JP2005123357A - Surface-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface emitting device which can provide uniform surface emission with any of several kinds of LED lamps which emit different-colored light. <P>SOLUTION: The surface emitting device 1 is such that many light transmission particles 7, 7, 7, ... which have a refractive index different from that of a synthetic resin body 2 having a translucency are mixed into the synthetic resin body 2 to form a lamp support 2A, an LED lamp 3 is embedded in a lamp embedding hole 19 formed in the lamp support 2A, and a face 17 behind the LED lamp 3 of the lamp support 2A is covered by a light reflection layer 4. By adjusting a mixing ratio of the light transmission particles 7 into the synthetic resin body 2, the light transmittance of the lamp support 2A is set to not less than 16% nor more than 18%. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a surface light emitting device that emits light from an LED lamp from the front and side surfaces of a lamp support.

  Conventionally, this type of surface emitting device is shown in FIG. The surface light emitting device 51 shown in the figure includes a lamp support 52 molded into a square plate shape, a light reflecting layer 4 covering the rear surface 17 of the lamp support 52, and side surfaces 6 of the lamp support 52. The light reflecting layers 4A, 4A, 4A, and 4a covering the rear portions of 6, 6, and 6 and the LED lamp 3 embedded in the rear surface of the lamp support 52 are configured. The lamp support 52 is composed of a synthetic resin body 2 having translucency as a base material, and a large number of light transmitting particles 30, 30, 30,... (Polyethylene having a refractive index different from that of the synthetic resin body 2. Particles) and fine light reflecting particles (not shown) are mixed and dispersed in the synthetic resin body 2.

In the surface light emitting device 51, the light emitted from the LED lamp 3 is incident on the light transmitting particles 30, 30, 30,... Refracted or reflected on the surface of the particles, or the light reflecting particles. Reflect on the surface. On the other hand, the light traveling behind the lamp support 2 </ b> A is reflected by the light reflecting layer 4 or the light reflecting layer 4 </ b> A and directed toward the front part of the side surfaces 6, 6, 6, 6 or the front surface 5. In this way, the light emitted from the LED lamp 3 is repeatedly reflected and refracted in the light reflecting layers 4 and 4A and the lamp support 52, whereby the front part of the side surfaces 6, 6, 6 and 6 and the front surface 5 are reflected. It comes out from. An apparatus similar to the surface light emitting apparatus 51 is disclosed in, for example, Patent Document 1 below.
JP 11-219138 A

  By the way, the mixing ratio of the light transmitting particles 30 to the synthetic resin body 2 differs depending on the color light type of the LED lamp 3. For example, even if the mixing ratio of the light transmitting particles 30 that allows uniform surface emission with a blue LED lamp is replaced with a green LED lamp, the outer peripheral portion of the lamp support 2A may become dark, so-called uneven brightness may occur. . This is due to the fact that the light intensity varies depending on the color. Nevertheless, the present inventor has considered that there is a common mixing ratio with which uniform surface emission can be obtained for a plurality of types of LED lamps that emit different color lights.

  The present invention has been made in view of the above-described conventional problems, and provides a surface light emitting device capable of obtaining uniform surface light emission using any of a plurality of types of LED lamps that emit different colored light. With the goal.

  In order to achieve the above object, a surface light emitting device according to the present invention includes a light-transmitting synthetic resin body in which a large number of light transmitting particles having a refractive index different from that of the synthetic resin body are mixed. In a surface light emitting device in which an LED lamp is embedded in the lamp support and the surface behind the LED lamp of the lamp support is covered with a light reflecting layer, the mixing ratio of light transmitting particles to the synthetic resin body is adjusted. Thus, the light transmittance of the lamp support is set to 16% or more and 18% or less.

  Also, a lamp support is formed by mixing a light-transmitting synthetic resin body with a large number of light-transmitting particles having a refractive index different from that of the synthetic resin body, and an LED lamp is embedded in the lamp support. In the surface light emitting device in which the rear surface of the LED lamp of the support is covered with a light reflection layer, the corner edge of the front surface of the lamp support is notched to form a notch.

  Then, a lamp support is formed by mixing a light-transmitting synthetic resin body with a large number of light-transmitting particles having a refractive index different from that of the synthetic resin body, and an LED lamp is embedded in the lamp support. In a surface light emitting device formed by coating the back surface of an LED lamp with a light reflecting layer, a translucent thin plate is laminated on the front surface of the lamp support, and a corner edge of the front surface of the translucent thin plate is cut away. The notch is formed.

  According to the surface light emitting device of the present invention, the light transmittance of the lamp support is set to be 16% or more and 18% or less. Therefore, even when an LED lamp emitting any color light is used, the lamp support is supported. A uniform and beautiful surface luminescence was obtained from the whole body without spots.

