JP2011253694A - Led lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting device solving problems like color unevenness and luminance unevenness and having less loss and high efficiency.SOLUTION: In the LED lighting device having at least one LED light source 2 and a reflector 4 reflecting the light emitted from the LED light source, the reflecting face 4A of the reflector 4 is constructed of a plurality of convex curved surfaces 4a and is made of a rotation curved surface which surrounds the LED light source 2 and expands in an light emitting direction from the light source 2, and the dimensions are set so that the light from the LED light source 2 may be reflected only once by each of the convex curved surfaces 4a. Further, the plurality of the convex curved surfaces 4a are structured of a part of spherical surfaces having different curvatures. Furthermore, curvature radiuses of the plurality of convex curved surfaces are set to be larger as they are separated from the LED light source 2.

Description

  The present invention relates to an LED lighting device for irradiating light emitted from an LED light source by reflecting it with a reflector.

  For example, as a light source for an illumination device such as a spotlight, an LED light source with low power consumption and high durability has recently been used in place of conventional incandescent bulbs and fluorescent lamps. While the brightness of the emitted light is sometimes high, it has a disadvantage that the illuminance is low when used as a light source of a lighting device.

  Therefore, Patent Document 1 discloses a light whose illuminance is increased by arranging a plurality of LEDs (light emitting diodes) on a white substrate and placing one of them on the optical axis of a reflector (mirror surface portion). Proposed.

JP 2003-016805 A

  However, in the light proposed in Patent Document 1, there is a problem that color unevenness and illuminance unevenness peculiar to LED occur because the reflecting surface of the reflector (mirror surface portion) is composed of one sheet. Specifically, from the optical characteristics of the LED, in the case of the LED light source 2 configured as shown in FIG. 12, the light path that passes through the phosphor 2b as the light exits in an angular direction that is orthogonal to the optical axis. Because of its long length, the light is close to yellow. In FIG. 12, 2a is an LED chip.

  In addition, as a measure for improving the illuminance of the light, there is a problem that since there is no reflector for each LED light source, there is little controllable light, resulting in a large loss. In addition, when a plurality of LEDs are used, there is a problem that shadows are multiplexed.

  The present invention has been made in view of the above problems, and its object is to solve the problems of color unevenness and illuminance unevenness, and to provide an LED lighting device with low loss and high efficiency.

  In order to achieve the above object, an invention according to claim 1 is an LED lighting device including at least one LED light source and a reflector that reflects light emitted from the LED light source, wherein the reflecting surface of the reflector has a plurality of convex surfaces. In addition to the curved surface, the LED light source is surrounded by a rotating curved surface that extends in the direction of light emission from the LED light source, and the dimensions are set so that the light from the LED light source is reflected only once by each convex curved surface. It is characterized by that.

  A second aspect of the invention is characterized in that, in the first aspect of the invention, the plurality of convex curved surfaces are constituted by a part of spherical surfaces having different curvatures.

  A third aspect of the invention is characterized in that, in the first or second aspect of the invention, the radius of curvature of the plurality of convex curved surfaces is set larger as the distance from the LED light source is increased.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein a plurality of the LED light sources are provided, and an outer edge in a front view of the reflecting surface of the reflector is a plurality of centered on each LED light source. It is characterized by having a shape obtained by removing a portion of the circumference that overlaps the adjacent circumference.

  According to the first and second aspects of the present invention, since the reflecting surface of the reflector is composed of a plurality of convex curved surfaces, for example, a part of spherical surfaces having different curvatures, the light reflected by the plurality of convex curved surfaces is scattered within a certain range. By mixing light on the optical axis to light in a direction perpendicular thereto, the problems of color unevenness and illuminance unevenness that have conventionally occurred due to the optical characteristics of the LED can be solved. In addition, the light from the LED light source is reflected only once on each convex curved surface of the reflecting surface of the reflector and is not reflected again on the reflecting surface of the reflector, so that the loss of light is kept low and the light utilization efficiency is increased. As a result, the illuminance of the LED illumination device is increased.

