JP2014182995A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting system capable of delivering light ranging to side face directions or back face directions even when using a light source such as a light emitting diode (LED).SOLUTION: According to the embodiment, the lighting system includes a base material 2 having a top face, a light source 4 arranged on the base material top face 2a, an optical component 5 formed into a domed cross-sectional shape with a lower end opening 5a, and fixed at its lower end opening side to the base material top face to cover the light source, and a translucent cover 6 fixed to the base material top face to cover the light source and the optical component. The optical component has a wall part of which the thickness is smaller than the diameter of the lower end opening. The optical component also has a plurality of prisms 10 provided on at least one of a dome inner face where light enters from the light source and a dome outer face where the light exits to the outside. The prisms emit beams entering thereinto after changing the latitude-direction angles of the beams into the south-semisphere directions of the optical component of which the dome top is defined as a north pole. The translucent cover has a lower transmissivity than the optical component.

Description

  Embodiments of the present invention relate to an illumination device using a light source having a narrow light distribution in the normal direction of a surface mounted like a light emitting diode (LED).

  Incandescent light bulbs and fluorescent lamps have been widely used as lighting devices, but have problems such as lifetime, luminous efficiency, mercury contamination, and ultraviolet light leakage. 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.

  However, the LED light source emits light strongly in the normal direction of the mounting substrate, and has a directivity in which the light intensity attenuates in proportion to cos θ, where θ is an angle with the normal direction of the mounting substrate. This is because the structure of a general LED light source is such that the LED chip that emits primary light is covered in a planar shape with a protective layer containing a phosphor that converts primary light to secondary light. is there. Therefore, in the light bulb-type lighting device, the light intensity distribution is such that the light in the normal direction of the mounting substrate is strong, and the light is hardly emitted from the side of the mounting substrate toward 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 walls changes significantly, resulting in a different illuminance space. End up.

  As a technique for emitting light in the back direction with a light bulb-type lighting device using an LED light source, there is a three-dimensional mounting technique in which a plane on which an LED is mounted is a polyhedron and is arranged facing the side or the back direction. As another technique, there is an illumination device in which a phosphor that is excited by light from an LED light source is applied to the inner surface of a translucent cover so that the translucent cover itself shines.

Japanese Patent No. 4290887 JP-A-2005-05546 Japanese Patent No. 4945690 JP 2011-142060 A JP 2012-64558 A JP 2012-74364 A JP 2012-146450 A

  The problem to be solved by the present invention is to provide an illuminating device capable of irradiating light in a side surface direction or a back surface direction even when a light source such as a light emitting diode (LED) is used.

  According to the embodiment, the lighting device is formed in a dome-like cross-sectional shape having a base material having a top surface, a light source disposed on the base material top surface, and a lower end opening, and the lower end opening side is formed on the top surface of the base material. An optical component that is fixed and covers the light source, and a translucent cover that is fixed to the top surface of the substrate and covers the light source and the optical component. The optical component is formed so that the wall thickness is smaller than the diameter of the lower end opening. The optical component has a plurality of prisms provided on at least one of the inner surface of the dome on which light from the light source enters or the outer surface of the dome that emits light to the outside. The incident light beam is emitted with the latitude angle changed to the southern hemisphere direction of the optical component, and the translucent cover has a lower transmittance than the optical component.

FIG. 1 is a cross-sectional view showing a light bulb-shaped illumination device according to a first embodiment. FIGS. 2A and 2B are diagrams showing a comparison of changes in orientation when a dome-shaped optical component is present and when it is not present. FIG. 3 is a diagram illustrating a light intensity distribution with respect to the transmittance of the light-transmitting cover and how to shine when the illumination device is viewed from the side surface in the first embodiment. FIG. 4 is a diagram illustrating the efficiency and light distribution angle with respect to the transmittance of the light-transmitting cover in the first embodiment. FIG. 5 is a cross-sectional view showing a light bulb-shaped illumination device according to a first modification. FIG. 6 is a cross-sectional view showing a light bulb-shaped illumination device according to a second modification. FIG. 7 is a cross-sectional view illustrating a light bulb-shaped illumination device according to a second embodiment. FIG. 8 is a cross-sectional view showing a light bulb-shaped illumination device according to a third modification. FIG. 9 is a perspective view showing a fluorescent lamp-type lighting device according to a third embodiment.

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 showing an LED bulb 1 as a bulb-type lighting device according to the first embodiment. The LED bulb 1 has a rotationally symmetric shape with respect to the central axis C.

  The LED bulb 1 includes a base material 2 having a flat base material top surface 2a on the front surface, a light source 4 composed of LEDs mounted on the base material top surface 2a, and a light source 4 arranged on the base material top surface 2a. A dome-shaped optical component 5 that covers the light source 4 and a translucent cover 6 that covers the light source 4 and the optical component 5 are also provided.