  In addition, when the cut-out portion is formed by cutting out the corner edge of the front surface of the lamp support body, light is not absorbed and attenuated at the corner edge portion, unlike those having the corner edge portion as it is. The entire front surface, notch, and side surface of the body can emit light uniformly without uneven brightness.

  Then, when a translucent thin plate material is laminated on the front surface of the lamp support, and a notch is formed by cutting out the corner edge of the front surface of the translucent thin plate material, the light enters the translucent thin plate material from the lamp support. Part of the light is repeatedly reflected between the inner side of the front surface of the translucent thin plate material and the front surface of the lamp support, and is brought to the peripheral portion of the translucent thin plate material. Even if the cutout portion on the front surface of the lamp support according to the invention is not cut out as much as the cutout portion, the front surface of the translucent thin plate material, the cutout portion, and the entire side surface of the lamp support can emit light uniformly without uneven brightness. .

Embodiments of the present invention will be described with reference to the drawings. The embodiment described below is merely an example embodying the present invention, and does not limit the technical scope of the present invention. FIG. 1 is an external view of a surface light emitting device according to an embodiment of the present invention, and FIG. 2 is a side sectional view of the surface light emitting device. However, the same components as those of the conventional surface light emitting device shown in FIG. 8 are denoted by the same reference numerals and detailed description thereof may be omitted.
In each drawing, the surface light emitting device 1 according to this embodiment covers and affixes a lamp support 2A molded in a square plate shape with a thickness H of, for example, 15 mm, and a rear surface 17 of the lamp support 2A. The light reflecting layer 4 is attached, and an LED (light emitting diode) lamp 3 embedded in a lamp embedding hole 19 drilled forward from the rear surface 17 of the lamp support 2A. The light reflecting layer 4 is composed of, for example, a metal film deposition sheet having a thickness of 0.1 to 0.2 mm.

  The lamp support 2A has a light-transmitting synthetic resin body 2 such as an acrylate resin as a base material, and has a large number of light-transmitting particles 7, 7, .., And a large number of light reflecting particles 8, 8, 8,... That reflect light are mixed and dispersed in the synthetic resin body 2. .. And the light reflecting particles 8, 8, 8,... Are mixed with the synthetic resin body 2 in the monomer liquid stage. In this case, the light transmissive particles 7, 7, 7,... Are adjusted by the mixing ratio with respect to the synthetic resin body 2 so that light emitted from the LED lamp 3 and emitted from the front surface 5 of the lamp support 2A is adjusted. The light transmittance is configured to be 16% or more and 18% or less. The lamp support 2A thus obtained has a milky white appearance, and the presence of the embedded LED lamp 3 cannot be seen from the outside. Further, in this surface light emitting device 1, the corner edges 18, 18, 18, 18 where the front surface 5 and the side surfaces 6, 6, 6, 6 of the lamp support 2A intersect are angular.

  The LED lamp 3 has an LED chip 11 mounted in a reflection cup 10 of a lead frame 9, and the LED chip 11 is connected to another lead frame 12 by a bonding wire (not shown) and is made of epoxy resin or silicone resin. It is encapsulated in a resin mold 13. The resin mold 13 in front of the LED chip 11 is a hemispherical lens. Both lead frames 9 and 12 of the LED lamp 3 are connected to an external power source and a control circuit (both not shown) via lead wires 14 and 14.

In the surface light emitting device 1 configured as described above, when the LED chip 11 is energized, light having high directivity is emitted from the LED lamp 3. As shown in FIG. 3, the light emitted from the LED lamp 3 is reflected and dispersed by the light reflecting particles 8, 8, 8,..., And the light transmitting particles 7, 7, 7,. Then, it enters the granule and is refracted or reflected on the particle surface. Then, the light directed toward the rear of the lamp support 2 </ b> A is reflected by the light reflecting layer 4 and returned toward the front surface 5 and the side surfaces 6, 6, 6, 6. In this way, the light emitted from the LED lamp 3 is emitted from the front surface 5 and the side surfaces 6, 6, 6, 6 by repeating reflection and refraction in the light reflecting layer 4 and the lamp support 2A.
As described above, in the surface light emitting device 1, the light transmittance of the lamp support 2A is set to 16% or more and 18% or less. Therefore, even when the LED lamp 3 that emits any color light is used, the entire surface of the lamp support 2A. The LED lamp 3 could not be visually recognized from the outside.

