JP2014086232A - Lens for light emitting device, light emitting device, and illuminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lens for a light emitting device with improved utilization efficiency of light.SOLUTION: A lens 1 for a light emitting device includes a recess 7 for arranging a light emission part 2a of a light emitting element 2, an emission face 5 for emitting light, and a reflection face 6 for reflecting light. A first incident face 3 is included on a bottom face of the recess 7, and a second incident face 4 is included on a side face of the recess. The reflection face 6 reflects light L2b incident from the second incident face 4, and the emission face 5 emits light L1b incident from the first incident face 3, and the light L2c incident from the second incident face 4 and reflected on the reflection face 6. Anti-reflection processing is applied to at least one of the first incident face 3 and the second incident face 4, and the emission face 5.

Description

  The present invention relates to a lens for a light emitting device, a light emitting device, and a lighting device.

  In recent years, power-saving and long-life LED light-emitting devices have been developed and put into practical use. Among them, an LED light-emitting device provided with a lens has been proposed as one that can collect emitted light at a narrow angle (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 60-130001

  However, in the LED light emitting device described above, not all of the light emitted from the LED and hitting the lens is incident on the lens, but there is light that is reflected to the outside of the lens at the incident surface of the lens. In addition, on the exit surface of the lens, there is light reflected inside the lens. As described above, the above-described LED light emitting device has reflected light that does not reach the lens, and the light use efficiency is low.

  Accordingly, an object of the present invention is to provide a lens for a light emitting device, a light emitting device, and an illumination device with improved light use efficiency.

In order to achieve the above object, the lens for a light emitting device of the present invention comprises:
Including a recess for disposing the light emitting part of the light emitting element, an exit surface for emitting light, and a reflective surface for reflecting light,
Including a first incident surface on the bottom surface of the recess;
A second incident surface on the concave side surface;
The reflective surface reflects light incident from the second incident surface;
The emission surface emits light incident from the first incident surface and light incident from the second incident surface and reflected by the reflection surface,
An antireflection treatment is performed on at least one of the first incident surface and the second incident surface and the emission surface.

The light emitting device of the present invention is
Including a light emitting element and a lens for a light emitting device,
The lens is the lens of the present invention,
The light emitting portion of the light emitting element is disposed in the concave portion of the lens.

  The illuminating device of the present invention includes the light emitting device of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the lens for light-emitting devices, light-emitting device, and illuminating device which improved the utilization efficiency of light.

FIG. 1 is a cross-sectional view illustrating the lens for a light emitting device according to the first embodiment. FIG. 2 is a cross-sectional view illustrating the lens for a light emitting device according to the second embodiment. FIG. 3 is a cross-sectional view illustrating a lens for a light emitting device according to a third embodiment. FIG. 4 is a cross-sectional view showing the light emitting device of the fourth embodiment. FIG. 5 is a schematic diagram illustrating an illumination apparatus according to the fifth embodiment. FIG. 6 is a perspective view showing the lighting apparatus of the sixth embodiment. FIG. 7 is a perspective view illustrating an example of use of the lighting apparatus according to the sixth embodiment.

  In the light emitting device of the present invention, the light emitting element is preferably an LED.

  In the light emitting device of the present invention, the LED is preferably a white LED.

  The lighting device of the present invention may include an embodiment in which a plurality of the light emitting devices are included and the plurality of light emitting devices are arranged on a surface.

  Hereinafter, a lens for a light emitting device, a light emitting device, and an illumination device of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited or limited to the following embodiments. In addition, in the following FIG. 1 to FIG. 7, the same parts are denoted by the same reference numerals, and the description thereof may be omitted. In the drawings, for convenience of explanation, the structure of each part may be simplified as appropriate, and the dimensional ratio of each part may be schematically shown, unlike the actual case.

