JP7656435B2 - Light-emitting devices and electrical appliances - Google Patents

Description

The present invention relates to a light flux control member, a light emitting device, and an electrical device.

In recent years, light-emitting diodes (hereinafter also referred to as "LEDs") have been used as light sources for illumination in order to conserve energy and reduce size. Light-emitting devices that combine an LED with a light direction conversion optical element (light flux control member) that controls the distribution of light emitted from the LED have come into use (see, for example, Patent Document 1).

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 of the silicone lens that corresponds to the leg is fitted into the recess.

In the light-emitting device described in Patent Document 1, the outer periphery of the silicone lens disposed inside the recess may be sealed with a sealant in order to prevent the silicone lens from coming off the package.

U.S. Pat. No. 8,283,693

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, and the desired optical characteristics may not be obtained. In addition, the sealant may expand when heated, which may cause the silicone lens to easily come off the light-emitting device.

The object of the present invention is to provide a light flux control member that can obtain desired optical characteristics even when the light flux control member is sealed with a sealant, and a light emitting device that has the light flux control member and in which the light flux control member is unlikely to come off.

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

The light emitting device of the present invention also includes 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 of the present invention disposed within the recess so as to intersect with the optical axis of the light emitting element, and a hardened sealant injected into the recess so as to contact the inclined surface.

The electrical device of the present invention also has the light-emitting device of the present invention.

The light flux control member, light emitting device, and electrical machinery and equipment of the present invention maintain the desired optical characteristics because they do not deform during use, even when the light flux control member is sealed with a sealant.

FIG. 1 is a cross-sectional view of a light emitting device according to an embodiment of the present invention. 2A to 2C are diagrams showing a configuration of a light flux controlling member according to an embodiment of the present invention. 3A to 3C are diagrams illustrating a method of assembling a light emitting device according to one embodiment of the present invention. 4A and 4B are diagrams for explaining the effects of the light emitting device according to one embodiment of the present invention. 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.

Below, one embodiment of the present invention will be described in detail with reference to the drawings.

(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 disposed inside an indoor unit or a dehumidifier in an air conditioner (electrical equipment).

Figure 1 is a cross-sectional view of a light-emitting device 100 according to the present invention.

As shown in FIG. 1, the light emitting device 100 has a housing 110, a light emitting element 120, a light flux control member 130, and a cured sealant 140 (see FIG. 3).

The housing 110 has a first recess 113 including a bottom surface 111 and a side surface 112. The light emitting element 120 and the light flux control member 130 are placed inside the first recess 113, and a sealant is injected. The shape of the first recess 113 is not particularly limited as long as it can perform the above-mentioned functions. The planar shape of the first recess 113 (bottom surface 111) may be circular or rectangular. In this embodiment, the planar shape of the first recess 113 is circular. The depth of the first recess 113 (height of the side surface 112) is not particularly limited as long as it can perform the above-mentioned functions. The material of the housing 110 is not particularly limited as long as it does not deform due to heat generated during use. The bottom surface 111 may be a substrate on which the light emitting element 120 is mounted.

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.

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 the method of 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, a light flux controlling member 130 that is circularly symmetric about central axis CA will be described.

The linear expansion coefficient of the light flux control member 130 is lower than the linear expansion coefficient of the cured sealing material 140.

The material of light flux control 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 control member 130 is a light-transmitting resin such as polymethylmethacrylate (PMMA), polycarbonate (PC), epoxy resin (EP), silicone, or glass. In this embodiment, since the light to be controlled is ultraviolet light, the material of light flux control member 130 is preferably silicone.

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

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 portion 135, and flange 134 may further have convex portion 144. Incident surface 131, reflecting surface 132, exit surface 133, and flange 134 all have a rotationally symmetric shape with central axis CA as the center of rotation.

The incident surface 131 allows the light emitted from the light emitting element 120 to enter. The shape of the incident surface 131 is not particularly limited as long as it can perform the above-mentioned function. In this embodiment, the incident surface 131 is the inner surface of the second recess 136 formed on the back side, and has a first incident surface 137 and a second incident surface 138.

