JP7117856B2 - Lens arrays and luminaires - Google Patents

Description

The present invention relates to lens arrays and lighting fixtures. In particular, it relates to a lighting fixture that performs light distribution control using a lens.

In general, facilities such as factories, warehouses, and gymnasiums have high ceilings. There are lighting fixtures that are attached to or suspended from such high ceilings (see Patent Document 1, for example).

JP 2014-026803 A

Lighting fixtures installed in facilities with high ceilings require a large amount of light so that they can shine brightly even from a high position. Here, in order to perform efficient irradiation, light distribution control or the like is performed by narrowing the beam using a lens or the like according to the height of the ceiling.
In general, LEDs have higher luminous efficiency when used at low current and low temperature. LEDs are arranged in a small number in many cases (see, for example, Patent Document 1).
On the other hand, using LEDs with a low current increases the luminous efficiency, but to obtain a large amount of light, it is necessary to arrange a large number of LEDs. However, there was a problem that it became large in size.

In order to solve the above-described problems, the present invention provides a lens array and an efficient lighting system that can perform light distribution control with high optical system efficiency without increasing the size of a large number of arranged LEDs. The purpose is to obtain an instrument.

In order to solve the above problems, a lens array according to the present invention is a lens array for controlling light distribution of light emitted from a plurality of LED elements, wherein the lens array corresponds to the LED elements on a one-to-one basis. , having a plurality of lenses for controlling the light distribution of light emitted by the LED element, the lenses are provided on the side portion having a side portion reflection surface provided with a total reflection surface for totally reflecting light, and on the irradiation side, A concave portion having a concave side wall that refracts light passing through the inside of the lens in the direction of the optical axis of the light, and a convex portion that refracts the light that has passed through the lens central portion at the bottom of the concave portion serving as the lens central portion. The side wall of the protrusion on the side is divided into a plurality of surfaces .

According to the lens array of the present invention, since each lens has a side surface portion and a concave portion, light distribution can be efficiently narrowed without increasing the lens diameter. Therefore, a large number of LED elements and lenses can be densely mounted, and the efficiency of the lighting equipment can be improved.

1 is an exploded perspective view showing a lighting fixture 100 according to Embodiment 1 of the present invention; FIG. It is a figure which shows the external appearance of the lens array 20 which concerns on Embodiment 1 of this invention. 3 is a diagram showing the appearance of a single lens 21 included in the lens array 20 according to Embodiment 1 of the present invention; FIG. It is a figure which shows the cross section which cut|disconnected the lens 21 based on Embodiment 1 of this invention in the up-down direction. It is a figure explaining the optical path of the light which passes through the lens 21 which concerns on Embodiment 1 of this invention. FIG. 2 is a diagram showing a light distribution curve of lighting fixture 100 according to Embodiment 1 of the present invention; It is a figure which shows comparison of color unevenness etc. based on Embodiment 1 of this invention. FIG. 4 is a diagram illustrating the arrangement of LED packages 11 of LED module 10 and lenses 21 of lens array 20 in lighting fixture 100 according to Embodiment 2 of the present invention. FIG. 7 is a diagram showing the relationship between an LED module 10 and a lens array 20 according to Embodiment 3 of the present invention;

Hereinafter, lighting fixtures according to embodiments of the invention will be described with reference to the drawings. In the following drawings, the same reference numerals denote the same or corresponding parts, and are common throughout the embodiments described below. The forms of the constituent elements shown in the entire specification are merely examples, and are not limited to the forms described in the specification. In particular, the combination of components is not limited only to the combinations in each embodiment, and the components described in other embodiments can be applied to other embodiments. Also, in the following description, basically, the ceiling side will be referred to as the "upper side" and the floor side will be referred to as the "lower side". In addition, in the drawings, the size relationship of each component may differ from the actual size.

Embodiment 1.
FIG. 1 is an exploded perspective view showing lighting fixture 100 according to Embodiment 1 of the present invention. A lighting fixture 100 of Embodiment 1 includes an LED module 10 , a lens array 20 , a heat sink 30 and a protective cover 40 . The heat sink 30, the LED module 10, the lens array 20, and the protective cover 40 are arranged in this order in the up-down direction (longitudinal direction) from the upper side to the lower side, which is the irradiation (emission) direction.

