light guide perpendicular to the light guide direction is smaller than the cross-sectional area of the first light guide perpendicular to the light guide direction.

  Provided are a linear illumination device and a collective linear illumination device that are easy to control light distribution characteristics, achieve high brightness, and are small and light.

FIG. 1A is a schematic perspective view of the linear illumination device according to the first embodiment, FIG. 1B is a schematic perspective view of the front cover portion, and FIG. 1C is a linear shape excluding the front cover portion. It is a model perspective view of an illuminating device. It is a schematic cross section of the linear illuminating device concerning 1st Embodiment. FIG. 3A is a schematic perspective view of a first modification of the first light guide, and FIG. 3B is a schematic perspective view of a second modification. 4A is a schematic perspective view of a modified example of the front cover, FIG. 4B is a schematic perspective view of a second modified example of the first light guide, and FIG. 4C is a schematic perspective view of the support. . It is a schematic cross section of the structure which provided the ferrule between the 2nd light guide and the opening part of the support body. FIG. 6A is a ray tracing diagram of the linear illumination device according to the first embodiment, and FIG. 6B is a schematic cross-sectional view along the line BB. When a light source is a semiconductor laser element, it is a model perspective view which shows the beam spread of a laser beam. FIG. 8A is a schematic cross-sectional view of a first modification of the first embodiment, and FIG. 8B is a schematic diagram illustrating the optical axis. FIG. 9A is a schematic perspective view of a second modification of the first embodiment, FIG. 9B is a schematic perspective view of the front cover portion, and FIG. 9C is a linear illumination excluding the front cover portion. It is a model perspective view of an apparatus. FIG. 10A is a schematic cross-sectional view of the linear illumination device according to the second embodiment, and FIG. 10B is a schematic cross-sectional view along the line BB. FIG. 11A is a schematic cross-sectional view of the linear illumination device according to the third embodiment, and FIG. 11B is a schematic cross-sectional view along the line BB. 12A is a schematic perspective view of the linear illumination device according to the fourth embodiment, FIG. 12B is a schematic cross-sectional view along the line CC, and FIG. 12C is a ray tracing diagram. . 13A is a schematic perspective view of a horizontal one-dimensional collective linear illumination device, FIG. 13B is a schematic perspective view of a vertical one-dimensional collective linear illumination device, and FIG. 13C is a two-dimensional collective line. It is a model perspective view of a planar illumination device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a schematic perspective view of the linear illumination device according to the first embodiment, FIG. 1B is a schematic perspective view of the front cover portion, and FIG. 1C is a linear shape excluding the front cover portion. It is a model perspective view of an illuminating device.
The linear illumination device 5 includes a first light source 10, a first light guide 30, a second light guide 20, a support 50, and a front cover part 70.

  The first light source 10 is a semiconductor laser element capable of emitting laser light 10a in the ultraviolet to visible light wavelength range. If the semiconductor is a nitride-based material, laser light in the ultraviolet to green wavelength range is emitted. When the semiconductor is made of a material such as InGaAlP or AlGaAs, laser light in the green to red wavelength range is emitted.

  The first laser light 10 a from the first light source 10 is guided through the second light guide 20 and then enters the first light guide 30. The first laser light 10 a incident on the first light guide 30 is guided upward in the first light guide 30 and upward from the exit surface 30 c exposed at the opening provided in the front cover 70. Released (emitted light G). If a phosphor layer is provided between the first light guide 30 and the support 50, the scattered light of the first laser light 10a and the wavelength converted light from the phosphor layer 40 are emitted. Thus, mixed light such as white light can be obtained as the outgoing light G.

  In the linear illumination device 5, for example, the width W can be 5 to 20 mm, the height T can be 5 to 20 mm, the length L can be 20 to 100 mm, and the like.

FIG. 2 is a schematic cross-sectional view of the linear illumination device according to the first embodiment.
FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. The 2nd light guide 20 has the 1st end surface 20a and the 2nd end surface 20b provided in the opposite side to the 1st end surface 20a. The first laser beam 10a introduced from the first end face 20a is guided and emitted from the second end face 20b. The second light guide 20 can be, for example, a thin glass rod or an optical fiber.

  The first light guide 30 includes a bottom surface 30a, an emission surface 30c provided on the side opposite to the bottom surface 30a, and a first inclined surface 30d that forms an acute angle α with the bottom surface 30a. The bottom surface 30 c of the first light guide 30 includes a first incident region 30 b that is connected to the second end face 20 b of the second light guide 20. The first laser light 10a incident on the first light guide 30 is emitted as scattered light upward from the emission surface 30c while being guided (emitted light G). The 1st light guide 30 shall consist of transparent resin or glass, for example.

