JP2007265722A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To interlink many hybrid lenses in a light-emitting device and reduce optical variation arising near the outer peripheral side of an outgoing plane of the hybrid lens. <P>SOLUTION: A light-emitting device 1 includes a light source 2, a substrate 3 for mounting the light source 2, a first optical member 4 which forms an outer block of a body of rotation having a large bottom face 41 and a small bottom face 42 and using a normal line of the substrate 3 as an axis and which refracts a light outgoing from the light source 2 to the predetermined direction, and a second optical member 5 which makes contact with the outer peripheral side of the large bottom face 41 and extends from the outer peripheral side to the outside for supporting the first optical member 4. An inner peripheral side 51 facing the large bottom face 41 of the second optical member 5 takes the shape of a circular conical surface, wherein an inclination angle to the substrate side of this inner peripheral side 51 is irradiated from the center of the light source 2 and is formed to be almost the same as an inclination angle to the substrate side of a light passing through a ridge line 51a between the inner peripheral side 51 and large bottom face 41. This prevents a light passing through the ridge line 51a from being reflected by the inner peripheral side 51 and reduces optical variation arising near the outer peripheral side of the large bottom face 41. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light-emitting device that is used in a display device or the like and refracts and condenses light emitted radially from a light source such as a light-emitting diode (LED) by a lens and irradiates it in a predetermined direction.

  2. Description of the Related Art In recent years, light emitting devices including LEDs and the like are used in addition to general filament lamps for display devices such as roads and automobiles. In a light emitting device used for such a display device or the like, light emitted from a light source such as an LED need only be emitted in a predetermined direction according to the intended use. However, since light from a light source is normally emitted radially, in order to effectively use light emitted from a light source such as an LED, conventionally, as shown in Patent Document 1 or Patent Document 2, 2. Description of the Related Art A light emitting device including a lens that collects light emitted from an LED or the like and emits the light in a predetermined direction is known.

  Here, a configuration of a light emitting device including a general single light source will be described with reference to FIGS. A light emitting device 101 having a single light source is a substrate 103 on which an LED 102 is disposed, and a collimating (condensing) lens for refracting light emitted from the LED 102 at a predetermined angle, and the incident side surface of the lens. And a hybrid lens 104 having a concave surface 144 formed thereon. For example, as indicated by a solid arrow L1 in FIG. 2B, the light emitted from the LED 102 is primarily refracted when entering the concave surface 144 of the hybrid lens 104, and is reflected on the inner surface of the outer surface 143 of the lens. After the secondary refraction, the light is emitted from the exit surface 141 of the hybrid lens 104 to the outside of the lens. The light emitting device 101 emits light incident on the hybrid lens 104 in a predetermined direction by adjusting the shape and refractive index of the hybrid lens 104 itself.

Moreover, as a light emitting device used for a display device such as a road or an automobile, a device provided with a plurality of light sources is known as shown in Patent Document 1 or Patent Document 2, for example. This is because, like the light emitting device 111 shown in FIG. 3, a plurality of LEDs 102 as light sources are arranged on the substrate 103 at a predetermined interval, and the concave surface 144 of the hybrid lens 104 is arranged on each of them. Therefore, the upper part of the outer surface 143 of the plurality of hybrid lenses 104 is extended outward and bridged to support the hybrid lens 104 at a predetermined position. In addition, as described above, the manufacturing cost can be reduced by arranging and forming the plurality of hybrid lenses 104 integrally.
JP 2003-281909 A JP-A-60-130001

  However, as described above, the upper portions of the outer surface 143 of the plurality of hybrid lenses 104 are bridged by extending outward from the lens center, and the material of the bridged portions is the same material as the hybrid lens 104. If there is no difference in refractive index, light directed toward the upper inner surface of the outer surface 143 of the lens is not emitted from the emission surface 141 as indicated by a dotted arrow L2 in FIG. Therefore, in a light emitting device having a lens having a configuration shown in Patent Document 1 or Patent Document 2, sufficient luminance may not be obtained.

