JP2010225341A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily achieve a light-condensing action without causing an increase in the number of components and an increase in manufacturing man-hours. <P>SOLUTION: A light-emitting device (10) is configured as follows. A long translucent solid member (14) is housed inside a long translucent tube (11). The inner peripheral face of the tube (11) and a portion of the outer peripheral face of the solid member (14) are brought into contact with each other. The outer peripheral face, on the side opposite to the contact face with the tube (11), of the solid member (14) is brought into contact with a light-emitting face (17a) of an LED light source (17). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device, and more particularly, to a light emitting device configured by arranging a large number of LED light sources in a line.

  LED light sources are being used to replace existing light sources in various fields because they have less heat generation than existing light sources such as incandescent light bulbs and have excellent power saving performance. For example, in signboard lighting, a light emitting device configured by arranging a large number of LED light sources in a line instead of a neon tube has been used. Hereinafter, the term “light-emitting device” refers to this type of device, that is, “a plurality of LED light sources arranged in a line”.

  An LED light source is a semiconductor element (Light Emitting Diode) having a mechanism in which when a DC voltage is applied between electrodes (anode and cathode), current flows and light is emitted. The light emission colors are red, blue, and green, which are the three primary colors of light. By combining these, light of all colors including white can be created.

  As described above, the LED light source has features such as power saving and various emission colors, but has a drawback that the light amount per light source is small and it is darker than existing light sources such as an incandescent light bulb.

  For example, those disclosed in Patent Documents 1 and 2 below are known as conventional techniques that take measures against this defect. Hereinafter, the one described in Patent Document 1 is referred to as Conventional Technology A, and the one described in Patent Document 2 is referred to as Conventional Technology B.

In the prior art A, a plurality of LEDs are soldered to a printed circuit board, a convex lens is arranged in front of some of the LEDs, the optical axes of the corresponding LEDs and convex lenses are aligned, and a transparent flat surface is placed in front of the other LEDs. Place the face plate. The transparent flat plate is made of plastic, and the aforementioned convex lens is formed integrally therewith.
In the prior art B, an LED unit in which a plurality of light emitting diodes are arranged on a substrate is housed in a light-transmitting globe, and a lens unit that narrows the diffusion angle of the light emitting diodes corresponding to the front of the light emitting diodes is arranged. Set up.

FIGS. 5A and 5B are conceptual diagrams of countermeasures of the prior art, in which FIG. 5A is the one before the countermeasure and FIG. 5B is the one after the countermeasure. First, as shown to (a), in the LED light source 1, since the emitted light has a tendency to diffuse, the light 2 emitted from the LED light source 1 has a certain angular spread. Hereinafter, this spread angle is referred to as a light emission angle (or simply a radiation angle) α.
In the prior arts A and B described above, so-called condensing is performed by using a lens to narrow the radiation angle. (B) is a conceptual diagram thereof. The light 2 from the LED light source 1 is bent by a lens 3 provided on the optical path. However, since this lens 3 is a convex lens when viewed from the LED light source 1 side, it is condensed, and eventually before the countermeasure is taken. A radiation angle β narrower than the radiation angle α can be obtained.

JP 2000-36203 A JP 2005-63782 A

  However, since both of the prior arts A and B are provided with an independent lens for each LED light source, first, when the number of LED light sources is N, N lenses are also required. There is a drawback that the number of parts increases, and secondly, there is a disadvantage that the optical axis alignment for each LED light source is necessary and the number of manufacturing steps increases.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a light emitting device that can easily obtain a light condensing function without causing an increase in the number of parts or an increase in the number of manufacturing steps.