  The base material 2 is a metal casing and a heat radiating member. The base material 2 is formed in a substantially truncated conical shape and has a substantially circular base top surface 2a which is flat at the upper end (front surface). A base 8 is provided. The light source 4 is disposed at the center of the base material top surface 2a. A drive circuit 11 that drives the light source 4 is housed inside the base material 2. The power supplied from the base 8 is supplied to the light source 4 by the drive circuit 11 so that the light source 4 emits light. The base material 2 holds the translucent cover 6 and the base 8 to form the outer shape of the LED bulb 1 and also serves as a heat sink and a heat sink for the heat of the light source 4.

  The translucent cover 6 is formed in a spherical shape having a circular lower end opening 6a. The translucent cover 6 has its lower end opening 6 a side fixed to the peripheral edge of the base material top surface 2 a and covers the light source 4 and the optical component 5. The translucent cover 6 is made of, for example, a milky white material having a transmittance of 74%, and appropriately diffuses the light emitted to the outside, and prevents the internal optical component 5 and the light source 4 from being seen from the outside of the translucent cover. I have to.

  The optical component 5 is formed in a thin dome shape having a circular lower end opening 5a and a dome apex T located on the central axis C. That is, the optical component 5 is formed in a vertically long shape whose height along the central axis C is larger than the diameter of the lower end opening 5a. The optical component 5 is disposed coaxially with the central axis C by covering the light source 4 by fixing the lower end on the lower end opening 5 a side to the base material top surface 2 a around the light source 4.

  The optical component 5 is made of, for example, a transparent resin having a transmittance of 90% or more, and the light from the light source 4 is incident on the incident surface 5b that is the inner surface of the dome, and the light is emitted to the outside from the output surface 5c that is the outer surface of the dome. To do. The optical component 5 integrally includes a plurality of prisms formed on at least one of the incident surface (dome inner surface) 5b or the emitting surface (dome outer surface) 5c. In the present embodiment, a plurality of prisms 10 are formed over the entire exit surface 5 c of the optical component 5. Each prism 10 has a triangular (wedge-like) cross section, for example, and is formed in an annular shape coaxial with the central axis C. The plurality of prisms 10 are formed side by side from the dome apex T to the lower end opening 5a.

  The prism 10 refracts or reflects light incident from the light source 4 so that the incident ray (broken arrow) does not act in the longitude direction when the dome apex T of the optical component 5 is the north pole, and only the latitude direction is in the southern hemisphere direction. Bend and emit to the outside (solid arrow). Thereby, the optical component 5 emits the light emitted from the light source 4 toward the side surface direction and the back surface direction of the light source.

  FIG. 2 is a diagram showing a difference in luminous intensity distribution depending on the presence or absence of the dome-shaped optical component 5 with the translucent cover 6 removed. When there is no optical component 5, it has strong light finger characteristics in the normal (front) direction. However, when the dome-shaped optical component 5 is installed, the light finger characteristics in the lateral direction and the rear direction are provided. Can be changed. However, it is difficult to control the action of the optical component 5 gently, and as shown in the drawing, the luminous intensity distribution is locally intense and intense.

  FIG. 3 shows the luminous intensity distribution when the milky degree of the translucent cover 6 is changed, and how the translucent cover 6 shines when the lighting device 1 is viewed from the side surface direction. In FIG. 3, the upper numerical value indicates the transmittance of the translucent cover 6. For example, T74% indicates that the translucent cover 6 has a transmittance of 74%. The leftmost is a translucent cover 6 using a transparent resin material, and the level of milky white is increased toward the right.

  When the translucent cover 6 is formed of a transparent resin, there is no diffusion by the translucent cover 6, so that the local light intensity distribution is intense as shown in FIG. 2. It is directly seen that the optical component 5 in the inside emits light. On the other hand, in this embodiment, the light intensity distribution is gentle by forming the translucent cover 6 from a milk white material, that is, by making the transmissivity of the translucent cover 6 lower than the transmissivity of the optical component 5. In addition, it is possible to prevent the inside of the translucent cover 6 from being viewed directly and to change the entire translucent cover 6 to emit light.

  FIG. 4 shows the efficiency due to the difference in transmittance of the light-transmitting cover 6 and the light distribution angle (2θ · 1/2) of the lighting device 1 as in FIG. 3. Here, the light distribution angle (2θ · 1/2) is a value obtained by doubling the angle at which the light source 4 has a half value of 0 degree with the normal direction of the light source 4 (the direction of the central axis C of the illumination device 1) being 0 degree. It is. In the case of the translucent cover 6 (transmittance 90%) formed of a transparent resin material, the light is sufficiently irradiated on the back side in terms of power, but the distribution based on the definition is due to the intensity of local light intensity. The light angle is very narrow. On the other hand, in the translucent cover 6 formed of milky white resin material, the local light intensity by the optical component 5 is sensitively relaxed by the light diffusibility of the translucent cover 6, and the light distribution is gentle. The light distribution angle is stable and wide light distribution.