  Here, a light-emitting device 121 that solves the above-described problems is shown in FIG. This is formed by extending outward from the outer periphery of the emission surface 141 of the plurality of hybrid lenses 104 to form a cross-linked portion. With this configuration, as indicated by the dotted arrow L2 in FIG. 4, the light traveling toward the upper part of the lens outer surface is totally reflected by the inner surface of the outer surface 143 of the lens and is emitted from the output surface 141 to be used as effective light. It will be used.

  However, when the light emitted from the light source enters the concave surface 144 of the hybrid lens 104 and then travels radially in the lens and exits from the exit surface 141 of the hybrid lens 104, a one-dot chain line arrow L3 in FIG. As shown in FIG. 4, some of the light is reflected by the desired inner peripheral surface 151 to the exit surface 141 of the hybrid lens 104 at the bridged portion, and the exit surface 141 of the hybrid lens 104 is reflected by this reflected light. Light unevenness may occur in the vicinity of the outer periphery of the.

  The present invention solves the above-described problems, and an object of the present invention is to provide a light-emitting device in which a plurality of hybrid lenses are connected and unevenness of light is suppressed near the outer periphery of the emission surface of the hybrid lens.

  In order to solve the above-mentioned problems, the invention of claim 1 comprises an outline of a rotating body having a light source, a substrate on which the light source is mounted, and a large bottom surface and a small bottom surface with the normal of the substrate as axes. Then, the concave surface provided on the small bottom surface becomes the incident surface of the light emitted from the light source, the first optical member that refracts the light and emits it in a predetermined direction, and the light source arranged on the substrate In order to determine and support the position of the first optical member in accordance with the arrangement of the first optical member, the first optical member is in contact with at least the outer periphery of the large bottom surface of the first optical member and extends outward from the outer periphery. And an inner peripheral surface facing the large bottom surface of the second optical member has a conical surface shape, and the second optical member includes the inner peripheral surface. The angle of inclination of the surface with respect to the substrate surface is irradiated from substantially the center of the light source, Are those formed substantially the same as made as an inclined angle with respect to the substrate surface of the light passing through the ridge surface and the large bottom surface.

  According to a second aspect of the present invention, in the light emitting device according to the first aspect, the inner peripheral surface is a rough surface.

  According to the first aspect of the present invention, the light irradiated from the center of the light source and passing through the ridge line between the inner peripheral surface and the large bottom surface of the second optical member is reflected by the inner peripheral surface of the second optical member. Therefore, it is possible to suppress unevenness of light that occurs in the vicinity of the outer periphery of the large bottom surface of the first optical member.

  According to the invention of claim 2, even if a part of the light passing through the ridge line between the inner peripheral surface and the large bottom surface comes into contact with the inner peripheral surface, the inner peripheral surface is a rough surface, Since the light reflected by the peripheral surface is diffused, it is possible to more effectively suppress the unevenness of the light that occurs near the outer periphery of the large bottom surface.

  A light emitting device 1 according to an embodiment of the present invention will be described with reference to FIGS. The light emitting device 1 includes a light source 2 that diverges light, a substrate 3 on which the light source 2 is mounted, a first optical member 4 that refracts light emitted from the light source 2 and emits the light in a predetermined direction, a first The plurality of optical members 4 are in contact with the outer periphery of the large bottom surface 41 and extend outward from the outer periphery of the large bottom surface 41 of the first optical member 4, and are arranged adjacent to each other on the substrate 3. A second optical member 5 that determines and supports the position of the first optical member 4 in accordance with the arrangement of the light source 2. Hereinafter, each component will be described in detail.

