JP2008053660A - Light emitting module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable uniform surface light emission at a low cost in a light emitting module comprising an optical member for diffusing radiation of a light output from a light source by reflecting and refracting the same. <P>SOLUTION: A light emitting module 1 comprises a substrate 2, a light emitting element 3 provided on the substrate 2, and an optical member 4 having a substantially rotatable member shape with the normal L as its axis provided substantially on the center of the light emitting element 3 with respect to the substrate 2. In the optical member 4, the surface on the opposite side of the surface to be mounted on the substrate 2 is provided as a reflecting surface 41 for reflecting a light from the light emitting element 3, and the outer circumferential surface of the optical member 4 is provided as a transmitting surface 42 for transmitting a light from the reflecting surface 41. Moreover, the surface on the substrate 2 transmitted by a light through the transmitting surface 42 is provided as a diffusing reflecting surface 21. Since a light from the light emitting element 3 after being reflected by the reflecting surface 41 is refracted or transmitted by the transmitting surface 42, and reaches the diffusing reflecting surface 21 so as to be diffused and reflected by high efficiency, the diffusing reflecting surface 21 can be presented to a viewer as if it has uniform surface light emission. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light emitting module that diffuses and radiates light irradiated from a light source such as a light emitting diode (LED) by reflecting and refracting light with a lens.

  Conventionally, lighting equipment capable of surface light emission has been used for signboard lighting and the like. However, in order to realize uniform surface light emission with only the light emitting elements, it is necessary to arrange a large number of light emitting elements closely, resulting in an increase in cost. Therefore, for example, as disclosed in Patent Document 1, light emitted from a light source such as an LED is reflected and refracted by an optical member such as a lens and diffused to emit light so that light can be emitted over a wide range. There is a device. In this light emitting device, an emission area that directly emits light emitted from the light source and a total reflection area that totally reflects the light are provided at the front interface of the resin lens that seals the light source. A concave mirror-like light reflecting portion is provided, and a part of the light emitted from the light source is emitted forward through the emission region, and the other light is totally reflected in the total reflection region The light reflected from the light reflecting portion and emitted forward from the total reflection area allows the light from the light source to be irradiated from the entire surface of the resin lens over a wide range.

Moreover, as shown in Patent Document 2, a ring-shaped optical member optically bonded to the outside of the LED and a reflecting member disposed on the outer periphery of the optical member are provided, and the LED is irradiated upward. There is a light emitting device in which light is reflected by a reflecting surface of an optical member and emitted in a substantially horizontal direction, and the light is reflected in a substantially vertical direction by the reflecting member.
JP 2002-94129 A JP 2004-88007 A

  However, in the light emitting device disclosed in Patent Document 1, since the resin lens surface is the light emitting surface, a large lens is required to realize uniform surface light emission. Large lenses are difficult to mold and require advanced lens processing techniques to achieve the desired optical properties, which may increase costs.

  Further, in the light emitting device shown in Patent Document 2, in order to allow the reflecting member to efficiently reflect the light emitted from the optical member in the substantially horizontal direction in the substantially vertical direction, it corresponds to the shape of the optical member. Since it is necessary to employ a specific reflecting member, it is not suitable for manufacturing a light emitting module having excellent versatility. In addition, in order to realize uniform surface light emission by the light reflected by the reflecting member, it is necessary to provide a separate diffuse reflecting member, which causes an increase in cost.

  The present invention solves the above-described problem, and a light emitting module that enables uniform surface light emission at low cost by using a small optical member that can irradiate light emitted from a light source over a wide range. The purpose is to provide.

  In order to solve the above-mentioned problems, the invention of claim 1 is directed to a substrate, a light emitting element provided on the substrate, and a substantially rotating body shape about a normal line passing through a substantial center of the light emitting element with respect to the substrate. A surface of the optical member opposite to the mounting surface of the optical member, including a reflective surface that reflects the light emitted from the light emitting element. The outer peripheral surface of the optical member is a transmission surface that transmits light from the reflection surface, and a surface that is substantially parallel to the substrate and irradiated with light transmitted through the transmission surface is a diffusion reflection surface. It is what has been.

