JP2015011897A - Bulb type lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bulb type lighting device capable of lighting in a manner similar to an incandescent light bulb without narrowing light distribution.SOLUTION: A bulb type lighting device includes: a base material 2; a light source 6 disposed at a top face 2a of the base material; a light guide body 7 disposed on an emission side of the light source for guiding the light emitted from the light source; and a dome-shaped translucent cover 4 for covering the light source and the light guide body. The light guide body 7 includes a first light guide part 9 for guiding part of the light emitted from the light source in a normal direction of the light source, and diffusely emitting light from a light emission part located above the light source in the normal direction, and a second light guide part 12 disposed in the periphery of the first light guide part for guiding at least part of the light that is not incident on the first light guide part of the light emitted from the light source, to a lateral side of the light source.

Description

  Embodiments described herein relate generally to a light bulb-type illuminating device that emits light from a light source having a narrow light distribution that is mounted in a plane like a white light emitting diode (LED).

  Incandescent light bulbs that use light emission by the heat of filaments have been widely used as lighting devices, but have problems such as short life and luminous efficiency. In recent years, as a technique for solving these problems, LED light sources and EL (electroluminescence) light sources have been developed, and in particular, the use of LED light sources for general lighting devices is accelerating.

  In general, an LED bulb has an outer shape composed of a base attached to a metal base material and a hemispherical light-transmitting cover, and a mounting substrate on which the LED light source is mounted at a position corresponding to the center of the light-transmitting cover. It is attached. The light source emits light via the drive circuit built in the base material by the electric power supplied from the base.

  However, light from a light source mounted on a mounting substrate such as an LED light source emits light strongly in the normal direction of the mounting substrate, and light is not emitted from the side surface to the back surface. . Therefore, when a conventional incandescent light bulb with a nearly uniform light intensity distribution from the front to the back is replaced with a light bulb type lighting device using an LED light source, the brightness of the ceiling and wall changes significantly, and the illuminance space is different. There is a problem of becoming.

  Incandescent light bulbs have a transparent cover that allows the internal filament light emitting part to be seen as it is. However, when an LED light source is used, it has been difficult to shine small at the center of the transparent cover as in the past.

  As a technique for solving the problem that the light distribution is narrowed, a technique has been proposed in which the LEDs constituting the light source are three-dimensionally arranged with the side surfaces and the back direction directed. As another technique, a technique has been proposed in which a phosphor that is excited by light from an LED light source is applied to the inner surface of a light-transmitting cover so that the light-transmitting cover itself shines. As another technique, a technique has been proposed in which the scattering property of the light-transmitting cover is extremely increased and the light distribution is enlarged by the shape of the light-transmitting cover. However, although all of these technologies can widen the light distribution, the light emitting portion cannot be made to appear as a dot at the center of the transparent cover, unlike a filament-type light bulb.

Japanese Patent No. 4290887 JP-A-2005-05546 Japanese Patent No. 4945690 JP 2011-142060 A JP 2012-64558 A JP 2012-74264 A JP 2012-146450 A

  The present invention has been made in view of the above points, and the problem is that a light bulb-type illumination device that does not narrow the light distribution even when using an LED light source or the like, and also enables lighting similar to an incandescent bulb. Further, it is an object of the present invention to provide a light bulb type illumination device that is not affected by the design even if the light emitting area of the LED light source is increased for high output.

  According to the embodiment, the light bulb-type illumination device includes a base material, a light source installed on the top surface of the base material, a light guide installed on the light emission side of the light source and guiding light emitted from the light source. A light body and a dome-shaped translucent cover that covers the light source and the light guide. The light guide guides a part of light emitted from the light source in a normal direction of the light source and diffuses and emits light from a light emitting unit located above the light source in the normal direction. And a second light guide that is provided around the first light guide part and guides at least a part of the light emitted from the light source that does not enter the first light guide part to a side of the light source. And a light guide portion.

FIG. 1 is a cross-sectional view showing a light bulb type illumination device according to a first embodiment. FIG. 2 is a cross-sectional view showing a light bulb type illumination device according to a second embodiment. FIG. 3 is a cross-sectional view showing a light bulb type illumination device according to a third embodiment. FIG. 4 is a perspective view showing light guides of various shapes according to modified examples.