The LED module 10 includes a plurality of LED packages 11 having LED (Light Emitting Diode) elements arranged on a substantially rectangular substrate 12 . It is assumed that the LED package 11 of Embodiment 1 is of SMD (Surface Mounted Device) type (surface mount type). Also, the LED elements included in the LED package 11 of Embodiment 1 are assumed to be white LED elements that emit white light. The surface on which the LED package 11 is arranged becomes the light emitting surface. The light emitting surface faces downward.

The lens array 20 has a plurality of lenses 21 that control light distribution of light emitted from the LED packages 11 of the LED modules 10 . The lens array 20 covers the LED module 10 from the light emitting surface side. The lens array 20 will be detailed later. The heat sink 30 absorbs and releases heat from the LED module 10 . The heat sink 30 is in contact with the LED module 10 on the side opposite to the light emitting surface of the LED module 10 . Also, the heat sink 30 is attached to the lens array 20 at the frame portion of the lens array 20 and is in contact with the lens array 20 . The protective cover 40 protects the lens array 20, the LED module 10, and the like. The protective cover 40 is a transparent cover that transmits the light emitted by the LED module 10 and irradiates the floor surface with the light. A protective cover 40 covers the lens array 20 and is attached to the heat sink 30 .

As a general characteristic of LEDs, when the current flowing through the LED package or the temperature of the LED element decreases, the luminous efficiency (lm/W) of the LED package itself increases. Mounting a large number of LED packages to obtain the required amount of light can reduce the amount of current flowing through each LED package, and can also suppress the concentration of heat. Therefore, it is better to mount a large number of small LED packages on a board than to emit light by passing a large current through a large LED package, while obtaining the same amount of light (luminous flux), while increasing the luminous efficiency (lm/W). can be higher.

Further, when the light distribution of the LED package is controlled using a lens, it is preferable that one lens corresponds to one LED package. The optical system efficiency (light extraction efficiency) can be improved by controlling the light distribution of the omnidirectional light emitted from each LED package with the corresponding lens.

As described above, in the lighting device 100 of Embodiment 1, one lens 21 and one LED package 11 are associated one-to-one in order to efficiently perform light distribution control using the lens 21 .
Further, by making the diameter of the lens 21 as small as possible while narrowing the light distribution by the side surface portion 24 and the concave portion 25 of the lens 21, which will be described later, many LED packages 11 can be arranged without increasing the size of the LED module 10. make it

FIG. 2 is a diagram showing the appearance of the lens array 20 according to Embodiment 1 of the present invention. FIG. 2(a) is a diagram showing the appearance of the surface facing the protective cover 40. FIG. 2(b) is a diagram showing the appearance of the surface facing the LED module 10. As shown in FIG. The lens array 20 has a plurality of lenses 21 as described above. The lens array 20 of Embodiment 1 is an integrally molded product in which a plurality of lenses 21 are integrally molded. As described above, one lens 21 of the lens array 20 corresponds to one LED package 11 on a one-to-one basis.

FIG. 3 is a diagram showing the appearance of a single lens 21 included in the lens array 20 according to Embodiment 1 of the present invention. FIG. 3( a ) is a view of the lens 21 viewed from the light incident (incident) side facing the LED module 10 . 3B is a view of the lens 21 viewed from the irradiation (emission) side facing the protective cover 40. FIG. Further, FIG. 3(c) is a perspective view of the lens 21 with the light incident side as the center. FIG. 3D is a perspective view of the lens 21 centering on the irradiation side.

FIG. 4 is a cross-sectional view of the lens 21 according to Embodiment 1 of the present invention taken vertically. Furthermore, FIG. 5 is a diagram illustrating the optical path of light passing through the lens 21 according to Embodiment 1 of the present invention. FIG. 6 is a diagram showing a light distribution curve of lighting fixture 100 according to Embodiment 1 of the present invention.

Each lens 21 of the lens array 20 mainly has a transparent member that transmits light emitted by the LED package 11 . As shown in FIG. 5, among the light that is emitted from the LED package 11 and enters the lens 21, the light directed away from the optical axis (the light 202 and the light 201a in FIG. 5A) is the dome light. incident on the shaped side surface portion 24 . The side portion 24 is open at the top of the dome and has a space formed therein. Although not particularly limited, in the lighting fixture 100 of Embodiment 1, the convex portion of the LED package 11 is positioned in the space below the top of the opening. By surrounding the convex portion that is the light emitting portion of the LED package 11 with the side surface portion 24, the side surface portion 24 can efficiently take in the light that spreads in the hemispherical direction. The size and the like of the side surface portion 24 are not particularly limited, but are set, for example, by the angle of light reflected on the total reflection surface, as will be described later.