  The support 50 is provided with a first opening 50b that reaches the upper surface 50a. The first light guide 30 is disposed on the upper surface 50a side, and the second light guide 20 is provided in the first opening 50b.

  The front cover 70 can be disposed, for example, on the outer peripheral region of the upper surface 50a of the support 50. Since the beam spread of the first laser beam 10 a incident from the first light source 10 is small, the cross-sectional area S <b> 2 of the second light guide 20 orthogonal to the light guide direction 24 is orthogonal to the light guide direction 34. The cross-sectional area S1 of the first light guide 30 may be smaller.

  When the support 50 is a heat conducting member made of metal, ceramic such as AlN, etc., it becomes easy to discharge the heat generated in the phosphor layer 40 by absorbing the first laser beam 10a. Further, when the upper surface 50a of the support 50 includes a metal, the light reflectance can be increased. As a result, the scattered light or wavelength-converted light of the first laser light 10a that has passed through the phosphor layer 40 is reflected upward, and the light extraction efficiency can be increased. Further, a groove or a recess for accommodating the first light guide 30 may be provided on the upper surface 50 a of the support 50.

  When the second light guide 20 is substantially orthogonal to the bottom surface 30a of the first light guide 30, the first angle can be obtained by appropriately selecting the angle α formed between the bottom surface 30a and the first inclined surface 30d. The amount of total reflection on the inclined surface 30d can be increased. Note that the first light guide 30 and the second light guide 20 may have an integrated structure made of the same material. A reflective layer such as a mirror surface using a metal material or a highly reflective film may be provided on the first inclined surface 30d. Furthermore, the first laser beam 10a is totally reflected at the interface between the first light guide 30 and the outside, so that the phosphor layer 40 can be irradiated with the first laser beam 10a more uniformly. it can. In this case, the first laser beam 10a is reflected by the first inclined surface 30d, the bottom surface 30a, the emission surface 30c, the end surface 30e, the surface 50a of the support 50, and the like of the first light guide 30. The end face 30e and the side faces 30f, 30h are desirably inclined faces that form an acute angle with respect to the bottom face 30a so that the first laser beam 10a is reflected by the bottom face 30a. In this way, the wavelength conversion efficiency can be increased by irradiating the phosphor layer 40 with a smaller number of reflections. Further, the cross section of the first inclined surface 30d along the line AA may be curved. The propagation of the first laser beam 10a in the second light guide 20 will be described in detail later.

FIG. 3A is a schematic perspective view of a first modification of the first light guide, and FIG. 3B is a schematic perspective view of a second modification.
The cross-sectional shape of the first light guide 30 is not limited to a rectangle, and may be a circle, an ellipse, a trapezoid, or the like. In FIG. 3A, the emission surface 30c has a collective lens shape capable of controlling the light distribution characteristics. Further, as shown in FIG. 3B, a part of the side surfaces 30f and 30h on both sides of the emission surface 30c may be inclined.

4A is a schematic perspective view of a modified example of the front cover, FIG. 4B is a schematic perspective view of a second modified example of the first light guide, and FIG. 4C is a schematic perspective view of the support. .
The front cover 70 may be provided so as to cover the side surface of the first light guide 30 and the side surface of the support 50. For example, the inner width W70 of the front cover 70 is equal to or slightly wider than the width W30 of the first light guide 30, and is equal to or slightly wider than the width W50 of the support 50. In this case, a fixing structure such as fitting or screwing is provided between the front cover 70 and the support body 50. If it does in this way, an adhesion state can be maintained among light guide 30, phosphor layer 40, and support 50. For this reason, efficient heat dissipation of the heat generated in the phosphor layer 40 and an integrated structure with high adhesive strength are possible.

FIG. 5 is a schematic cross-sectional view of a structure in which a ferrule is provided between the second light guide and the opening of the support.
When the second light guide 20 is connected to the bottom surface 30 a of the first light guide 30 by contact and welding, the second light guide 20 can be optically coupled to the first light guide 30. Alternatively, optical coupling is possible even if a lens or index matching oil is used between the second light guide 20 and the first light guide 30.
Further, as shown in FIG. 5, the ferrule 80 in which the second light guide 20 is inserted is inserted into the first opening 50b, and the ferrule 80 and the support 50 are press-fitted or bonded or bonded. It may be fixed by welding or the like. Further, even if there is a space between the second light guide 20 inserted and fixed in the ferrule 80 and the bottom surface 30a of the first light guide 30, optical coupling is possible. In addition, the 2nd light guide 20 and the bottom face 30a of the 1st light guide 30 are "light coupling | bonding". The laser beam discharge | released from the 2nd light guide 20 is 1st light guide. 30 is incident on the bottom surface 30a.