[Embodiment 1]
The present embodiment is an example of a lens for a light emitting device in which an antireflection treatment is performed on the first incident surface and the outgoing surface. FIG. 1 is a cross-sectional view illustrating a lens for a light emitting device according to the present embodiment. 1 shows a light emitting element 2 in addition to the light emitting device lens 1 of the present embodiment for convenience of explanation. Details of the light-emitting element 2 will be described in Embodiment 4 below. In FIG. 1, for convenience of explanation, the parallel oblique lines (hatching) of the light emitting device lens 1 are omitted, and the lens surface on which the antireflection treatment is performed is indicated by a wavy line. These points are the same in FIGS. 2 and 3. As shown in FIG. 1, the lens 1 for a light emitting device of the present embodiment includes a recess 7 for disposing the light emitting portion 2 a of the light emitting element 2, an emission surface 5 for emitting light, and a reflecting surface 6 for reflecting light. including. In the recess 7, the entire light emitting part 2 a of the light emitting element 2 may be arranged, or only a part of the light emitting part 2 a of the light emitting element 2 may be arranged. In FIG. 1, the light emitting portion 2 a of one light emitting element 2 is disposed in the concave portion 7, but the light emitting device lens 1 of the present embodiment is not limited to this. In the lens 1 for light emitting device of the present embodiment, the light emitting portions 2a of the plurality of light emitting elements 2 may be disposed in the concave portion 7, and the same applies to Embodiments 2 to 6 described later. The bottom surface of the recess 7 includes the first incident surface 3. The concave side surface includes a second incident surface 4. The reflecting surface 6 reflects the light L2b incident from the second incident surface 4. The emission surface 5 emits the light L1b incident from the first incident surface 3 and the light L2c incident from the second incident surface 4 and reflected by the reflection surface 6. The first entrance surface 3 and the exit surface 5 are subjected to antireflection treatment. The antireflection treatment applied to the first incident surface 3 is prevention of reflection of the light L1a incident from the light emitting element 2 to the outside of the light emitting device lens 1. The antireflection treatment applied to the emission surface 5 is antireflection to the inside of the light emitting device lens 1. Details of the movement of light on each surface of the light emitting device lens 1 will be described later.

  The lens 1 for light emitting device is formed of a translucent material. Examples of the translucent material include resin materials, glass, ceramics, and the like. Examples of the resin material include polymethyl methacrylate, polycarbonate, acrylic, and polyolefin.

  The first incident surface 3 has a substantially spherical surface formed so as to be convex toward the light emitting element 2, and refracts the light L 1 a incident from the light emitting element 2 toward the emission surface 5. The second incident surface 4 is formed in a tapered shape so that the opening of the concave portion 7 is wider than the bottom surface (first incident surface 3) of the concave portion 7, and the light L2a incident from the light emitting element 2 is reflected on the reflective surface. Refract toward 6. The reflecting surface 6 has a curved surface that extends from the end of the second incident surface 4 on the opening side of the recess 7 to the end of the exit surface 5, and substantially reflects the light L 2 b incident from the second incident surface 4. It is formed to reflect.

  As described above, the first entrance surface 3 and the exit surface 5 are subjected to antireflection treatment. The antireflection treatment may be any treatment as long as it can prevent reflection of incident light. For example, frost treatment, application of an antireflection film, application of an antireflection agent such as magnesium fluoride is possible. Etc. As the antireflection film, for example, a commercially available product may be used. Examples of the commercially available product include a trade name “Lumiclear (registered trademark)” manufactured by Toray Industries, Inc. and a product name “CV film” manufactured by FUJIFILM Corporation. In addition to the antireflection treatment, the first entrance surface 3 and the exit surface 5 may be textured or may have a microlens array shape.

  Referring to FIG. 1, the movement of light on each surface of the light emitting device lens 1 is incident on the first incident surface 3 from the light emitting element 2 and on the second incident surface 4 from the light emitting element 2. This will be described separately for light.

