JP2008159453A - Light source device and lamp equipped with the light source device - Google Patents

Abstract

Provided is a light source device capable of improving the luminance of an exit surface of a light guide that guides light from a plurality of LEDs with a simple configuration.
A light source device includes a light emitting unit and a light guide. The light emitting unit 12 includes a plurality of LEDs 14 arranged in a predetermined region. The light guide 17 has an incident surface 18 having substantially the same shape and area as the region where the LEDs 14 are disposed, and an exit surface 19 having an area 0.7 to 0.92 times the area of the incident surface 18, and A frustum shape in which the height value from the incident surface 18 to the output surface 19 is set to a value within 10 times the area of the incident surface 18 is formed. The light guide body 17 is characterized in that an air layer is provided between the LED 14 and the incident surface 18 is opposed to the LED 14.
[Selection] Figure 1

Description

  The present invention relates to a light source device having a plurality of LEDs (light emitting diodes) and a lamp configured to include the light source device.

  Conventionally, as a light source device in which light emitted from a plurality of LEDs is guided by a light guide, a cylindrical lens is disposed facing a light emitting diode unit on which the plurality of LEDs are mounted, and a cylindrical shape is formed from each LED. The light incident on the entrance surface of the lens is propagated while being totally reflected by this cylindrical lens, guided to the tip of the hemispherical lens, and diffused by unevenness on the surface of the tip of the lens. A technique for emitting light to the surroundings is known (for example, see Patent Document 1).

  Similarly, as a light source device in which light emitted from a plurality of LEDs is guided by a light guide, the light emitted from the plurality of LEDs is made into a substantially parallel light beam by a reflector and emitted to a condenser lens. Is known to allow light that has passed through a condenser lens to enter a rod integrator that is aligned with the optical axis, and to propagate the light while totally reflecting it by the integrator and to emit it from the exit surface of the integrator. (For example, see Patent Document 2).

In addition, a tapered rod whose cross-sectional area gradually increases as it moves away from the LED is arranged for one LED, and the light from the LED is propagated while being totally reflected by this taper rod. A technique for emitting light from the end face having the largest cross-sectional area is known (for example, see Patent Document 3).
JP 2006-79845 A (paragraphs 0011-0022, FIGS. 1 to 3) JP 2006-285043 A (paragraphs 0005-0017, FIGS. 1 to 5) Japanese Patent Laying-Open No. 2004-102132 (paragraphs 0070-0097, FIGS. 1 to 4)

  The area of the region where a plurality of LEDs are arranged, the area of the entrance surface of the cylindrical lens facing the area, and the area of the exit surface of the lens viewed from the front are all the same. In the technology, the light guided by the cylindrical lens is absorbed by the lens constituent material, so that the luminous flux divergence value substantially equivalent to the luminance is smaller than that without the lens. This is disadvantageous for increasing the brightness of the exit surface.

  In the technique of Patent Document 2 in which light from a plurality of LEDs is condensed and guided by a rod integrator, the cross-sectional area of each part of the rod integrator is the same, so the collected light is absorbed by the constituent material of the rod integrator. However, this is disadvantageous in increasing the brightness of the exit surface of the rod integrator. In addition, a condenser lens for condensing light is necessary, which is disadvantageous in terms of cost.

  The technique of patent document 3 which guides the light of one LED arranged opposite to this by the taper rod cannot only mix while guiding the light of a plurality of LEDs, but also from the incident surface of the taper rod. Since the exit surface is large, the light spreads from the entrance surface to the exit surface in addition to the light absorption by the constituent material of the taper rod, which is disadvantageous in increasing the brightness of the exit surface of the taper rod.

  In addition, the present inventor is developing a clear lamp using a plurality of LEDs in the light emitting portion instead of a general clear light bulb having a light source that includes a light source and a light source cover through which the light source can be seen through. It is. In this case, it is considered that light from a plurality of LEDs is guided by a light guide and light is emitted using a light exit surface of the light guide as a pseudo light source.

