Light-emitting devices and electrical appliances

Abstract

To provide a light flux control member which obtains desired optical characteristics without deforming a light flux control member even when the light flux control member is sealed with a sealing material.SOLUTION: A light flux control member is a light flux control member for controlling light distribution of light emitted from a light-emitting element and has: an incident surface which is arranged on a rear side and makes light emitted from the light-emitting element incident thereon; an emission surface which is arranged on a surface side opposite to the incident surface and emits light travelling inside the light flux control member; and a flange arranged outside the incident surface and the emission surface. The flange is formed on the surface side so as to approach a central axis of the light flux control member toward the surface side from the rear side, and includes an inclination surface for contacting the sealing material for sealing the light flux control member.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a light flux controlling member, a light emitting device, and an electric appliance. [Background technology]

[0002] In recent years, light-emitting diodes (hereinafter also referred to as "LEDs") have been used as light sources for illumination from the viewpoint of energy saving and miniaturization. Light-emitting devices that combine an LED with a light direction converting optical element (light flux control member) that controls the distribution of light emitted from the LED have come to be used (for example, see Patent Document 1).

[0003] Patent Document 1 describes a light-emitting device having a silicone lens. The light-emitting device described in Patent Document 1 has a heat sink, a package, a light-emitting diode, and a silicone lens. A recess is formed on the top surface of the package, and the part corresponding to the leg of the silicone lens is fitted into the recess.

[0004] In the light emitting device described in Patent Document 1, for example, it is conceivable to seal the outer periphery of the silicone lens disposed inside the recess with a sealant in order to prevent the silicone lens from coming off the package. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 8,283,693 Summary of the Invention [Problem to be solved by the invention]

[0006] In the light-emitting device described in Patent Document 1, in which a silicone lens is sealed with a sealant, the silicone lens may deform due to heat from the LED during use, making it difficult to obtain the desired optical characteristics. In addition, the silicone lens may easily come off the light-emitting device due to the sealant expanding when heated.

[0007] An object of the present invention is to provide a light flux controlling member that can obtain desired optical characteristics even when the light flux controlling member is sealed with a sealant, and a light emitting device that has the light flux controlling member and in which the light flux controlling member is unlikely to come off. [Means for solving the problem]

[0008] The light flux controlling member of the present invention is a light flux controlling member for controlling the light distribution of light emitted from a light-emitting element, and has an incident surface arranged on the back side for receiving light emitted from the light-emitting element, an exit surface arranged on the front side opposite the incident surface for exiting light that has progressed inside the light flux controlling member, and a flange arranged outside the incident surface and the exit surface, the flange being formed on the front side so as to approach a central axis of the light flux controlling member as it moves from the back side to the front side, and including an inclined surface for contact with a sealing material for sealing the light flux controlling member.

[0009] The light emitting device of the present invention further comprises a housing having a recess including a bottom surface and a side surface, a light emitting element arranged on the bottom surface, a light flux control member of the present invention arranged within the recess so as to intersect with the optical axis of the light emitting element, and a hardened product of a sealant injected into the recess so as to contact the inclined surface.

[0010] Moreover, an electrical appliance of the present invention includes the light emitting device of the present invention. Effect of the Invention

[0011] The light flux controlling member, light emitting device, and electrical machine and appliance of the present invention do not deform during use even when the light flux controlling member is sealed with a sealant, and therefore can maintain desired optical characteristics. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view of a light emitting device according to an embodiment of the present invention. [Diagram 2] 2A to 2C are diagrams showing a configuration of a light flux controlling member according to an embodiment of the present invention. [Diagram 3] 3A to 3C are diagrams illustrating a method of assembling a light emitting device according to an embodiment of the present invention. [Figure 4] 4A and 4B are diagrams illustrating the effects of a light emitting device according to an embodiment of the present invention. [Diagram 5] 5A to 5C are diagrams showing the configuration of a light flux controlling member according to a modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0014] (Configuration of the Light Emitting Device) Light-emitting device 100 has light-emitting element 120 and light flux control member 130, and is a device for emitting light with a predetermined light distribution. Light-emitting device 100 can be incorporated into various devices. In the present embodiment, light-emitting device 100 has light-emitting element 120 that emits ultraviolet light, and is a sterilization device that is placed inside an indoor unit or a dehumidifier in an air conditioner (electrical equipment).

[0015] FIG. 1 is a cross-sectional view of a light emitting device 100 according to the present invention.

[0016] As shown in FIG. 1, light emitting device 100 has housing 110, light emitting element 120, light flux controlling member 130, and cured product 140 of a sealant (see FIG. 3).