Here, in the lighting fixture 100 of Embodiment 1, as shown in FIG. 4, the cross-sectional wall surface shape of the side portion light incident surface 24A of the side portion 24 is an S-curve shape. The cross-sectional shape of the side light incident surface 24A is made into an S-curve shape, and the central light incident surface with the microlens portion 27 is set within a set range, and the top opening is widened, so that the side portion 24 and the LED package 11 You can increase the distance between Therefore, a margin can be provided so that the lens 21 does not come into contact with the LED package 11 . As described above, it is particularly effective when the light emitting portion of the LED package 11 is arranged at a position where it enters the space on the light incident side of the side surface portion 24 .

The role of the side reflecting surface 24B and the recessed portion 25 functioning in relation thereto will be described with reference to FIG. In the side portion 24, the inner side of the side portion reflection surface 24B is a total reflection surface that totally reflects light passing through the lens 21 in a direction away from the optical axis via the side portion light entrance surface 24A.

If the diameter of the exit side of the side reflecting surface 24B is increased, the light 201c is reflected in the optical axis direction and the light distribution is easily narrowed, but the lens 21 becomes large (FIG. 5(c)). Further, if the diameter of the exit side of the side reflecting surface 24B is made small, the light 201b is reflected in a direction away from the optical axis and the light distribution cannot be narrowed (FIG. 5(b)).

Therefore, the concave portion 25 is provided while reducing the diameter of the exit side of the side reflecting surface 24B. As a result, the light reflected by the side reflecting surface 24B is refracted by the recess side wall 25A toward the optical axis direction and emitted (light 201a in FIG. 5A). can do.

As described above, among the light emitted from the LED package 11, when the optical axis that is the center of the emission direction is 0°, the light emitted in the direction away from the optical axis is reflected by the side surface which is a total reflection surface. The optical path is controlled toward the optical axis direction side by the partial reflection surface 24B and the concave portion 25 . Then, as shown in FIG. 6, light of about 45° or more is suppressed, and a light distribution in which light is concentrated in the optical axis direction is obtained.

The lens 21 of Embodiment 1 further has a convex portion 26 at the center portion of the lens, which is the bottom portion of the concave portion 25 . As shown in FIG. 5A, the convex portion 26 refracts the light that has passed through the central portion of the lens, reduces the re-entering of the light into the lens 21, and causes the light to exit in the direction of the optical axis (FIG. 5A). light 203). Therefore, the efficiency of the optical system is improved, and the beam can be further focused. The diameter of the convex portion 26 at the center of the lens on the irradiation side is made larger than the diameter at the center of the lens on the light entrance side where the microlens portion 27 (to be described later) is installed. In addition, the inner diameter of the side reflecting surface 24</b>B, which serves as the total reflecting surface, is set to be larger than the diameter of the convex portion 26 . By defining the sizes of the side surface portion 24 and the convex portion 26 based on the diameter relationship as described above, the optical system efficiency can be increased.

Further, the lens 21 of the lighting fixture 100 of Embodiment 1 has a microlens portion 27 having a plurality of round convex microlenses 27A at the center of the lens on the light incident side. The microlens 27A is formed on the light incident side (FIGS. 3A and 4).

Further, in Embodiment 1, the side wall reflecting surface 24B and the side wall of the projection 26 are divided into a plurality of surfaces (FIG. 3). The inner total reflection surface of the side reflection surface 24B is divided into a plurality of parts in the vertical direction (vertical direction) and the circumferential direction. Dividing into a plurality of surfaces can improve the quality of light emitted from the lighting device 100 as described below.

For example, a general LED package that emits white light emits white light obtained by mixing blue light emitted by an LED element and mainly yellow light emitted by a phosphor using blue light as excitation light. emit. Due to the difference in the distance that blue light passes through the phosphor layer, the light tends to be blue or yellow depending on the direction. When the light of this white LED is controlled by a lens or the like, the directionally biased color of the light source may also affect the irradiation surface. In the past, the exit surface of the lens was roughened to diffuse the light so that the colors would not be biased. Although this is a simple method, it has the drawback that the shape of the light distribution is deformed and glare is caused because the light is diffused.