  It is possible to apply the techniques of Patent Documents 1 to 3 to such a lamp. However, as described above, the luminance of the exit surface of a light guide such as a cylindrical lens, a rod integrator, or a tapered rod is not sufficiently high. Therefore, further improvement is required to produce a pseudo light source having a luminance suitable for a lamp.

  The objective of this invention is providing the light source device which can improve the brightness | luminance of the output surface of the light guide which guides the light from several LED with a simple structure, and a lamp provided with the same.

  A light source device according to a first aspect of the present invention includes: a light emitting unit having a plurality of LEDs arranged in a predetermined region; an incident surface having substantially the same shape and area as the region in which the LEDs are disposed; A frustum shape having an exit surface with an area 0.7 to 0.92 times the area, and having a height value from the entrance surface to the exit surface within 10 times the diameter of the entrance surface And a light guide body provided with an air layer between the LED and the incident surface facing the LED.

  In the present invention and each of the following inventions, an area where the LEDs are arranged side by side is defined as a “predetermined area”. In this invention and each of the following inventions, each LED that emits white light can be used. In addition, red, green, and blue are mixed in the light guide so that white light is emitted from the emission surface. It is also possible to use a plurality of LEDs that emit light of the same number.

  In this invention and each of the following inventions, the light guide is solid rather than hollow, and can be formed of a light-transmitting synthetic resin such as light-transmitting glass or acrylic resin. The shape of the light body is “frustum shape”, which is typically the shape of a truncated cone and a truncated pyramid, but also includes the shape of an oblique truncated cone and an inclined truncated pyramid, and the incident that forms the bottom of the truncated cone. A shape in which the exit surface is not parallel to the surface but is oblique is also included. The light guides in the shape of the truncated pyramid and the oblique truncated pyramid are easier to mix the light guided while totally reflecting than the light guides in the shape of the truncated cone and the oblique truncated cone. Is preferable in that white light can be emitted from the emission surface of the light guide by improving the mixing performance of these colors.

  In this invention and each of the following inventions, the diameter of the incident surface of the light guide refers to the diameter of the incident surface that forms a circle when the light guide has a truncated cone shape and an oblique truncated cone shape. When the light guide has a truncated pyramid shape and an oblique truncated pyramid shape, it indicates the diameter of a virtual circle drawn inscribed on each side of the incident surface. Further, in the present invention and each of the following inventions, a plurality of minute prisms may be provided on the conical surface of the light guide having a frustum shape in order to further promote mixing of light in the light guide.

  In the first aspect of the invention, the height of the light guide from the entrance surface to the exit surface of the light guide having a frustum shape is set to a value within 10 times the diameter of the entrance surface, and the light guided is transmitted by the light guide. Absorption can be suppressed by limiting the length of the light guide, and the area of the exit surface with respect to the area of the entrance surface of the light guide is 0.7 times or more, so that the decrease in efficiency of the light source device is substantially ignored. Since it is suppressed to the extent possible, even if the efficiency decreases, it can be kept within about 2% at the maximum. Further, the area of the exit surface with respect to the area of the entrance surface of the light guide having the frustum shape is set to 0.92 times or less, and the guided light is condensed as it is guided to the exit surface side. It is possible to prevent the value of the luminous flux divergence from becoming smaller than when the light guide is not used. Therefore, the luminance of the exit surface of the light guide that has guided the light from the plurality of LEDs can be improved, and this luminance improvement is realized by the configuration of the light guide, so it is easy without requiring a condensing lens or the like. Can be realized with a simple configuration.

  A light source device according to a second aspect of the present invention includes a light emitting unit having a plurality of LEDs arranged in a predetermined region; an emission surface, and an incident surface having substantially the same shape and area as the region where the LEDs are disposed. And a frustum-shaped exit end portion having the exit surface and a truncated cone-shaped light guide main body extending from the exit end portion to the entrance surface, and an angle of the cone surface of the exit end portion Is made steeper than the angle of the conical surface of the light guide main part continuous with the conical surface, and the cross-sectional area of the boundary between the emission end part and the light guide main part is 0.7 times to the area of the incident surface. 0.92 times the area and the height from the incident surface to the boundary is formed as a value within 10 times the diameter of the incident surface, and an air layer is provided between the LED and the incident surface. And a light guide disposed so as to face the LED.

