JP7455354B2 - Lighting device using reflective material - Google Patents

Description

The present invention relates to a lighting device using a reflecting member for reflecting light emitted from a light source in a predetermined direction.

The reflecting member of the irradiation device includes a reflecting member main body having a reflecting surface for reflecting irradiated light from a light source (see, for example, Patent Document 1). The reflective surface of this reflective member is provided on the inner circumferential surface of the reflective member main body, and this inner circumferential surface (reflective surface) is formed in the shape of a paraboloid. placed at the focal point.

In such a reflecting member, the reflecting surface is subjected to a surface treatment such as aluminum vapor deposition, thereby increasing the reflection efficiency and reflecting the irradiated light from the light source in a predetermined direction.

Patent No. 3694310

However, in the above-mentioned reflective member, the reflective surface of the reflective member body must be subjected to surface treatment such as aluminum vapor deposition, which increases the number of manufacturing steps, complicates the manufacturing process, and causes a decrease in yield. There is a problem of high cost. In addition, in order to improve the reflection efficiency of the aluminum vapor deposited on the reflective surface of the reflective member body, special equipment such as applying an additional reflective coating is required, and if materials other than aluminum with high reflection efficiency are used, manufacturing There are also issues with cost and durability, and for these reasons, there has been a need for a means to easily improve reflection efficiency.

An object of the present invention is to provide a lighting device using a reflective member that is relatively easy to manufacture and can improve reflection efficiency.

The lighting device of the present invention includes a reflective member that reflects light, a circuit board that supports the reflective member, and an LED light source that is disposed in a focal region of the circuit board that corresponds to the focal point of the reflective member. Prepare ,
The reflecting member includes a reflecting member main body that reflects the irradiated light from the LED light source , and the reflecting member main body has a partially parabolic shape with one end converging and the other end being open. It has a circumferential base portion and a plurality of protrusions provided in the circumferential direction on the outer peripheral surface of the base portion, and the plurality of protrusions extend radially from the one end side to the other end side of the reflecting member main body. and
Further, an imaginary plane connecting the tops of the plurality of protrusions defines a part of a paraboloid, and the cross section of the top of the plurality of protrusions is at a right angle,
Further, the wall thickness of the base portion of the reflecting member main body is t1, and the wall thickness of the plurality of ridges of the reflecting member main body from the inner circumferential surface of the base portion to the top of the plurality of ridges is t2. Then, the LED light source is disposed at the focal point of a paraboloid where the virtual thickness ta of the reflecting member main body is ta=[(t1+t2)/2],
The irradiated light from the LED light source passes through the base portion, reaches the plurality of protrusions , and is reflected by the plurality of protrusions toward the other end side of the reflecting member main body. do.

According to the lighting device of the present invention, a plurality of protrusions are provided in the circumferential direction on the outer peripheral surface of the base portion of the reflecting member main body, and a virtual plane connecting the tops of these protrusions defines a part of the paraboloid. Since the cross-sections of the tops of these protrusions are at right angles, the irradiated light from the light source passes through the base of the reflective member body and reaches the protrusions, and these protrusions reflect the light on the reflective member body. The light is now reflected toward the other end, thereby making it possible to efficiently reflect the light from the light source.
Further, if the thickness of the base portion of the reflecting member main body is t1, and the wall thickness from the inner circumferential surface of the base portion to the top of the plurality of ridges in the plurality of ridges of the reflecting member main body is t2, the LED light source is Since it is arranged at the focal point of the paraboloid where the virtual thickness ta of the reflecting member body is ta=[(t1+t2)/2], the illuminance can be increased by reflecting the irradiated light from the LED light source more efficiently. I can do it.
Further, such a reflective member can be formed by resin molding, for example injection molding, and can be manufactured relatively easily and at low cost. Furthermore, in such a reflective member, the reflective efficiency can be increased without applying general aluminum vapor deposition, so that manufacturing steps can be reduced, yields can be improved, and the reflective member itself can be recycled when it is disposed of.

