JP2007265721A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device which achieves sufficient luminance by reflecting a light outgoing from a light source to a second optical member supporting a first optical member to be available as an effective light. <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 has an incidence plane for a light outgoing from the light source 2 for emitting the light to the predetermined direction through the refraction, and a secondary optical member 5 which makes contact with the top side of an outer block face 43 at the first optical member 4 and extends from the top side of the outer block face 43 to the outside for positioning and supporting the first optical member 4. An intersecting plane of the outer block face 43 of the first optical member 4 and the second optical member 5 is served as a reflective plane 40. As a result, a light outgoing from the light source 2 to the second optical member supporting the first optical member is reflected by the reflective plane 40 to be available as an effective light. <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 collimating (condensing) lens for refracting light emitted from a substrate 103 on which an LED 102 is disposed and the LED 102 at a predetermined angle, and is provided on an incident side surface of the lens. It is comprised from the hybrid lens 104 in which the concave surface 144 was formed. For example, as indicated by a solid arrow L1 in FIG. 5B, 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. 6, a plurality of LEDs 102 are arranged at a predetermined interval on the substrate 103, and the concave surface 144 of the hybrid lens 104 is arranged on each of them. In addition, the upper portions of the outer surfaces 143 of the plurality of hybrid lenses 104 are extended outward and cross-linked, whereby the hybrid lens 104 is determined and supported at a predetermined position.
JP 2003-281909 A JP-A-60-130001

  In the light emitting device 101 having the single light source described above, for example, as indicated by a dotted arrow L2 in FIG. 5B, the light is refracted primarily by the concave surface 144 of the hybrid lens 104, and the upper portion of the inner surface of the outer surface 143 of the lens. The light traveling toward the outer side is totally reflected on the inner surface of the outer surface 143 due to the difference in refractive index between the outer surface 143 and the material in contact therewith (air in this case), and is emitted from the exit surface 141 on the upper surface of the lens.

  However, as in the light emitting device shown in Patent Document 1 or Patent Document 2, when the upper portions of the outer surface 143 of the plurality of hybrid lenses 104 extend from the lens center to the outside and are bridged, the bridges are cross-linked. When the material of the portion is the same as that of the hybrid lens 104, there is no difference in refractive index, so that light directed toward the upper inner surface of the outer surface 143 of the lens is emitted as indicated by the dotted arrow L2 in FIG. The light is not emitted from the surface 141. Therefore, in a light emitting device having a lens having a configuration shown in Patent Document 1 or Patent Document 2, sufficient brightness may not always be obtained.

  The present invention solves the above problem, and in a light-emitting device having a configuration in which upper portions of outer surfaces of a plurality of hybrid lenses extend outward from the lens center and are bridged, the light is emitted from a light source and is contained in the lens. An object of the present invention is to provide a light emitting device capable of effectively condensing light that has reached the upper part of the inner surface of the outer surface of a lens among incident light, and can obtain sufficient luminance.

  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 second optical member, the second optical member is in contact with at least the upper portion of the outer surface of the first optical member and extends outward from the upper portion of the outer surface. The light-emitting device having the optical member is a surface where the outer surface of the first optical member intersects with the second optical member is a reflective surface.

  According to a second aspect of the present invention, in the light emitting device according to the first aspect, the reflecting surface includes an outer surface of the first optical member and a material having a refractive index smaller than the refractive index of the first optical member. It is configured by touching.

  According to a third aspect of the present invention, in the light emitting device according to the first or second aspect, the reflective surface is configured by contacting an outer surface of the first optical member and an air layer.

  According to a fourth aspect of the present invention, in the light emitting device according to any one of the first to third aspects, the second optical member extends outward from the outer periphery of the large bottom surface of the first optical member. A contact portion that contacts the first optical member, and a non-contact portion that is partitioned by the reflecting surface and does not contact the first optical member, and the contact portion is integrated with the first optical member. It is what has become.

  According to the first aspect of the present invention, the light reaching the upper inner surface of the outer surface of the first optical member is reflected by the reflecting surface and irradiated in a direction substantially orthogonal to the large bottom surface. As the light that can be used as the light emitting device increases, sufficient luminance can be obtained.

  According to the second aspect of the present invention, the second optical member made of a light-transmitting resin such as polyethylene resin having a refractive index smaller than that of the first optical member is brought into contact with the outer surface of the first optical member. Since the reflecting surface can be configured by installing the reflecting member on the outer surface of the first optical member, the reflecting surface can be configured at a lower cost than a method of depositing metal on the outer surface of the first optical member.