[0017] Housing 110 has first recess 113 including bottom surface 111 and side surface 112, and light emitting element 120 and light flux controlling member 130 are arranged inside first recess 113, and a sealant is injected. The shape of first recess 113 is not particularly limited as long as it can exert the above-mentioned function. The shape of first recess 113 (bottom surface 111) in a plan view may be circular or rectangular. In the present embodiment, the shape of first recess 113 in a plan view is circular. The depth of first recess 113 (height of side surface 112) is not particularly limited as long as it can exert the above-mentioned function. The material of housing 110 is not particularly limited as long as it is not deformed by heat generated during use. Bottom surface 111 may be a substrate on which light emitting element 120 is mounted.

[0018] The light emitting element 120 emits light of a predetermined wavelength. The light emitting element 120 is appropriately selected depending on the wavelength of the emitted light. Examples of the light emitting element 120 include a light emitting diode (LED), a mercury lamp, a metal halide lamp, a xenon lamp, and a laser diode (LD). The central wavelength or peak wavelength of the light emitted from the light emitting element 120 is not particularly limited. When the light emitted from the light emitting element 120 is ultraviolet light, the central wavelength or peak wavelength of the ultraviolet light is 200 nm or more and 350 nm or less.

[0019] Light flux controlling member 130 controls the light distribution of light emitted from light emitting element 120. The shape of light flux controlling member 130 is appropriately designed depending on a method for controlling the light distribution of light emitted from light emitting element 120. Light flux controlling member 130 may be a so-called condensing lens or a so-called diffusing lens. Light flux controlling member 130 may have a refractive Fresnel lens portion, a reflective Fresnel lens portion, or other structure for achieving a desired light distribution. The shape of light flux controlling member 130 may or may not be circularly symmetric about central axis CA. In the following description, light flux controlling member 130 that is circularly symmetric about central axis CA will be described.

[0020] The linear expansion coefficient of light flux controlling member 130 is lower than the linear expansion coefficient of cured product 140 of the sealing material.

[0021] The material of light flux controlling member 130 is not particularly limited as long as it can transmit the light to be controlled (light emitted from light emitting element 120). When the light to be controlled is visible light, the material of light flux controlling member 130 is a light-transmitting resin such as polymethylmethacrylate (PMMA), polycarbonate (PC), epoxy resin (EP), silicone, or glass. In the present embodiment, the light to be controlled is ultraviolet light, so that the material of light flux controlling member 130 is preferably silicone.

[0022] (Configuration of Light Flux Controlling Member) Figures 2A to 2C are diagrams showing the configuration of light flux controlling member 130. Figure 2A is a plan view of light flux controlling member 130 according to the present invention, Figure 2B is a bottom view, and Figure 2C is a cross-sectional view taken along line AA shown in Figure 2A.

[0023] 2A to 2C, light flux controlling member 130 has incident surface 131, reflecting surface 132, exit surface 133, and flange 134. Light flux controlling member 130 may further have leg portions 135, and flange 134 may further have convex portion 144. Incident surface 131, reflecting surface 132, exit surface 133, and flange 134 all have shapes that are rotationally symmetrical about central axis CA.

[0024] The light emitted from the light emitting element 120 is incident on the incident surface 131. The shape of the incident surface 131 is not particularly limited as long as it can exhibit the above-mentioned functions. In the present embodiment, the incident surface 131 is the inner surface of a second recess 136 formed on the back side, and has a first incident surface 137 and a second incident surface 138.

[0025] First incident surface 137 allows light emitted from light emitting element 120 with a small emission angle to enter. First incident surface 137 is disposed so as to intersect with optical axis LA of light emitting element 120. In a cross section including central axis CA, first incident surface 137 is formed so that its central portion smoothly protrudes toward the back side.

[0026] The second incident surface 138 allows light emitted from the light emitting element 120 with a large emission angle to enter. The second incident surface 138 connects the first incident surface 137 and the reflecting surface 132. The second incident surface 138 is formed so as to approach the central axis CA from the back side to the front side. In a cross section including the central axis CA, the second incident surface 138 may be linear or curved. In this embodiment, the second incident surface 138 is formed in a linear shape in the cross section.

[0027] Reflective surface 132 mainly reflects light incident from second entrance surface 138 toward exit surface 133. The distance between reflecting surface 132 and central axis CA may be constant or may gradually increase from the back side to the front side. In a cross section including central axis CA, reflecting surface 132 may have a curved shape convex toward the outside (the side away from central axis CA) or may have a linear shape. In this embodiment, reflecting surface 132 has a curved shape in the cross section.

