JP6988372B2 - A light guide and an instrument equipped with the light guide - Google Patents

Description

The present invention relates to a light guide body and a device provided with the light guide body.

With the widespread use of small light sources including LEDs (Light Emitting Diodes), technologies have been developed to improve the aesthetic appearance by emitting light from the target parts of the instrument such as the switch box of a vehicle and the display of an instrument.

In this regard, Patent Document 1 discloses a light guide body that introduces light from a light source into a ring-shaped light guide body and emits light from the bottom surface of the light guide body.

However, in the light guide body described in Patent Document 1, the emitted light from the region near the light introduction portion is strong and the emitted light from the distant region is weak, so that the irradiation light becomes uneven and the appearance is poor. be.

Japanese Unexamined Patent Publication No. 2006-100009

The present invention has been made under the above-mentioned circumstances, and an object of the present invention is to provide a light guide body capable of easily achieving a good-looking lighting effect and a device provided with the light guide body.

The light guide body according to the present invention is a light guide body made of a light-transmitting material, and emits a light incident portion to which light from a light source is incident and a light incident to the light input portion to the outside. It is provided with a light emitting portion, an optical path portion provided on the outer peripheral portion of the light emitting portion to transmit light incident on the light input portion to the light emitting portion, and a single recess surrounding the outer edge portion of the optical path portion. The inner side wall of the single recess on the light emitting portion side functions as a reflecting surface that reflects the light incident on the light entering portion toward the light emitting portion, and the light entering portion has the light entering surface. It is characterized in that a plurality of recesses for diffusely reflecting the light incident on the portion are formed so as to bite into the optical path portion.

Further, the device according to the present invention emits light among a light guide body having the above configuration, a case for holding the light guide body made of a light-impermeable material, a light source, and the surface of the light guide body. It is characterized by comprising a panel made of a light-impermeable member, which is attached to at least a part of a portion other than the portion.

In the light guide body according to the present invention, a recess for diffusely reflecting the light incident on the light input portion is formed on the reflecting surface that reflects the incident light toward the light emitting portion. Therefore, unevenness of light is suppressed.

It is a figure which shows the appearance of the switch box which concerns on embodiment. It is a perspective view which includes the cross section which shows the structure of a switch box. It is a schematic diagram which shows the internal structure of a switch box. It is a perspective view which shows the appearance of a light guide body. It is a figure which shows the structure of a light guide body, (a) is a front view, (b) is a sectional view of A5-A6 of (a), (c) is a side view, (d) is a bottom view. It is sectional drawing which shows the structure of a groove part. It is sectional drawing which shows the structure of the recess in a groove portion. It is a schematic diagram which shows the path of light in an incident part. It is a schematic diagram which shows the path of light and the arrangement of the concave part in an optical path part. It is a conceptual diagram which shows an example of the reflection of light on a reflection surface. It is a conceptual diagram which shows an example of diffuse reflection of light in the reflection surface provided with a recess. It is a conceptual diagram which shows an example of diffuse reflection of light in the reflection surface provided with a recess. It is a figure which shows the appearance of the back surface of a light guide body. It is sectional drawing which shows the structure of the groove part in the modification of embodiment.

Hereinafter, the switch box 1 provided with the light guide according to the embodiment of the present invention will be described with reference to the drawings. When viewed from the front, the switch box 1 has an appearance as shown in FIG. The switch box 1 is a device mounted on a vehicle such as a construction machine.

A keyhole 60 into which an ignition key for activating the vehicle equipped with the switch box 1 is inserted is opened on the front surface of the switch box 1. The keyhole 60 is surrounded by a light emitting ring 270 having an annular light emitting surface. As will be described later, the light emitting ring 270 as the light emitting unit is a part of the light guide body 20 and emits light in a ring shape in response to the light emitted by the LED (Light Emitting Diode) bulb 40 which is a light source.

A panel 50 is arranged on the front surface of the switch box 1.