  According to the invention of claim 3, since the reflecting surface is configured by the outer surface of the first optical member and the air layer being in contact with each other, the reflecting surface can be formed at a low cost, and the entire light emitting device can be produced. Cost can also be reduced.

  According to the invention of claim 4, the second optical member formed with the contact portion in contact with the first optical member and the non-contact portion not in contact is fitted from above the outer periphery of the large bottom surface of the first optical member. By combining, the contact portion of the first optical member and the second optical member is integrated, and a gap, that is, a reflection surface, is formed between the first optical member and the non-contact portion of the second optical member. Therefore, the production cost of the light emitting device can be further reduced, and the first optical member can be positioned and supported accurately.

  A light emitting device 1 according to a first embodiment of the present invention will be described with reference to FIGS. The light emitting device 1 of the present embodiment includes a light source 2 that diverges light, a substrate 3 on which the light source 2 is mounted, and a first optical member 4 that refracts light emitted from the light source 2 and emits it in a predetermined direction. A plurality of light sources 2 arranged in contact with the upper part of the outer surface 43 of the first optical member 4 and extending outward from the upper part of the outer surface 43 and arranged adjacent to each other on the substrate 3. In addition, a second optical member 5 that determines and supports the position of the first optical member 4 is provided. 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 a light emitting device 1 in which a single light source 2 is arranged on a substrate 3, but in the present embodiment, depending on the use application of the light emitting device 1, The plurality of light sources 2 may be arranged in a vertical and horizontal matrix form, a radial form, or an annular 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 this light is refracted on the inner surface of the outer surface 43 and emitted 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. The light emitted from the light source 2 and enters 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 is indicated by a solid line arrow L1 in FIG.

  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 is determined and supported so that the first optical member approaches or is mounted on the substrate 3. The second optical member 5 is in contact with the upper part of the outer surface 43 of the first optical member 4 and extends outward from the lens center from the upper part of the outer surface 43. The material of the second optical member 5 is not necessarily the same material as that of the first optical member, and may be an impermeable material that does not transmit light. The second optical member 5 is supported by extending the second optical member 5 further outward and fixing the tip. The first optical member 4 and the second optical member 5 are fixed with an adhesive 6. For example, an acrylic adhesive or the like is used for the adhesive 6.

  If the first optical member 4 and the second optical member 5 are in contact with each other and are made of materials having the same refractive index, the first optical member 4 is the same as the dotted arrow L2 shown in FIG. A portion of the light guided into the second optical member 5 enters the second optical member 5 without being refracted at the surface where the first optical member 4 and the second optical member 5 intersect, In some cases, the light is lost as stray light without being controlled in the direction, or the light is emitted at an angle different from a predetermined direction, causing the user to feel glare.

  However, if the first optical member 4 and the second optical member 5 are in contact with each other and are made of materials having different refractive indexes, the first optical member 4 and the second optical member 4 are separated by the difference in refractive index. The surface where the second optical member 5 intersects becomes the reflection surface 40 of the light reaching this surface. As a result, as indicated by the dotted arrow L2 in FIG. 1B, a part of the light guided into the first optical member 4 is refracted by the reflecting surface 40, and is substantially reflected on the large bottom surface 41. Irradiates in a direction that goes straight. In the present embodiment, for example, an acrylic resin is used for the first optical member 4, and a polyethylene resin having a refractive index lower than that of the first optical member 4 is used for the second optical member 5. Thereby, the light reaching the reflecting surface 40 can be refracted in a direction substantially perpendicular to the large bottom surface 41.

  In the light emitting device 1 having the above configuration, the light reaching the upper outer side of the outer surface 43 of the first optical member 4 is reflected by the reflecting surface 40 and is irradiated in a direction substantially orthogonal to the large bottom surface 41. When the reflecting surface 40 is not configured, light that is not used can be used as effective light, and sufficient luminance as a light emitting device can be obtained. The reflecting surface 40 is formed by bringing the outer surface 43 of the first optical member 4 into contact with the second optical member 5 having a refractive index lower than that of the first optical member 4 and made of an inexpensive material. The reflecting surface can be configured at a lower cost than a method such as vapor deposition of metal on the outer surface 43 of the first optical member 4.