  According to a second aspect of the present invention, in the light emitting module according to the first aspect, of the surface including the reflective surface, the vicinity of the normal line is a direction in which the light of the light emitting element is substantially parallel to the normal line. It is configured to be a refracting surface that refracts and transmits light.

  According to a third aspect of the present invention, in the light emitting module according to the first or second aspect, the distance between the surface including the reflective surface and the substrate increases from the normal to the outer circumferential direction. It is configured.

  According to a fourth aspect of the present invention, in the light emitting module according to any one of the first to third aspects, the distance between the transmissive surface and the substrate increases from the normal to the outer peripheral direction. It is comprised so that it may do.

  According to a fifth aspect of the present invention, in the light emitting module according to the second aspect, in the cross section including the normal, the distance from the substrate is monotonous from one end of the cross section to the other end. It is configured to include a shape that increases or monotonously decreases.

  According to a sixth aspect of the present invention, in the module according to any one of the first to fifth aspects, the shape of the reflective surface is substantially rotationally symmetric with respect to the normal line, and a cross section of the reflective surface. The shape includes a part of a parabola or a parabolic approximate curve focusing on the approximate center of the light emitting element or the vicinity thereof, and the cross-sectional shape of the transmission surface focuses on a point on or near the diffuse reflection surface. It is comprised so that a part of hyperbolic or hyperbolic approximate curve may be included.

  According to a seventh aspect of the present invention, in the light emitting module according to any one of the first to sixth aspects, the reflection surface is a total reflection surface.

  According to an eighth aspect of the present invention, in the light emitting module according to any one of the first to seventh aspects, the diffuse reflection surface is substantially parallel to the substrate and is substantially centered on the light emitting element. Concentric circular steps are used, and the half beam angle is approximately 30 to 60 °.

  According to the first aspect of the present invention, the light emitted from the light emitting element is reflected by the reflecting surface, then refracts and transmits the transmitting surface, reaches the diffuse reflecting surface, and is diffusely reflected with high efficiency. It is possible to make it appear to the viewer that the entire range where the light emitted from the optical member reaches among the diffuse reflection surface is emitting light. In addition, even a small optical member can make light reach a relatively wide range of the diffusive reflection surface, so that a light emitting module capable of emitting light at low cost without using a large lens or the like is provided. Can do.

  According to the invention of claim 2, since the light incident on the refracting surface is refracted and transmitted in a direction substantially parallel to the normal line, the surface including the reflecting surface of the optical member also emits light. It can be seen that the entire light emitting module is evenly emitting light to the viewer.

  According to the invention of claim 3, since the incident angle of the light irradiated from the light emitting element with respect to the reflection surface is increased and the reflection angle is also increased, the light can reach far from the optical member, and diffuse reflection A wide range of the surface can emit light. In addition, since the incident angle of the light reflected by the reflecting surface with respect to the transmitting surface becomes small, the amount of light reflected into the optical member is reduced, and the reflection loss of light due to Fullel reflection and total reflection on the transmitting surface can be reduced. .

  According to the fourth aspect of the present invention, since the incident angle of the light reflected by the reflecting surface with respect to the transmitting surface becomes smaller, it is possible to further reduce the reflection loss of light due to the fullnel reflection and total reflection on the transmitting surface.

  According to the invention of claim 5, the light emitted from the light emitting element and incident on the refracting surface is refracted and transmitted in a direction in which the distance from the substrate monotonously increases in the shape of the refracting surface. That is, it is possible to increase the amount of light irradiated from the refractive surface in a specific direction depending on the mounting direction of the optical member.

  According to the sixth aspect of the present invention, the light reflected by the reflecting surface can be collected in a substantially concentric narrow area of the diffuse reflecting surface, and the viewer can visually recognize the substantially concentric light emitting surface. Can do.

  According to the invention of claim 7, since it is not necessary to form a vapor deposition film on the reflecting surface, the manufacturing cost can be reduced, and glare caused by reflection of external light on the reflecting surface is also suppressed.