FIG. 1 is a side view showing a first embodiment of a reflective member used in a lighting device according to the present invention. FIG. 2 is a plan view showing the reflective member of FIG. 1; 3 is a sectional view taken along line III-III in FIG. 2. FIG. FIG. 2 is a partially enlarged sectional view showing a part of the lighting device using the reflective member of FIG. 1. FIG. FIG. 2 is a partially enlarged end view showing a part of the reflective member of FIG. 1 in an enlarged manner. 6(a) is a plan view of the reflecting member, FIG. 6(b) is a front view thereof, and FIG. 6(c) is a diagram showing the dimensions of the reflecting member of Example 1 used in the simulation experiment and the irradiation experiment. is its bottom view. FIG. 7(a) is a diagram showing the simulation results of the reflective member of Example 1, and is a diagram showing the illuminance distribution of the reflected light from the reflective member, and FIG. 7(b) is a diagram showing the illuminance distribution of the reflected light from the reflective member. FIG. 4 is an actual data diagram showing the illuminance distribution of reflected light from a reflective member obtained through an irradiation experiment. 8(a) is a front view of the reflective member, and FIG. 8(b) is a bottom view thereof . FIG. FIG. 9(a) is a diagram showing the simulation results of the reflective member of Comparative Example 1, and is a diagram showing the illuminance distribution of the reflected light from the reflective member, and FIG. 9(b) is a diagram showing the simulation results of the reflective member of Comparative Example 1. FIG. 4 is an actual data diagram showing the illuminance distribution of reflected light from a reflective member obtained through an irradiation experiment. FIG. 7 is a diagram showing simulation experiment results of Example 2, and is a diagram showing the illuminance distribution of reflected light from a reflecting member. FIG. 7 is a diagram showing the results of a simulation experiment of Comparative Example 2, and is a diagram showing the illuminance distribution of reflected light from a reflecting member.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a lighting device according to the present invention will be described with reference to the accompanying drawings. First, a first embodiment of a lighting device according to the present invention will be described with reference to FIGS. 1 to 5.

In FIGS. 1 to 3, the illustrated reflecting member 2 used in the lighting device includes a reflecting member main body 4 for reflecting irradiated light, and this reflecting member main body 4 is attached to a predetermined portion of a circuit board 6. As shown in FIGS. 1 to 3, the reflecting member main body 4 has a half shape that is convergent at one end (the left end in FIGS. 1 and 3) and open at the other end (the right end in FIGS. 1 and 3). It is formed in a parabolic shape (in other words, a shape of 180 degrees in the circumferential direction), and its lower surface side is supported by the surface of the circuit board 6. Such a reflecting member body 4 is formed by molding a transparent resin material, for example, by injection molding of acrylic resin.

This reflecting member main body 4 has a base portion 8 provided on the inner circumferential side, and a plurality of protrusions 10 provided continuously in the circumferential direction on the outer circumferential surface of the base portion 8. The base portion 8 extends radially over substantially the entire length from one end side to the other end side. The plurality of protrusions 10 are continuously provided on the outer circumferential surface of the base portion 8, and their top portions 12 (see FIG. 5) are formed at right angles. The light from the light source 14 (see FIG. 4) can be efficiently reflected toward the other open end of the reflecting member main body 4.

In this embodiment, the plurality of protrusions 10 have a cross-sectional shape, for example, a right isosceles triangle shape, and as the angular width of the protrusions 10 in the circumferential direction increases, the reflection efficiency decreases, so that it is not practical for practical use. Considering the application, it is set, for example, in an angular range of 0.5 to 5 degrees, preferably in an angular range of 1 to 4 degrees, which in this embodiment is, for example, 4 degrees. If the angular width of these protrusions 10 is smaller than 0.5 degrees, the size of the protrusions 10 will be too small and will be easily influenced by the apex R during processing, so that the irradiation light from the LED light source 14 will not reach these protrusions 10. , and the reflection efficiency decreases. Moreover, if the angular width of these protrusions 10 is larger than 5 degrees, the size of the protrusions 10 becomes too large and is easily affected by a shift in the focal point position, reducing the reflection efficiency of the irradiated light from the LED light source 14. .

Such a reflecting member main body 4 is configured such that a virtual plane Q (see FIG. 5) connecting the tops 12 (specifically, apexes) of the plurality of protrusions 10 defines a part of a paraboloid, With this configuration, the LED light source 14 (its light emitting part) has a focal region P of a semi-paraboloid defined by the virtual surface Q (specifically, a focal region P corresponding to this focal region on the circuit board 6). By arranging it in this way, the irradiated light from the LED light source 14 can be efficiently reflected toward the other end side of the reflecting member main body 4.