[0028] Exit surface 133 emits light incident from incident surface 131. Exit surface 133 is disposed on the front side opposite to incident surface 131. Exit surface 133 may be a flat surface or a curved surface. In this embodiment, exit unit 123 is a circular flat surface.

[0029] Flange 134 facilitates handling of light flux controlling member 130 and prevents light flux controlling member 130 from coming off housing 110. In plan view, flange 134 is disposed outside incident surface 131 and exit surface 133 about central axis CA. This makes it difficult for stress caused by expansion of cured product 140 of the sealing material to act on incident surface 131 and exit surface 133, thereby further suppressing deformation of light flux controlling member 130.

[0030] Flange 134 includes a tube portion 141, a back surface 142, an inclined surface 143, and a convex portion 144. Tubular portion 141 is formed so as to surround incident surface 131 and exit surface 133. Back surface 142 functions as an adhesive surface for adhering to bottom surface 111 of first recess 113. In this embodiment, back surface 142 is a flat surface.

[0031] Inclined surface 143 is formed on the front side so as to approach the central axis of light flux controlling member 130 from the back side to the front side. Inclined surface 143 comes into contact with a sealant for sealing light flux controlling member 130. In the direction along central axis CA (front-rear direction of light flux controlling member 130), the upper end of inclined surface 143 is located on the back side of the upper end of incident surface 131.

[0032] The shape of the inclined surface 143 in a cross section including the central axis CA is not particularly limited. The shape may be a straight line or a curved line. In the present embodiment, the shape is a straight line. That is, the shape of the inclined surface 143 is the same as the side surface of a truncated cone.

[0033] Inclined surface 143 with respect to central axis CA is preferably at an angle of 30 to 60°, and more preferably at an angle of 40 to 50°. If the inclination angle of inclined surface 143 with respect to central axis CA is within this range, stress caused by expansion of cured product 140 of the sealing material can be released so that light flux controlling member 130 does not deform.

[0034] The convex portion 144 is disposed outside the inclined surface 143. The shape of the convex portion 144 in a plan view is annular. The shape of the convex portion 144 in a cross section including the central axis CA is not particularly limited. The shape of the convex portion 144 in a cross section including the central axis CA may be triangular, rectangular, or arc-shaped. In this embodiment, the shape of the convex portion 144 in a cross section including the central axis CA is rectangular. That is, in this embodiment, the outer side of the inner surface of the convex portion 144 in the cross section including the central axis CA is formed in a linear shape. The inclined surface 143 and the convex portion 144 may be directly connected to each other, or may be connected to each other via a connecting surface.

[0035] Legs 135 function to position light flux controlling member 130 with respect to bottom surface 111 of housing 110. Legs 135 are arranged on back surface 142 of flange 134. The number of legs 135 is not particularly limited as long as light flux controlling member 130 can be positioned. In the present embodiment, the number of legs 135 is three. Furthermore, the arrangement of legs 135 is also not particularly limited as long as the above-mentioned function can be performed. In the present embodiment, legs 135 are arranged at equal intervals in the circumferential direction of back surface 142.

[0036] In other words, flange 134 in light flux controlling member 130 according to the present embodiment has tube portion 141, back surface 142, inclined surface 143, and a groove. The inner surface of the groove is constituted by a part of inclined surface 143 and the inner side surface of convex portion 144.

[0037] Hardened sealant 140 fixes light flux controlling member 130 to housing 110. Hardened sealant 140 is in contact with inclined surface 143. The material of the sealant is not particularly limited. Examples of the material of the sealant include urethane resin and epoxy resin. The linear expansion coefficient of hardened sealant 140 is preferably higher than the linear expansion coefficient of light flux controlling member 130.

[0038] Next, a method for assembling the light emitting device 100 will be described.

[0039] As shown in FIG. 3A, a sealant is applied to a position corresponding to the back surface 142 of the flange 134.

[0040] 3B, light emitting element 120 is mounted on bottom surface 111 (substrate) of first recess 113 of housing 110. Then, light flux controlling member 130 is temporarily fixed to housing 110 by hardening the sealing material.

[0041] 3C , a sealant is filled into first recess 113 of housing 110, outside light flux controlling member 130. At this time, the sealant is preferably filled until it covers inclined surface 143. This can further suppress deformation of light flux controlling member 130.

[0042] Through the above steps, light flux controlling member 130 is sealed (fixed) to housing 110.