According to the first aspect of the present invention, a long solid member having translucency is accommodated in a long tube having translucency, and the inner peripheral surface of the tube and the solid member are accommodated. Light emission characterized in that a part of the outer peripheral surface is brought into contact with and the outer peripheral surface of the solid member opposite to the contact surface with the tube is brought into contact with the light emitting surface of the LED light source. Device.
The invention according to claim 2 is the light emitting device according to claim 1, wherein the tube has a cross section of any one of a cylindrical shape, a square shape, a substantially “Ω” character shape, or a horseshoe shape. is there.
The invention according to claim 3 is the light emitting device according to claim 1, wherein the solid member has a cross section of any one of a columnar shape, a prismatic shape, or a semicircular shape.
The invention according to claim 4 is the light emitting device according to claim 1, wherein the tube and the solid member are made of a translucent material.
The invention according to claim 5 is the light emitting device according to claim 1, wherein the tube and the solid member are made of a flexible material.

  ADVANTAGE OF THE INVENTION According to this invention, the light-emitting device which can obtain a condensing effect easily can be provided, without causing the increase in a number of parts and the increase in a manufacturing man-hour.

It is a block diagram of embodiment. It is operation | movement explanatory drawing of embodiment. It is a figure which shows the modification of embodiment. It is a figure which shows the further modification of embodiment. It is the conceptual diagram which compared the radiation angle of the existing light source and the LED light source.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of the embodiment. In this figure, (a) is an external view of the light emitting device 10, and this light emitting device 10 includes a cylindrical long tube 11, two caps 12 and 13 that respectively close both ends of the tube 11, and A long cylindrical solid member 14, a substrate 15, and a spacer 16 are provided in the tube 11.

  A large number of LED light sources 17 are arranged on the substrate 15, and these LED light sources 17 emit light upon receiving power from a cable 18 connected to the substrate 15 through one cap 12. The cable 19 pulled out from the other cap 13 supplies power to the connected light emitting device (the same as the illustrated light emitting device 10) when the illustrated light emitting device 10 is connected in a daisy chain. It is for the purpose, and it is unnecessary when not connecting rosary.

  Both the tube 11 and the solid member 14 are made of a material that easily transmits light, such as transparent plastic or glass, and a large number of tubes 11 and the solid member 14 are arranged on the substrate 15 through the tube 11 and the solid member 14. The light from the LED light source 17 is emitted to the outside. In addition to translucency, the solid member 14 is required to have a characteristic for giving a required refraction to transmitted light. Refraction refers to changing the direction of travel at the boundary of different media where waves such as light and sound waves are different, and this phenomenon is explained by the fact that the speed of wave travel varies depending on the medium. Assume that there are medium a and medium b, a and b are different from each other, and medium a and medium b are in contact with each other at a certain flat boundary surface. When a wave (wave) passes through the boundary surface from a to b, the traveling direction of the wave (incident angle to refraction angle) changes at the boundary surface. Snell's law holds between the incident angle and the refraction angle. In order to obtain such a refractive action of light, the material of the solid member 14 has a high refractive index (a ratio in which the straight traveling wave changes the angle of the traveling direction at the boundary of different media), for example, It is desirable to use acrylic or polycarbonate.

  FIG. 2B is a cross-sectional view in the longitudinal direction of the light emitting device 10, and FIG. In these drawings, a spacer 16, a substrate 15, an LED light source 17 and a solid member 14 are stacked inside the tube 11 from the bottom to the top of the drawing.

  The spacer 16 is for suppressing “backlash” of the substrate 15, the LED light source 17, and the solid member 14, and may be made of an elastic material such as rubber or sponge that can be compressed and deformed.

  The light emitting surface 17a of the LED light source 17 mounted on the substrate 15 is in contact with the outer peripheral surface of the solid member 14 (near the lower portion of the outer peripheral surface in the drawing). It is in contact with the inner surface of the tube 11.

Next, the operation will be described.
FIG. 2 is an operation explanatory diagram of the embodiment. The light from the LED light source 17 is a “bright spot” emitted from one point of the light emitting surface 17a. In short, the LED light source 17 is a point light source. The light emitted from the point light source diffuses at a predetermined spread angle (see the radiation angle α in FIG. 5) as described at the beginning, but the light travels in the optical axis direction (vertical direction of the light emitting surface 17a). P1 passes through the inside of the solid member 14 in contact with the light emitting surface 17a of the LED light source 17 from the bottom to the top of the drawing, and further from the inner surface to the outer surface of the tube 11 in contact with the upper portion of the outer peripheral surface of the solid member 14. And finally radiated to the outside world. During this time, P1 goes straight and is not bent by refraction. This is because P1 is incident on the solid member 14 and the tube 11 in the vertical direction.