  According to the invention of claim 8, since the light reflected by the diffuse reflection surface can be efficiently irradiated in a range of 30 to 60 ° centering on the normal direction of the substrate, light emission according to the installation environment Surface specifications are possible.

  Below, the light emitting module which concerns on the 1st Embodiment of this invention is demonstrated with reference to FIG. The light emitting module 1 includes a substrate 2, a light emitting element 3 provided on the substrate 2, and an optical member 4 having a substantially rotating body shape with a normal L passing through the approximate center of the light emitting element 3 with respect to the substrate 2 as an axis. . Of the optical member 4, the surface opposite to the mounting surface to the substrate 2 is a surface 40 including a reflective surface 41 that reflects light emitted from the light emitting element 3, and the outer peripheral surface of the optical member 4 is The transmission surface 42 is configured to transmit light from the reflection surface 41. Further, the surface that is substantially parallel to the substrate 2 and irradiated with the light transmitted through the transmission surface 42 is configured to be the diffuse reflection surface 21. Hereinafter, each component will be described in detail.

  The substrate 2 is a general-purpose printed circuit board, which is excellent in dimensional stability and has little variation such as warpage and twist. On the back of the substrate 2, an appropriate heat sink or the like (not shown) using a material with high heat dissipation such as copper is mounted in order to efficiently dissipate heat generated from the light emitting element 3. As the material of the substrate 2, for example, a glass epoxy substrate in which a glass cloth (cloth) is superimposed and impregnated with an epoxy resin is used.

  The diffuse reflection surface 21 is preferably one in which an acrylic or urethane white paint is sprayed on the substrate 2, but is particularly limited as long as the total reflectance is about 80% or more and has optical characteristics of substantially diffusion characteristics. There is no. The entire surface of the substrate 2 may be the diffuse reflection surface 21, or only the portion of the surface irradiated with the light reflected by the optical member 4 may be the diffuse reflection surface 21.

  The light emitting element 3 includes, for example, a blue LED, a YAG (Yttrium Aluminum Garnet) phosphor that converts light in a wavelength band of 380 nm to 480 nm into light of 480 nm to 780 nm, a BOS (Barium ortho-Silicate) phosphor, and the like. A white LED is used in combination with a sheet containing the same. Moreover, in this embodiment, not only said LED but a small incandescent lamp, a small halogen bulb, etc. can be used if it generates visible light. Further, the shape of the light emitting surface of the light emitting element 3 is not particularly limited, and may be embedded in the optical member 4.

  In the optical member 4, the surface 40 on the side opposite to the mounting surface to the substrate 2 includes a reflective surface 41 that reflects the light emitted from the light emitting element 3. Are configured to have a substantially parallel surface shape. Further, the outer peripheral surface of the optical member 4 is a transmission surface 42 that transmits light from the reflection surface 41 and radiates the light toward the substrate 2 side. As the material of the optical member 4, plastic such as polycarbonate, acrylic, silicon, epoxy, or glass is used. The optical member 4 further includes a lens holder (not shown) for maintaining a positional relationship between the light emitting element 3 and the optical member 4 and obtaining a desired light distribution. This lens holder is the substrate 2 or the light emitting module 1. Is fixed to a housing (not shown).

  In the light emitting module 1 of the present embodiment, the entire surface 40 on the side opposite to the mounting surface to the substrate 2 corresponds to the reflecting surface 41. Moreover, the surface of the reflective surface 41 is configured to ensure a reflectance of approximately 80 to 100% by performing a treatment such as vapor deposition or sputtering of silver or aluminum as necessary. Further, the reflection surface 41 may be a total reflection surface that does not require vapor deposition or the like unless the size of the optical member 4 is restricted. In that case, the reflectance is 100%.

  The configuration of the transmission surface 42 is determined appropriately by the designer depending on how much light is irradiated on the diffuse reflection surface 21 on which the optical member 4 is mounted, but in this embodiment, the configuration is determined. The cylindrical shape is perpendicular to the substrate 2.