[0043] Note that, in the case where light flux controlling member 130 has legs 135, it can be positioned and fixed to housing 110 by legs 135. In this way, in the case where light flux controlling member 130 can be fixed to housing 110 in advance by legs 135 of light flux controlling member 130 or the like, the sealing material may be filled in until it covers inclined surface 143 after light flux controlling member 130 is placed in housing 110, without temporarily fixing the sealing material as in the above process.

[0044] Here, the effects of the present invention will be described with reference to the drawings. For comparison, the case of light emitting device 500 having light flux controlling member 530 according to a comparative example that does not have inclined surface 143 will also be described.

[0045] 4A and 4B are diagrams illustrating the effects of the present invention. Fig. 4A is a diagram illustrating the case of light emitting device 500 having light flux controlling member 530 according to a comparative example, and Fig. 4B is a diagram illustrating the case of light emitting device 100 having light flux controlling member 130 according to the present invention.

[0046] 4A, light emitting device 500 according to the comparative example has housing 110, light emitting element 120, light flux controlling member 530, and cured product 140 of the sealing material. Light flux controlling member 530 has incident surface 131, reflecting surface 132, exit surface 133, flange 534, and leg portion 135. Flange 534 has tube portion 141 and back surface 142. That is, light flux controlling member 530 in light emitting device 500 according to the comparative example does not have inclined surface 143.

[0047] When heat is generated by use of light emitting device 100, 500, cured product 140 of the sealant expands. At this time, light flux controlling members 130, 530 also expand, but since the linear expansion coefficient of cured product 140 of the sealant is larger than the linear expansion coefficient of light flux controlling members 130, 530, the stress generated by the expansion of cured product 140 of the sealant acts dominantly on light emitting devices 100, 500.

[0048] In light emitting device 500 according to the comparative example, when cured product 140 of the sealing material expands, in a cross section including central axis CA, the stress from cured product 140 of the sealing material pushes light flux controlling member 530 from the outside to the inside, and also pushes housing 110 from the inside to the outside. At this time, since housing 110 has high hardness, light flux controlling member 530 is further pushed from the outside to the inside by the reaction force pushing housing 110 from the inside to the outside.

[0049] This distorts light flux controlling member 530. At this time, stress acting from the outside to the inside of light flux controlling member 530 does not act toward the underside of light flux controlling member 530, and instead acts toward the front side of light flux controlling member 530. Therefore, heat generated by use of light emitting device 500 distorts light flux controlling member 530, or light flux controlling member 530 comes off from first recess 113.

[0050] 4B, in light emitting device 100 according to the present embodiment, when cured product 140 of the sealing material expands, in a cross section including central axis CA, the stress from cured product 140 of the sealing material pushes light flux controlling member 130 from the outside to the inside, and also pushes housing 110 from the inside to the outside. At this time, since housing 110 has high hardness, light flux controlling member 130 is further pushed from the outside to the inside by a reaction force pushing housing 110 from the inside to the outside.

[0051] At this time, since the present invention has inclined surface 143, part of the stress acting from the outside to the inside acts downward. As a result, in light emitting device 100 of the present invention, the stress acting on entrance surface and exit surface 133 of light flux controlling member 130 is smaller than in light emitting device 500 of the comparative example. Therefore, light flux controlling member 130 of the present embodiment is less likely to be distorted, or detachment from first recess 113 can be suppressed, compared to light emitting device 500 of the comparative example.

[0052] (effect) As described above, light emitting device 100 according to the present embodiment has inclined surface 143 on flange 134, and therefore part of the stress caused by the expansion of cured product 140 of the sealing material acts toward the back side (the side of bottom surface 111 of first recess 113), thereby suppressing deformation of light flux controlling member 130 and separation from first recess 113. Furthermore, light emitting device 100 according to the present embodiment has inclined surface 143 and convex portion 144 functioning as wedges, thereby further suppressing separation of light flux controlling member 130 from first recess 113.

[0053] (Modification) A light emitting device according to a modification of the present embodiment differs from light emitting device 100 according to embodiment 1 only in the configuration of light flux controlling member 230. Therefore, the same configurations as those of light emitting device 100 according to embodiment 1 are denoted by the same reference numerals and description thereof will be omitted.

[0054] (Configuration of the Light Emitting Device)

[0055] Although not particularly shown, the light emitting device according to the modified example of the present invention has housing 110, light emitting element 120, light flux controlling member 230, and hardened product 140 of the sealant.

[0056] Figures 5A to 5C are cross-sectional views showing the configuration of light flux controlling member 230 according to a modified example of the present invention. Figure 5A is a plan view of light flux controlling member 230 according to a modified example, Figure 5B is a bottom view, and Figure 5C is a cross-sectional view taken along line AA shown in Figure 5A.