Hereinafter, illumination devices according to various embodiments will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view of an LED bulb 1 as a bulb-type illumination device according to the first embodiment.
As shown in FIG. 1, the LED bulb 1 includes a base material 2, a light source 6 made of LEDs, a thin, thin, hollow, dome-shaped (substantially conical) light-transmitting cover (optical component) 4, The light guide 7 is disposed on the light source 6, and each member is configured to be rotationally symmetric with respect to the central axis C.

  The base material 2 is, for example, a metal housing such as aluminum and a heat radiating member. The upper portion is formed in a substantially truncated cone shape and has a flat top surface 2a at the upper end of a large diameter, and has a small diameter. A base 3 is attached to the lower end. A drive circuit 14 that drives the light source 6 is housed inside the base material 2. The surface of the base material 2 excluding the top surface 2a is coated with white so that the reflectance is higher than that of the other portions, so as not to absorb light as much as possible, and the external efficiency is high due to the high emissivity of the paint. The heat is dissipated.

  A mounting substrate 5 is installed at a substantially central portion of the top surface 2 a of the base material 2, and one or more light sources 6 are mounted on the mounting substrate 5 in a plane and located on the central axis C. The light source 6 includes, for example, an LED chip and a sealing resin that covers the LED chip, and phosphor particles that convert primary light from the LED chip into white light are dispersed and mixed in the sealing resin. . The electric power supplied from the base 3 is supplied to the light source 6 through the drive circuit 14, and the light source 6 emits white light. Since the white light is formed by the primary light scattered by the phosphor particles and the secondary light emitted by the phosphor particles, the white light has a strong luminous intensity in the normal direction of the mounting substrate 5, that is, in the forward direction of the LED bulb 1. Emit light.

  As shown in FIG. 1, in the present embodiment, the translucent cover 4 is formed of a transparent polycarbonate resin in the shape of a vertically long triangular dome having a thickness of 1 to 3 mm, and the base axis is substantially coincident with the light source 6. The material 2 is fixed and supported on the peripheral edge of the top surface 2a. Thereby, the translucent cover 4 covers the light source 6 and the light guide 7.

  The light guide 7 is disposed in front of the light source 6 in the translucent cover 4 and supported by the top surface 2 a of the base 2. The light guide 7 is formed coaxially with the central axis C of the lighting device 1 and in a shape to be rotated with respect to the central axis C. The light guide 7 extends in a normal direction with respect to the emission surface of the light source 6, and has a columnar shape, for example, a columnar first light guide (first lens) 9, and a first light guide. A disc-shaped (annular) second light guide part (second lens) 12 that is curved from the upper side to the back side from the base end is integrally provided.

  The light guide 7 includes a cylindrical first light guide 9 extending in the vertical direction coaxially with the central axis C, and a disk-shaped second light that covers the top surface 2 a of the substrate 2 around the first light guide 9. And a light guide unit 12.

  The first light guide unit 9 and the second light guide unit 12 both have a first light incident unit 9a and a second light incident unit 12a facing the emission surface of the light source 6, and the second light incident unit 12a is a first light. It is located around the incident part 9a. Moreover, the 1st light-projection part 9b and the 2nd light-projection part 12b which radiate | emit light to the exterior of the light guide 7 in the edge part on the opposite side of each of the 1st light-incidence part 9a and the 2nd light-incidence part 12a. have.

  The first light guide unit 9 has a slim cylindrical shape, and mainly guides light incident from the light source 6 through the first light incident unit 9a upward in the normal direction, thereby generating the first conical light. Light is emitted from the emission part 9b to the outside. In other words, since the first light guide portion 9 is a slim columnar shape and the first light emitting portion 9b is the tip portion of the column, it realizes light emission with a dotted shape and high brightness, as if it were a conventional filament type light bulb. Thus, it can be made to shine in the shape of a dot at the center of the translucent cover 4. In addition, the cross section of at least a part of the first light guide unit 9 is not limited to a circular shape, and may be an elliptical shape, an oval shape, or the like.