  According to the light emitting module 1 of the present embodiment configured as described above, the light emitted from the light emitting element 3 is reflected by the reflecting surface 41 and reaches the transmitting surface 42 as indicated by the dotted line, and this transmission After being refracted and transmitted through the surface 42, it is diffusely reflected by the diffuse reflection surface 21 (the appearance of diffusely reflected light is indicated by a dotted circle). As a result, the light emitting module 1 can appear to the viewer as if the entire diffuse reflection surface 21 is emitting light.

  In addition, even if the optical member 4 is small, light can reach a relatively wide range of the diffusive reflecting surface 21. Therefore, light emission that allows surface emission at low cost without using a large lens or the like. Module 1 can be manufactured. Further, the shape and the like of the diffuse reflection surface 21 are not particularly limited, and the light emitting module 1 having excellent versatility can be manufactured.

  If the reflection surface 41 is a total reflection surface, it is not necessary to form a vapor deposition film, so that not only the manufacturing cost can be reduced, but also when the light emitting module 1 is used for outdoor signage illumination, external light is reflected. The resulting glare is suppressed.

  Next, a light emitting module according to a second embodiment of the present invention will be described with reference to FIG. In the light emitting module 1 of the present embodiment, in the surface 40 including the reflecting surface 41 of the optical member 4, the vicinity of the normal L refracts light from the light emitting element 3 in a direction substantially parallel to the normal L. Thus, the refracting surface 43 is transmitted. In addition, the board | substrate 2, the diffuse reflection board 21, the light emitting element 3, and the transmissive surface 42 are the same as that of the light emitting module 1 of the said 1st Embodiment.

  In the light emitting module 1 of the present embodiment, the surface on which the reflection surface 41 is not configured among the surfaces 40 opposite to the mounting surface to the substrate 2 corresponds to the refractive surface 43. In addition, the shape of the refracting surface 43 is appropriately designed according to the required luminance value when the light emitting module 1 is used. For example, it is processed into a concave shape when light emission with relatively low luminance is sufficient, and is formed into a convex shape when light emission with high luminance is required.

  According to the present embodiment, of the light emitted from the light emitting element 3, the light incident on the refracting surface 43 is refracted and transmitted by the refracting surface 43 and is emitted in a direction substantially parallel to the normal line L. Therefore, the light emitting module 1 of the present embodiment seems to emit light from the optical member 4 including the reflecting surface 41, so that the entire light emitting module 1 emits light to the viewer. In particular, it is possible to emit light with high brightness in the normal L direction.

  Next, a light emitting module according to a third embodiment of the present invention will be described with reference to FIG. The light emitting module 1 of the present embodiment is configured such that the distance from the substrate 2 increases as the surface 40 including the reflective surface 41 of the optical member 4 moves from the normal L to the outer circumferential direction. In addition, the board | substrate 2, the diffuse reflection board 21, the light emitting element 3, and the transmissive surface 42 are the same as that of the light emitting module 1 of the said 1st Embodiment.

  In the light emitting module 1 of the first and second embodiments, a part of the light irradiated from the light emitting element 3 with a small incident angle with respect to the reflecting surface 41 is reflected toward the substrate 2 and is effective. It may not be used as light. In addition, among the light reflected by the reflection surface 41, a part of the light having a large incident angle with respect to the transmission surface 42 is totally reflected by the transmission surface 42 and may not be used as effective light. On the other hand, in the light emitting module 1 according to the third embodiment, the incident angle of the light irradiated from the light emitting element 3 with respect to the reflection surface 41 is increased and the reflection angle is increased. The light is reflected at an angle close to the horizontal direction. Therefore, the incident angle of the light reflected by the reflection surface 41 with respect to the transmission surface 42 is reduced, and the light reflected by the transmission surface 42 into the optical member 4 is reduced, so that light is reflected by the full surface reflection or total reflection at the transmission surface 42. Loss can be reduced. Furthermore, since the light reflected by the reflecting surface 41 reaches far from the optical member 4, a wide range of the diffuse reflecting surface 21 can be emitted.