By the way, since the surface light emitting device 1 does not include the side light reflecting layer 4A as in the conventional device 51, light is emitted from the entire side surfaces 6, 6, 6 and 6 of the lamp support 2A. Thus, even if the light emission from the front surface 5 is somewhat sacrificed, the light emission from the side surfaces 6, 6, 6 and 6 with the same light density as that of the front surface 5 is one of the characteristic configurations of the surface light emitting device 1. .
However, depending on the color of light emitted from the LED lamp 3, as shown in FIG. 4, due to a decrease in the amount of light emitted from the front surface 5, the corner edges 18, 18, 18 of the four sides of the lamp support 2A as viewed from the front surface. , 18 may be darker and darker in the area 15 and darker in the area 16 than the area 15.

  Therefore, the corner edges 18, 18, 18, and 18 of the front surface 5 of the lamp support 2A in the surface light emitting device 1 are notched, and R having a curvature radius R1 (for example, about 3 mm) as shown in FIGS. Parts (notches) 20, 20, 20, 20 were formed. In the surface light emitting device 1a manufactured in this way, the light that reaches the R portions 20, 20, 20, and 20 is emitted from the position, so that the corner edges 18, 18, 18, and 18 as in the surface light emitting device 1 are used. In the vicinity of, light is not absorbed and attenuated. Accordingly, the entire front surface 5, R portion 20, and side surface 6 of the lamp support 2A emit light uniformly without uneven brightness.

On the other hand, in the surface light emitting device 1b shown in FIG. 7, the translucent thin plate material 21 is laminated on the front surface 5 of the lamp support 2A with an adhesive, and the four corners of the front surface 23 of the translucent thin plate material 21 are cut out. R portions (notches) 22, 22, 22, 22 having a radius of curvature R2 (for example, about 0.8 mm) are formed. The translucent thin plate material 21 is made of a material different from that of the transparent synthetic resin body 2, for example, a 2 to 5 mm thick, translucent or slightly translucent ABS resin.
Therefore, part of the light incident on the translucent thin plate material 21 from the lamp support 2A is between the inside of the front surface 23 of the translucent thin plate material 21 and the boundary surface between the lamp support 2A and the translucent thin plate material 21. The reflection is repeated and proceeds as indicated by an arrow W in the figure, and is brought to the peripheral portion. Therefore, even if the curvature radius R2 of the R portion 22 is not as large as the curvature radius R1 in the surface light emitting device 1a described above, that is, even if the notch amount is small, the front surface 23 of the translucent thin plate material 21, the R portion 22, and the lamp The entire side surface 6 of the support 2A emits light uniformly without uneven brightness. In addition, since the radius of curvature R2 is relatively small, it is difficult to notice the presence of the R portions 22, 22, 22, and 22 when viewed from the front, giving an impression that is almost the same as the appearance of the surface light emitting device 1 described above. Further, the front surface 5 of the lamp support 2 </ b> A can be prevented from being damaged by the covering with the translucent thin plate material 21.

  Next, an embodiment corresponding to the surface light emitting device 1 shown in FIGS. 1 to 3 will be described. Acrylic acid ester monomer (Mitsubishi Rayon, Acrysilap SY-430, Polymer refractive index (D / 20 ° C.) 1.40) 100 parts by weight, Monomer curing agent (Mitsubishi Rayon, MEK peroxide) 1 part by weight, Hardening accelerator (manufactured by Mitsubishi Rayon, SY-A) 0.3 parts by weight, titanium dioxide powder (manufactured by Yoneyama Pharmaceutical Co., Ltd., light reflecting particles), 0.1 part by weight, and amorphous wet silica powder (manufactured by Tokuyama, Toxeal, refractive index (D / 20 ° C.) 1.46, light-transmitting particles 5 parts by weight are put in a sealed container for mixing, and stirred and mixed under normal temperature and normal pressure. Hold and vacuum degas the mixture. The defoamed mixture was poured into a mold and allowed to stand for 1 to 2 days under normal temperature and normal pressure to be cured. Thereby, a plate-like molded body having a thickness (H) of 15 mm was obtained. Then, a lamp embedding hole 19 having an inner diameter of 4 mm was drilled forward from the back side of the molded body. Furthermore, a light-reflective metal vapor-deposited film having a thickness of 0.1 to 0.2 mm was attached to the entire rear surface of the molded body as the light-reflecting layer 4 to obtain a lamp support 2A. In this embodiment, the LED lamp 3 that emits white light is used by being mounted in the lamp embedding hole 19 of the lamp support 2A.