FIG. 6A is an optical path in the linear illumination device according to the first embodiment, and FIG. 6B is a schematic cross-sectional view.
FIG. 6A shows the optical path of the first laser beam 10a by the ray tracing simulation of the linear illumination device according to the first embodiment shown in FIG. The first laser beam 10a incident on the first light guide 30 and reflected by the first inclined surface 30d directly irradiates the phosphor layer 40, or on the emission surface 30c adjacent to the first inclined surface 30d. After the total reflection, the phosphor layer 40 is irradiated. As a result, most of the emitted wavelength converted light propagates while spreading from the surface of the phosphor layer 40 and is emitted to the outside from the emission surface 30c. In addition, when the reflective layer 60 is provided on the end surface 30e opposite to the first inclined surface 30d, the first laser beam 10a and the first light that does not reach the wavelength-converted light due to the irradiation to the phosphor layer 40 are provided. The laser beam 10a can be reflected in the direction of the phosphor layer 40. As a result, more wavelength-converted light is finally generated and emitted from the exit surface 30c.

  FIG. 6B is a schematic cross-sectional view along the line BB. The first laser light 10a that propagates while spreading along the light guide direction 34 irradiates the phosphor layer 40 while being reflected by the side surfaces 30f and 30h of the first light guide 30 (light g1). The wavelength-converted light generated by the light g1 is emitted from the emission surface 30c while spreading upward. In addition, among the first laser light 10a irradiated on the phosphor layer 40, the scattered light of the laser light 10a that has not been wavelength-converted is emitted from the upper emission surface 30c. Thus, the outgoing light G in which the scattered light of the first laser light 10a and the wavelength-converted light are mixed is emitted from the outgoing surface 30c.

FIG. 7 is a schematic perspective view showing the spread of laser light when the first light source 10 is a semiconductor laser element.
The size of the light emitting point of the first laser beam 10a is, for example, 1 μm or less in the thickness direction of the light emitting layer and around 10 μm in the horizontal direction of the light emitting layer, and is smaller than the LED. Further, the full width at half maximum θv in the vertical direction with respect to the light emitting layer of the semiconductor laser is in the range of 30 to 40 degrees, the full width at half maximum θh in the horizontal direction is approximately 10 degrees, and the like, and has a sharp directivity. When the light emitting point and the first end face 20a of the second light guide 20 are brought close to each other, the first laser light 10a is efficiently incident on the first end face 20a.

  The first laser light 10a propagated in the second light guide 20 along the light guide direction 24 is the second end face 20b on the side opposite to the first end face 20a, or the first light guide. From the welded portion of the body 30 and the second light guide 20, the light enters the first light guide 30 through the incident region 30 b.

  When the light guide direction 24 of the second light guide 20 is orthogonal to the first light guide 30, the second end face 20b of the second light guide 20 or the first light guide 30 and the second The optical axis 21 of the first laser light 10a emitted from the welded portion of the light guide 20 to the first light guide 30 is such that the optical axis 21 passing through the center O1 of the second light guide 20 is the first. By intersecting the inclined surface 30d, reflection occurs at the first inclined surface 30d. Light incident on the first inclined surface 30 d at an angle larger than the critical angle is totally reflected and propagates in the first light guide 30.

  The cross-sectional shape of the second light guide 20 is not limited to a circle, and may be an ellipse or a rectangle. Further, when the second light guide 20 is an optical fiber, the shape is flexible, so that the light source can be easily arranged.

  A sensation is generated on the exit surface of the lighting device in which a large number of LEDs are arranged. On the other hand, according to the first embodiment, continuous and natural white light emission can be realized. By reducing the width of the exit surface 30c of the first light guide 30, it is easy to increase the brightness, and the optical system can be reduced, and the light distribution characteristics can be easily controlled. As a result, the linear illumination device can be reduced in size and weight.

