Light-emitting device

The present invention relates to an improvement of a light guide used in a light emitting device. The present invention also relates to a light emitting device that decorates a mark with light. The present invention applies, for example, to automobile emblems.

Conventionally, various measures have been taken to improve the design and luxury of the appearance of vehicles and the like. As one of them, a mark (emblem) attached to the rear part of the body of an automobile is made to emit light or is illuminated. For example, Patent Document 1 and Patent Document 2 disclose a configuration in which a plurality of LEDs are arranged on the back surface side of a mark body made of a light-transmitting material, and the mark is emitted by extracting the LED light through the mark body.

<patcit num="1"><text>Jikkenhei 5-1597 Gazette</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 9-202178</text></patcit>

<p> In the above-mentioned conventional configuration, the visibility of the mark at night or the like is improved by displaying the mark by light emission. However, since the light of the LED, which is a point light source, is directly used for the light emission of the mark, the light emission mode of the mark has an extremely high brightness region corresponding to the position of the LED. In other words, the light emitting mode is accompanied by a feeling of particles, which is inferior in design and lacks a sense of quality. Therefore, it is an object of the present invention to provide a structure that is a mark having a high degree of design and a high sense of quality.</p>

<p> The present invention has the following configuration in order to achieve the above object. That is, the mark main body, the substrate arranged on the back surface side of the mark main body, the LED mounted on the surface of the substrate opposite to the mark main body, and the LED side of the substrate, the upper surface thereof. It is a light emitting device including a light introducing surface for introducing LED light, a light emitting surface on the side surface, and a light guide body having a plurality of rib-shaped protrusions on the back surface side.</p>

<p> In the above configuration, the LED light is introduced from the upper surface of the light guide body and finally taken out from the side surface of the light guide body. Most of the light introduced into the light guide body is reflected by the back surface of the light guide plate in the process of being taken out to the outside. Here, according to the above configuration, when the light emitting device is attached to an attachment portion such as a vehicle body, a rib-shaped protrusion provided on the back surface side of the light guide body can be used. That is, the light emitting device can be attached by connecting the tip of the rib-shaped protrusion and the attachment portion with double-sided tape, an adhesive, or the like. In this case, only the tip of the rib-shaped protrusion is directly involved in the connection, and the other region on the back surface of the light guide plate is in an open state. Therefore, in this region, the loss of light and the decrease in reflection efficiency due to the influence of the above connection are eliminated. As described above, since the loss of light on the back surface of the light guide plate is reduced and good reflection efficiency is obtained, an excellent light guide action is exhibited and the light utilization rate is also improved. As a result, light having low brightness unevenness and high brightness is emitted from the side surface of the light guide plate, and the mark body is indirectly illuminated from behind the mark body. In such a lighting state, not only the effect of improving the visibility of the mark by light can be obtained, but also a high effect of effect can be obtained, and the mark portion has a high design and a high-class feeling. .. Further, since the light is generated behind the mark body to give a three-dimensional effect as if the mark is raised, it is possible to produce unexpectedness in addition to the points of design and luxury. On the other hand, according to the above configuration, the portions involved in the connection with the mounting portion such as the vehicle body are discretely present in a rib shape, and can be connected over a wide range with a high coupling force. This makes it possible to firmly fix the light emitting device of the present invention to the mounting portion.</p>

Hereinafter, the components of the lighting device in the present invention will be described in detail. (Mark body) The light emitting device of the present invention is applied to a mark attached to, for example, a PC (personal computer) or a mobile phone, including an automobile emblem. Therefore, the shape of the mark body is not particularly limited. For example, it may be in the shape of a character or symbol representing a trademark such as a character or symbol representing the manufacturer of the product or the like in which it is used. As the material of the mark body, for example, a resin such as ABS resin, polypropylene resin, or polycarbonate resin can be adopted. The surfaces of these resins can be plated or the like.