  On the other hand, the efficiency deteriorates as the transmissivity of the translucent cover 6 decreases. In particular, the efficiency deteriorates rapidly when the transmissivity is less than 50%. For this reason, the transmittance of the translucent cover 6 is optimally 50 to 88%.

  As shown in FIG. 1, the dome-shaped optical component 5 is designed to have a maximum thickness of 5 mm because the inner surface is hollowed out. For this reason, the dome-shaped optical component 5 is easily cooled by a thermoforming process such as an injection molding process and is lighter than an existing solid cylindrical optical component, and thus has a very high mass productivity.

  Further, the dome-shaped optical component 5 has a wider lower end opening 5 a as compared with conventional lens components and light guide components, and the incident surface 5 b on which light from the light source 4 is incident is sufficiently separated from the light source 4. Therefore, the probability that the light reflected by the incident surface 5b is reabsorbed by the light source 4 is small, and the efficiency loss is small. Furthermore, since the prism 10 is separated from the light source 4, it is very insensitive to the specifications of the light source 4, and the dome has the same specifications for COB (chip on mode) light sources and various arrangements of SMD (surface mount type) light sources. It is possible to cope with the optical component 5 having a shape. Therefore, even when the specification of the LED light source is switched, the optical component 5 can be used as it is. Thereby, the dome-shaped optical component 5 can be shared by a wide range of products.

  According to the first embodiment configured as described above, there is provided a light bulb-shaped illumination device that achieves a light intensity distribution like an incandescent light bulb that can receive light in the side and back directions even when using an LED light source or the like. Can be obtained.

  In the first embodiment, the prism 10 is provided on the dome-shaped outer surface of the translucent cover 6. However, the present invention is not limited thereto, and a plurality of prisms may be provided on the dome-shaped inner surface, or both the inner surface and the outer surface are provided. A prism may be provided.

  Next, lighting devices according to various modifications will be described. Note that, in the various modifications described below, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and detailed description will be made focusing on different parts.

(First modification)
FIG. 5 is a cross-sectional view showing an LED bulb 1 as a bulb-type illumination device according to a first modification. In the first modification, the basic configuration of the LED bulb 1 is the same as that of the first embodiment, but the translucent cover 6 is not spherical but is formed in a dome shape having a vertically elliptical cross section. Yes. In other words, the shape of the translucent cover 6 is not limited as long as it covers the internal optical component 5.

(Second modification)
FIG. 6 is a cross-sectional view showing an LED bulb 1 as a bulb-type illumination device according to a second modification. In the second modification, the basic configuration of the LED bulb 1 is the same as that of the first embodiment, but the translucent cover 6 is formed in a bottomed cylindrical shape. The shape of the translucent cover 6 is not limited as long as it covers the internal optical component 5.

  Next, a lighting device according to another embodiment will be described. In other embodiments described below, the same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and different parts will be described in detail.

(Second Embodiment)
FIG. 7 is a cross-sectional view showing an LED bulb 1 as a bulb-type illumination device according to the second embodiment. In the second embodiment, the basic configuration of the LED bulb 1 is the same as that of the first embodiment, but the dome-shaped optical component 5 is not a vertically long dome but a horizontally long dome. That is, the optical component 5 is formed such that the height H along the central axis C is smaller (D> H) than the diameter D of the lower end opening 5a. The optical component 5 is formed of a transparent material, and a plurality of prisms 10 are integrally provided on an incident surface (dome-shaped inner surface) 5b. Each prism 10 has a triangular or wedge-shaped cross section, for example, and is formed in an annular shape coaxial with the central axis C. The plurality of prisms 10 are formed side by side on the incident surface from the dome apex T to the lower end opening 6a.
By using the compact optical component 5 having a low height as in the present embodiment, the light distribution may be enhanced mainly in the side surface direction.

(Third Modification)
FIG. 8 is a cross-sectional view showing an LED bulb 1 according to a third modification. In the third modification, the optical component 5 is formed in a vertically long dome shape. That is, the optical component 5 is formed so that the height along the central axis C is larger than the diameter of the lower end opening 5a. A plurality of prisms 10 are integrally provided on the incident surface 5 b of the optical component 5. In the third modification, the other configuration of the LED bulb 1 is the same as that of the second embodiment.

  Thus, by making the height of the optical component 5 larger than the diameter of the lower end opening 5a (H> D), the light reflected from the incident surface 5b with the incident surface 5b being moved away from the light source 4 is reabsorbed by the light source 4. In addition, it can be made insensitive to the spread of the light source 4 and the LED specification, that is, the detailed specification of the light source 4 can be inadvertently used, and can be used in common with various light source 4 specifications.