  Next, a light emitting module according to a fourth embodiment of the present invention will be described with reference to FIG. The light emitting module 1 of the present embodiment is configured such that the distance from the substrate 2 increases as the transmission surface 42 moves from the normal L to the outer circumferential direction. In addition, the board | substrate 2, the diffuse reflection board 21, the light emitting element 3, and the reflective surface 41 are the same as that of the light emitting module 1 of the said 3rd Embodiment.

  According to the light emitting module 1 of the present embodiment, the incident angle of the light reflected by the reflection surface 41 with respect to the transmission surface 42 is further smaller than that of the third embodiment, so that the Frenel reflection or total reflection at the transmission surface 42 is achieved. The light reflection loss due to the light can be further reduced, and the amount of light transmitted through the transmission surface 42 is increased, whereby the light emitting module 1 can emit light with high luminance.

  Next, a light emitting module according to a fifth embodiment of the present invention will be described with reference to FIGS. In the light emitting module 1 of the present embodiment, the shape of the refracting surface 43 is such that the distance from the substrate 2 monotonously increases or monotonously decreases from one end to the other end of the cross section including the normal L. It is comprised so that a shape may be included. In addition, the surface of the refracting surface 43 whose distance from the substrate 2 is monotonously increasing or monotonically decreasing has a convexly curved shape. In addition, the board | substrate 2, the diffuse reflection board 21, the light emitting element 3, and the reflective surface 41 are the same as that of the light emitting module 1 of the said 2nd Embodiment.

  In the light emitting module 1 of the present embodiment, the light incident on the refracting surface 43 from the light emitting element 3 monotonously increases the distance from the substrate 2 in the shape of the refracting surface 43 as shown in FIG. Refracted and emitted in the direction. That is, the light emitting module 1 of the present embodiment can increase the amount of light irradiated from the refractive surface 43 in a specific direction depending on the mounting direction of the optical member 4.

  Moreover, as shown in FIG. 6, it is assumed that the light emitting module 1 of this embodiment is installed in the signboard illumination B installed in a position higher than the eyes of the viewer A. At this time, the light emitting module 1 is set in the mounting direction in which the amount of light irradiated in the ground direction is increased, so that it is possible to emit light with high luminance in the direction in which the viewer A is present. As a modification of the light emitting module 1 of the present embodiment, as shown in FIG. 7, the surface of the refracting surface 43 whose distance from the substrate 2 is monotonously increasing or monotonically decreasing is flat. It may be configured.

  Next, a light emitting module according to a sixth embodiment of the present invention will be described with reference to FIGS. In the light emitting module 1 of the present embodiment, the shape of the reflective surface 41 is substantially rotationally symmetric with the normal L as an axis, and the cross-sectional shape of the reflective surface 41 is focused on the approximate center of the light emitting element 3 or its vicinity. A parabola or a part of an approximate curve of a parabola is included, and the cross-sectional shape of the transmissive surface 42 is configured to include a hyperbola or a part of an approximate curve of a hyperbola that focuses on a point on or near the diffuse reflection surface 21. Has been. The substrate 2, the diffuse reflector 21, the light emitting element 3, the refracting surface 43, and the like are the same as those of the light emitting module 1 of the second embodiment.

  According to the light emitting module 1 of the present embodiment, the light reflected by the reflecting surface 41 can be collected in a substantially concentric narrow range on the diffuse reflecting surface 21, as shown in FIG. 8B. The viewer can visually recognize the substantially concentric light emitting surface (shaded portion in the figure). In the figure, the light irradiated from the refractive surface 43 is not shown.

  Next, a light emitting module according to a seventh embodiment of the present invention will be described with reference to FIG. In the light emitting module 1 of the present embodiment, the diffuse reflection surface 21 is substantially parallel to the substrate 2, is configured in a step shape in a substantially concentric manner with the light emitting element 3 as the center, and has a 1/2 beam. It is comprised so that an angle | corner may be about 30-60 degrees. The light emitting element 3, the reflection surface 41, the transmission surface 42, and the like are the same as those of the light emitting module 1 of the second embodiment.