In the lighting fixture 100 of Embodiment 1, the side wall reflecting surface 24B and the side wall of the convex portion 26 are composed of a plurality of surfaces. In addition, a microlens portion 27 having a plurality of microlenses 27A is formed in the central portion of the lens on the light entrance side. By having such a configuration, while suppressing the influence on the light distribution shape and efficiency, light is appropriately mixed to suppress color unevenness. Here, either one of the configurations may be used.

FIG. 7 is a diagram showing a comparison of color unevenness and the like according to Embodiment 1 of the present invention. FIG. 7(a) shows light emitted through the lens 21 of the first embodiment. FIG. 7(b) shows the light emitted when the microlens portion 27, the side wall reflecting surface 24B, and the side wall of the convex portion 26 in the lens 21 of Embodiment 1 are not provided with a multi-surface structure. . As shown in FIG. 7, by passing the light emitted from the LED package 11 through the lens 21 and irradiating it, color unevenness can be suppressed. In addition, it can be seen that the projection image of the LED chip image that would otherwise be irradiated is alleviated, and natural circular light is irradiated.

Here, in the lighting fixture 100 of Embodiment 1, it is assumed that a plurality of LED packages 11 are arranged in four directions on the LED module 10 . Therefore, the lenses 21 in the lens array 20 are also arranged in four directions. At this time, as shown in FIG. 3 and the like, by setting the number of vertical divisions of the total reflection surface of the side reflection surface 24B of the lens 21 to a multiple of 4, the distance to the adjacent lens 21 can be minimized. can. Therefore, the LED elements of the LED package 11 can be arranged more densely. In Embodiment 1, as shown in FIG. 3, it is divided into 16 parts.

In Embodiment 1, the number of divisions in the vertical direction is a multiple of 4 as an optimum example, but the number is not limited to this. It may be changed according to the distance and arrangement between the LED packages 11, the distance and arrangement between the lenses 21, and the like, within the range where the optical system efficiency is allowed.

As described above, in the lighting fixture 100 of Embodiment 1, in each lens 21 of the lens array 20, the side portion 24 having the side portion reflecting surface 24B provided with a total reflection surface and the side portion 24 that refracts light toward the optical axis. It has a recess 25 that allows Therefore, the lens diameter can be reduced while suppressing the spread of light. In addition, the LED package 11 and the lens 21 can be densely mounted, and by mounting a large number of LEDs in the same area, the efficiency of the lighting device 100 can be improved.
In addition, by providing the lens 21 with the convex portion 26 in the lens central portion, it is possible to refract the light passing through the lens central portion and reduce the re-entering of the light into the lens 21 . Therefore, the efficiency of the optical system is improved, and the beam can be further focused.
By providing the microlenses 27A and forming the side reflecting surfaces 24B and the side walls of the convex portions 26 with a plurality of surfaces, it is possible to suppress color unevenness.

Moreover, the lighting device 100 of Embodiment 1 has a transparent protective cover 40 attached to the heat sink 30 to cover the LED module 10 and the lens array 20 . Therefore, the lens array 20 (lenses 21) is prevented from being displaced by an external impact such as a ball hitting the lighting device 100. - 特許庁Therefore, it is possible to prevent the LED package 11 (LED module 10) from being damaged. Then, troubles such as not lighting the LED package 11 are prevented.

Embodiment 2.
FIG. 8 is a diagram illustrating the arrangement of lenses 21 of lens array 20 in lighting fixture 100 according to Embodiment 2 of the present invention. In Embodiment 1, it is assumed that the LED packages 11 of the LED module 10 and the lenses 21 of the lens array 20 are arranged in four directions.

In the lighting fixture 100 of Embodiment 2, as shown in FIG. 8, the lenses 21 of the lens array 20 are arranged in a hexagonal arrangement (honeycomb arrangement). FIG. 8 shows part of the lens array 20. As shown in FIG. When the lenses 21 are concentric circles or polyhedrons close to concentric circles, the lenses 21 can be arranged most densely by arranging the lenses 21 in a hexagonal arrangement. Therefore, the LED elements can be arranged more densely. Although not shown in the drawing, the LED packages 11 of the LED module 10 are also hexagonally arranged in the same positional relationship as the lenses 21 .