  In the second aspect of the present invention, the exit end portion having the exit surface has a frustum shape having a steeper surface with a steeper angle than the conical surface of the light guide main body, so that the size of the exit surface is further reduced. I can do it. The light guide has a light emitting end portion and at least a light guide main portion of the other light guide main portion having a frustum shape, and the light guide and the light emitting end portion are guided from the incident surface of the light guide. Limiting the length of the light guide body so that the light guided is absorbed by the light guide, with the height reaching the boundary with the main body portion being a value within 10 times the diameter of the incident surface As the cross-sectional area of the boundary with respect to the area of the incident surface of the light guide is 0.7 times or more, the reduction in the efficiency of the light source device is suppressed to a level that can be substantially ignored. It can be within 2% at maximum. Further, since the cross-sectional area of the boundary with respect to the area of the incident surface of the light guide having a frustum shape is 0.92 times or less, the guided light is condensed as it is directed toward the boundary. The value of the luminous flux divergence can be made smaller than when the light guide is not used. Therefore, the luminance of the exit surface of the light guide that has guided the light from the plurality of LEDs can be improved, and this luminance improvement is realized by the configuration of the light guide, so it is easy without requiring a condensing lens or the like. Can be realized with a simple configuration.

  A light source device according to a third aspect of the present invention includes a light emitting unit having a plurality of LEDs arranged in a predetermined region; an emission surface, and an incident surface having substantially the same shape and area as the region where the LED is disposed. And a hemispherical exit end having the exit surface or a substantially hemispherical exit end having the exit surface composed of a small circle parallel to the entrance surface and the exit end to the entrance surface. A frustoconical light guide main part, and the cross-sectional area of the boundary between the light emitting end part and the light guide main part is 0.7 to 0.92 times the area of the incident surface, The height from the incident surface to the boundary is formed as a value within 10 times the diameter of the incident surface, and an air layer is provided between the LED and the incident surface is arranged to face the LED. And a light guide that is made up of.

  In the invention of claim 3, the exit end portion having the exit surface has a hemispherical shape or a substantially hemispherical shape having an exit surface composed of a small circle parallel to the entrance surface, so that the size of the exit surface is further reduced. I can do it. The light guide has a frustoconical shape at least among the light exit end and the other light guide main portions, and the light guide is guided from the light incident surface to the light exit end. Limiting the length of the light guide main body so that the light guided is absorbed by the light guide, with the height reaching the boundary of the light main body being a value within 10 times the diameter of the incident surface As the cross-sectional area of the boundary with respect to the area of the incident surface of the light guide is 0.7 times or more, the reduction in the efficiency of the light source device is suppressed to a level that can be substantially ignored, so the efficiency is reduced. Can be kept within 2% at the maximum. Furthermore, since the cross-sectional area of the boundary with respect to the area of the entrance surface of the light guide main body having a truncated cone shape is 0.92 times or less, the guided light is condensed as it is directed toward the boundary. It is possible to prevent the light flux divergence value of the light source device from becoming smaller than when the light guide is not used. Therefore, the luminance of the exit surface of the light guide that has guided the light from the plurality of LEDs can be improved, and this luminance improvement is realized by the configuration of the light guide, so it is easy without requiring a condensing lens or the like. Can be realized with a simple configuration.

  The light source device according to a fourth aspect of the invention is characterized in that a concave portion that opens toward the center of the emission surface and tapers toward the incidence surface is formed in the light guide.

  In the present invention, among the light guided toward the exit surface, the light incident on the surface formed with the depression opening on the exit surface is diffused to the side of the light guide on this surface, and the light guide In addition to the exit surface, the side surface of the exit surface can be illuminated.