This focal region P is a region at or near the focal point of the semi-paraboloid defined by the virtual surface Q, and this near position means the focal point of the semi-paraboloid on the reflecting member main body 4. This refers to the position corrected in consideration of wall thickness.

In such a reflecting member main body 4, the overall outer shape is a semi-paraboloid with one end converged and the other end open. The height of the protrusions 10 is low, and the height of the protrusions 10 is high on the other end side (open side), and the height of these protrusions 10 gradually increases from one end side to the other end side (Fig. 2 and Figure 3).

In this embodiment, a flange portion 16 that protrudes radially outward is provided at the other end of the reflecting member main body 4, and protruding mounting portions 18 that protrude outward are provided at both lower ends of this flange portion 16, A slit 20 (only one of which is shown in FIG. 1) is provided in the protruding attachment portion 18. With this structure, the reflecting member main body 4 is attached to the attachment member 22 by screwing the attachment screw (not shown) into the attachment member 22 through the slit 20 of the protruding attachment portion 18, and such attachment is possible. A member 22 is attached to the circuit board 6, for example.

Although not shown, this mounting member 22 is provided with an irradiation opening (not shown) corresponding to the other end side opening 24 (see FIG. 3) of the reflecting member main body 4, and the irradiation opening from the LED light source 14 The light is reflected by the reflecting member main body 4 as will be described later, and then is projected through the irradiation opening of the mounting member 22.

In the reflecting member 2 of this embodiment, the reflected light from the LED light source 14 is reflected in the following manner. Referring mainly to FIGS. 3 and 4, for example, a surface-mounted top-view type LED is used as the LED light source 14, and the irradiated light from the LED light source 14 is directed upward (upward in FIG. 3). is attached to the surface of the circuit board 16.

The irradiated light from this LED light source 14 passes through the base portion 8 of the reflecting member main body 4 and reaches the protrusion 10 as shown by the arrow in FIGS. 3 and 4, and then the outer surface of this protrusion 10 (i.e. (the boundary surface between the protrusion 10 and the atmosphere) and is irradiated through the opening 24 at the other end of the reflecting member main body 4. At this time, since the plurality of protrusions 10 are formed in the shape of a right triangle in which the angle of the apex 12 is a right angle, the irradiation light from the LED light source 14 passes through the protrusions 10 and the inner slope of one side thereof. 32, further passes through this protrusion 10 and is reflected by the inner slope 34 on the other side, and the irradiated light thus reflected is projected to the outside through the other end opening 24 side of the reflecting member main body 4. (See Figure 4).

In the lighting device using this reflective member 2, the irradiated light from the LED light source 14 is efficiently reflected by the plurality of protrusions 10 of the reflective member main body 4, and is irradiated to the outside through the other end opening 24 of the reflective member main body 4. The illuminance of the irradiated light is high, and it can be brightly illuminated through the other end opening 24. Further, this reflective member 2 can reflect the irradiated light from the LED light source 14 with high efficiency without performing surface treatment such as aluminum vapor deposition, and a highly efficient reflective member can be provided relatively easily and at low cost. be able to. Furthermore, by adopting a structure in which the semi-parabolic reflecting member 2 is provided on the circuit board 6 on which the LED light source 14 is attached, the reflected light from the reflecting member 2 is almost never blocked by the LED light source 14. This allows the light projected through the opening 24 on the other end of the reflecting member 4 to be brighter.

In the lighting device using this reflective member 2, the virtual plane Q (see FIG. 5) connecting the tops 12 of the plurality of protrusions 10 of the reflective member 2 is configured to be a semi-paraboloid. In this case, the LED light source 14 (specifically, its light emitting part) is arranged at the focal point of the semi-paraboloid of the virtual surface Q, and by being arranged in this way, the irradiation light from the LED light source 14 is can be reflected with high efficiency, but by correcting the placement position of the LED light source 14 in consideration of the thickness of the reflecting member main body 4, it is possible to reflect more efficiently and increase the illuminance of the irradiated light. .

