JP2014182994A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device capable of controlling an irradiation region free from generation of multi-shadow.SOLUTION: The lighting device includes: a plurality of light sources 3 each having light distribution with strong directionality in a normal line and disposed side by side on a plane surface; a plurality of collimator lenses 4 each set opposite to the light source and focusing light emitted from the light sources; and a lens part 5 that emits the focused light toward more outside relative to the center of a light source group comprising the plurality of light sources as the distance from the center is larger.

Description

  Embodiments of the present invention relate to a lighting device such as a spotlight or a downlight using a light emitting diode (LED), for example.

  Illumination devices include spotlights that collect and irradiate a relatively small space, and downlights that irradiate the floor from the ceiling. When such an illuminating device is realized by an LED light source, in general, a plurality of LED light sources are arranged in a grid pattern on the mounting surface of the illuminating device in order to obtain a necessary light amount and flatten the illuminating device. Yes. In the case of a condensing type such as a spotlight, a collimator lens or reflector is installed for each LED light source arranged in a plane, or a Fresnel lens or reflector that collects all the LED light sources at once is installed. Is shining. In the case of a type that does not require a light collecting function as much as a downlight, the light collecting means described above is irradiated as it is without being mounted.

Japanese Patent No. 5079635

  In conventional spotlights and downlights, a plurality of LED light sources are arranged at different positions in a grid pattern on the plane, so the shadow projected on the floor surface for each LED light source is shifted for each of the plurality of light sources. There is a problem that so-called multi-shadows appear in multiple images. This problem can be alleviated by concentrating the light sources in as small an area as possible so that the deviation of individual shadows is not noticeable. There was a problem that there were restrictions. In addition, the conventional illumination device has a fixed irradiation area, and for example, it has not been possible to control the degree of light collection or control the movement of the irradiation area.

  The present invention has been made in view of the above points. An object of the present invention is to provide an illuminating device that can significantly reduce multi-shadows and control an irradiation area.

  According to the embodiment, each of the lighting devices has a light distribution having a strong directivity in the normal direction, and is provided with a plurality of light sources arranged side by side on a plane, respectively, facing the light sources, A plurality of collimator lenses that collect light rays emitted from a light source and a distance from the center of a light source group composed of the plurality of light sources is larger, and the collected light rays are directed outward with respect to the center. And a lens unit that emits light.

FIG. 1 is a perspective view showing an illumination apparatus according to the first embodiment. FIG. 2 is a plan view showing the bottom surface side with the base material of the illumination device omitted. FIG. 3 is an enlarged sectional view showing a collimator lens and a light source of the illumination device. FIG. 4 is a cross-sectional view of the lighting device. FIG. 5 is a plan view showing an illumination apparatus according to the second embodiment. FIG. 6 is a cross-sectional view of the illumination device according to the second embodiment along the line AA in FIG. 4. FIG. 7 is a perspective view showing an illumination apparatus according to the second embodiment. FIG. 8 is a perspective view showing an illumination device according to a third embodiment. FIG. 9 is a cross-sectional view illustrating a 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 perspective view showing an illumination device 1 according to the first embodiment, FIG. 2 is a plan view of an LED light source, a collimator lens, and a wedge lens as viewed from the substrate side, and FIG. 3 shows the operation of the collimator lens. It is sectional drawing and sectional drawing of the illuminating device of FIG.

  As shown in FIGS. 1, 2, and 4, the lighting device 10 includes, for example, a disk-shaped substrate 2, a plurality of LED light sources 3 mounted on one flat surface of the substrate, and each LED light source 3. A plurality of collimator lenses 4 provided above, and a wedge lens 5 disposed on the collimator lens 4 and integrally joined to the collimator lens 4 are provided. A cylindrical support frame 6 made of, for example, metal is mounted around the lens, and the outer periphery of the substrate 2 and the outer periphery of the wedge lens 5 are supported by the support frame 6.

  Moreover, although the illuminating device 10 has a housing and a drive circuit in the back side of the board | substrate 2, since these have various forms, they are not illustrated. The casing has a function of radiating heat from the substrate 2 or fixing it to the ceiling or wall, and the drive circuit converts and supplies power for driving the LED light source 3 from commercial power.