  According to the third aspect of the present invention, since the curvature radii of the plurality of convex curved surfaces formed on the reflecting surface of the reflector are set larger as the distance from the LED light source is increased, the occurrence of uneven color and uneven illumination is more effectively prevented. be able to.

  According to invention of Claim 4, the outer edge in the front view of the reflective surface of the reflector provided with respect to each of the plurality of LED light sources is an adjacent circumference among the plurality of circumferences around each LED light source. Therefore, the problem of multiple shadows can be solved at the same time while suppressing the occurrence of color unevenness and illuminance unevenness due to the illuminance improvement of the LED light source.

It is a perspective view of the LED lighting apparatus which concerns on Embodiment 1 of this invention. It is a front view of the LED lighting apparatus which concerns on Embodiment 1 of this invention. It is a side view of the LED lighting apparatus which concerns on Embodiment 1 of this invention. (A) is a perspective view of the reflector of the LED illuminating device which concerns on Embodiment 1 of this invention, (b) is a perspective view which shows a part of reflective surface of the reflector. It is a sectional side view which shows reflection of the light in the reflector of the LED lighting apparatus which concerns on Embodiment 1 of this invention. It is a sectional side view which shows reflection of the light in the reflector of the LED lighting apparatus which concerns on Embodiment 1 of this invention. It is a sectional side view which shows reflection of the light in the reflector of the LED lighting apparatus which concerns on Embodiment 1 of this invention. It is a sectional side view which shows reflection of the light in the reflector of the LED lighting apparatus which concerns on Embodiment 1 of this invention. It is a perspective view of the LED lighting apparatus which concerns on Embodiment 2 of this invention. It is a front view of the LED lighting apparatus which concerns on Embodiment 2 of this invention. It is a side view of the LED lighting apparatus which concerns on Embodiment 2 of this invention. It is a sectional side view of the LED light source of LED lighting apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
1 is a perspective view of an LED illumination device according to Embodiment 1 of the present invention, FIG. 2 is a front view of the LED illumination device, FIG. 3 is a side view of the LED illumination device, and FIG. 4 (a) is a perspective view of a reflector. FIG. 4 and FIG. 4B are perspective views showing a part of the reflector, and FIGS. 5 to 8 are side sectional views showing reflection of light by the reflector.

  The LED lighting device 1 according to the present embodiment is a spotlight including a single LED light source 2 as a light source. As shown in FIGS. 1 to 3, the bottomed cylindrical housing 3 has a circular dome shape. The reflector 4 is accommodated, and the surface of the reflector 4 is covered with a transparent or translucent lens (not shown).

  A reflective surface 4A that is recessed in a circular shape is formed at the center of the reflector 4, and one LED light source 2 is disposed at the center of the bottom of the reflective surface 4A. A decorative portion 4B having a ring-shaped convex curved surface is formed around the reflecting surface 4A of the reflector 4. In the present embodiment, the entire reflector 4 is integrally formed of resin, and the surface thereof is subjected to a reflection process such as painting or aluminum deposition. The reflector 4 may be integrally formed with a metal having a high reflectance.

  Here, the reflecting surface 4A of the reflector 4 is a rotating curved surface (for example, a rotating ellipsoid) having the optical axis of the LED light source 2 that surrounds the LED light source 2 and extends along the light emission direction from the LED light source 2 as a central axis. As shown in FIG. 4A, the reflective surface 4A is formed with a large number of minute convex curved surfaces 4a formed of a part of a spherical surface. Specifically, a plurality of strip-like reflectors 4A-1 extending radially in the vertical direction as shown in FIG. 4B are arranged in the circumferential direction as shown in FIG. The plurality of convex curved surfaces 4a constituting each band-like reflector 4A-1 are set to be larger as the radius of curvature is further away from the LED light source 2 (that is, toward the upper side). ing. In the present embodiment, a plurality of convex curved surfaces 4a having different radii of curvature are formed on the reflecting surface 4A of the reflector 4. However, all the convex curved surfaces 4a are constituted by a part of a spherical surface having the same curvature radius or another curved surface. May be.