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

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.

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

The exit surface 133 emits the light incident from the entrance surface 131. The exit surface 133 is disposed on the front side opposite the entrance surface 131. The exit surface 133 may be a flat surface or a curved surface. In this embodiment, the exit section 123 is a circular flat surface.

Flange 134 facilitates handling of light flux controlling member 130 and prevents light flux controlling member 130 from coming off housing 110. When viewed in a 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 sealant 140 to act on incident surface 131 and exit surface 133, thereby further suppressing deformation of light flux controlling member 130.

The flange 134 includes a cylindrical portion 141, a back surface 142, an inclined surface 143, and a convex portion 144. The cylindrical portion 141 is formed to surround the entrance surface 131 and the exit surface 133. The back surface 142 functions as an adhesive surface for adhering to the bottom surface 111 of the first recess 113. In this embodiment, the back surface 142 is a flat surface.

Inclined surface 143 is formed on the front side so as to approach the central axis of light flux controlling member 130 as it moves from the back side to the front side. A sealant for sealing light flux controlling member 130 comes into contact with inclined surface 143. 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.

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 this embodiment, the shape is a straight line. In other words, the shape of the inclined surface 143 is the same as the side of the truncated cone shape.

The inclination angle of the inclined surface 143 with respect to the central axis CA is preferably 30 to 60°, and more preferably 40 to 50°. If the inclination angle of the inclined surface 143 with respect to the central axis CA is within this range, the stress caused by the expansion of the cured sealant 140 can be released so that the light flux control member 130 does not deform.

The convex portion 144 is disposed outside the inclined surface 143. The planar shape of the convex portion 144 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 a 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, or may be connected via a connecting surface.

Legs 135 function to position light flux controlling member 130 with respect to bottom surface 111 of housing 110. Legs 135 are disposed 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. 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 disposed at equal intervals in the circumferential direction of back surface 142.

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

The hardened sealant 140 fixes the light flux control member 130 to the housing 110. The hardened sealant 140 is in contact with the inclined surface 143. The material of the sealant is not particularly limited. Examples of the sealant material include urethane resin and epoxy resin. It is preferable that the linear expansion coefficient of the hardened sealant 140 is higher than the linear expansion coefficient of the light flux control member 130.

Next, a method for assembling the light-emitting device 100 will be described. Figures 3A to 3C are diagrams for explaining how to assemble the light-emitting device 100.

As shown in FIG. 3A, the sealant is applied to the location corresponding to the back surface 142 of the flange 134.

Next, as shown in FIG. 3B, the light emitting element 120 is mounted on the bottom surface 111 (substrate) of the first recess 113 of the housing 110. Then, the sealing material is cured to temporarily fix the light flux control member 130 to the housing 110.

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

Through the above steps, the light flux control member 130 is sealed (fixed) to the housing 110.

When light flux controlling member 130 has legs 135, it can be positioned and fixed to housing 110 by legs 135. In this way, when 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, it is possible to fill the sealing material until it covers inclined surface 143 after placing light flux controlling member 130 on housing 110, without temporarily fixing the sealing material as in the above process.

Here, the effects of the present invention will be explained using the drawings. For comparison, the case of a light emitting device 500 having a light flux control member 530 according to a comparative example that does not have an inclined surface 143 will also be explained.

Figures 4A and 4B are diagrams for explaining the effects of the present invention. Figure 4A is a diagram for explaining the case of light-emitting device 500 having light flux controlling member 530 according to a comparative example, and Figure 4B is a diagram for explaining the case of light-emitting device 100 having light flux controlling member 130 according to the present invention.

As shown in FIG. 4A, light emitting device 500 according to the comparative example has housing 110, light emitting element 120, light flux controlling member 530, and cured sealant 140. 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.