  The plurality of LED light sources 3 are arranged in a hexagonal lattice pattern on one flat surface of the substrate 2 and are distributed over almost the entire surface. The plurality of LED light sources 3 include a light source provided at the center of the substrate 2 and a plurality of light sources arranged gradually away from the central light source toward the outer peripheral edge of the substrate 2.

  As shown in FIG. 4, each LED light source 3 emits strong light in the normal direction of the substrate 2, that is, in a direction parallel to the central axis C of the substrate 2, and the angle from the normal direction is θ. , Directivity in which the luminous intensity in the side surface direction becomes weaker in proportion to cos θ. Accordingly, when the collimator lens 4 is not provided, the angle is twice the half value, that is, 2θ · 1/2 is 120 degrees with respect to the central luminous intensity, and the light distribution is widened.

  As shown in FIGS. 2 to 4, the collimator lens 4 is formed of a transparent resin such as polycarbonate or acrylic. The collimator lens 4 includes a concave portion 4a that is formed at the lower center portion and receives light from the LED light source 3, a curved outer wall surface 4b that reflects a part of the incident light toward the upper surface, and these And a flat outer upper surface (emission surface) 4c that emits light upward. Each collimator lens 4 is placed on the substrate 2 so as to cover the LED light source 3 so that the LED light source 3 is positioned in the recess 4a.

  As shown in FIG. 3, the collimator lens 4 configured in this manner collimates the light emitted from the LED light source 3, that is, condenses it into parallel light in the normal direction with respect to the substrate 2. In the present embodiment, the collimator lens 4 is set so that 2θ · 1/2 is about 20 degrees.

  As shown in FIGS. 1 and 4, the wedge lens 5 constituting the lens unit is formed of a transparent resin such as polycarbonate or acrylic. The wedge lens 5 includes a flat lower surface (incident surface) 5a for receiving the light emitted from the collimator lens 4, a cylindrical outer peripheral surface 5b, and a spherical upper surface (exit surface) from which the incident light is emitted. ) 5b and a thin disk-like rotationally symmetric shape. The wedge lens 5 is disposed on the plurality of collimator lenses 4 with the lower surface 5 a in contact with the upper surface 4 c of the collimator lens 4, and is disposed coaxially with the plurality of collimator groups and the substrate 2. That is, the wedge lens 5 constitutes a concave lens that smoothly covers the entire plurality of light sources. The wedge lens 5 may be formed separately from the collimator lens 4 on the collimator lens, or may be formed integrally with the plurality of collimator lenses 4 as in this embodiment.

  The action on the light beam by the wedge lens 5 will be described. As shown in FIG. 4, the light beam emitted from the LED light source 3 and collimated by the collimator lens 4 is incident on the lower surface 5a of the wedge lens 5 and is diverged and diverged by the concave lens formed by the upper surface 5c. Exit. In the wedge lens 5 of the present embodiment, the concave upper surface 5 c is formed so that the inclination angle increases as the distance from the center of the wedge lens 5 increases. Therefore, the wedge lens 5 can strengthen the diverging action as the part is farther from the center. That is, as the LED light source 3 located on the outer side from the center of the illuminating device 10, the emitted light beam is bent outward with respect to the center of the light source group, and thus the LED light source 3 that is spread on the surface mounted on the substrate 2. Although it is an array, it is substantially equivalent to irradiation from a point light source disposed behind the plane of the substrate 2 by the action of the wedge lens 5.

In this embodiment, the distance from the center of the light source group (LED light source located on the central axis C) composed of the plurality of LED light sources 3 to each LED light source 3 is Li, and the light emitted from each LED light source 3 is a wedge. When the inclination angle bent by the lens 5 is θi, the diverging action of the wedge lens 5, that is, the shape of the concave upper surface 5 c is set so that Li / tan θi becomes a substantially constant value. Thereby, the light rays emitted from the plurality of LED light sources 3 are converted into point light sources. Therefore, the irradiation area by the light emitted from the LED light source 3 and each LED light source 3 have a one-to-one correspondence, and the occurrence of multi-shadows can be suppressed. Further, the entire illumination device can be made thin so that the emitted light can be used effectively.
In this embodiment, a collimator lens 4 having the same specifications with 2θ · 1/2 of 20 degrees is installed for each LED light source 3, and a concave lens-shaped wedge lens 5 with a divergence angle of 15 degrees is disposed so as to cover the whole. As a lighting device, a condensing type lighting device with 2θ · 1/2 of 40 degrees is realized.