  The second light guide unit 12 has a curved shape in which a cross-sectional shape draws an arc from the center to the periphery in a direction parallel to the emission surface of the light source 6, and a base material around the first light guide unit 9. 2 has a disk shape covering the top surface 2a. The second light guide unit 12 enters a light beam that leaks from the light source 6 without entering the first light guide unit 9 from the first light incident unit 12a, and does not leak to the outside in the middle of the top surface 2a of the substrate 2. Light is emitted mainly from the side of the light source to the back side by the second light emitting part 12b arranged in a ring shape at the peripheral part. In other words, the emission surface of the second light emission part 12b is oriented in the horizontal direction, that is, the direction parallel to the emission surface of the light source 6 (the side of the light source), or toward the back side of the light source 6 from the horizontal direction. The original function of the second light guide unit 12 is to conceal the light from the point light source 6 that does not enter the first light guide unit and is directly viewed from the outside so that it is not visually recognized by the above-described function. It is to be. As a result, only the first light emitting portion 9b shines in a dot shape at the central portion of the translucent cover 4 and suppresses conspicuous light emission in the vicinity of the light source 6 and reproduces the same way of light as an existing filament type bulb. . Moreover, the 2nd light guide part can also exhibit the function irradiated from a side surface to a back surface. Since the second light emitting portion 12b can emit light in a ring shape at the periphery of the top surface 2a of the base material 2, the second light can be emitted without impairing the above-described point-like high-intensity light emission of the first light emitting portion 9b. Light can be irradiated to the side surface or the back surface side from the emitting portion 12b to broaden the light distribution.

  In the embodiment, the area of the first light guide unit 9 is smaller than the area of the light source 6, and a filament type light bulb that intentionally performs irradiation from the side surface to the back surface by the second light guide unit 12 is realized.

  Conventionally, if the area of the light source is increased to increase the output, the lens (light guide) also needs to be increased, which impairs the design of the lighting device, and depending on the shape of the transparent cover, the transparent cover There was a problem that could not fit inside. On the other hand, according to the LED bulb 1 according to the present embodiment, it is possible to widen the light distribution after solving all these problems.

  From the above, even if an LED light source or the like is used, the light distribution is not narrowed, and a light bulb-type lighting device that enables a similar lighting method to an incandescent bulb with a transparent cover in which a conventional filament is directly viewed is realized. Furthermore, even if the light emitting area of the LED light source is increased for higher output, a light bulb-type lighting device that is not affected by the design can be obtained.

  In addition, in 1st Embodiment mentioned above, although the LED light source put together in one is used, not only this but a light source may use several LED light sources distributedly arranged, and some of them may be used. It is good also as a light guide which makes light enter with respect to a LED light source.

  In the first embodiment described above, the first light guide unit 9 and the second light guide unit 12 are integrally formed. However, the first light guide unit 9 and the second light guide unit 12 are formed of different members. May be.

  Next, a light bulb type illumination device according to another embodiment will be described. In other embodiments to be described later, the same parts as those in the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

(Second Embodiment)
FIG. 2 is a cross-sectional view showing an LED bulb 1 according to the second embodiment. The basic configuration of the LED bulb 1 excluding the second light emitting portion 12b of the light guide 7 is the same as that of the first embodiment described above. As shown in FIG. 2, according to the second embodiment, at least part of the second light emitting part (light emitting surface) 12 b of the second light guide part 12, here, all is outside the translucent cover 4. Exposed on the surface.

  With this configuration, the light utilization efficiency can be improved as compared with the first embodiment shown in FIG. That is, in the first embodiment, light emitted from the second light emitting unit 12b of the second light guide unit 12 is reflected inside the translucent cover 4, whereas in the second embodiment, the second light is emitted from the second light emitting unit 12b. Since the light emitting part 12b directly emits light to the outside of the light-transmitting cover 4, no loss due to reflection inside the light-transmitting cover 4 occurs.

  Furthermore, the LED bulb 1 can also irradiate the back side. That is, in the first embodiment, the light emitted from the second light emitting portion 12b is restricted from being irradiated on the back side by the edge of the top surface 2a of the substrate 2, whereas in the second embodiment, Since the two-light emitting part 12b is exposed to the outside, it is possible to irradiate light almost right behind.

  Even in the second embodiment, a light bulb-type illumination device that does not narrow the light distribution even when an LED light source or the like is used, and that can also emit light similar to an incandescent light bulb with a transparent cover in which a conventional filament is directly viewed. Further, it is possible to obtain a light bulb-type lighting device that is not influenced by the design even if the light emitting area of the LED light source is increased for higher output.

(Third embodiment)
FIG. 3 is a cross-sectional view showing an LED bulb 1 according to the third embodiment.
In the present embodiment, the second light emission part (light emission surface) 12 b of the second light guide part 12 of the light guide 7 faces the top surface 2 a of the substrate 2. In addition, a light absorbing portion, for example, an annular black coating film 16 is formed on the top surface 2a of the substrate 2 at a position facing the second light emitting portion 12b. The second light emitting part (light emitting surface) 12 b is in contact with the black coating film 16.