In the following, the horizontal direction of the switch box 1 will be described as the x-axis direction, the vertical direction will be described as the y-axis direction, and the depth direction will be described as the z-axis direction. It is assumed that the x-axis, y-axis, and z-axis are orthogonal to each other. The side of the switch box 1 where the keyhole 60 is exposed and operated by the user is the front surface (+ z direction).

FIG. 2 shows a perspective view including a cross section of the switch box 1 cut along the line A1-A2 in FIG. Further, FIG. 3 shows a conceptual diagram of the internal structure when cut along the A3-A4 line in FIG. As shown in FIGS. 2 and 3, the switch box 1 is provided with an upper case 10 on the front surface and side surfaces, a lower case 80 on the rear surface, and a middle case 30 inside.

The upper case 10 and the lower case 80 are members forming the outer shell of the switch box 1 formed of a light-impermeable material such as a colored acrylonitrile butadiene styrene resin (ABS resin), a polypyrene resin, or an aluminum alloy. be. The upper case 10 and the lower case 80 are fixed to each other by, for example, hooks or screws. As shown in FIGS. 2 and 3, an opening is provided in the front surface of the upper case 10. A recess 10a into which the light guide body 20, which is a flat plate-shaped member, can be inserted is provided on the side surface of the opening of the upper case 10.

A light guide body 20 which is a member on a flat plate is inserted into the recess 10a of the upper case 10. As a result, the light guide body 20 forms the front surface portion of the switch box 1. The light guide body 20 is formed of a material that transmits light, such as acrylic resin, and guides the light of the LED bulb 40 incident on the incident portion 210 to the periphery of the keyhole 60, which is a portion to be illuminated, and has the shape of the light emitting ring 270. Illuminate to. In the present embodiment, as will be described later, by devising a physical structure that guides the light to the light emitting ring 270, the light emission unevenness in the light emitting ring 270 is reduced.

The middle case 30 is a member that holds the internal structure of the switch box 1 and is formed of a light-impermeable material like the upper case 10 and the lower case 80. Specifically, as shown in FIGS. 2 and 3, the middle case 30 holds the LED bulb 40, which is a light source, at a portion corresponding to the incident portion 210 (for example, directly below the −z axis direction). The middle case 30 is fixed to the upper case 10 and the lower case 80 by screws, for example. Further, the middle case 30 holds the ignition switch at a position corresponding to the keyhole 60 inside the switch box 1.

The LED bulb 40 includes a light emitting element (LED) which is a light source that emits light under the control of a control unit (not shown). The LED bulb 40 illuminates the light emitting ring 270 via the optical path portion 220 of the light guide body 20 as described later. In the present embodiment, for cost reduction and space saving, the light source for incident light on the light guide body 20 in the switch box 1 is one LED bulb 40. Further, there is only one incident portion 210 in which the light of the LED bulb 40 is incident on the light guide body 20.

As shown in FIG. 3, the panel 50 is in close contact with the portion of the flat surface portion on the front surface side (+ z-axis side) of the light guide body 20 other than the light emitting ring 270. In the present embodiment, the panel 50 is attached to the front surface of the light guide body 20 (particularly, the portion of the optical path portion 220 described later) with an adhesive. The method of fixing the panel 50 to the front surface of the light guide body 20 is not limited to this, and may be fixed by using screws. Further, it may be fixed to the front surface of the light guide body 20 by inserting it into the recess 10a of the upper case 10 together with the light guide body 20.

The panel 50 is a flat plate-shaped member made of a light-impermeable material, and the portion of the front surface of the light guide body 20 other than the light-emitting ring 270 is shielded from light to emphasize the illumination in the light-emitting ring 270. Further, the panel 50 may be provided with a design including characters and marks indicating the function of the keyhole 60. Further, a configuration may be adopted in which the design portion of the panel 50 is capable of transmitting light and the design is illuminated by the light of the LED bulb 40.