  A general-purpose light emitting diode (LED) is used as the light source 2. For example, a blue LED and a YAG (Yttrium Aluminum Garnet) phosphor or BOS that converts light in a wavelength band of 380 nm to 480 nm into light of 480 nm to 780 nm. A white LED in combination with a sheet containing (Barium ortho-Silicate) phosphor or the like is used. Further, in the present embodiment, not only the above-described white LED, it is only necessary to generate visible light and be sufficiently small as compared with the entire capacity of the light emitting device 1, for example, a small incandescent lamp, a small halogen bulb, etc. Can also be used. Further, the shape of the light emitting surface of the light source 2 is not particularly limited.

  The substrate 3 is a general-purpose printed circuit board, which is excellent in dimensional stability and has little variation such as warpage and twist. As a material of the substrate 3, for example, a glass epoxy substrate in which a glass cloth (cloth) is superimposed and impregnated with an epoxy resin is used. In addition, an appropriate heat sink or the like (not shown) using a material with good heat dissipation such as copper is mounted on the back of the substrate 3 in order to efficiently dissipate the heat generated from the light source 2. In general, the light source 2 is soldered on the substrate 3 so as to be electrically energized, but may be fixed by, for example, an adhesive. 1A and 1B show the light-emitting device 1 in which a plurality of light sources 2 are arranged in a row on the substrate 3, the plurality of light sources 2 depends on the usage of the light-emitting device 1. Thus, it may be installed in a vertical and horizontal matrix form, a radial form or a ring form.

  The first optical member 4 is basically a hybrid lens, and forms an outer surface 43 of a rotating body having a large bottom surface 41 and a small bottom surface 42 about the normal line of the substrate 3. A concave surface 44 provided on 42 serves as an incident surface for light emitted from the light source 2, and refracts and emits the light in a predetermined direction. The first optical member 4 is installed so as to be mounted close to or above the substrate 3, and is installed so that the concave surface 44 covers each of the plurality of light sources 2 fixed on the substrate 3. The As the material of the first optical member 4, a transparent material such as acrylic resin, polycarbonate, or glass is used. The first optical member 4 is generally manufactured by an injection molding method, but may be manufactured by cutting.

  Although the shape of the large bottom surface 41 is a plane in FIGS. 1A and 1B, there are other concave surfaces, convex surfaces, and the like, which are appropriately determined depending on the required light distribution. Further, the large bottom surface 41 may be subjected to a diffusion process (for example, a sandblast process) in order to avoid irradiation unevenness on the irradiation surface.

  Of the small bottom surface 42, the concave surface 44 includes an incident front surface 46 that faces the light source 2 and an incident conical surface 47 that faces the side surface of the light source 2. The incident front surface 46 guides light emitted from the light source 2 directly to the large bottom surface 41. In addition, the shape of the incident front surface 46 includes a flat surface, a concave surface, a convex surface, and the like, and is appropriately determined depending on a required light distribution. The incident conical surface 47 guides the light emitted from the light source 2 to the large bottom surface 41 after being totally reflected by refraction. Lights emitted from the light source 2 and incident on the first optical member 4 from the incident front surface 46 or the incident conical surface 47 and guided to the large bottom surface 41 are indicated by solid line arrows L1 and dotted line arrows L2 in FIG. Yes.

  The second optical member 5 is used to bridge and connect each of the plurality of first optical members 4, and in accordance with the arrangement of the plurality of light sources 2 arranged at a predetermined interval on the substrate 3. The position of the first optical member 4 is determined and supported so that the first optical member 4 is close to or mounted on the substrate 3. The second optical member 5 is in contact with the outer periphery of the large bottom surface 41 of the first optical member 4 and extends from the inside of the outer periphery of the large bottom surface 41 outward from the lens center. The material of the second optical member 5 is basically the same light transmissive material as that of the first optical member 4. In particular, if a light transmitting material different from that of the first optical member 4 is used in a portion where the second optical member 5 and the first optical member 4 are close to each other, light refraction occurs at each contact surface. , It becomes difficult to control the light in a desired direction.