  As described above, the light L1a incident on the first incident surface 3 from the light emitting element 2 is refracted toward the emission surface 5, and becomes light L1b. Here, since the first incident surface 3 is subjected to the antireflection treatment, the reflected light L1d indicated by the broken arrow is prevented from being generated, and almost all of the light L1a passes through the first incident surface 3. The light is transmitted and becomes light L1b. As a result, the light utilization efficiency is improved. The light L1b is refracted by the emission surface 5 and emitted to the outside of the light emitting device lens 1 (emitted light L1c). Here, since the exit surface 5 is subjected to the antireflection treatment, the reflected light L1e indicated by the dashed arrow is prevented from being generated, and almost all of the light L1b is transmitted through the exit surface 5, and the exit light L1c. It becomes. As a result, the light utilization efficiency is improved. Note that when the light L1a is incident on the first incident surface 3 perpendicularly, the light L1a passes through the first incident surface 3 as it is, but such light is rare. Since almost all of the light L1a is incident at an angle with respect to the direction perpendicular to the first incident surface 3 as shown in FIG. 1, the light L1a tends to be reflected by the first incident surface 3, but the light emitting device of this embodiment This is prevented in the use lens 1. About these points, it is the same in each surface where the antireflection process of the lens 1 for light-emitting devices was performed.

  As described above, the light L2a incident on the second incident surface 4 from the light emitting element 2 is refracted toward the reflecting surface 6 to become light L2b. Here, although the reflected light L2e at the second incident surface 4 of the light L2a is generated, since the reflected light is prevented from being generated at the first incident surface 3 and the outgoing surface 5, sufficient light is generated. The effect of improving the use efficiency is obtained. As described above, the light L2b is substantially totally reflected by the reflecting surface 6 and becomes the light L2c. The light L2c is refracted at the emission surface 5 and emitted to the outside of the light emitting device lens 1 (emitted light L2d). Here, since the exit surface 5 has been subjected to antireflection treatment, the reflected light L2f indicated by the dashed arrow is prevented from being generated, and almost all of the light L2c is transmitted through the exit surface 5, and the exit light L2d. It becomes. As a result, the light utilization efficiency is improved.

  When the light emitting element 2 is a white LED to be described later, it is possible to reduce the color unevenness generated on the irradiation surface of the light emitted from the emission surface 5, so that at least one of the second incident surface 4 and the reflection surface 6 It is preferable that light diffusion treatment is performed. Examples of the light diffusion treatment include application of an acrylic white paint using titanium oxide or the like as a diffusing substance, formation of a periodic prism, formation of a concave surface or a convex surface having a predetermined curvature. In addition, the said concave surface or convex surface means the concave surface or convex surface when the 2nd incident surface 4 or the reflective surface 6 is seen from the light incident side. Such a light diffusion process does not necessarily have to be performed over the entire area of the second incident surface 4 or the reflection surface 6, and may be performed including at least a region in the vicinity of the light emitting element 2 side end portion of each surface. . In addition to the antireflection treatment, the light diffusing treatment may be applied to the emission surface 5.

[Embodiment 2]
The present embodiment is an example of a lens for a light emitting device in which antireflection treatment is performed on the second entrance surface and the exit surface. FIG. 2 is a cross-sectional view showing the light emitting device lens of the present embodiment. As shown in FIG. 2, the lens 1 for a light emitting device of the present embodiment is the same as that shown in FIG. 1 except that the second incident surface 4 is subjected to antireflection treatment instead of the first incident surface 3. It is the same as that of the lens for light emitting devices of Embodiment 1 shown.

  Referring to FIG. 2, the movement of light on each surface of the light emitting device lens 1 is incident on the first incident surface 3 from the light emitting element 2 and on the second incident surface 4 from the light emitting element 2. This will be described separately for light.

  The light L1a incident on the first incident surface 3 from the light emitting element 2 is refracted toward the emission surface 5 to become light L1b. Here, the reflected light L1d at the first incident surface 3 of the light L1a is generated, but the reflected light is prevented from being generated at the second incident surface 4 and the outgoing surface 5, as will be described later. Therefore, a sufficient light use efficiency improvement effect can be obtained. The light L1b is refracted by the emission surface 5 and emitted to the outside of the light emitting device lens 1 (emitted light L1c). Here, since the exit surface 5 is subjected to the antireflection treatment, the reflected light L1e indicated by the dashed arrow is prevented from being generated, and almost all of the light L1b is transmitted through the exit surface 5, and the exit light L1c. It becomes. As a result, the light utilization efficiency is improved.