  In the second embodiment and the third modification, the optical component 5 is different from the first embodiment in the shape and the formation position of the prism 10, but as in the first embodiment, the optical component 5 also emits light in the side surface direction and the back surface direction. Therefore, it is possible to obtain a light bulb-shaped lighting device that achieves a light intensity distribution like an incandescent light bulb.

  In the first and second embodiments, the LED light source is not limited to a single integrated light source such as a chip on board (COB), but may be a form in which a plurality of LEDs are arranged.

(Third embodiment)
FIG. 9 is a perspective view showing a fluorescent lamp-type lighting device 1 according to the third embodiment. In 3rd Embodiment, the basic composition of the illuminating device 1 is the same as 1st Embodiment.
The illuminating device 1 is an elongated illuminating device in which the LED light sources 4 are linearly arranged. As shown in FIG. 9A, the illuminating device 1 is, for example, a rod-shaped three-dimensional shape stretched linearly by about 1.2 m, or As shown to (b), it has the cyclic | annular form extended in the curve shape.

  The lighting device 1 includes an elongated linear or annular base material 2 extending over almost the entire length of the lighting device, and a plurality of LED light sources 4 arranged side by side on the top surface 2 a of the base material 2. . These LED light sources 4 are arranged at predetermined intervals along the longitudinal direction of the substrate 2. An optical member 5 having a dome-shaped cross section is mounted on the substrate 2 and covers the light source 4. Further, a translucent cover 6 is attached on the substrate 2 and covers the optical member 5. The optical member 5 and the translucent cover 6 are formed in a linear shape or an annular shape that extends over the entire length of the substrate 2.

  The optical component 5 is formed of, for example, a transparent resin, and integrally includes a plurality of prisms 10 formed on at least one of the incident surface (dome inner surface) 5b or the emission surface (dome outer surface) 5c. The optical component 5 emits light emitted from the light source 4 toward the side surface direction and the back surface direction of the light source.

The translucent cover 6 is formed in a spherical shape with a cross-sectional shape having a lower end opening. The translucent cover 6 has a lower end opening side fixed to the peripheral edge of the top surface 2 a of the base material and covers the light source 4 and the optical component 5. The translucent cover 6 is made of, for example, a milky white material having a transmittance of 74%, and appropriately diffuses the light emitted to the outside, and prevents the internal optical component 5 and the light source 4 from being seen from the outside of the translucent cover. I have to.
Covers 23 are mounted between both ends of the linear base material 2 and the translucent cover 6 or between both ends of the annular base material and the translucent cover 6, for example, a lighting (not shown) that drives the light source 4 in the cover 23. A circuit or the like is provided.
Also in the fluorescent lamp type illumination device 1 configured as described above, it is possible to obtain the same effects as those of the first embodiment described above.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements 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.
Although the above-described embodiment has been described as an LED bulb or a phosphor-type lighting device, the lighting device according to the present invention is a combination of a directional light source, an optical member surrounding the light source, and a translucent cover. The present invention can also be applied to street lighting.

DESCRIPTION OF SYMBOLS 1 ... LED bulb, 2 ... Base material, 2a ... Base material top surface, 4 ... Light source, 5 ... Optical component,
5a ... lower end opening, 6 ... translucent cover, 6a ... lower end opening, 10 ... prism,
11 ... Drive circuit

Claims (8)

A substrate having a top surface;
A light source disposed on the top surface of the substrate;
An optical component having a dome-like cross-sectional shape having a lower end opening, the lower end opening side being fixed to the top surface of the base material and covering the light source;
A translucent cover fixed to the top surface of the base material and covering the light source and the optical component,
The optical component is formed such that the wall thickness is smaller than the diameter of the lower end opening,
The optical component has a plurality of prisms provided on at least one of the inner surface of the dome on which light from the light source is incident or the outer surface of the dome that emits light to the outside. The illumination device has a transmissivity that is lower than that of the optical component.   The lighting device according to claim 1, wherein the translucent cover is formed of a milky white material having a transmittance of 50 to 88%.   The illumination device according to claim 1, wherein the optical component is formed of a transparent material.   The illumination device according to claim 1, wherein the optical component is made of a material having a transmittance of 90% or more.   5. The illumination device according to claim 1, wherein the illumination device has a light distribution that emits light with the strongest luminous intensity in a side surface direction of the optical component.   The lighting device according to claim 1, wherein the optical component is formed in a vertically long shape having a height along a central axis larger than a diameter of the lower end opening.   The lighting device according to claim 1, wherein the lighting device is a bulb-type lighting device having an LED light source that simulates an incandescent light bulb.   The lighting device according to any one of claims 1 to 6, wherein the lighting device is a fluorescent lamp type lighting device having a plurality of LED light sources simulating a fluorescent lamp.

Images