In this case, as shown in FIG. 5, the wall thickness of the base portion 8 of the reflecting member main body 4 is set to t1, and the plurality of protrusions 10 are separated from the inner circumferential surface of the base portion 8 in the plurality of protrusions 10 of the reflecting member main body 4. If the wall thickness up to the top 12 is t2, then the virtual thickness ta of the reflective member body 4 is a paraboloid Q2 where ta=[(t1+t2)/2] (in other words, the outer shape of the reflective member body 4 is Qa) It is preferable to correct the position of the LED light source 14 so that it is placed at the focal point on the paraboloid (paraboloid), and this position correction involves moving the reflecting member main body 4 along the surface of the circuit board 6. This can be easily done by

Although one embodiment of the lighting device has been described above, the present invention is not limited to this embodiment, and various changes and modifications can be made without departing from the scope of the present invention.

For example, in the embodiment described above, a semi-parabolic shape (in other words, a shape of 180 degrees in the circumferential direction) is used as the reflective member, but the shape is not limited to this, and the angle in the circumferential direction is A paraboloid shape smaller than 180 degrees, such as a paraboloid shape with an appropriate angle such as 60 degrees, 90 degrees, 120 degrees, 150 degrees, or a paraboloid shape with a circumferential angle larger than 180 degrees. For example, a parabolic shape having an appropriate angle such as 240 degrees, 270 degrees, 300 degrees, or 360 degrees may be used.

In order to confirm the effect of the reflective member used in the lighting device of the present invention, as Example 1, the reflection efficiency when using the reflective member with the shape shown in FIG. 6 was determined by simulation. A reflective member (having a plurality of radial protrusions on the outer circumferential surface) was manufactured, and an irradiation experiment was conducted using the manufactured reflective member.

<Reflection member of Example 1>
External shape of the reflecting member body: semi-parabolic shape (shape of 180 degrees in the circumferential direction)
Width W of the opening on the other end side of the reflecting member main body: 46 mm
Height of the opening on the other end of the reflecting member main body: 23 mm
Length L from the inner surface on one end side of the base part of the reflecting member main body to the opening on the other end side: 29.5 mm
Axial length P of the protrusion of the reflecting member main body: 26.5 mm
Location of protrusion: Entire area of outer circumferential surface of reflecting member main body Angular width of protrusion in circumferential direction: 4 degrees Angle of top of protrusion: 90 degrees Luminous flux of LED light source: 18.6 lumens Half-value angle of LED light source: 140 degrees Arrangement position of LED light source: Focus position of the semi-paraboloid of the external shape of the reflecting member main body Material of the reflecting member main body: Acrylic resin The simulation results of the reflecting member of this Example 1 are as shown in FIG. 7(a) Met. As shown in FIG. 7(a), the maximum illuminance of the reflected light at this time was approximately 338 lux, and the reflection efficiency of the reflective member was confirmed to be approximately 71.7%.

In the irradiation experiment using the reflective member of Example 1, an LED light source was placed at the focal position of the semi-paraboloid of the external shape of the reflective member (specifically, in a focal region taking into account the wall thickness), and this LED light source After reflecting the light from a reflective member, it was irradiated onto a screen installed 1 m away. The distribution of reflected light projected on the screen at this time was as shown in FIG. 7(b). The maximum illuminance of the reflected light at this time was approximately 343 lux according to actual measurement data, and it was confirmed that the reflection efficiency of the reflective member was approximately 73.0% according to actual measurement data.

As a comparative example, the reflection efficiency when using a reflective member (conventional type) with the shape shown in Fig. 8 was determined by simulation. An irradiation experiment was conducted using the fabricated reflective member.

<Reflective member of Comparative Example 1>
Inner peripheral surface shape of the reflecting member main body: semi-parabolic shape (shape of 180 degrees in the circumferential direction)
Width of the opening on the other end of the reflecting member main body: 45 mm
Height h of the opening on the other end of the reflecting member main body: 22.5 mm
Length l from the inner surface on one end side of the base part of the reflecting member main body to the opening on the other end side: 30 mm
Luminous flux of LED light source: 18.6 lumens Half value angle of LED light source: 140 degrees Arrangement position of LED light source: Focal position of semi-paraboloid of inner peripheral surface shape of reflecting member main body Surface treatment of inner peripheral surface of reflecting member main body: Aluminum vapor deposition (reflectance setting in simulation experiment is 85%)
The simulation results for the reflective member of Comparative Example 1 were as shown in FIG. 9(a). As shown in FIG. 9(a), the maximum illuminance from the LED light source was stronger than that in Example 1, and was about 831 lux, but the reflected and emitted light flux was small; The reflection efficiency of the member was approximately 68.5%, which was approximately 3.2% lower than that of Example 1.