(Board and LED) The board is placed on the back side of the mark body. The shape and size of the substrate are not particularly limited as long as they are not visible from the observation surface side (front surface side) of the mark body. For example, a shape similar to the plan view shape of the mark body and slightly smaller than the mark body can be adopted. In one embodiment of the present invention, a cover arranged between the mark body and the substrate is used. The cover is used for the purpose of waterproofing and / or dustproofing the substrate and the light guide described later.

In the present invention, the substrate surface on the opposite side of the mark body is the LED mounting surface. The type of LED is not particularly limited, and various types such as a cannonball type and an SMD type can be adopted. The number of LEDs to be used and their arrangement can be determined in consideration of the shape of the mark body, the required amount of light, and the like. When a plurality of LEDs are used, it is preferable to arrange the LEDs at appropriate intervals so that the light of the LEDs spreads over as wide a range as possible of the light guide body described later. This is because the uneven brightness of the emitted light can be reduced. Depending on the shape of the mark body, for example, LEDs can be arranged at approximately equal intervals. The emission color of the LED is not particularly limited, and an LED that generates light in a visible region such as white, red, green, and blue may be adopted in consideration of mark visibility, decorative effect, and the like. The LED lighting control may be performed in conjunction with other devices, or may be performed manually with a switch. For example, in the case of a mark attached to an automobile, the lighting control may be performed in conjunction with the lighting control of the side light.

(Light guide body) The light guide body is arranged on the LED side of the substrate. The material of the light guide is not particularly limited as long as it is light transmissive, and synthetic resins such as acrylic resin, polyethylene terephthalate (PET), polycarbonate resin, silicone resin, and epoxy resin, and inorganic materials such as glass can be used. it can. As for the shape of the light guide body, it is preferable that the plan view shape thereof is similar to the plan view shape of the mark body. In such a configuration, since the side surface (light emitting surface) of the light guide body is along the outer circumference of the mark main body, uniform light emission along the shape of the mark main body can be obtained behind the mark main body. As a result, the entire mark body is observed as if it were raised, and a high effect is produced. More preferably, the plan view shape of the light guide body is substantially the same as the plan view shape of the mark body. In such a configuration, the side surface (light emitting surface) of the light guide body is formed directly below the outer circumference of the mark body, so that higher brightness and uniform light emission can be obtained along the outer circumference of the mark body behind the mark body. Be done. As a result, the entire mark body is observed as if it is raised, and a higher effect is produced.

The upper surface of the light guide body faces the LED and serves as a light introduction surface for introducing the light of the LED. It is preferable to provide a recess at a position corresponding to the LED on the upper surface side (light introduction surface side) of the light guide body. According to such a configuration, the light guide body can be installed so as to wrap (include) the LED. As a result, substantially all the light of the LED is directed to the light guide. In this case, a light transmitting material can be filled between the LED and the light guide. According to such a configuration, the light of the LED can be satisfactorily introduced into the light guide body. As the material of the light transmissive material to be filled, it is preferable that the refractive index is close to or substantially the same as the refractive index of the light guide body. By doing so, the refraction and / or reflection of the LED light at the interface between the filled light-transmitting material and the light guide is reduced. Therefore, the LED light is better incident on the light guide. On the other hand, the LED and the light guide body may be integrally configured. In such a configuration, the gap between the LED and the light guide is substantially eliminated. As a result, the LED light can be introduced into the light guide more efficiently.