  In the LED bulb 1 configured as described above, the light emitted from the second light emitting portion 12b is absorbed by the black coating film 16 by about 50%, and the light distribution to the side (horizontal direction) or the back direction of the light source 6 is suppressed. can do. Accordingly, it is possible to realize a light bulb type illumination device that suppresses light emission from the second light emitting unit 12b and emits light that closely resembles a filament type light bulb.

  The light absorbing material is not limited to black paint, and other materials may be used. Alternatively, the top surface 2a of the substrate 2 may be an unpolished surface of aluminum, and this surface may absorb the light emitted from the second light emitting portion 12b. Alternatively, the peripheral portion of the top surface 2a of the base material 2 may be dug down, and the light emission may be suppressed by enclosing the second light emitting portion in the recess.

(Modification)
4A to 4L show various modifications in which the shape of the first light guide portion 9 of the light guide 7 is variously changed. In any shape of the first light guide, the same effects as those of the above-described embodiment can be obtained. The first light guide portion 9 extending in the normal direction (vertical direction) with respect to the light exit surface of the light source 6 has at least a partial cross section formed into a smooth curve such as a circle, an ellipse, or an oval. Yes. The first light emitting portion 9b at the tip of the first light guide portion 9 has a protruding shape having at least one apex, or has a concave shape having at least one deepest point portion. . In any case, the first light emitting unit 9b emits light from a portion having an acute angle. The emission direction can be adjusted by adjusting the angle of the shape at this time. In addition, if fine irregularities are formed on a part of the first light emitting portion 9b by a graining process or the like, light can be further emitted locally. These shapes can be arbitrarily selected from design properties and target performance. In addition, the light emitting surface of the second light emitting unit of the second light guide unit 12 may be subjected to a graining process to form fine irregularities.

  The present invention is not limited to the above-described embodiment or modification as it is, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 ... LED bulb, 2 ... Base material, 2a ... Top surface, 3 ... Base, 4 ... Translucent cover,
DESCRIPTION OF SYMBOLS 5 ... Mounting board, 6 ... Light source, 7 ... Light guide, 9 ... 1st light guide part, 9a ... 1st light incident part,
9b ... 1st light emission part, 12 ... 2nd light guide part, 12a ... 2nd light incident part,
12b ... second light emitting part, 14 ... driving circuit

Claims (11)

A substrate;
A light source installed on the top surface of the substrate;
A light guide that is installed on an emission side of the light source and guides light emitted from the light source;
A dome-shaped translucent cover that covers the light source and the light guide,
The light guide guides a part of light emitted from the light source in a normal direction of the light source and diffuses and emits light from a light emitting unit located above the light source in the normal direction. And
A second light guide unit that is provided around the first light guide unit and guides at least a part of light emitted from the light source that does not enter the first light guide unit to a side of the light source. And a light bulb type lighting device.   The bulb-type lighting device according to claim 1, wherein the second light guide portion covers a top surface of the base material.   The bulb-type illumination device according to claim 1 or 2, wherein an area of the first light incident portion of the light guide is smaller than an area of a light emitting region of the light source.   2. The first light guide of the light guide is formed in a column shape extending in a normal direction of the light source, and at least a part of the cross section of the first light guide has a circular shape or an oval shape. 4. The light bulb-type lighting device according to any one of items 3 to 3.   5. The light bulb-type lighting device according to claim 1, wherein the light emitting portion of the first light guide portion has a protruding shape having at least one apex.   The light-bulb illumination device according to any one of claims 1 to 4, wherein the light emitting portion of the first light guide portion has a concave shape having at least one deepest point portion.   The light bulb-type lighting device according to any one of claims 1 to 6, wherein the light emitting part of the first light guide part is subjected to a graining process.   The light bulb type according to any one of claims 1 to 7, wherein the second light emitting portion of the light guide has a light emitting surface that faces a back side of the light source rather than a side or a side of the light source. Lighting device.   The bulb-type illumination device according to any one of claims 1 to 8, wherein at least a part of an emission surface of the second light emission part of the light guide is exposed on an outer surface side of the light transmission cover.   The light bulb-type lighting device according to any one of claims 1 to 9, wherein a texture treatment is applied to at least a part of an emission surface of the second light emission unit.   The emission surface of the second light emission part faces an end of the top surface of the base material, and the top surface is a light absorption part that absorbs light emitted from the emission surface of the second light emission part. The light bulb-type lighting device according to any one of claims 1 to 7.

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