  In the LED illumination device 1 configured as described above, when power is supplied to the LED light source 2, the LED chip 2 a (see FIG. 12) of the LED light source 2 emits light, but the light is reflected on the reflecting surface of the reflector 4. The light is reflected by 4A, passes through a lens (not shown), and exits forward (front side in FIG. 2, upper side in FIGS. 5 to 8) to be used for front illumination.

  Here, how light is reflected in each region of the reflecting surface 4A of the reflector 4 is shown in FIGS. 5 to 8, respectively, but in the present embodiment, a number of minute convex curved surfaces 4a are formed on the reflecting surface 4A. Light that is reflected by a large number of convex curved surfaces 4a can be scattered within a certain range, and is conventionally generated due to the optical characteristics of the LED by mixing from light on the optical axis to light in a direction perpendicular thereto. The problem of uneven color and uneven illumination can be solved. In particular, in the present embodiment, the curvature radii of the plurality of convex curved surfaces 4a are set to increase as the distance from the LED light source 2 increases, so that the occurrence of uneven color and uneven illumination can be more effectively prevented.

  Further, in the present embodiment, the light from the LED light source 2 is reflected only once at each convex curved surface 4a by the size of the reflecting surface 4A of the reflector 4 (maximum diameter X1, minimum diameter X2, and height Y shown in FIG. 8). It is set as follows. For example, as shown in FIG. 8, the dimension of the reflecting surface 4A is set so that light reflected at the maximum angle θ with respect to the optical axis is not reflected again by the reflecting surface 4A. In this way, the light from the LED light source 2 is reflected only once by each convex curved surface 4a of the reflecting surface 4A of the reflector 4 and is not reflected again by the reflecting surface 4A of the reflector 4, so that the loss of light is kept low, The light use efficiency is increased, and the illuminance of the LED lighting device 1 is increased.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.

  9 is a perspective view of the LED illumination device according to Embodiment 2, FIG. 10 is a front view of the LED illumination device, and FIG. 11 is a side view of the LED illumination device. In these drawings, FIGS. The same elements as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted below.

  In the LED illumination device 1 ′ according to the present embodiment, three LED light sources 2 are used as light sources, and the reflector 4 is formed with a reflective surface 4A similar to that of the first embodiment for each LED light source 2. ing. And the outer edge in the front view of each reflective surface 4A of the reflector 4 is made into the petal shape which remove | excluded the part which overlaps with the adjacent circumference among the circumferences centering on each LED light source 2. FIG.

  Thus, the LED lighting device 1 ′ according to the present embodiment can obtain the same effect as that obtained by the LED lighting device 1 according to the first embodiment, but the front surface of the three reflecting surfaces 4 </ b> A of the reflector 4. Since the outer edge in view is made into a petal-like shape by removing a portion that overlaps with an adjacent circumference from the circumference around each LED light source 2, an effect that the problem of multiple shadows can be solved is obtained. .

  Although the present invention has been described with respect to a form in which the present invention is applied to a spotlight, the present invention can be similarly applied to any other LED illumination device regardless of the number of LED light sources. is there.

DESCRIPTION OF SYMBOLS 1,1 'LED illuminating device 2 LED light source 3 Housing 4 Reflector 4A Reflective surface of a reflector 4A-1 Reflective band-like reflector 4a Convex curved surface of a reflective surface 4B Reflector decoration part

Claims (4)

In an LED lighting device comprising at least one LED light source and a reflector that reflects light emitted from the LED light source,
The reflecting surface of the reflector is composed of a plurality of convex curved surfaces, and is formed into a rotating curved surface that surrounds the LED light source and spreads in the direction of light emission from the LED light source. An LED lighting device that is set to reflect only once on a curved surface.   The LED lighting device according to claim 1, wherein the plurality of convex curved surfaces are configured by a part of spherical surfaces having different curvatures.   3. The LED lighting device according to claim 1, wherein a radius of curvature of the plurality of convex curved surfaces is set to increase as the distance from the LED light source increases. A plurality of the LED light sources are provided, and an outer edge in a front view of the reflecting surface of the reflector is formed in a shape in which a portion overlapping with an adjacent circumference is removed from a plurality of circumferences around each LED light source. The LED lighting device according to claim 1.

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