As shown in FIG. 4, the light guide body 20 is a member having a plate shape as a whole. In the present embodiment, the light guide body 20 includes an incident portion 210, an optical path portion 220, a groove portion 230 provided on the peripheral edge of the optical path portion 220, and a light emitting ring 270. Further, the groove portion 230 has a function of defining the outer edge of the optical path portion 220, and a plurality of recesses 250a, 250b, 250c, ... Formed in a concave shape are provided on the inner wall surface of the groove portion 230. When the concave portion 250 is described by the shape of the groove portion 230, the groove portion 230 is convexly biting into the optical path portion 220. In other words, the optical path portion 220 is formed in a shape in which a plurality of convex portions from the groove portion 230 bite into the optical path portion 220. The recesses 250a, 250b, 250c, ... Form a hollow substantially semi-cylindrical shape in a plan view. When a plurality of recesses are not distinguished, it is simply referred to as a recess 250. The same applies hereinafter.

The light guide body 20 has the shape shown in FIG. 5, which is a three-view view. 5A is a front view of the light guide body 20, FIG. 5B is a sectional view taken along line A5-A6 of FIG. 5A, FIG. 5C is a side view, and FIG. 5D is a bottom view.

The incident portion 210 has a function of incident the light of the LED bulb 40, which is arranged at a position facing the LED bulb 40 (for example, a position adjacent to the LED valve 40) in the light guide body 20, into the optical path portion 220. It is a part. The incident portion 210 includes a reflecting surface 210a and a reflecting surface 210b, as will be described later.

The optical path portion 220 is a region of the light guide body 20 which is a light transmissive flat plate member, in which the inner circumference is surrounded by the light emitting ring 270 and the outer circumference is surrounded by the groove portion 230. In other words, the optical path portion 220 is located on the outer peripheral portion of the light emitting ring 270. Further, an annular groove portion 230 (and a reflection surface 240 provided on the inner wall of the groove portion 230, which will be described later) are continuously provided on the outer peripheral portion (outer edge portion) of the optical path portion 220.

The front surface (plate surface on the + z direction side) of the optical path portion 220 is a mirror-finished flat surface portion. Further, the back surface (plate surface on the −Z direction side) of the optical path portion 220 is a mirror-finished flat surface portion. In the state of being fixed to the upper case 10, the front surface and the rear surface of the optical path portion 220 are both substantially parallel to the xy plane, and the thickness of the optical path portion 220 is substantially the same in the entire area of the optical path portion 220. The front surface and the back surface of the optical path portion 220 function as a reflecting surface that reflects the light incident on the incident portion 210 and reflects the light incident on the optical path portion 220 in the extending direction.

The optical path portion 220 is integrally formed with the incident portion 210, and when the light of the LED bulb 40 is incident on the incident portion 210, the light is further provided so as to be incident on the optical path portion 220. Further, the optical path portion 220 and the light emitting ring 270 are integrally formed, and have a structure in which the light transmitted through the optical path portion 220 and reflected by the reflecting surface 240 can reach the light emitting ring 270.

The groove portion 230 is a recess provided continuously so as to surround the outer edge portion (outer peripheral portion) of the optical path portion 220. A reflective surface 240 is provided on the side wall inside the groove 230 (on the light emitting ring 270 side) to reflect the light incident on the incident 210 in the extending direction of the optical path 220 and in the direction of the light emitting ring 270. ing. The reflective surface 240 is mirror-treated to efficiently reflect light. Further, the reflective surface 240 is provided with a plurality of recesses 250a, recesses 250b, recesses 250c, .... The plurality of recesses 250 provided on the reflecting surface 240 diffusely reflect (diffuse and reflect) the light transmitted through the optical path portion 220, so that the light emitting ring 270 emits light evenly.

The light emitting ring 270 protrudes in the front surface (+ z-axis direction) with respect to the optical path portion 220 in the light guide body 20 formed of a light transmitting member, and is continuously curved in an arc shape along the extending direction (annular). The light emitting surface is formed.