Ribbed protrusions are formed on the back surface side of the light guide. Therefore, the back surface of the light guide body is divided into a region where the protrusion is formed and a region where the protrusion is not formed. The light emitting device of the present invention is usually attached to a mounting portion such as an automobile body by utilizing the rib-shaped protrusion. Specifically, for example, the tip of the rib-shaped protrusion and the mounting portion are connected with double-sided tape, an adhesive, or the like. When the light emitting device is attached in this way, light cannot be efficiently reflected at the tip of the rib-shaped protrusion of the light guide, and light loss occurs. On the other hand, such light loss does not occur in the region where the rib-shaped protrusions are not formed on the surface of the light guide body. For this reason, it is preferable to increase the area of the region where the rib-shaped protrusions are not formed in order to increase the light reflection efficiency on the back surface side of the light guide. On the other hand, if the area of the region where the rib-shaped protrusions are formed is too small, a sufficient bonding force with the mounting portion may not be obtained. In consideration of the above, on the back surface side of the light guide body, the area of the region where the rib-shaped protrusion is formed (projection-forming region) is the region where the rib-shaped protrusion is not formed (protrusion non-forming region). It is preferably smaller than the area. It is preferable that the protrusion forming region is 1/20 to 1/2 of the protrusion non-forming region. More preferably, the protrusion-forming region is 1/20 to 1/3 of the non-protrusion region, and even more preferably 1/20 to 1/5.

It is preferable that the plurality of rib-shaped protrusions are formed over the entire back surface side of the light guide body. This is because when the light guide body is attached to the mounting portion by using the tip of the rib-shaped protrusion, the light guide body can be connected with a high coupling force over the entire light guide body. The shape of the protrusion is not particularly limited, and for example, the cross section may have a square shape, an arch shape, a wavy shape, a zigzag shape, or the like. The cross-sectional shape of the protrusion does not have to be constant in the height direction. For example, it may be a protrusion having a shape that tapers toward the tip. Further, the height of the protrusion is not particularly limited. It is not necessary for all the protrusions to have the same height, and for example, the height of each protrusion may be adjusted according to the shape of the mounting partner so as to obtain a good connecting force. The number of protrusions is also not particularly limited.

Hereinafter, the configuration of the light guide body will be further described with reference to the drawings. FIG. 1 is a perspective view showing an example of a light guide body in the present invention. FIG. 2 is a vertical sectional view of AA in FIG. As shown in the figure, in the light guide body 1, protrusions 2 are formed in a rib shape at substantially equal intervals on the back surface side 3 in the direction along the outer edge. The distance D between the protrusions 2 is larger than the thickness C of the protrusions (for example, about 3 times). In the light guide body 1, the total area of the region where the protrusion 2 is formed (that is, the total surface area of the tip of the protrusion 2) is smaller than the total area of the region where the protrusion 2 is not formed. By increasing the area of the non-protrusion region in this way, the loss of light due to the protrusion is reduced.

FIG. 3 shows another example of the light guide. In the light guide body 6 of this example, the second protrusion 8 is continuously formed along the outer edge of the light guide body 6 so as to be integrated with the rib-shaped protrusion 7. The rib-shaped protrusion 7 of this example has a through hole 9. The space formed by the rib-shaped protrusion and the second protrusion 8 communicates with each other through the through hole 9. Then, when the light guide body 6 is attached to the body of a car or the like, if a through hole is also provided in the attachment partner so that the space is not sealed, the light guide body 6 is separated from the attachment partner due to the expansion of the gas in the space. There is less risk of doing it. In addition, it is possible to prevent the generation of water vapor in the space. As a result, it is possible to suppress a decrease in reflectance on the back surface of the light guide body (region where the protrusion is not formed).

The light guide may contain a phosphor. A phosphor that emits a desired fluorescent color can be appropriately selected and used regardless of whether it is an organic type or an inorganic type as long as it fluoresces in response to the light of an LED. By using an organic phosphor, it is possible to obtain light having a clear fluorescent color. When an inorganic phosphor is used, it is possible to obtain fluorescent-colored light with a matte feeling.

Further, it is also possible to convert the emission color of the LED by using a colored transparent light guide body, forming a color conversion layer on the upper surface or the side surface of the light guide body, or the like. That is, according to such a configuration, it is possible to emit light of a color different from the original emission color of the LED.