An illuminance meter (manufactured by Minolta, model number: T-10) was installed 50 cm in front of the device of the above example in a dark room, and the illuminance of light emitted from the lamp support 2A when the LED lamp 3 was turned on was measured. The light transmittance (percentage) of the lamp support 2A was calculated by dividing the measured illuminance thus obtained by the blank illuminance measured at a position 50 cm ahead of the bare LED lamp 3. The blank illuminance is measured in advance for each LED lamp having a different emission color. The light transmittance at this time was 17.5%.
In this example apparatus, various LED lamps 3 that emit different colored lights (white, red, blue, green, emerald, light bulb, yellow, orange, lemon) were sequentially replaced and turned on. As a result, the apparatus of this embodiment shines uniformly and beautifully on the entire surface except for the rear surface 17 of the lamp support 2A, regardless of the LED lamp 3 that emits any color light, and the installation position of the LED lamp 3 is almost distinguishable. There wasn't.

Comparative Example 1
Except for using 3.5 parts by weight of amorphous wet silica powder (light-transmitting particles), a surface light-emitting device was manufactured in the same manner as in the above Example, and the illuminance was measured to calculate the light transmittance. The light transmittance was 18.6%. In the surface light emitting device according to the comparative example 1, when the LED lamp 3 that emits white light or yellow light was mounted, the light emitted uniformly and beautifully as in the example. However, when the LED lamp 3 that emits red light or blue light is used, the red light or blue light passes through the lamp support 2A so that the presence of the LED lamp 3, that is, the installation position thereof is known, and the original features of the apparatus. The problem of deteriorating the sense of luxury.

Comparative Example 2
Except for using 8 parts by weight of amorphous wet silica powder (light-transmitting particles), a surface light-emitting device was manufactured and the illuminance was measured in the same manner as in the above Example, and the light transmittance was calculated. The light transmittance was 15.8%. According to the surface light emitting device according to the comparative example 2, when the red or blue LED lamp 3 that gives a strong impression to human eyes is used, the light is emitted uniformly. However, when the yellow or green LED lamp 3 that is easy on human eyes is used, the brightness around the LED lamp 3 installation position on the lamp support 2A becomes brighter and the portion far from the LED lamp 3 becomes darker. It was.

In the above-described embodiment, amorphous wet silica powder is used as the light transmitting particle. However, for example, polyethylene powder or the like can be used as the light transmitting particle of the present invention.
Moreover, as a material which comprises the synthetic resin body of this invention, methacrylic ester resin etc. can also be used other than said acrylic ester resin, for example.
And the light reflection layer of this invention can be substituted with a white coating film etc. instead of said metal vapor deposition film film. Further, the notch portions provided at the corner edges of the lamp support or the semi-transparent thin plate material do not have to be curved like the R portions 20 and 22, and may be, for example, a planar shape.

1 is an external view of a surface light emitting device according to an embodiment of the present invention. It is side sectional drawing of the said surface emitting device. It is explanatory drawing which shows the advancing state of the light in the lamp | ramp support body of the said surface emitting device. It is a front view of the surface emitting device. It is an external view of the surface emitting device according to another embodiment of the present invention. It is a sectional side view of another surface emitting device. It is a sectional side view of the surface light-emitting device which concerns on other embodiment of this invention. It is a sectional side view of the conventional surface emitting device.

Explanation of symbols

1, 1a, 1b Surface light emitting device 2 Synthetic resin body 2A Lamp support 3 LED lamp 4 Light reflection layer 5 Front surface 7 Light transmitting particle body 17 Surface 18 Corner edge 19 Lamp embedding hole 20 R portion (notch portion)
21 Translucent thin plate material 22 R part (notch)
23 Front

Claims (3)

A lamp support is formed by mixing a light-transmitting synthetic resin body with a large number of light-transmitting particles having a refractive index different from that of the synthetic resin body, and an LED lamp is embedded in the lamp support. In the surface light emitting device formed by coating the rear surface of the LED lamp with a light reflecting layer, the mixing ratio of the light transmitting particles to the synthetic resin body is adjusted so that the light transmittance of the lamp support is 16% or more and 18% or less. A surface emitting device characterized by being set. A lamp support is formed by mixing a light-transmitting synthetic resin body with a large number of light-transmitting particles having a refractive index different from that of the synthetic resin body, and an LED lamp is embedded in the lamp support. A surface light emitting device in which the rear surface of the LED lamp is covered with a light reflecting layer, and a notched portion is formed by notching a corner edge of the front surface of the lamp support. A lamp support is formed by mixing a light-transmitting synthetic resin body with a large number of light-transmitting particles having a refractive index different from that of the synthetic resin body, and an LED lamp is embedded in the lamp support. In the surface light emitting device in which the rear surface of the LED lamp is coated with a light reflecting layer, a translucent thin plate material is laminated on the front surface of the lamp support, and a corner edge portion of the front surface of the translucent thin plate material is cut out. A surface light emitting device characterized in that is formed.