  According to a fifth aspect of the present invention, there is provided a lamp according to a fifth aspect of the present invention, comprising: a peripheral wall portion; a light source mounting portion continuous with the peripheral wall portion; and an outer member having a recess surrounded by the peripheral wall portion and the light source mounting portion; The light source device according to claim 1, wherein the back surface of the light emitting unit of the device is brought into contact with the outer surface of the light source mounting unit, and the light emitting surface of the light guide of the light source device is separated from the outer surface. A light source device mounted on the light source mounting portion; a light source cover that covers the light source device and is attached to the outer member; a lighting circuit that is housed in the concave portion and lights the light source device; and an opening edge of the concave portion And a base disposed on the part side.

  In the present invention, when implemented as a clear type lamp, it is sufficient to use a light source cover in which at least a portion corresponding to the light emitting direction from the light guide is made transparent. When the lamp is not a type, for example, a light source cover having diffuse translucency such as ground glass may be used for the entire cover.

  In this invention, it is provided with the light source device as described in any one of Claim 1 to 4 which can improve the brightness | luminance of the output surface of the light guide which guides the light from several LED by simple structure, This light source device As a light source that replaces the filament with the portion from which the light is emitted from the light guide as a pseudo light source, a lamp having the necessary luminance can be provided.

  According to the light source device of the first to third aspects of the invention, the luminance of the exit surface of the light guide that guides the light from the plurality of LEDs can be improved with a simple configuration.

  According to the light source device of the fourth aspect of the present invention, not only the exit surface of the light guide but also the end surface of the exit surface can be illuminated.

  According to the invention of claim 5, the brightness of the exit surface of the light guide that guides light from the plurality of LEDs can be improved with a simple configuration, and a lamp using the exit surface as a light emitting source instead of the filament can be provided.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 shows a clear lamp. The lamp 1 includes a metal outer member 2, a light source device 11, a light source cover 21, a lighting circuit 25, and a base 31.

  The outer member 2 also functions as a heat radiating member for releasing heat emitted from the LED, which will be described later, to the outside. The outer member 2 has a cylindrical peripheral wall portion 3 and a light source mounting portion 4 with one axial end of the peripheral wall portion 3 closed. The peripheral wall portion 3 and the light source mounting portion 4 are integrated, and a concave portion 5 formed so as to be surrounded by these is opened at the other axial end of the peripheral wall portion 3. The outer periphery of the peripheral wall 3 has a smaller diameter toward the opening side of the recess 5. A cover mounting groove 2a is formed at a portion where the peripheral wall portion 3 and the light source mounting portion 4 are integrally continuous. The cover mounting groove 2 a is annular and is open to the outer surface of the peripheral portion of the light source mounting portion 4.

  The light source device 11 includes a light emitting unit 12 and a light guide body 17.

  The light emitting unit 12 is formed by mounting a plurality of (only two are shown in FIG. 1) LEDs 14 in a predetermined region, for example, the central portion of the light emitting unit substrate 13, and has a planar shape. The light emitting unit substrate 13 is made of, for example, a printed circuit board in which a conductive pattern is provided on an insulating layer covering one surface of a metal base. Each LED 14 is of, for example, an SMD (Surface Mount Device) type and emits white light.

  The light emitting unit 12 is attached by a screw 15 penetrating the light emitting unit substrate 13 and screwed into the light source mounting unit 4 so that the metal base forming the back surface of the light emitting unit 12 is in close contact with the outer surface of the light source mounting unit 4. . In order to improve the heat conduction from the metal base to the light source mounting portion 4, a heat transfer layer may be provided by filling a heat transfer element such as silicon or grease between them. An annular support member 16 is attached to the light emitting unit substrate 13. The support member 16 has a seat 16a that is retracted toward the light emitting unit substrate 13 from the tip thereof, and is provided so as to surround the central portion of the light emitting unit substrate 13 on which the plurality of LEDs 14 are arranged.

  The light guide 17 is made of a translucent material such as a transparent acrylic resin. The light guide 17 has a frustum shape having an entrance surface 18 and an exit surface 19 parallel to each other, for example, a truncated cone shape. The entrance surface 18 forms the bottom surface of the truncated cone, and the exit surface 19 forms the top surface of the truncated cone.

  The shape of the incident surface 18 of the light guide 17 is substantially the same as the region of the light emitting unit substrate 13 where the plurality of LEDs 14 are arranged, and the area of the incident surface 18 is approximately the same size as the region. Furthermore, the end of the light guide 17 on the incident surface 18 side is sized to be fitted into the support member 16 and supported by the seat 16a.