The method of attaching or fixing the light guide body to the attachment partner such as the vehicle body is not particularly limited. For example, double-sided tape, adhesive and the like can be used. In the present invention, by forming rib-shaped protrusions on the back surface of the light guide body, light is reflected using the surface generated between the protrusions on the back surface, and reflection with the front surface of double-sided tape or the like is avoided. can do. Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 4 shows an exploded perspective view of the emblem light emitting device 10 which is an embodiment of the present invention. The emblem light emitting device 10 is attached to the rear part of the body of the automobile (for example, on the boot lid). As shown in FIG. 4, the emblem light emitting device 10 is provided with a cover 30, a substrate 40, and a light guide body (light guide plate) 50 arranged in this order on the back surface side of the mark main body 20. Reference numeral 60 is a double-sided tape. The plan view shape of the mark body 20 is a shape in which a part of two large and small ellipses is fused. The mark body 20 is made of ABS resin, and its observation surface (surface) is plated. The plan view shape of the substrate 40 is similar to the lower half of the plan view shape of the mark body 20, and is slightly smaller. The board 40 mounts four LED 41s on the surface opposite to the mark body 20 near the upper ends of the four protrusions. LED41 is an SMD type (surface mount type) white light emitting LED that is electrically connected to the light source of the side light of the vehicle (not shown) via a wiring pattern (not shown) on the board 40. ..

The shape of the cover 30 is substantially the same as the lower half of the plan view shape of the light guide plate 50. The cover 30 is arranged so as to cover the substrate 40 fitted in the light guide plate 50. On the other hand, the double-sided tape 60 has a plan view shape substantially the same as the plan view shape of the light guide plate 50. The back surface 53 of the light guide plate 50 is connected to the body of the automobile by the double-sided tape 60, and the cover 30, the substrate 40 and the light guide plate 50 are fixed to the body by screws 70 through the screw holes 31, 42 and 55. After that, the mark body 20 is fixed to the cover 30 with double-sided tape. The plan view shape of the light guide plate 50 is substantially the same as the plan view shape of the mark body 20. The light guide plate 50 is provided with two recesses (51, 52) on the upper surface. The recess 51 is formed along the substrate 40 so that the substrate 40 is arranged so as to be fitted on the upper surface of the light guide plate 50. The recess 52 is formed at a position facing the LED 41 on the upper surface of the light guide body 50. In this way, a two-stage recess is formed on the upper surface of the light guide plate 50. When the substrate 40 is fitted into the recess 51, the LED 41 enters the recess 52. In this way, the LED 41 is wrapped (included) in the light guide plate 50. On the other hand, the side surface 56 of the light guide plate 50 is textured. FIG. 5 is a plan view of the light guide plate 50 in FIG. 4 as viewed from the back surface side. FIG. 6 shows a vertical cross-sectional view of the EE in FIG. FIG. 7 shows a vertical sectional view of FF in FIG. As shown in FIG. 5, a plurality of rib-shaped protrusions 55 are formed on the back surface side of the light guide plate 50 over the entire surface. On the back surface side, the total area of the region 53 where the protrusions are not formed is larger than the total area of the region where the protrusions 55 are formed. Here, the region 53 is blasted so that the light introduced into the light guide plate 50 can be efficiently reflected and diffused. By forming the highly reflective and highly diffusive surface widely in this way, it is possible to reduce the loss of light from the back surface side of the light guide plate and to achieve a good light guide action.