  On the other hand, light other than P1, for example, P2, P3, and P4, is bent as shown in the figure by receiving a required refraction action. Explaining this in detail, P2, P3, and P4 emitted from the light emitting surface 17a of the LED light source 17 first pass through the interface K1 between the light emitting surface 17a of the LED light source 17 and the solid member 14, and then the solid surface. It passes through an interface K2 between the member 14 and air, an interface K3 between the air and the tube 11, and finally an interface K4 between the tube 11 and the air.

  Here, since the solid member 14 and air, and the tube 11 and air are different media, the light incident obliquely on the boundary between them is bent by the light refraction action. Further, since the light emitting surface 17a of the LED light source 17 and the material of the solid member 14 are also different (that is, the medium is different), the light refraction action can be obtained also at this interface.

  For simplicity of explanation, if the light emitting surface 17a of the LED light source 17 and the material of the solid member 14 are the same (that is, the same medium), the light refraction action is obtained at the interfaces K2-4. It will be. At these interfaces K2 to K4, first, at K2, light travels from the high refractive index solid member 14 to the low refractive index air, so the light path when not passing through this interface K2 (dashed arrow line) The optical path is bent toward the obtuse angle side. Next, in K3, the light travels from the low refractive index air to the high refractive index tube 11, so that the optical path is bent to the obtuse angle side in this case as well. Finally, at K4, the light travels from the high refractive index tube 11 to the low refractive index air. In this case as well, the optical path is bent to the obtuse angle side.

  Therefore, due to the refracting action of the light at each of these interfaces K1 to K4, these interfaces K1 to K1 with respect to the radiation angle α of the light path (see the dashed arrow line) when not passing through these interfaces K1 to K4. The radiation angle β of the light path when passing through K4 can be reduced, and so-called condensing can be performed.

  As described above, according to the present embodiment, since the radiation angle of the light from the LED light source 17 is reduced from the original α to β, so-called light collection can be performed. In the embodiment, even if the LED light source 17 has a small amount of light, the first effect that the brightness can be increased by collecting light can be obtained.

  In addition, in the present embodiment, the first effect can be obtained only by combining the cylindrical tube 11 made of a material that easily transmits light and the columnar solid member 14. The second effect of not incurring the disadvantages of the prior art A and B described at the beginning is also obtained.

  In other words, the prior art A and B require a large number of lenses, and the alignment of the optical axes for each lens is necessary, leading to an increase in the number of parts and an increase in the number of manufacturing steps. In this embodiment, regardless of the number of the LED light sources 17, it is sufficient to prepare one tube 11 and one solid member 14 each having an arbitrary length, so that the number of parts does not increase. Furthermore, it is only necessary to bring the outer peripheral surface of the solid member 14 inserted into the tube 11 into contact with the light emitting surface 17a of the LED light source 17, and alignment of the optical axis can be made unnecessary.

  The technique of the present invention is not limited to the above embodiment. It goes without saying that various modifications and developments are included within the scope of the idea, and for example, the following may be adopted.

First, in the above embodiment, the material of the tube 11 and the solid member 14 is “easy to transmit light”, that is, a material having translucency. A measure of translucency is light transmittance. From the viewpoint of light transmission loss, it is desirable that this transmittance be as high as possible, that is, transparent. This is because the light 18 from the LED light source 17 can be used as illumination light without loss, and the power efficiency can be improved accordingly.
However, for example, in order to obtain a wide light emission angle, one or both of the material of the tube 11 and the solid member 14 has a low light transmittance (for example, a cloudy translucent material). It is better to use plastic. This is because the light 18 from the LED light source 17 is further diffused and a wide radiation angle is obtained.
Thus, the transmittance of the material of the tube 11 and the solid member 14 should be appropriately selected depending on whether importance is placed on suppression of light transmission loss or on obtaining a wider radiation angle. It is a matter, and it is not limited to either one here.

