JP2012123911A - Led bulb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED bulb with which light-distribution close to that of an incandescent bulb can be obtained and whose compatibility with a lighting fixture can be enhanced.SOLUTION: In the LED bulb 11, a board 12 for mounting a plurality of light-emitting sections 13 as an LED module is arranged in a base 15 directly under an end face of a lamp globe 16, a light guide pillar 17 is installed on the board 12 so as to cover the light-emitting sections 13, and white fine particles 18 are distributed on the light guide pillar 17. The LED bulb 11 has a dimensional shape equivalent to that of the incandescent bulb. Light emitted from the light-emitting sections 13 in this structure is pulled out in all directions by diffusing and reflecting with the light-diffusing fine particles 18 after being incident to the light guide pillar 17. Consequently, the light distribution close to that of the incandescent bulb can be attained, and compatibility to the lighting fixture can be enhanced.

Description

  The present invention relates to an LED bulb and an illuminating device that can be used in place of an incandescent bulb, and more particularly to a technique for improving light distribution.

  Conventionally, in a light bulb-shaped LED light bulb using an LED as a light emitting element, a metal radiator that expands toward one end side is used, and a substantially hemispherical globe is attached to one end of the radiator, A base is attached to the other end side, and a substrate provided with LEDs inside the radiator and the globe is provided in contact with the radiator. The light emitted from the LED is emitted through the lens and the globe, and the heat generated by the LED is radiated to the outside mainly from the substrate through the heat radiating body (see, for example, Patent Documents 1 and 2).

Japanese Patent Laid-Open No. 2001-243809 JP 2010-251009 A

  However, in the LED bulb proposed in the prior art document, the light emitted from the LED passes through the globe, the light scattering light guide, and the lens and is emitted in the direction opposite to the base. Since the light is blocked by the substrate and the radiator, the base side becomes dark, light distribution close to an incandescent light bulb cannot be obtained, for example, when desired reflected light is not obtained when mounted on a lighting fixture with a reflector There is a problem with the suitability for lighting equipment. In addition, when mounted on a translucent columnar lighting fixture, the base portion of the lighting fixture, which is the base portion, is dark and the ceiling portion is dark, and the impression of the lighting space created by the incandescent bulb tends to be different.

  The present invention has been made in view of the above points, and while using an LED, a light distribution close to that of an incandescent bulb can be obtained, improving compatibility with a lighting fixture, and obtaining an illumination space equivalent to that of an incandescent bulb. An object of the present invention is to provide an LED bulb that can be used.

  In order to solve the above-described problem, an aspect of the light bulb according to the present invention includes a substrate, a light emitting unit including an LED disposed on the substrate, a globe covering the light emitting unit, and the globe side from the light emitting unit. A light guide column extending toward the LED, and a base for supplying power to the LED from the outside. The base has an opening, the substrate is fixed inside the opening, and the globe is open. And the end of the opening is fixed in contact with the peripheral portion of the upper surface of the substrate, one end of the light guide column is in contact with the light emitting unit, and the other end is located in the center of the globe, and the light guide column It contains a fine particle that diffuses light from the light emitting part.

  With such a configuration, light distribution close to that of an incandescent lamp can be realized.

  Furthermore, in one aspect of the light bulb according to the present invention, the diameter of the fine particles is 50 μm to 1 mm, and the concentration of the fine particles increases from one end of the light guide column to the other end. It can be configured such that 0 to 0.2 wt% and the concentration at the other end is 0.9 to 1.1 wt%.

  With this configuration, light can be emitted from the center of the globe.

  According to the present invention, a radiator is not provided, a base on which a base is mounted immediately below the lamp globe end surface, a substrate on which a plurality of light emitters that are LED modules are mounted, and a light guide column is provided so as to cover the light emitter. By adopting a configuration in which white fine particles are dispersed in the light, the light emitted from the light emitting portion passes through the light guide column, is incident on the fine particles, is irregularly reflected, and is extracted in all directions. As a result, a light distribution close to that of an incandescent bulb can be obtained, and compatibility with a lighting fixture can be improved.

The sectional side view of the LED bulb which shows one embodiment of this invention Sectional view around the light emitting part of the LED bulb

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side sectional view of an LED bulb.

  FIG. 2 is a cross-sectional view around the light emitting portion of the LED bulb.

  In FIG. 1, 11 is an LED bulb. The light emitting unit 13 is mounted on one surface side of the substrate 12, the lighting circuit 14 is screwed to the other surface side, the end surface of the substrate 12 is in contact with the inner periphery of the base 15, and is fixed by caulking. It is housed in a space formed by the substrate 12 and the base 15.