With the light emitting device having the above configuration, the following light emitting modes can be obtained. As shown in FIGS. 6 and 7, the light of the LED 41 is introduced into the light guide plate 50 from the surface of the recess 52 of the light guide plate 50. A part of the introduced light reaches the inside of the rib-shaped protrusion 55, and the other part reaches the region 53 where the rib-shaped protrusion 55 is not formed. Here, the light that has traveled into the rib-shaped protrusion 55 is reflected, scattered, or absorbed by the side surface and the end face of the rib-shaped protrusion 55. Therefore, most of the light is not used for light emission from the light guide plate side surface 56. On the other hand, the light that reaches the region where the rib-shaped protrusion 55 is not formed is reflected and absorbed with high efficiency in the region. Therefore, the light is used for light emission from the light guide plate side surface 56 with a high utilization rate. In the configuration of this embodiment, since the region where the rib-shaped protrusion 55 is not formed is widened, the loss of light as described above in the rib-shaped protrusion 55 is reduced, and the region where the rib-shaped protrusion 55 is not formed is high. The light utilization rate can be obtained. Therefore, high-intensity light can be emitted from the side surface 56 of the light guide plate. On the other hand, since the side surface 56 of the light guide plate 50 is textured, the received light is diffusely emitted to the outside and diffusely reflected inside the light guide plate 50. Therefore, the light of the LED 41 incident on the light guide plate 50 is efficiently guided in the light guide plate 50 by the back surface 53, the upper surface 54, and the side surface 56 of the light guide plate 50, and is uniformly distributed in the light guide plate 50. Light with high brightness and uniform brightness and less uneven brightness is efficiently emitted from the side surface 56. A part of the light emitted from the side surface 56 irradiates the automobile body of the emblem light emitting device 10. As a result, the mark body 20 is indirectly illuminated.

As described above, in the emblem light emitting device 10, the mark main body 20 is indirectly illuminated by the high-luminance and low-luminance unevenness light emitted from the side surface 56 of the light guide plate 50 located behind the mark main body 20. As a result, a highly designed and luxurious light emitting mode is provided. Moreover, a surprising light emitting mode is provided in which a three-dimensional effect as if the mark is raised is obtained in a dark place such as at night. In addition, in the emblem light emitting device 10, since the LED 41 is included in the light guide plate 50, the thickness of the entire device can be reduced. As a result, the mark does not stand out excessively even in a bright place such as in the daytime.

Next, another embodiment of the present invention will be described. An exploded perspective view of the emblem light emitting device 100 is shown in FIG. FIG. 9 is a plan view of the light guide plate 200 used in the emblem light emitting device 100 as viewed from the back surface side. FIG. 10 shows a vertical sectional view of the GG in FIG. FIG. 11 shows a vertical sectional view of FF in FIG. In this example, the same members as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted. As shown in FIG. 9, a plurality of rib-shaped protrusions 250 are formed over the entire area along the outer edge direction on the back surface side of the light guide plate 200. On the other hand, on the outer edge portion, the protrusion 280 is continuously formed integrally with the protrusion 250. The rib-shaped protrusion 250 is provided with a through hole 290 in order to ensure ventilation with other spaces. Further, in order to ensure air permeability to the outside, a through hole 61 is provided between the body and the body via the double-sided tape 60 in a part of the space. As a result, the expansion of the space 270 due to the temperature rise of the outside air can be avoided. Further, when the emblem light emitting device 100 is used in rainy weather, it is possible to prevent rainwater from flowing into the light guide plate by providing a continuous protrusion 280 on the outer edge of the light guide plate. Therefore, it is suitable for use of the emblem light emitting device 100 in rainy weather. If the through hole 290 of the rib-shaped protrusion 250 and the through hole 61 between the body are not provided, the region composed of the protrusion 250, the outer edge protrusion 280, and the back surface 230 is both sides of the light guide plate 200. When connected to the tape 60, it forms a sealed space 270. Since this space 270 is in a sealed state, as the temperature rises, the gas trapped in the space 270 expands, and the light guide plate 200 and the double-sided tape 60 may peel off. Even in the above configuration, by providing the rib-shaped protrusions on the light guide plate, it is possible to obtain a high light utilization rate in the region where the rib-shaped protrusions are not formed while reducing the light loss in the rib-shaped protrusions. As a result, a highly-designed and high-class light emitting mode is provided as in the first embodiment.