  The light L2a incident on the second incident surface 4 from the light emitting element 2 is refracted toward the reflecting surface 6 to become light L2b. Here, since the antireflection treatment is performed on the second incident surface 4, it is possible to prevent the reflected light L <b> 2 e indicated by the dashed arrow, and almost all of the light L <b> 2 a passes through the second incident surface 4. The light is transmitted and becomes light L2b. As a result, the light utilization efficiency is improved. The light L2b is substantially totally reflected by the reflecting surface 6 and becomes light L2c. The light L2c is refracted at the emission surface 5 and emitted to the outside of the light emitting device lens 1 (emitted light L2d). Here, since the exit surface 5 has been subjected to antireflection treatment, the reflected light L2f indicated by the dashed arrow is prevented from being generated, and almost all of the light L2c is transmitted through the exit surface 5, and the exit light L2d. It becomes. As a result, the light utilization efficiency is improved.

  When the light emitting element 2 is a white LED to be described later, the color unevenness generated on the irradiation surface of the light emitted from the emission surface 5 can be reduced, so that the reflection surface 6 is subjected to a light diffusion process. preferable. The light diffusion process is the same as that of the first embodiment. In addition to the antireflection treatment, the light diffusion treatment may be performed on at least one of the second reflection surface 4 and the emission surface 5.

[Embodiment 3]
The present embodiment is an example of a lens for a light-emitting device in which antireflection processing is performed on three surfaces of a first incident surface, a second incident surface, and an output surface. FIG. 3 is a cross-sectional view showing the light emitting device lens of the present embodiment. As shown in FIG. 3, the lens 1 for light emitting device of the present embodiment is for the light emitting device of Embodiment 1 shown in FIG. 1 except that the second incident surface 4 is also subjected to antireflection treatment. It is the same as the lens.

  Referring to FIG. 3, the movement of light on each surface of the light emitting device lens 1 is incident on the first incident surface 3 from the light emitting element 2 and incident on the second incident surface 4 from the light emitting element 2. This will be described separately for light.

  The light L1a incident on the first incident surface 3 from the light emitting element 2 is refracted toward the emission surface 5 to become light L1b. Here, since the first incident surface 3 is subjected to the antireflection treatment, the reflected light L1d indicated by the broken arrow is prevented from being generated, and almost all of the light L1a passes through the first incident surface 3. The light is transmitted and becomes light L1b. As a result, the light utilization efficiency is improved. The light L1b is refracted by the emission surface 5 and emitted to the outside of the light emitting device lens 1 (emitted light L1c). Here, since the exit surface 5 is subjected to the antireflection treatment, the reflected light L1e indicated by the dashed arrow is prevented from being generated, and almost all of the light L1b is transmitted through the exit surface 5, and the exit light L1c. It becomes. As a result, the light utilization efficiency is improved.

  The light L2a incident on the second incident surface 4 from the light emitting element 2 is refracted toward the reflecting surface 6 to become light L2b. Here, since the antireflection treatment is performed on the second incident surface 4, it is possible to prevent the reflected light L <b> 2 e indicated by the dashed arrow, and almost all of the light L <b> 2 a passes through the second incident surface 4. The light is transmitted and becomes light L2b. As a result, the light utilization efficiency is improved. The light L2b is substantially totally reflected by the reflecting surface 6 and becomes light L2c. The light L2c is refracted at the emission surface 5 and emitted to the outside of the light emitting device lens 1 (emitted light L2d). Here, since the exit surface 5 has been subjected to antireflection treatment, the reflected light L2f indicated by the dashed arrow is prevented from being generated, and almost all of the light L2c is transmitted through the exit surface 5, and the exit light L2d. It becomes. As a result, the light utilization efficiency is improved.