Further, by setting the number of divisions in the vertical direction (vertical direction) of the total reflection surface of the side reflection surface 24B of the lens 21 to a multiple of 6, the distance to the adjacent lens 21 can be minimized. Therefore, the LED elements of the LED package 11 can be arranged more densely. In FIG. 8, it is divided into 12 parts.

Embodiment 3.
FIG. 9 is a diagram showing the relationship between the LED module 10 and the lens array 20 according to Embodiment 3 of the present invention. FIG. 9A is an enlarged view of part of the lens array 20. FIG. Moreover, FIG.9(b) is a figure explaining joint tightening. Although not specifically mentioned in the first and second embodiments described above, in lighting device 100 , lens array 20 has screw holes 29 . The lens array 20 and the LED module 10 are fastened together to the heat sink 30 with screws 50 through screw holes 29 . By adopting a co-fastening structure, positional deviation between each LED package 11 of the LED module 10 and each lens 21 of the lens array 20 can be reduced.

Further, as shown in FIG. 9A, the lens array 20 is provided with a boss 28. As shown in FIG. The boss 28 suppresses warping of the lens array 20. - 特許庁For example, the lens array 20 bends toward the substrate 12 of the LED module 10 and the bosses 28 hit the substrate 12 . At this time, the boss 28 functions as a stopper, and the warping of the lens array 20 can be suppressed. Therefore, positional deviation between the LED package 11 and the lens 21 can be reduced, and contact between the LED package 11 and the lens 21 can be eliminated.

10 LED module, 11 LED package, 12 substrate, 20 lens array, 21 lens, 24 side surface, 24A side light entrance surface, 24B side surface reflecting surface, 25 concave portion, 25A side wall of concave portion, 26 convex portion, 27 microlens portion , 27A microlens, 28 boss, 29 screw hole, 30 heat sink, 40 protective cover, 50 screw, 100 luminaire, 201a, 201b, 201c, 202, 203 light.

Claims (12)

A lens array for controlling light distribution of light emitted from a plurality of LED elements,
The lens array has a plurality of lenses that correspond to the LED elements one-to-one and control the light distribution of the light emitted by the LED elements,
the lens has a side portion having a side portion reflecting surface provided with a total reflection surface that totally reflects the light;
a recess provided on the irradiation side and having a recess sidewall that refracts light that has passed through the inside of the lens in the direction of the optical axis of the light;
a convex portion that refracts light that has passed through the lens central portion at the bottom portion of the concave portion serving as the lens central portion;
A lens array in which a side wall of the projection on the irradiation side is divided into a plurality of surfaces. 2. The lens array according to claim 1 , wherein the diameter of the entire range of the side reflecting surface when cut in the direction of the optical axis of the light is larger than the diameter of the convex portion. 3. The lens array according to claim 1, wherein the side reflecting surface is divided into a plurality of surfaces. 4. The lens array according to any one of claims 1 to 3 , further comprising a microlens portion having a plurality of round convex microlenses in the center portion of the lens on the light entrance side. 5. The lens array according to claim 4 , wherein the convex portion has a diameter larger than that of the microlens portion . 6. The lens array according to any one of claims 1 to 5, wherein a wall surface of the side portion light incident surface when the side portion is cut in the direction of the optical axis of the light has an S-shaped curve. an LED module in which a plurality of surface-mounted LED packages having LED elements are mounted on a substrate;
A lighting fixture comprising the lens array according to any one of claims 1 to 6, for performing light distribution control of light emitted from the LED package of the LED module. 8. The lighting fixture according to claim 7, wherein the LED packages of the LED module and the lenses of the lens array are arranged in four directions. 8. The lighting fixture according to claim 7, wherein the LED packages of the LED module and the lenses of the lens array are hexagonally arranged. further comprising a heat sink for dissipating heat;
The lighting fixture according to any one of claims 7 to 9, wherein the lens array and the LED module are fastened together to the heat sink with screws. The lighting fixture according to any one of claims 7 to 10, wherein the lens array has bosses. The lighting fixture according to any one of claims 7 to 11, further comprising a protective cover that protects the lens array and the LED module.

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