When heat is generated by using the light emitting device 100, 500, the hardened sealant 140 expands. At this time, the light flux control member 130, 530 also expands, but since the linear expansion coefficient of the hardened sealant 140 is greater than that of the light flux control member 130, 530, the stress generated by the expansion of the hardened sealant 140 dominates in the light emitting device 100, 500.

In light emitting device 500 according to the comparative example, when cured sealant 140 expands, in a cross section including central axis CA, the stress from cured sealant 140 pushes light flux control member 530 from the outside toward the inside, and also pushes housing 110 from the inside toward the outside. At this time, since housing 110 has a high hardness, the reaction force pushing housing 110 from the inside toward the outside pushes light flux control member 530 further from the outside toward the inside.

This causes light flux controlling member 530 to distort. At this time, the stress acting on light flux controlling member 530 from the outside to the inside does not act toward the underside of light flux controlling member 530, but rather acts toward the front side of light flux controlling member 530. Therefore, heat generated by use of light emitting device 500 causes light flux controlling member 530 to distort, or light flux controlling member 530 to detach from first recess 113.

On the other hand, as shown in FIG. 4B, in light-emitting device 100 according to the present embodiment, when cured sealant 140 expands, in a cross section including central axis CA, the stress from cured sealant 140 pushes light flux controlling member 130 from the outside toward the inside, and also pushes housing 110 from the inside toward the outside. At this time, since housing 110 has a high hardness, the reaction force pushing housing 110 from the inside toward the outside pushes light flux controlling member 130 further from the outside toward the inside.

At this time, since the present invention has inclined surface 143, part of the stress acting from the outside toward 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 according to the present embodiment is less likely to be distorted or to be detached from first recess 113 than in light emitting device 500 of the comparative example.

(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, and therefore can further suppress separation of light flux controlling member 130 from first recess 113.

(Modification)
The light emitting device according to the modified example 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 components as those in light emitting device 100 according to embodiment 1 are denoted by the same reference numerals and description thereof will be omitted.

(Configuration of the light-emitting device)

Although not specifically shown, the light emitting device according to the modified example of the present invention has a housing 110, a light emitting element 120, a light flux control member 230, and a cured sealant 140.

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 A-A shown in Figure 5A.

As shown in Figures 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.

The inclined surface 243 is formed so as to move away from the central axis CA as it moves from the front side to the back side of the light flux control member 230. In the modified example, the inclined surface 243 is formed in a curved shape in a cross section including the central axis CA. More specifically, the inclined surface 243 is formed so that the angle between the tangent of the inclined surface 243 and the central axis CA gradually increases in a cross section including the central axis CA.

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 control member 230. More specifically, the outer side of the inner surface of convex portion 244 is formed so that the angle between the tangent of the inner surface and central axis CA gradually decreases in a cross section including central axis CA.

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 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.

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

(effect)
As described above, in the light emitting device of this embodiment, in addition to the effects 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 control member 230 from first recess 113.

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 components of the air conditioner (electrical equipment). If the housing 110 is formed integrally with other components of the air conditioner (electrical equipment), the light-emitting device 100 cannot be separated from the air conditioner (electrical equipment).

The light flux control member and light emitting device according to the present invention are resistant to deformation of the light flux control member. Therefore, they are useful for sterilization using ultraviolet light, for example, inside the indoor unit of an air conditioner or inside a dehumidifier.

REFERENCE SIGNS LIST 100, 500 Light emitting device 110 Housing 111 Bottom surface 112 Side surface 113 First recess 120 Light emitting element 130, 230, 530 Light flux controlling member 131 Incident surface 132 Reflecting surface 133 Emitting surface 134, 234, 534 Flange 135 Leg portion 136 Second recess 137 First incident surface 138 Second incident surface 141 Tube portion 142 Back surface 143, 243 Inclined surface 144, 244 Convex portion

Claims (5)

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 . The light emitting device according to claim 1 , wherein the material of the light flux controlling member is silicone. 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. 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. An electrical appliance comprising the light emitting device according to claim 1 .