FIG. 8A is a schematic cross-sectional view of a first modification of the first embodiment, and FIG. 8B is a schematic diagram illustrating the optical axis.
As shown in FIG. 8A, the second light guide 20 may form an intersection angle β (where 0 <β <90 °) with respect to the bottom surface 30 a of the first light guide 30. When the crossing angle β is close to the inclination angle α of the first inclined surface 30d, total reflection is likely to occur, and light escaping from the first inclined surface 30d to the outside can be reduced.

  In FIG. 8B, the optical axis of the first laser beam 10a passes through the center O2 of the second end face 20b and is refracted according to Snell's law with respect to the light guide direction 24. When the refractive index n30 of the first light guide 30 and the refractive index n20 of the second light guide 20 are equal, the optical axis 21a is on the extension of the light guide direction 24.

  When the refractive index n20 of the second light guide 20 is higher than the refractive index of the first light guide 30, the optical axis 21b is refracted as shown in FIG. When the refractive index of the second light guide 20 is lower than the refractive index of the first light guide 30, the optical axis 21c is refracted as shown in FIG.

FIG. 9A is a schematic perspective view of a second modification of the first embodiment, FIG. 9B is a schematic perspective view of the front cover portion, and FIG. 9C is a linear illumination excluding the front cover portion. It is a model perspective view of an apparatus.
The first opening provided in the support body 50 may not be a hole penetrating the support body 50 up and down. In the second modification, the first opening is a groove 50 c provided on the side surface of the support 50. When the groove 50c is provided, it is easy to connect the second end face 20b of the second light guide 20 and the incident region 30b of the first light guide 30 by welding or the like. Alternatively, it is easy to dispose on the upper surface 50a of the support 50 after welding.

FIG. 10A is a schematic cross-sectional view of the linear illumination device according to the second embodiment, and FIG. 10B is a schematic cross-sectional view along the line BB.
Instead of the phosphor layer, a light scattering layer 42 in which a light scattering material is mixed with a liquid transparent resin and cured can be used. As shown in FIG. 10A, the light propagating in the light guide direction 34 enters the light scattering layer 42, and the light scattered by the light scattering layer 42 is emitted upward. Further, a part of the light reflected by the upper surface 50 a of the support 50 is further reflected by the reflection layer 60 and is emitted to the outside or can enter the phosphor layer 40.

  On the other hand, the light g5 reflected by the side surface 30f of the first light guide 30 in the first laser light 10a enters the light scattering layer 42 as shown in FIG. The light diffused by the light scattering layer 42 is emitted upward. In addition, the light g6 reflected by the side surface 30f is reflected by the upper surface 50a of the support 50 and emitted from the emission surface 30c (emitted light G).

FIG. 11A is a schematic cross-sectional view of the linear illumination device according to the third embodiment, and FIG. 11B is a schematic cross-sectional view along the line BB.
The phosphor layer is not provided between the bottom surface 30a of the first light guide 30 and the support 50, and light is applied to at least one of the bottom surface 30a, the emission surface 30c, the end surface 30e, and the side surfaces 30f and 30h. By providing the scattering layer, light obtained by converting the first laser light 10a into scattered light is emitted from the emission surface 30c. In the third embodiment, high-intensity light in the green to red wavelength range corresponding to the incident first laser light 10a can be emitted with a simple structure.

12A is a schematic perspective view of a linear illumination device according to the fourth embodiment, FIG. 12B is a schematic cross-sectional view along the line CC, and FIG. 12C is a ray tracing diagram. is there.
The fourth embodiment further includes a third light guide 22 that guides the second laser light 12 a along the light guide direction 26 and introduces it in the direction perpendicular to the bottom surface 30 a of the first light guide 30. doing. That is, the linear illumination device 5 can include the second light guide 20 and the third light guide 22 that are substantially symmetrical in the schematic cross-sectional view of FIG.

  The first light guide 30 includes a first inclined surface 30d that is bilaterally symmetric and a second inclined surface 30k. In addition, the support 50 has a first opening 50b and a second opening 50d at positions that are substantially symmetrical. Further, the linear illumination device 5 has a second light source 12 capable of emitting the second laser light 12a.

  In the fourth embodiment, since the first laser light 10a and the second laser light 12a are respectively introduced from both sides of the first light guide 30, the luminance distribution can be made flatter. . Further, if the first laser beam 10a and the second laser beam 12a have substantially the same characteristics, the luminance distribution along the emission surface 30c can be easily made symmetrical. In this case, the laser light from one light source may be divided into first and second laser lights.