  The area of the exit surface 19 of the light guide 17 is 0.7 to 0.92 times larger than the area of the entrance surface 18. The light guide 17 is provided with a recess 20 that is open at the center of the exit surface 19. The recess 20 has a shape symmetric with respect to the central axis of the light guide 17 and is formed in a tapered shape, for example, in a mortar shape toward the incident surface 18.

  The height of the light guide body 17, in other words, the height value from the incident surface 18 to the output surface is a value within 10 times the diameter of the incident surface 18.

  The light guide 17 is supported on the light emitting unit substrate 13 by bonding the incident surface 18 of the light guide 17 to the seat 16a of the support member 16 or the like. Accordingly, an air layer is formed between the incident surface 18 of the light guide 17 and each LED 14 using the seat 16a as a spacer, and the incident surface 18 faces each LED 14 at a close distance by this arrangement. By mounting the light guide 17 on the light source mounting portion 4, the exit surface 19 of the light guide 17 is arranged away from the outer surface of the light source mounting portion 4 according to the height of the light guide 17 and the seat 16 a. Yes.

  The entire light source cover 21 is formed in a substantially hemispherical shape by a translucent material such as transparent glass. The light source cover 21 is attached to the outer member 2 while the opening edge 21a is fitted in the cover mounting groove 2a while being held by the adhesive 22. The light source cover 21 covers the light source device 11, and the emission surface 19 of the light guide 17 is positioned corresponding to the intermediate position of the light source cover 21 in the height direction. In addition, only the closed cover part on the upper side in FIG. 1 is made transparent with reference to the two-dot chain line drawn in FIG. 1, and the opened cover part on the lower side is frosted to be ground glass. Alternatively, a reflective film may be provided on the inner surface to function as a reflector.

  A lighting circuit 25 for lighting each LED 14 of the light source device 11 is accommodated in the recess 5. The lighting circuit 25 is unitized by attaching various circuit components 27 to a circuit board 26. The lighting circuit 25 and the light source device 11 are electrically connected to each other through an insulation coated electric wire (not shown) that penetrates the light source mounting portion 4. 1 indicates a cup-shaped insulating member provided along the inner surface of the recess 5 in order to electrically insulate the outer member 2 and the lighting circuit 25 from each other.

  A base 31 for supplying power to the lighting circuit 25 includes a base element 32 and a connecting member 33 fixed to the base element 32. The connecting member 33 made of an electrical insulating material is connected to the end of the outer member 2 on the opening side of the recess 5.

  When the lamp 1 having the above-described configuration is turned on, the light emitted from each LED 14 passes through an air layer between each LED 14 and the incident surface 18 of the light guide 17 facing the LED 14 and is bent at the incident surface 18. After being incident on the light guide 17, it propagates in the direction of the exit surface 19 while repeating total reflection at the conical surface (side surface) 17 f in the light guide 17 and exits from the exit surface 19. In addition, at the exit surface side end portion of the light guide body 17, a recess 20 opened in the exit surface 19 is formed in the light guided toward the exit surface 19 while propagating as described above. Light incident on the mortar-shaped surface 20a is diffused to the side of the light guide body 17 by the surface 20a. Therefore, not only the exit surface 19 of the light guide 17 but also the conical surface at the end of the exit surface can be illuminated. That is, the pseudo light source unit including the emission surface 19 can be illuminated.

  As described above, the light emitting surface 19 of the light guide 17 and the periphery thereof are illuminated as a pseudo light source, so that the light emitted from the pseudo light source can be illuminated through the light source cover 21.

  In this case, in the lamp 1 having the above-described configuration, the luminance of the light source 17 that guides the light incident from the plurality of LEDs 14 can be improved.