  When the light emitting element 2 is a white LED to be described later, the color unevenness generated on the irradiation surface of the light emitted from the emission surface 5 can be reduced, so that the reflection surface 6 is subjected to a light diffusion process. preferable. The light diffusion process is the same as that of the first embodiment. In addition to the antireflection treatment, the light diffusion treatment may be performed on at least one of the second reflection surface 4 and the emission surface 5.

[Embodiment 4]
This embodiment is an example of the light emitting device of the present invention. FIG. 4 is a cross-sectional view of the light emitting device 10 of the present embodiment. As shown in FIG. 4, the light emitting device 10 of the present embodiment is a light bulb including the light emitting element 2, the light emitting device lens 1 of the present invention, and a housing 11. In FIG. 4, the lens 1 for a light emitting device of the present invention is simplified, but actually, as indicated by the wavy line in FIGS. 1 to 3, at least one of the first incident surface and the second incident surface. And the antireflection process is performed to the output surface. 4 illustrates the light emitting device (bulb) 10 including the housing 11, the light emitting device of the present invention is not limited to this. The light emitting device of the present invention may take any form as long as it includes the light emitting element and the lens for the light emitting device of the present invention.

  Examples of the light emitting element 2 include an LED, an organic EL, an inorganic EL, and the like, and an LED is preferable. Although LED is not specifically limited, A conventionally well-known thing can be used, but it is preferable that it is white LED. In FIG. 4, the light emitting element 2 is mounted on a wiring pattern formed on a substrate (not shown) having excellent thermal conductivity, for example, at the bottom of the housing 11. In the light emitting device (light bulb) 10 of the present embodiment, the light emitting element 2 may be included in, for example, a silicone resin, and a phosphor may be dispersed in the silicone resin. In such a form, for example, white light can be obtained by using the light emitting element 2 as a blue LED and the phosphor as a combination of a yellow phosphor or a red / green phosphor. Also, white light can be obtained by using a light emitting element 2 as a near-ultraviolet LED (UV-LED) and the phosphor as a combination of red, green, and blue phosphors (RGB phosphor). In the light emitting device (light bulb) 10 shown in FIG. 4, a case in which a lighting circuit or the like is accommodated is fixed to the outside of the bottom of the housing 11, but the light emitting device of the present invention is not limited to this example. .

[Embodiment 5]
This embodiment is an example of the illumination device of the present invention. FIG. 5 is a schematic diagram showing the illumination device 20 of the present embodiment. As shown in FIG. 5, the illuminating device 20 of this embodiment uses the light-emitting device (bulb) 10 of Embodiment 4 shown in FIG. 4 as a light with an arm. Etc. In addition to the light emitting device (light bulb) 10, the illumination device (light with arm) 20 can freely move the light emitting device (light bulb) 10 and a power supply circuit (not shown) that supplies power to the light emitting device (light bulb) 10. And an arm for supporting. The arm includes a plurality of pipes 21, a plurality of joint portions 22 that connect the plurality of pipes 21, and a shaft portion 23 that rotatably supports the plurality of connected pipes 21 and the plurality of joint portions 22. Yes.

[Embodiment 6]
This embodiment is another example of the illumination device of the present invention. FIG. 6 is a perspective view showing the illumination device 30 of the present embodiment. As shown in FIG. 6, the illumination device 30 of the present embodiment includes a plurality of light emitting devices (light bulbs) 10 of Embodiment 4 shown in FIG. 4 (24 in 3 rows × 8 columns in FIG. 6). A plurality of light emitting devices (light bulbs) 10 are arranged on the surface of the light bulb case 31. The light bulb case 31 is a plate-like body having a plurality of hollow portions that can contain a plurality of light bulbs 10 made of, for example, polycarbonate or acrylic. In the lighting device of the present invention, the number of the light emitting devices of the present invention is not limited to the example shown in FIG.