13A is a schematic perspective view of a horizontal one-dimensional collective linear illumination device, FIG. 13B is a schematic perspective view of a vertical one-dimensional collective linear illumination device, and FIG. 13C is a two-dimensional collective line. It is a model perspective view of a planar illumination device.
FIG. 13A shows a one-dimensional collective line illumination device in which two linear illumination devices 6 are arranged in the light guide direction. FIG. 13B is a one-dimensional collective linear illumination device in which four linear illumination devices 6 are arranged in a direction substantially orthogonal to the light guide direction. FIG. 13C is a two-dimensional collective linear illumination device in which the linear illumination devices 6 are arranged in a 2 × 2 manner. Further, the plurality of linear illumination devices 6 can emit light simultaneously or individually.

  2, an inclined surface having the same inclination as the inclination (angle α) of the first inclined surface 30d can be provided inside the front cover 70. Further, a slight gap can be provided between the first opening 50 b and the second light guide 20. In this way, when the plurality of first light guides 30 are arranged one-dimensionally or two-dimensionally, the positions of the first light guides 30 are finely adjusted along the inclined surface of the corresponding front cover 70. Thus, it is easy to dispose at a predetermined position.

  According to the first to fourth embodiments and the modifications associated therewith, it is possible to provide a linear illumination device that is easy to control light distribution characteristics, increase brightness, reduce thermal resistance, and reduce size and weight. These linear illumination devices may have a length L shorter than that of a linear illumination device for a copying machine. Further, since the laser beam can be introduced from the bottom surface side, the array arrangement is easy.

  By using a plurality of linear illumination devices according to the present embodiment and a collective linear illumination device using the linear illumination devices in a staircase shape or an annular illumination device, for example, for in-vehicle use , Head lamps, fog lamps, various interior lighting, various exterior lighting, and the like. Of course, it can also be set as a general lighting device.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

5, 6 linear illumination device, 10 first light source, 10a first laser light, 12 second light source, 12a second laser light, 20 second light guide, 21 optical axis, 22 third Light guide, 24, 26, 34 light guide direction, 30 first light guide, 30c exit surface, 30d first inclined surface, 30k second inclined surface, 40 phosphor layer, 50 support, 50a upper surface , 50b first opening, 50c groove, 50d second opening, G outgoing light

Claims (6)

A first light source that emits a first laser light;
A support having a top surface and provided with a first opening reaching the top surface;
1st which is arrange | positioned at the upper surface side of the said support body, and has a bottom face, the output surface provided in the opposite side to the said bottom face, and the 1st inclined surface which makes an acute angle with respect to the said bottom face. A light guide;
A second light guide having a first end surface into which the first laser light is introduced and guiding the first laser light, the optical axis of the first laser light being the first A second light guide that is optically coupled to the bottom surface of the first light guide so as to intersect the inclined surface of the first light and is provided in the first opening;
With
The introduced first laser light is emitted from the emission surface while being guided in the first light guide,
A linear illumination device in which a cross-sectional area of the second light guide orthogonal to the light guide direction is smaller than a cross-sectional area of the first light guide orthogonal to the light guide direction.   And a phosphor layer that is provided between the upper surface of the support and the bottom surface of the first light guide and absorbs the first laser light and emits wavelength-converted light. Item 2. The linear illumination device according to item 1.   The linear illumination device according to claim 1, further comprising a reflective layer provided on an end surface of the first light guide that is on a side opposite to the first inclined surface. A second light source that emits a second laser light;
A third light guide having a first end surface into which the second laser light is introduced and guiding the second laser light;
Further comprising
The support is further provided with a second opening reaching the upper surface,
The first light guide further includes a second inclined surface that forms an acute angle with respect to the bottom surface on a side opposite to the first inclined surface,
The third light guide is optically coupled to the bottom surface of the first light guide so that an optical axis of the second laser light intersects the second inclined surface, and the second light guide Provided in the opening,
The introduced second laser light is emitted from the emission surface while being guided in the first light guide,
The linear illumination device according to claim 1, wherein a cross-sectional area of the third light guide orthogonal to the light guide direction is smaller than a cross-sectional area of the first light guide orthogonal to the light guide direction.   Provided between the upper surface of the support and the bottom surface of the first light guide, absorbs the first laser light and the second laser light and emits wavelength-converted light, respectively. The linear illumination device according to claim 4, further comprising a phosphor layer.   An aggregate linear illumination device in which a plurality of linear illumination devices according to claim 1 are arranged one-dimensionally or two-dimensionally.

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