  That is, by setting the height value from the incident surface 18 to the exit surface 19 of the light guide 17 having a truncated cone shape to a value within 10 times the diameter of the incident surface 18, the guided light is guided. Absorption by the body 17 can be limited to the extent that there is no practical problem. FIG. 2 shows the height of the light guide 17 when the light guide 17 is made of a transparent acrylic resin and the value obtained by dividing the area of the exit surface 19 by the area of the entrance surface 18 is 0.7. The relationship between the value divided by the diameter (horizontal axis) and the efficiency (vertical axis) of the light source device 11 is shown. According to FIG. 2, the efficiency of 90% when the value is 1 is the highest, and the efficiency tends to decrease as the height of the light guide 17 increases and the numerical value increases, and the numerical value is smaller than 10. In some cases, the efficiency falls within about 2% at the maximum, but when the numerical value exceeds 10, it can be seen that the degree of the reduction in efficiency becomes stronger. The decrease in the efficiency of the light source device 11 within about 2% is substantially negligible. Accordingly, as described above, the height value from the incident surface 18 to the output surface 19 of the light guide body 17 having a truncated cone shape is set to a value within 10 times the diameter of the incident surface 18, thereby approximately 90%. Can maintain efficiency.

  Further, the area of the exit surface 19 with respect to the area of the entrance surface 18 of the light guide 17 having a truncated cone shape is 0.7 times or more, so that the reduction in the efficiency of the light source device 11 can be substantially ignored at most. Can be within 2%. FIG. 3 shows a value (horizontal axis) obtained by dividing the area of the exit surface 19 by the area of the entrance surface 18 when the height of the transparent acrylic resin light guide 17 is 100 mm and the efficiency of the light source device 11 ( The vertical axis). According to FIG. 3, the efficiency when the value is 0.7 or more falls within an efficiency drop of approximately 2% at the maximum, but the efficiency when the value is less than 0.7 is the boundary when the value is 0.7. It turns out that it falls rapidly. Therefore, the efficiency of about 90% can be maintained by setting the area of the exit surface 19 to 0.7 times or more the area of the entrance surface 18 of the light guide 17 having a truncated cone shape as described above.

  In addition, since the area of the exit surface 19 with respect to the area of the entrance surface 18 of the light guide 17 having a truncated cone shape is 0.92 times or less, the light flux regardless of the light absorption of the light guide 17 itself made of transparent acrylic resin. It is possible to prevent the divergence value from becoming smaller than when the light guide 17 is not used. FIG. 4 shows the value (horizontal axis) obtained by dividing the area of the exit surface 19 by the area of the entrance surface 18 when the height of the light guide 17 made of transparent acrylic resin is 100 mm and the efficiency of the light source device 11 ( The vertical axis). Also, the dotted line in FIG. 4 indicates the change in the luminous flux divergence when the LEDs 14 are directly illuminated without using the light guide 17. In FIG. 4, the value at the intersection of the solid line and the dotted line is 0.92. FIG. 4 shows that when the value exceeds 0.92, the luminous flux divergence is lower than the luminous flux divergence indicated by the dotted line, in other words, the light emitted from the LED 14 is diffused to the surroundings, and the value is 0.92 or less. Then, it can be seen that the luminous flux divergence exceeds the luminous flux divergence indicated by the dotted line, and the light emitted from the LED 14 is collected on the emission surface 19 of the light guide 17. Therefore, as described above, by setting the area of the exit surface 19 to 0.92 times or less of the area of the entrance surface 18 of the light guide body 17 having a truncated cone shape, the value of the luminous flux divergence of the light source device 11 can be reduced. It can be made smaller than when the body 17 is not used. In other words, the light guided by the light guide 17 from the plurality of LEDs 14 is condensed as it is guided to the exit surface 19 side, and the luminance at the exit surface 19 portion of the light guide 17 can be improved.

  By using the light source device 11 having the above-described configuration, it is possible to improve the luminance of the pseudo light source including the emission surface 19 of the light guide 17 that guides light from the plurality of LEDs 14 and the surrounding portion. Thereby, the said pseudo light source of the lamp | ramp 1 can be approximated to the light emission brightness | luminance of a filament coil, and required and sufficient brightness | luminance can be obtained.