On the back surface of the optical path portion 220, a reflecting surface 260 is provided along a portion corresponding to the light emitting ring 270 on the inner circumference. The reflecting surface 260 reflects the light that the reflecting surface 240 and the recess 250 have reached the inner peripheral portion of the optical path portion 220 forward (in the + z direction), so that the light reaches the light emitting surface of the light emitting ring 270. The light that reaches the light emitting ring 270 is emitted from the light emitting surface to the outside of the light guide body 20. In this way, the flat surface provided on the front surface of the light emitting ring 270 can be used as the light emitting surface.

The groove portion 230 has the structure shown in FIGS. 6 and 7. FIG. 6 is a cross-sectional view of the groove portion 230 in the portion where the recess 250 is not provided. FIG. 7 is a cross-sectional view of the groove portion 230 at the portion where the recess 250 is provided. As shown in FIG. 6, of the groove 230, the inner wall surface (the wall surface facing the light emitting ring 270) is provided with a mirror-treated reflective surface 240. As shown in FIG. 7, the recess 250 has a structure in which the reflective surface 240 is recessed in an arc shape toward the light emitting ring 270 side as compared with the portion other than the recess 250. With this structure, the recess 250 diffusely reflects the light incident on the incident portion 210 and transmitted along the extending direction of the optical path portion 220.

Next, the path of light from the LED bulb 40 to the light emitting ring 270 will be described. As shown in FIG. 8, the light of the LED bulb 40 is first incident on the incident portion 210 existing directly above the + z axis direction. Then, it is reflected in the extending direction of the optical path portion 220, which is an annular portion, by the reflecting surface 210a and the reflecting surface 210b included in the incident portion 210. Specifically, the reflecting surface 210a reflects the light emitted by the LED bulb 40 in the + x direction, and the reflecting surface 210b reflects the light emitted by the LED bulb 40 in the + y direction. In FIG. 8, the direction in which the light travels is indicated by a dotted arrow. Hereinafter, the same applies unless otherwise specified. In this way, in the incident portion 210, the light of the LED bulb 40 is incident on the optical path portion 220.

In this embodiment, the groove 230 extends along a path combining straight lines and curves, as shown in FIGS. 4 and 5. The shape of the groove portion 230 is designed based on structural analysis so that the light introduced from the incident portion 210 efficiently travels in the extending direction along the path of the optical path portion 220. Specifically, it is provided so that the ratio of the light transmitted through the optical path portion 220 and incident on the reflecting surface 240 as refracted light and emitted to the outside of the groove portion 230 is reduced. Further, the shape of the groove 230 is designed so that a predetermined ratio of the light that has reached the reflecting surface 240 is reflected toward the light emitting ring 270. With such a structure, the optical path portion 220 efficiently transmits the light incident on the incident portion 210 over the entire path surrounding the light emitting ring 270, and guides the light to the light emitting ring 270.

As shown in FIG. 9, the light incident on the optical path portion 220 by the incident portion 210 travels in the extending direction of the optical path portion 220 while being reflected by the front and back surfaces of the optical path portion 220 and the reflecting surface 240. ..

A part of the light incident on the optical path portion 220 in the incident portion 210 directly reaches the inner circumference of the optical path portion 220 (particularly in a portion close to the incident portion 210) and causes the light emitting ring 270 to emit light (dotted line arrow La in FIG. 9). ). On the other hand, other light reaches (incidents on) the reflecting surface 240 of the groove 230. Depending on the angle and location of the incident, a part of the light path portion 220 is further reflected in the extending direction (dotted line arrow Lb). Part of it is reflected in the direction toward the light emitting ring 270 (dotted arrow Lc). In particular, when the portion reaches the portion where the concave portion 250 is provided, the portion is diffusely reflected, so that the ratio of reflection in the direction toward the light emitting ring 270 is high (dotted line arrow Ld). Some of the light repeatedly reflects and travels in the direction in which the optical path portion 220 extends, and the keyhole 60 and light emission of the optical path portion 220 far from the incident portion 210 (the keyhole 60 and light emission on the optical path of the optical path portion 220 with respect to the incident portion 210). It reaches to the part corresponding to the back side bypassing the ring 270 (dotted arrow Le).