  Next, a light emitting device 1 according to a second embodiment of the present invention will be described with reference to FIG. In the light emitting device 1 of the present embodiment, a slight gap is provided between the outer surface 43 of the first optical member 4 and the second optical member 5 in the first embodiment, and the air layer 7 is formed in this gap. It is formed. Due to the difference in refractive index between the first optical member 4 and the air layer 7, the outer surface 43 of the first optical member 4 and the surface in contact with the air layer 7 become the reflecting surface 40, which is the same as in the first embodiment. An effect can be obtained. In addition, the production cost can be reduced by using air to form the reflecting surface 40. The reflective surface 40 can also be configured by filling the gap with airgel and forming a vacuum layer between the outer surface 43 of the first optical member 4 and the second optical member 5.

  A modification of the light emitting device 1 according to the second embodiment will be described with reference to FIG. In this modification, in the second embodiment, the first optical member 4 or the second optical member 4 is formed in a gap provided between the outer surface 43 of the first optical member 4 and the second optical member 5. A member 8 (referred to as another member) different from the optical member 5 is sandwiched. If the surface of the separate member 8 has a roughness equal to or greater than the wavelength of light, sufficient reflection occurs as in the case of the air layer 7 described above, and the outer surface 43 of the first optical member 4 and the separate member 8. The surface in contact with becomes the reflecting surface 40, and the same effect as described above can be obtained.

  Next, a light emitting device 1 according to a third embodiment of the present invention will be described with reference to FIG. In the light emitting device 1 of the present embodiment, the second optical member 5 in the first and second embodiments is extended from the outer periphery of the large bottom surface 41 of the first optical member 4, and the first optical member 4. A contact portion 51 that contacts the outer periphery of the large bottom surface 41, and a non-contact portion 52 that is partitioned by the reflective surface 40 and does not contact the first optical member 4. It is integrated with the optical member 4.

  In the light emitting device 1 having the above-described configuration, the second optical member 5 formed by forming a portion 51 (referred to as a contact portion) that contacts the first optical member and a portion 52 (referred to as a non-contact portion) that does not contact the first optical member is used as the first optical member. The first optical member 4 and the contact portion 51 of the second optical member 5 can be integrally formed by fitting from above the outer periphery of the four large bottom surfaces 41. Therefore, a gap, that is, a reflecting surface 40 is formed between the non-contact portions 52 of the first optical member 4 and the second optical member 5, and the first optical member 4 is positioned and supported accurately. Can do. Moreover, the fixation of the first optical member 4 and the second optical member 5 and the creation of the reflection surface 40 can be performed simultaneously, and the production cost of the entire light emitting device 1 can be further suppressed.

  The present invention is not limited to the above configuration, and various modifications can be made. For example, in the second embodiment, the separate member 8 sandwiched between the first optical member 4 and the second optical member 5 is an adhesive resin, and the adhesive 6 is not used. The first optical member 4 and the second optical member 5 may be fixed.

(A) is a perspective view of the light-emitting device concerning the 1st Embodiment of this invention, (b) is sectional drawing of the same device. The expanded sectional view of the part which the 1st optical member and 2nd optical member cross in the light-emitting device concerning the 2nd Embodiment of this invention. The figure which shows the modification of a light-emitting device same as the above. The expanded sectional view of the part which the 1st optical member and 2nd optical member cross in the light-emitting device which concerns on the 3rd Embodiment of this invention. (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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Light source 3 Board | substrate 4 1st optical member 40 Reflecting surface 41 Large bottom surface 42 Small bottom surface 43 Outer surface 44 Concave surface 5 2nd optical member 51 Contact part 52 Non-contact part 7 Air layer 8 Separate member

Claims (4)

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 is in contact with at least the upper part of the outer surface of the first optical member and extends outward from the upper part of the outer surface to support the light-emitting device,
The light-emitting device, wherein a surface where the outer surface of the first optical member and the second optical member intersect is a reflective surface.   The said reflective surface is comprised when the outer surface of the said 1st optical member and the material of refractive index smaller than the refractive index of the said 1st optical member contact | abut, It is comprised. Light emitting device.   3. The light emitting device according to claim 1, wherein the reflection surface is configured by contacting an outer surface of the first optical member with an air layer. 4. The second optical member extends outward from the outer periphery of the large bottom surface of the first optical member and is partitioned by the reflective surface and a contact portion that comes into contact with the first optical member and the first optical member. A non-contact portion that does not contact the optical member,
The light emitting device according to claim 1, wherein the contact portion is integrated with the first optical member.

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