  And since such brightness | luminance improvement was implement | achieved by the structure of the light guide 17 without requiring the lens for condensing, etc., it can implement | achieve with a simple structure. In addition, although the plurality of LEDs 14 are used in the light emitting unit 12, the pseudo light source is smaller than an area where the plurality of LEDs 14 are disposed. Therefore, the size of the pseudo light source is set to the size of the filament of a general light bulb. Can be approximated. At the same time, the plurality of LEDs 14 are not directly viewed, and the light guide 17 is viewed in a manner similar to a stem of a general light bulb having a filament, so that the image is very different from a general light bulb having a filament. Can with no lamp 1. Furthermore, as described above, the lamp 1 is an LED lamp that does not have a filament as a light source, and thus has a longer life than a general light bulb having a filament.

  A second embodiment of the present invention will be described with reference to FIG. Since 2nd Embodiment is the same as 1st Embodiment except the matter demonstrated below, about the same structure as 1st Embodiment, the same code | symbol as 1st Embodiment is attached | subjected and description is abbreviate | omitted.

  The second embodiment is different from the first embodiment in the configuration of the light guide body 17. Specifically, the light guide 17 includes a light guide main portion 17a occupying most of the light guide 17 and an emission end portion 17b continuous thereto. The light guide main portion 17a corresponds to the light guide described in the first embodiment, and therefore, the light emitting end portion 17b is added in the second embodiment. A virtual boundary W between the light guide main portion 17a and the emission end portion 17b is indicated by a dotted line in FIG.

  The light guide main body 17a is a part from the incident surface 18 to the boundary W, and has a truncated cone shape, for example, a truncated cone shape. Since the light guide main body 17a corresponds to the light guide described in the first embodiment as described above, the cross-sectional area of the boundary W between the emission end 17b and the light guide main body 17a is The area is 0.7 times to 0.92 times the area, and the height value from the incident surface 18 to the boundary W is within 10 times the diameter of the incident surface 18.

  The emission end portion 17 b is formed continuously with the end of the light guide main body 17 a having the smallest cross section, and has an emission surface 19 and a recess 20. The emission end portion 17b is made of a truncated cone whose conical surface (side surface) 17d is formed at a steeper angle than the conical surface (side surface) 17c of the light guide main body 17a continuous thereto. The area of the emission surface 19 is reduced. Matters other than the above are the same as in the first embodiment.

  Therefore, in the second embodiment, for the reason already described in the first embodiment, the luminance of the pseudo light source including the emission surface 19 of the light guide 17 that guides the light incident from the plurality of LEDs 14 can be improved with a simple configuration. A lamp 1 with a device 11 can be provided.

  In addition, since the light guide 17 has the emission end portion 17b having the above-described configuration, the efficiency of the light source device 11 is somewhat reduced, but the pseudo light source including the emission surface 19 can be made smaller. Therefore, the light source device 11 of the second embodiment can be suitably used as a light emission source of the downsized lamp 1.

  In the second embodiment, instead of the light guide body 17 shown in FIG. 5, when the light guide body main portion 17a has a truncated pyramid shape or an oblique pyramid shape, the emission end portion accordingly. 17b can be implemented as a truncated pyramid shape or an oblique truncated pyramid shape whose cone surface 17d is steeper than the truncated cone surface 17c of the light guide main body 17a.

  Furthermore, the light guide 17 shown in FIGS. 6A and 6B can be used instead of the light guide 17 shown in FIG. The light guide 17 in FIG. 6A has a configuration in which the light guide main portion 17a has a truncated cone shape and the emission end portion 17b has a hemispherical shape. In the light guide 17 in FIG. 6B, the light guide main portion 17 a has a truncated cone shape and the emission end portion 17 b has a substantially hemispherical shape, but the top of the hemisphere is parallel to the incident surface 18. This is a configuration in which an emission surface 19 made of a flat small circle is provided. Even when these light guides 17 are employed, the length of the pseudo light source can be shortened.

  5 and 6 are preferably formed integrally with the light guide main body 17a from the viewpoint of not causing a decrease in efficiency, but separately formed emission ends 17b. It is also possible to bond the light guide main body 17a with a transparent adhesive.