[0057] 5A to 5C, light flux controlling member 230 according to the modified example has incident surface 131, reflecting surface 132, exit surface 133, flange 234, and leg portion 135. Flange 234 has tube portion 141, back surface 142, inclined surface 243, and convex portion 244.

[0058] Inclined surface 243 is formed so as to move away from central axis CA from the front side to the back side of light flux controlling member 230. Inclined surface 243 in the modified example is formed in a curved shape in a cross section including central axis CA. More specifically, inclined surface 243 is formed so that the angle formed by a tangent to inclined surface 243 and central axis CA gradually increases in a cross section including central axis CA.

[0059] The outer side of the inner surface of convex portion 244 in a cross section including central axis CA is formed in a curved shape. The outer side of the inner surface is formed so as to approach central axis CA from the front side to the back side of light flux controlling member 230. More specifically, the outer side of the inner surface of convex portion 244 is formed so that the angle formed by the tangent to the inner surface and central axis CA gradually decreases in a cross section including central axis CA.

[0060] In other words, flange 234 in light flux controlling member 230 in the modified example has tube portion 141, back surface 142, inclined surface 243, and a groove. The inner surface of the groove is composed of a part of inclined surface 243 and the inner side surface of convex portion 244. As shown in FIG. 5C, the inner surface of the groove in a cross section including central axis CA is formed in an arc shape.

[0061] In the light emitting device according to the modified example, inclined surface 243 is formed so as to move away from central axis CA as it moves from the front side to the back side, and the outside of the inner surface of convex portion 244 is formed so as to move closer to central axis CA as it moves from the front side to the back side, so that a part of the stress acting from the outside to the inside acts continuously downward. Thus, compared to light emitting device 100 of the comparative example, light flux controlling member 230 is less likely to be distorted, and detachment from first recess 113 can be suppressed.

[0062] (effect) As described above, in the light emitting device of this embodiment, in addition to the effect of light emitting device 100 of embodiment 1, a portion of the stress acting from the outside to the inside continues to act downward, thereby further preventing detachment of light flux controlling member 230 from first recess 113.

[0063] As described above, the light emitting device 100 can be disposed in an air conditioner (electrical equipment). The light emitting device 100 may be configured to be separable from the air conditioner (electrical equipment), or the housing 110 may be formed integrally with other members of the air conditioner (electrical equipment). When the housing 110 is formed integrally with other members of the air conditioner (electrical equipment), the light emitting device 100 cannot be separated from the air conditioner (electrical equipment). [Industrial Applicability]

[0064] INDUSTRIAL APPLICABILITY The light flux controlling member and light emitting device according to the present invention are resistant to deformation of the light flux controlling member and are therefore useful for sterilization using ultraviolet light, for example, inside the indoor unit of an air conditioner or inside a dehumidifier. [Explanation of symbols]

[0065] 100, 500 Light emitting device 110 Cabinet 111 Bottom 112 Side 113 First recess 120 Light emitting element 130, 230, 530 Light flux control member 131 Incidence plane 132 Reflective surface 133 Exit surface 134, 234, 534 flanges 135 Legs 136 Second recess 137 1st entrance plane 138 Second entrance plane 141 Cylinder part 142 Back side 143, 243 Slope 144, 244 convex part

Claims

1. A housing having a recess including a bottom surface and a side surface; A light emitting element disposed on the bottom surface; a light flux control member fixed to the bottom surface in the recess so as to intersect with an optical axis of the light emitting element, the light flux control member controlling a light distribution of light emitted from the light emitting element; a hardened product of a sealant injected into the recess and sealing the light flux controlling member; and A light emitting device having The light flux controlling member is an incident surface disposed on the back side for receiving light emitted from the light emitting element; an exit surface that is arranged on a front side opposite to the entrance surface and that emits light that has traveled inside the light flux controlling member; a flange disposed on an outer side of the entrance surface and the exit surface; having The flange is an inclined surface formed on the front side so as to approach a central axis of the light flux controlling member from the back side toward the front side, the inclined surface being in contact with a cured product of the sealing material; a protruding portion that is disposed outside the inclined surface and that is in contact with the cured product of the sealing material; include, Light emitting device.

2. The light emitting device according to claim 1 , wherein the material of the light flux controlling member is silicone.

3. The light emitting device according to claim 1 , wherein the cured product of the sealing material is in contact with the bottom surface and the side surfaces.

4. The light emitting device according to claim 1 , wherein the light flux controlling member has a linear expansion coefficient lower than a linear expansion coefficient of the sealing material.

5. An electrical appliance comprising the light emitting device according to any one of claims 1 to 4.

Images