In the irradiation experiment of the reflective member of Comparative Example 1 for comparison, an LED light source was placed at the focal point of the reflective member, and after the light from the LED light source was reflected by the reflective member, it was irradiated onto a screen installed 1 m away. I let it happen. The distribution of reflected light projected on the screen at this time was as shown in FIG. 9(b). The maximum illuminance of the reflected light at this time is approximately 854 lux according to actual measurement data, and the reflection efficiency of the reflective member is approximately 65.9% according to actual measurement data, which is compared with the reflection efficiency of the reflective member in Example 1. It was about 7.1% lower.

As described above, as a result of the simulation experiment and the irradiation experiment of the reflective member, although the maximum illuminance is lower in Example 1, the difference in illuminance is small in the entire irradiation area, and the light is softer overall. It was also confirmed that the reflection efficiency was increased.

Next, a simulation experiment was conducted using a reflective member having the same shape as Example 1 as Example 2, and using a reflective member having the shape of Comparative Example 1 as Comparative Example 2, and setting the half-value angle of the LED light source to 120 degrees. However, the reflectance of the inner surface of Comparative Example 1 was set to 93% assuming an increased reflection coating. The illuminance distribution of the reflected light of Example 2 was as shown in FIG. 10, and the illuminance distribution of the reflected light of Comparative Example 2 was as shown in FIG. That is, FIG. 10 shows the simulation results of Example 2, and FIG. 11 shows the simulation results of Comparative Example 2. The reflection efficiency is approximately 94.6% for the shape of Example 2, and approximately 90.4% for the shape of Comparative Example 2, which is approximately 4.2% higher for Example 2 than for Example 1. Similar to the experimental results of Comparative Example 1, an increase in reflection efficiency was confirmed.

Furthermore, by changing the half-power angle of the LED light source from 140 degrees to 120 degrees, the reflection efficiency was higher in Example 2 than in Example 1. It is thought that this is because the proportion of light that does not hit the reflective member and directly leaks is significantly increased.

2, 2A, 2B, 2C Reflective member 4, 4A, 4B, 4C Reflective member body 6 Circuit board 8 Base portion 10 Projection 12 Top portion 14 LED light source 42, 52, 62 First area 44, 54, 64 Second area 66 Third area

Claims (3)

comprising a reflective member that reflects light, a circuit board that supports the reflective member, and an LED light source disposed in a focal region of the circuit board that corresponds to the focal point of the reflective member,
The reflecting member includes a reflecting member main body that reflects the irradiated light from the LED light source , and the reflecting member main body has a partially parabolic shape with one end converging and the other end being open. It has a circumferential base portion and a plurality of protrusions provided in the circumferential direction on the outer peripheral surface of the base portion, and the plurality of protrusions extend radially from the one end side to the other end side of the reflecting member main body. and
Further, an imaginary plane connecting the tops of the plurality of protrusions defines a part of a paraboloid, and the cross section of the top of the plurality of protrusions is at a right angle,
Further, the wall thickness of the base portion of the reflecting member main body is t1, and the wall thickness of the plurality of ridges of the reflecting member main body from the inner circumferential surface of the base portion to the top of the plurality of ridges is t2. Then, the LED light source is disposed at the focal point of a paraboloid where the virtual thickness ta of the reflecting member main body is ta=[(t1+t2)/2],
The irradiated light from the LED light source passes through the base portion, reaches the plurality of protrusions , and is reflected by the plurality of protrusions toward the other end side of the reflecting member main body. lighting equipment . The reflecting member main body has a semi-parabolic shape with one end converging and the other end being open, and the lower surface side thereof is supported on the surface of the circuit board, and the LED light source is connected to the reflecting member on the circuit board. The lighting device according to claim 1, wherein the lighting device is arranged at a focal point of a paraboloid whose virtual thickness ta of the main body is ta=[(t1+t2)/2]. The lighting device according to claim 1, wherein the angular width of the plurality of protrusions in the circumferential direction is 0.5 to 5 degrees.

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