  The end face of the glass globe 16 having an opening is attached to the opening of the base 15 with silicone resin. The outer shape of the base 15 and the globe 16 is similar to the shape of the base and globe of the incandescent bulb, and the LED bulb 11 has almost the same external dimensions as the incandescent bulb.

  A light emitting unit 13 including a blue LED chip 21 is disposed on the upper surface of the substrate 12. The light emitting unit 13 is sealed with a sealing resin 22 containing a YAG phosphor after the blue LED chip 21 is bonded to the substrate 12 with a die attach agent and then electrically connected with a wire or the like. This sealing resin 22 functions to protect the blue LED 21 from moisture and dust in the atmosphere and to fix the phosphors in a uniformly distributed state.

  A light guide column 17 having an outer diameter of 15 mm, an inner diameter of 14 mm, and a length of 30 mm is disposed on the light emitting unit 13. One end of the light guide column 17 is in contact with the light emitting unit 13, and the other end is located at the center of the globe 16.

  The substrate 12 is formed of an insulating material having good thermal conductivity. In this embodiment, alumina ceramic having a thickness of 1 mm is used. Heat generated in the light emitting unit 13 is radiated through the substrate 12 and the base 15.

  The light guide column 17 is a hollow gutter having a glass or resin outline, and is filled with a filler 19 containing white fine particles 18 (φ50 μm to 1 mm) made of alumina, glass frit, or the like. For the filler 19, a translucent resin such as silicone or glass can be used. The concentration of the fine particles 18 increases as it approaches the center position of the globe. This concentration gradient can be realized by a centrifugal separation method in which one end of the light guide column 17 is fixed and rotated at a high speed. In the embodiment of the present invention, one end of the light guide column 17 on the light emitting portion 13 side is 0 wt%, and the other end on the center side of the globe 16 is 1 wt%. In order to transmit light to the other end side with low loss and obtain a diffusion effect on the other end side, the concentration on one end side is 0 to 0.2 wt%, and the concentration on the other end side is 0.9 to 1.1 wt%. Is preferred. One end of the light guide column 17 is in contact with the light emitting unit 13 and is fixed on the surface of the substrate 12 with a translucent adhesive. As an effect including the fine particles 18, the heat from the light emitting unit 13 is propagated to the light guide column 17 to dissipate heat.

  The light emitted from the light emitting unit 13 with the above configuration enters the light guide column 17, is diffused by the fine particles 18, and is emitted in all directions. As a result, a light distribution angle of 300 ° close to that of an incandescent lamp is obtained, and an effect that suitability for a lighting fixture can be improved is obtained.

  The light guide column 17 may be any column as long as it guides the light from the light emitting unit 13 to the fine particles 18 and releases the heat of the light emitting unit 13 into the globe 16, and may be a column using a transparent resin or an optical fiber bundle. The shape is columnar, and the surface facing the light emitting portion 13 is preferably flat.

  Instead of the fine particles 18 made of alumina or glass frit, for example, plastic or metal fine particles may be used. When a metal having a high reflectance is used, a high light diffusion effect and a high heat dissipation effect can be exhibited simultaneously.

  The material and shape of the globe 16 are not limited as long as it transmits the light emitted from the light emitting unit 13. For example, a material such as glass or resin having light diffusibility may be integrally formed in a substantially spherical shape, or may be divided into a plurality of parts and combined in a substantially hemispherical shape.

  By this invention, the light distribution close | similar to an incandescent lamp is obtained, and the adaptability to a lighting fixture can be improved.

DESCRIPTION OF SYMBOLS 11 LED bulb 12 Board | substrate 13 Light emission part 14 Lighting circuit 15 Base 16 Globe 17 Light guide pillar 18 Fine particle 19 Filler 21 Blue LED chip 22 Sealing resin

Claims (2)

A substrate,
A light emitting unit including an LED disposed on the substrate;
A glove covering the light emitting part;
A light guide column extending from the light emitting part toward the globe,
A base for supplying power to the LED from the outside;
With
The base has an opening, and the substrate is fixed inside the opening,
The globe has an opening, and an end of the opening is fixed in contact with a peripheral portion of the upper surface of the substrate,
One end of the light guide column is in contact with the light emitting part, the other end is located at the center of the globe,
An LED bulb characterized in that the light guide column includes white fine particles that diffuse light from the light emitting unit. The diameter of the fine particles is 50 μm to 1 mm,
The concentration of the fine particles increases from one end of the light guide column to the other end,
The LED bulb according to claim 1, wherein the concentration at the one end side is 0 to 0.2 wt%, and the concentration at the other end is 0.9 to 1.1 wt%.

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