  In addition, the light source device 11 demonstrated above is not restrict | limited to the use as a light source part of the lamp | ramp 1, and can be applied to various uses other than a lamp | ramp.

The side view which shows a partial cross section of the lamp provided with the light source device which concerns on 1st Embodiment of this invention. The figure which shows the relationship between the efficiency in the light source device of FIG. 1, and the value of the height / incident surface diameter of the light guide which this device has. The figure which shows the relationship between the efficiency in the light source device of FIG. 2, and the value of the output area / incident area of the light guide which this device has. The figure which shows the relationship between the light beam divergence degree in the light source device of FIG. 2, and the value of the output area / incident area of the light guide which this device had. The side view which shows a partial cross section of the lamp provided with the light source device which concerns on 2nd Embodiment of this invention. (A) and (B) are sectional views showing different examples of other light guides that can be used in the light source device shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lamp, 2 ... Outer member, 3 ... Perimeter wall part, 4 ... Light source attachment part, 5 ... Recessed part, 11 ... Light source device, 12 ... Light emission part, 13 ... Light emission part board | substrate, 14 ... LED, 15 ... Screw, 16 ... Support member, 17 ... light guide, 17a ... light guide main part, 17b ... output end, 17c, 17d, 17f ... conical surface, 18 ... incident surface, 19 ... output surface, 20 ... indent, 20a ... indent Formed surface, 21 ... light source cover, 25 ... lighting circuit, 31 ... base, W ... boundary

Claims (5)

A light emitting unit having a plurality of LEDs arranged in a predetermined region;
An incident surface having substantially the same shape and area as the region where the LED is disposed, and an exit surface having an area 0.7 to 0.92 times the area of the entrance surface, and from the entrance surface to the exit surface A frustum shape having a height value within 10 times the diameter of the incident surface is formed, and an air layer is provided between the LED and the light incident surface facing the LED. With light bodies;
A light source device comprising: A light emitting unit having a plurality of LEDs arranged in a predetermined region;
The exit surface and the region where the LED is disposed have an entrance surface that is substantially the same in shape and area, and has a truncated cone-shaped exit end having the exit surface and the exit end to the entrance surface. A cone-shaped light guide body main part, the angle of the cone surface of the emission end portion is steeper than the angle of the cone surface of the light guide body main portion continuous to the cone surface, the emission end portion and the The cross-sectional area of the boundary of the main part of the light guide is 0.7 to 0.92 times the area of the incident surface, and the height from the incident surface to the boundary is 10 times the diameter of the incident surface. A light guide that is formed as a value within a double, and is provided with an air layer between the LED and the light incident surface facing the LED;
A light source device comprising: A light emitting unit having a plurality of LEDs arranged in a predetermined region;
The exit surface and the region where the LED is disposed have an entrance surface that has substantially the same shape and area, and is formed of a hemispherical exit end having the exit surface or a small circle parallel to the entrance surface. A substantially hemispherical emission end portion having an emission surface and a truncated cone-shaped light guide main portion extending from the emission end portion to the incidence surface, and a boundary between the emission end portion and the light guide main portion. The cross-sectional area is 0.7 to 0.92 times the area of the incident surface, and the height from the incident surface to the boundary is formed as a value within 10 times the diameter of the incident surface, A light guide provided with an air layer between the LED and the incident surface facing the LED;
A light source device comprising:   4. The light source device according to claim 1, wherein the light guide body is formed with a recess that opens toward a center portion of the emission surface and tapers toward the incidence surface. 5. . An outer shell member having a peripheral wall, a light source mounting portion continuous with the peripheral wall portion, and a recess surrounded by the peripheral wall portion and the light source mounting portion;
5. The light source device according to claim 1, wherein a rear surface of a light emitting unit of the device is brought into contact with an outer surface of the light source mounting unit, and an emission surface of a light guide body of the light source device is disposed. A light source device mounted on the light source mounting portion apart from the outer surface;
A light source cover that covers the light source device and is attached to the outer member;
A lighting circuit housed in the recess for lighting the light source device;
A base disposed on the opening edge side of the recess;
The lamp characterized by comprising.

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