  The diffuse reflection surface 21 is a treated surface obtained by subjecting aluminum or the like to chemical, polishing alumite treatment, shot treatment, or the like. The shape of the diffuse reflection surface 21 is formed so as to reflect in the direction centered on the optical axis of the light irradiated from the transmission surface 42.

  According to the light emitting module 1 of the present embodiment, the light reflected by the diffuse reflection surface 21 can be efficiently irradiated in a range of 30 to 60 ° centered on the normal direction of the signboard surface, Specification of the light emitting surface according to the installation environment is possible.

  In the present invention, the light emitted from the light-emitting element 3 is reflected by the optical member 4 toward the diffuse reflection surface 21 on the substrate 2, so that the optical member 4 and the entire diffuse reflection surface 21 are made to the viewer. The structure is not limited to the above as long as it is visible as if the surface is emitting light, and the optical member 4 and the diffuse reflection surface 21 can be variously modified.

Sectional drawing of the light emitting module which concerns on the 1st Embodiment of this invention. Sectional drawing of the light emitting module which concerns on the 2nd Embodiment of this invention. Sectional drawing of the light emitting module which concerns on the 3rd Embodiment of this invention. Sectional drawing of the light emitting module which concerns on the 4th Embodiment of this invention. (A) is sectional drawing of the light emitting module which concerns on the 5th Embodiment of this invention, (b) is a perspective view of the optical member of the light emitting module, The side view which shows the use condition as signboard illumination of the said light emitting module. Sectional drawing of the modification of the said light emitting module. (A) is sectional drawing of the light emitting module which concerns on the 6th Embodiment of this invention, (b) is a top view in the use condition of the light emitting module. Sectional drawing of the light emitting module which concerns on the 7th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emitting module 2 Board | substrate 21 Diffuse reflective surface 3 Light emitting element 4 Optical member 40 Surface including a reflective surface 41 Reflecting surface 42 Transmitting surface 43 Refractive surface L The normal line which passes along the approximate center of the light emitting element with respect to a board | substrate

Claims (8)

A light-emitting module comprising: a substrate; a light-emitting element provided on the substrate; and an optical member having a substantially rotating body with a normal passing through a substantially center of the light-emitting element with respect to the substrate as an axis.
Of the optical member, the surface opposite to the mounting surface to the substrate is a surface including a reflecting surface that reflects light emitted from the light emitting element,
The outer peripheral surface of the optical member is a transmission surface that transmits light from the reflection surface,
A light emitting module, wherein a surface that is substantially parallel to the substrate and irradiated with light transmitted through the transmission surface is a diffuse reflection surface.   Of the surface including the reflective surface, the vicinity of the normal is configured to be a refractive surface that refracts and transmits light of the light emitting element in a direction substantially parallel to the normal. The light emitting module according to claim 1.   3. The light emitting device according to claim 1, wherein the surface including the reflection surface is configured such that a distance from the substrate increases from the normal line toward an outer peripheral direction. module.   The said transmissive surface is comprised so that the distance with the said board | substrate may increase as it goes to the outer peripheral direction from the said normal line, The Claim 1 thru | or 3 characterized by the above-mentioned. Light emitting module.   The shape of the refracting surface is configured to include a shape in which the distance from the substrate monotonously increases or monotonously decreases from one end of the cross section to the other end in the cross section including the normal line. The light emitting module according to claim 2. The shape of the reflecting surface is substantially rotationally symmetric with the normal as an axis, and the cross-sectional shape of the reflecting surface is a parabola or a part of an approximate curve of a parabola whose focal point is the approximate center of the light emitting element or its vicinity. Including
The cross-sectional shape of the transmission surface is configured to include a hyperbola or a part of a hyperbola approximation curve focusing on a point on or near the diffuse reflection surface. The module according to any one of 5.   The light emitting module according to claim 1, wherein the reflection surface is a total reflection surface.   The diffuse reflection surface is substantially parallel to the substrate, is configured in a stepwise manner in a substantially concentric shape with the light emitting element as a center, and a 1/2 beam angle is approximately 30 to 60 °. The light emitting module according to any one of claims 1 to 7, wherein the light emitting module is configured.

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