Next, the light-emitting device that is the subject of the present invention is “configured by arranging a large number of LED light sources in a line”, and such light-emitting devices are provided to users in various lengths. However, particularly long ones are often considered to be “flexible” because they are easy to bend from the viewpoint of ease of installation in the field.
In order to give this configuration flexibility, at least the tube 11, the solid member 14, the substrate 15, and the spacer 16 may be flexible.

Next, in the above-described embodiment, the “cylindrical” tube 11 and the “columnar” solid member 14 are used. However, the present invention is not limited to this. For example, the following may be used.
FIG. 3 is a diagram illustrating a modification of the embodiment. In this figure, the tube 21 shown in (a) replaces the tube 11 of the above embodiment, and the difference from the tube 11 of the above embodiment is the internal shape of the tube 21. That is, the tube 21 of this modification has a first space 22 for housing the solid member 14 therein, recesses 23 and 24 for holding both ends of the substrate 15, and a spacer 16. It differs from the tube 11 of the said embodiment by having the 2nd space 25. FIG.
According to the modification shown in (a), the solid member 14, the substrate 15, and the spacer 16 can be reliably accommodated in the tube 21 without rattling, and the LED light source 17 when a disturbance such as vibration is input. Deviation from the outer peripheral surface of the solid member 14 can be eliminated. In this modification, since the backlash can be eliminated, the spacer 16 can be dispensed with.
Moreover, the aspect which does not provide the 1st space 22 may be sufficient. In this case, the inner peripheral surface 21a of the portion of the tube 21 where the first space 22 is present is the same as the tube 11 of the above-described embodiment, as indicated by a broken line in FIG.

  Next, the solid members 26 and 27 shown in (b) and (c) both replace the solid member 14 of the above-described embodiment, and the difference from the solid member 14 of the above-described embodiment is as follows. , In its cross-sectional shape. That is, the solid member 26 shown in (b) has a rectangular cross section, and the solid member 27 shown in (c) has a semicircular cross section. Although it is different from the member 14, even if it is the solid members 26 and 27 of the rectangular cross section or the semicircular cross section, the same effect (condensing effect) as the solid member 14 of the above embodiment can be obtained. The solid member 14 may be selected as appropriate and used in place of the solid member 14.

  FIG. 4 is a diagram illustrating a further modification of the embodiment. In this figure, (a) to (d) all show a replacement of the tube 11 of the above-described embodiment, (a) is a tube 28 having a square-shaped cross section, and (b) is an “Ω” character. A tube 29 having a cross-sectional shape similar to that shown in FIG. 5C is a tube 30 having a horseshoe-shaped cross section, and FIG. Any shape of the tubes 28, 29, 30, 31 can accommodate the solid member 14, the substrate 15 and the spacer 16 in the inside thereof without any trouble. What is necessary is just to select suitably in consideration of performance, cost, etc.

DESCRIPTION OF SYMBOLS 10 Light-emitting device 11 Tube 14 Solid member 17 LED light source 17a Light emission surface 21 Tube 26 Solid member 27 Solid member 28 Tube 29 Tube 30 Tube 31 Tube

Claims (5)

Inside the long tube having translucency, this accommodates a long solid member that also has translucency,
While contacting the inner peripheral surface of the tube and a part of the outer peripheral surface of the solid member,
A light-emitting device, wherein the solid member has an outer peripheral surface opposite to a contact surface with the tube in contact with a light-emitting surface of an LED light source.   The light-emitting device according to claim 1, wherein the tube has a cross section of any one of a cylindrical shape, a square shape, a substantially “Ω” character shape, or a horseshoe shape.   The light-emitting device according to claim 1, wherein the solid member has a cross section of a columnar shape, a prismatic shape, or a semicircular shape.   The light emitting device according to claim 1, wherein the tube and the solid member are made of a translucent material.   The light emitting device according to claim 1, wherein the tube and the solid member are made of a flexible material.

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