Next, another embodiment of the present invention will be described. FIG. 12 shows an exploded perspective view of the small advertisement light emitting device 300. In the small advertisement light emitting device 300, the substrate 500 and the light guide plate 600 are arranged in this order on the back surface side of the advertisement main body 400, and are fixed to the mounting partner by the double-sided tape 700. The size and material of the advertisement body 400 are not particularly limited. On the board 500, four LED 510s are mounted on the surface opposite to the mark body 400 near the upper ends of the four protrusions. The LED 510 is electrically connected to the outside via a wiring pattern on the board 500. The double-sided tape 700 has a plan view shape substantially the same as the plan view shape of the light guide plate 600. The back surface of the light guide plate 600 and the mounting partner are connected by the double-sided tape 700, and the advertising body 400, the substrate 500, and the light guide plate 600 are fixed to the mounting partner by a predetermined method such as a screw.

The shape of the protrusion 650 on the back surface side of the light guide plate 600 will be described below. Since the light introduction / reflection / emission process of the light guide plate 600 is the same as that of the first embodiment, the description thereof will be omitted. The shape of the light guide plate 600 is a rectangular parallelepiped, and the central portion is hollow, and the substrate 500 is fitted in the hollow portion. Further, the outer peripheral portion of the light guide plate 600 has a recess 620 capable of accommodating the LED 510. FIG. 13 shows a plan view of the light guide plate 600 as viewed from the back surface side. A plurality of rib-shaped protrusions 650 are provided on the back surface side along the outer edge direction, and no protrusions on the outer edge are provided. When using the small advertisement light emitting device 300, it is not necessary to provide a protrusion on the outer edge unless there is a risk of rainwater or the like entering the light guide plate. Therefore, the shape of the light guide plate 600 is suitable for indoor use of small advertisements. Further, by eliminating the protrusions on the outer edge, the area of the back surface 630 can be increased, and the introduced light can be effectively reflected and emitted. Furthermore, by eliminating the protrusions on the outer edge, a sealed space is not created, and expansion of the space due to an increase in temperature can be avoided. Even in the above configuration, by providing the rib-shaped protrusions on the light guide plate, it is possible to obtain a high light utilization rate in the region where the rib-shaped protrusions are not formed while reducing the light loss in the rib-shaped protrusions. The effect is achieved, and as a result, a highly designed and luxurious light emitting mode is provided as in the other embodiments.

As shown in the above examples, the light guide plate of the present invention is used for lighting an emblem for a vehicle, and can be applied to various applications such as small advertisements.

The present invention is not limited to the embodiment of the above invention and the description of the examples. Various modifications are also included in the present invention as long as they do not deviate from the claims and can be easily conceived by those skilled in the art.

<figref num="1">FIG. 1 is an example of a perspective view of the light guide body 1.</figref><figref num="2">FIG. 2 is an AA vertical cross-sectional view of the light guide body 1 in FIG.</figref><figref num="3">FIG. 3 is another example of a perspective view of the light guide body 1 as viewed from the back surface side.</figref><figref num="4">FIG. 4 is an exploded perspective view of the emblem light emitting device 10 of the first embodiment.</figref><figref num="5">FIG. 5 is a plan view of the light guide plate 50 as viewed from the back surface side.</figref><figref num="6">FIG. 6 is a vertical cross-sectional view of the EE in FIG.</figref><figref num="7">FIG. 7 is a vertical cross-sectional view of FF in FIG.</figref><figref num="8">FIG. 8 is an exploded perspective view of the emblem light emitting device 100 of the second embodiment.</figref><figref num="9">FIG. 9 is a plan view of the light guide plate 200 in FIG.</figref><figref num="10">FIG. 10 is a vertical cross-sectional view of the GG in FIG.</figref><figref num="11">FIG. 11 is a vertical cross-sectional view of HH in FIG.</figref><figref num="12">FIG. 12 is an exploded perspective view of the small advertisement light emitting device 300 of the third embodiment.</figref><figref num="13">FIG. 13 is a plan view of the light guide plate 600 in FIG. 12 as viewed from the back surface side.</figref>

Code description

1 Light guide 2 250 650 Rib-shaped protrusion 8 280 Outer edge protrusion 9 290 Through hole 20 Mark body 400 Small advertisement 40 500 Board 41 510 LED