  From the above, according to the present embodiment, it is possible to provide a lighting device for narrow-angle light distribution that does not generate multi-shadow and has a narrow light distribution angle.

  The present invention can also be applied to an illuminating device such as a downlight, which conventionally does not necessarily use the light collecting means. That is, if the condensing of each collimator lens 4 is loosened and the diverging action of the wedge lens 5 is strengthened, the generation of multi-shadows can be suppressed while expanding the irradiation area of the illumination device 10.

  Also, as shown in FIG. 4, in the embodiment of the present invention, the area irradiated by the individual LED light sources 3 is a part of the area irradiated by the illumination device 10, and therefore the individual LED light sources are individually driven and controlled. Thus, the irradiation area can be controlled. In other words, if only the LED light source 3 arranged at the center is driven, 2θ · 1/2 is condensed by 20 degrees, and the other LED light sources 3 are also driven in a timely manner to reduce 2θ · 1/2 to 20-40. It can be controlled within a range of degrees. Further, by driving and controlling the LED light source 3 with respect to time, it is possible to perform irradiation such as a swaying tree leak or irradiation that scans.

  In this embodiment, the collimator lens 4 having the above-described shape is used as a lens for collimating light. However, the lens 4 only needs to be able to collimate light, and is particularly limited to the above-described shape. is not. The plurality of LED light sources and the plurality of collimator lenses 4 are not limited to a hexagonal lattice arrangement, and various arrangements are possible depending on the shape of the substrate 2. For example, a plurality of LED light sources and a plurality of collimator lenses 4 may be arranged side by side on a plurality of concentric circles, or may be arranged in a triangular shape, a quadrangular shape, or other polygonal shapes.

  In the embodiment, the collimator lens 4 is individually installed for each LED light source 3, and the wedge lens 5 is formed as a separate component from the collimator lens, but this can replace the functions of the collimator lens 4 and the wedge lens 5 later. This is because. These may be integrated in a timely manner from the viewpoint of simplification of assembly. That is, a plurality of collimator lenses 4 may be integrated, and a single cover member may be integrated with a wedge lens.

  Next, a lighting 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, detailed description thereof is omitted, and different parts are mainly described in detail.

(Second Embodiment)
FIG. 5 is a plan view showing the lighting device 10 according to the second embodiment, FIG. 6 is a sectional view of the lighting device along line AA in FIG. 5, and FIG. 7 is a perspective view showing the lighting device. is there.
In the second embodiment, the basic configuration of the illumination device 1 is the same as that of the first embodiment, and the configuration of the wedge lens 5 is partially different.

  As shown in FIGS. 5 to 7, according to the second embodiment, the wedge lens 5 constituting the lens unit is composed of a plurality of separate wedge lenses and is individually arranged on the collimator lens 4. . Each wedge lens 5 has a flat lower surface (incident surface) 5a that is in contact with the upper surface (exit surface) 4c of the collimator lens 4 and an upper surface (exit surface) 5c that is inclined with respect to the upper surface 4c of the collimator lens 4. doing. The plurality of wedge lenses 5 are formed such that the inclination angle of the upper surface 5c becomes larger as the wedge lens is located farther outward from the center of the lens group. Further, the plurality of wedge lenses 5 are arranged so that the inclined upper surface 5c faces the center direction of the lens group. The plurality of wedge lenses 5 are formed in a wedge shape that is thinner toward the center of the light source group. The wedge lens 5 is not provided on the collimator lens 4 located at the center of the collimator lens group.

According to the illuminating device 10 according to the second embodiment configured as described above, the emitted light beam is the center of the light source group in the LED light source 3 located outside the illuminating device, as in the first embodiment. Therefore, the lighting device can be converted to a point light source, and the occurrence of multi-shadows can be suppressed. In the present embodiment, it is possible to individually control the lighting of the LED light sources 3 and to further increase the multi-shadow suppression effect.
The plurality of wedge lenses 5 may be formed integrally with the collimator lens 4, thereby eliminating the excess Fresnel reflection interface and improving the efficiency and simplifying the assembly. Further, the lenses for each of the plurality of LED light sources 3 may be connected to each other and integrally formed.