  With reference to FIG. 7, the usage example of the illuminating device 30 shown in FIG. 6 is demonstrated. As shown in FIG. 7, in this illuminating device 40, the panel board | substrate 42 in which the lighting circuit etc. was accommodated in the inside of the light bulb case 31 bottom part of the illuminating device 30 shown in FIG. 6 is being fixed. Further, in the lighting device 40 shown in FIG. 7, the lighting device 30 shown in FIG. 6 is covered with a cover 41 fixed to the panel substrate 42. FIG. 7 shows a state in which a part of the cover 41 is removed in order to show the inside of the cover 41. The cover 41 is, for example, an acrylic semi-cylindrical member. The lighting device 40 shown in FIG. 7 is used for, for example, indoor lighting, street lamps, and the like.

  Embodiments 5 and 6 are merely examples of the lighting device of the present invention. The lighting device of the present invention may take any form as long as it includes the light emitting device of the present invention.

  Next, examples of the present invention will be described together with comparative examples. In addition, this invention is not limited and restrict | limited by the following Example and comparative example.

Example 1
A lens for a light-emitting device having antireflection treatment applied to the first incident surface and the outgoing surface shown in FIG. 1 was produced. The lens for the light emitting device was formed using polymethyl methacrylate. The antireflection treatment of the first entrance surface and the exit surface was performed by frost treatment.

(Example 2)
A lens for a light-emitting device having antireflection treatment applied to the second incident surface and the outgoing surface shown in FIG. 2 was produced. The material for forming the lens for the light emitting device and the antireflection treatment method were the same as those in Example 1.

(Example 3)
A lens for a light-emitting device in which antireflection treatment was performed on three surfaces of the first entrance surface, the second entrance surface, and the exit surface shown in FIG. 3 was produced. The material for forming the lens for the light emitting device and the antireflection treatment method were the same as those in Example 1.

(Comparative Example 1)
A lens for a light-emitting device was produced in the same manner as in Example 1 except that the antireflection treatment was not performed on the first entrance surface and the exit surface.

  LEDs are arranged in the concave portions of the light emitting device lenses of Examples 1 to 3 and Comparative Example 1, and the light utilization rate of the light emitting device lenses of Examples 1 to 3 and Comparative Example 1 (the light emitting device lens with respect to the total luminous flux of the LEDs) The ratio of the total speed of light emitted from the light exit surface) was measured. The results are shown in Table 1.

(Table 1)
Light utilization rate Example 1 93%
Example 2 92%
Example 3 94%
Comparative Example 1 90%

  As shown in Table 1, the light-emitting device lenses of Examples 1 to 3 had a higher light utilization rate than the light-emitting device lens of Comparative Example 1 that was not subjected to the antireflection treatment.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the lens for light-emitting devices, light-emitting device, and illuminating device which improved the utilization efficiency of light. The lens for light emitting device, the light emitting device, and the lighting device of the present invention can be used for a wide range of applications.

DESCRIPTION OF SYMBOLS 1 Light emitting device lens 2 Light emitting element 2a Light emitting part 3 First incident surface 4 Second incident surface 5 Outgoing surface 6 Reflecting surface 7 Recessed portion 10 Light emitting device 20, 30, 40 Illuminating device

Claims (6)

Including a recess for disposing the light emitting part of the light emitting element, an exit surface for emitting light, and a reflective surface for reflecting light,
Including a first incident surface on the bottom surface of the recess;
A second incident surface on the concave side surface;
The reflective surface reflects light incident from the second incident surface;
The emission surface emits light incident from the first incident surface and light incident from the second incident surface and reflected by the reflection surface,
A lens for a light emitting device, wherein at least one of the first incident surface and the second incident surface and the exit surface are subjected to an antireflection treatment. Including a light emitting element and a lens for a light emitting device,
The lens according to claim 1,
A light emitting device, wherein a light emitting portion of the light emitting element is disposed in a concave portion of the lens. The light emitting device according to claim 2, wherein the light emitting element is an LED. The light-emitting device according to claim 3, wherein the LED is a white LED. An illuminating device comprising the light emitting device according to any one of claims 2 to 4. The lighting device according to claim 5, comprising a plurality of the light emitting devices, wherein the plurality of light emitting devices are arranged on a surface.

Images