  In the light emitting device 1 according to the present embodiment, the inner peripheral surface 51 facing the large bottom surface 41 of the second optical member 5 has a conical surface shape, preferably a rough surface. The optical member 5 is irradiated from the center of the light source 2 indicated by a one-dot chain line arrow L3 in FIG. It is formed to have the same inclination angle with respect to the substrate surface of the light passing through the ridge line 51 a between the surface 51 and the large bottom surface 41. Note that the tilt angle with respect to the substrate surface when light passing through the ridge line 51 a between the inner peripheral surface 51 and the large bottom surface 41 of the second optical member 5 exits the large bottom surface 41 constitutes the first optical member 4. Depending on the refractive index of the material, the shape of the outer surface 43 of the first optical member 4, the shape of the concave surface 44, the diameter of the large bottom surface 41, the distance from the light source 2 to the large bottom surface 41, etc. The inclination angle 51 with respect to the substrate surface is appropriately adjusted.

  With the above configuration, light that is irradiated from the center of the light source 2 and passes through the ridge line 51 a between the inner peripheral surface 51 and the large bottom surface 41 of the second optical member 5 is reflected by the inner peripheral surface 51 of the second optical member 5. Is prevented. For this reason, the light emitting device 1 according to this embodiment has an outer periphery of the large bottom surface 41 of the first optical member 4 as compared with a light emitting device in which the inner peripheral surface 51 of the second optical member 5 is not conical. Unevenness of light generated in the vicinity can be suppressed.

  Further, even when a part of the light passing through the ridge line 51a between the inner peripheral surface 51 and the large bottom surface 41 is in contact with the inner peripheral surface 51, the inner peripheral surface 51 is a rough surface. Since the light reflected by the peripheral surface 51 is diffused, the unevenness of the light that occurs in the vicinity of the outer periphery of the large bottom surface 41 can be more effectively suppressed.

  The present invention is not limited to the above configuration, and various modifications can be made. For example, in the above description, the inclination angle of the inner peripheral surface 51 of the second optical member 5 facing the large bottom surface 41 of the first optical member 4 with respect to the substrate surface is irradiated from the center of the light source 2, and The inclination angle of the light passing through the ridge line 51a with the bottom surface 41 with respect to the substrate surface is the same. This is because the amount of light irradiated from the center of the light source 2 is large and the influence of the light is large. The form of the inner peripheral surface 51 is irradiated from at least the approximate center of the light source 2 and the ridgeline. It may be substantially the same as the inclination angle of the light passing through 51a with respect to the substrate surface.

(A) is the fractured perspective view of the light-emitting device which concerns on the 1st Embodiment of this invention, (b) is sectional drawing of the apparatus. (A) is a perspective view of the light-emitting device provided with the conventional single light source, (b) is sectional drawing of the same device. Sectional drawing of the light-emitting device provided with the conventional several light source. Sectional drawing of the light-emitting device provided with the conventional several light source.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Light source 3 Board | substrate 4 1st optical member 41 Large bottom surface 42 Small bottom surface 43 Outer surface 44 Concave surface 5 2nd optical member 51 Inner peripheral surface 51a Ridge line

Claims (2)

An outer surface of a rotating body having a light source, a substrate on which the light source is mounted, and a large bottom surface and a small bottom surface with a normal line of the substrate as an axis, and a concave surface provided on the small bottom surface is emitted from the light source. The position of the first optical member is determined in accordance with the arrangement of the first optical member that becomes an incident surface of the light to be refracted and refracts the light in a predetermined direction and the light source arranged on the substrate. And a second optical member that contacts at least the outer periphery of the large bottom surface of the first optical member and extends outward from the outer periphery to support the light emitting device,
The inner peripheral surface facing the large bottom surface of the second optical member has a conical surface shape,
In the second optical member, an inclination angle of the inner peripheral surface with respect to the substrate surface is irradiated from a substantial center of the light source, and an inclination angle of the light passing through the ridge line between the inner peripheral surface and the large bottom surface with respect to the substrate surface. The light emitting device is formed so as to be substantially the same.   The light emitting device according to claim 1, wherein the inner peripheral surface is a rough surface.

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