(Third embodiment)
FIG. 8 is a perspective view showing the narrow-angle illumination device 10 according to the third embodiment, and FIG. 9 is a cross-sectional view of the illumination device 10. In the third embodiment, the basic configuration of the illumination device 1 is the same as that of the second embodiment, and the configuration of the wedge lens 5 is partially different.

  As shown in FIGS. 8 and 9, in the third embodiment, the wedge lens 5 is individually disposed on the plurality of collimator lenses 4 as in the second embodiment. The upper surface of each wedge lens 5 has a sawtooth cross-sectional shape, and the wedge lens 5 is formed into a Fresnel lens. The plurality of wedge lenses 5 are formed such that the inclination angle of the sawtooth of the upper surface 5c increases as the wedge lens is located outward from the center of the lens group. Further, the plurality of wedge lenses 5 are arranged so that the inclined upper surface 5c faces the center direction of the lens group. The wedge lens 5 is not provided on the collimator lens 4 located at the center of the collimator lens group, or a wedge lens having a flat upper surface is provided.

  According to the illuminating device 10 according to the third embodiment configured as described above, it is possible to obtain the same functions and effects as those of the second embodiment described above. Furthermore, by making the wedge lens 5 into a Fresnel lens, it is possible to reduce the lens thickness and reduce the thickness of the entire lighting device.

  In the above-described embodiment, the LED light sources 3 are arranged in a hexagonal lattice shape, but the present invention is not limited by the LED light source arrangement, and for example, arranged in a square lattice shape or in a ring shape. Or may be irregularly arranged.

  In the above-described embodiment, the amount of light emitted from each LED light source 3 is not specified, but the amount of light emitted from each LED light source 3 may be uniform or non-uniform. It is not limited by the amount of light flux. For example, the light distribution of the lighting device may be controlled by changing the amount of light flux of the LED light source according to the distance from the center of the LED light source group.

  In the above-described embodiment, since the collimator lens 4 and the wedge lens 5 need to act as a lens, the surface is generally mirror-finished. In this case, the outline of the shadow is sharp and clear. On the other hand, when it is desired to blur the outline of the shadow, the surface of the collimator lens 4 or the wedge lens 5 may be subjected to a graining process, and the present invention is not limited by the surface state of these lenses.

  Furthermore, in the above-described embodiment, a wedge lens is provided on the upper surface portion 4c of the collimator lens as a lens portion that bends the irradiated light beam from the normal direction, but the side surface portion 4b or the light incident portion 4a of each collimator lens is provided. It is good also as a structure for the lens part bent from a normal line direction by inclining a timely surface.

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.

2 ... base material, 3 ... LED light source, 4 ... collimator lens, 4a ... concave part,
5 ... wedge lens, 5c ... upper surface, 6 ... support frame, 10 ... lighting device,

Claims (7)

A plurality of light sources each having a light distribution with a strong directivity in the normal direction, arranged side by side on a plane,
A plurality of collimator lenses that are respectively provided facing the light source and collect the light emitted from the light source;
A lens unit that emits the collected light rays toward the outer side with respect to the center, as the distance from the center of the light source group composed of the plurality of light sources is larger,
A lighting device comprising:   The lighting device according to claim 1, wherein the lens unit includes a concave lens that covers the entire area of the plurality of light sources.   The lighting device according to claim 1, wherein the lens unit includes a wedge lens that covers each of the plurality of light sources.   The illumination device according to claim 1, wherein the lens unit is incorporated in the collimator lens.   The lighting device according to claim 2, wherein the lens unit is a Fresnel lens.   The illumination device according to claim 1, wherein the lens unit is formed in a rotationally symmetrical shape with respect to a central axis of the light source group.   When the distance from the center of the light source group of the light beam emitted from the lens unit is Li and the angle formed by the central axis of the light source group is θi, the light beam emitted from the lens unit has a substantially constant Li / tan θi. The lighting device according to any one of claims 1 to 6.

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