Since the optical path portion 220 guides the light incident from the incident portion 210 to the entire light emitting ring 270 having a continuous annular light emitting surface, the optical path extending around the light emitting ring 270 and the keyhole 60 when viewed from the incident portion 210. To prepare for. Therefore, as the distance from the incident portion 210 increases, the amount of light transmitted through the optical path portion 220 decreases. Further, the longer the light travels through the optical path portion 220, the smaller the difference in the direction of the vector in which the light travels tends to be. As a result, the amount of light that reaches the light emitting ring 270 tends to decrease as it travels along the optical path formed by the optical path portion 220 from the incident portion 210.

In particular, as in the present embodiment, in a configuration in which the entire annular light emitting ring 270 is illuminated by one light source and the optical path portion 220 provided on the outer periphery of the light emitting ring 270 is used as an optical path, the optical path portion 220 is the keyhole 60. In addition, since it is necessary to take a path for guiding light by bypassing the light emitting ring 270, uneven light emission is likely to occur. That is, in the light emitting ring 270, the portion having a short distance from the incident portion 210 emits light more strongly, and the portion having a long distance (because the light cannot reach unless it is strongly curved) becomes less intense. Therefore, in the present embodiment, a plurality of recesses 250 are provided in the reflecting surface 240 provided on the outer periphery of the optical path portion 220 to diffusely reflect the light, thereby reducing the light emission unevenness based on the distance from the incident portion 210.

In the present embodiment, as shown in FIG. 9, the number of recesses 250 provided in the reflective surface 240 is large in the outer peripheral portion of the optical path portion 220, which is farther from the portion closer to the incident portion 210 than the portion closer to the incident portion 210. Here, "large number" means the number of recesses 250 provided per unit length in the direction in which the outer peripheral portion of the optical path portion 220 extends (for example, per 1 cm in length in the tangential direction of the reflective surface 240). Indicates that there are many. In the present embodiment, a portion having a short distance from the incident portion 210 is expressed as a portion close to the incident portion 210, and a portion having a long distance from the incident portion 210 is expressed as being far from the incident portion 210. Further, the distance from the incident portion 210 may be defined, for example, by the length of the outer circumference of the optical path portion 220 in the extending direction. The same shall apply hereinafter.

Regarding the specific arrangement of the recess 250, based on the result of the structural analysis with the shapes of the optical path portion 220, the groove portion 230, and the light emitting ring 270 as variables, the inner peripheral side of the light emitting ring 270 where the amount of light emitted is low. The location and number of recesses 250 are determined so that more light is reflected towards.

For example, the region indicated by the double-headed arrow ARR in FIG. 9 has a longer distance through which the light incident from the incident portion 210 is transmitted in the optical path portion 220 than in the other regions. Further, since this region is hidden behind the keyhole 60 on the optical path when viewed from the incident portion 210, the degree of curvature of the optical path up to this portion is also large. Therefore, it is expected that the amount of light emitted from the light emitting ring 270 will decrease in the inner circumference of this portion. Therefore, more recesses 250 are provided in this region of the reflecting surface 240 than in other regions so that more light is reflected to the light emitting ring 270 side. For example, in the region of the double-headed arrow ARR, two recesses 250 are provided per 1 cm of the outer circumference of the optical path portion 220, while in the other regions, one recess 250 is provided per 1 cm of the outer circumference.

Further, in the present embodiment, in the reflective surface 240, the concave amount of the concave portion 250 (the maximum depth of the concave portion 250 in the reflective surface 240) is larger in the portion far from the incident portion 210 than in the portion close to the incident portion 210.

As shown in FIG. 10, the light incident on the incident portion 210 and transmitted through the optical path portion 220 has a low degree of diffuse reflection when it reaches the portion of the reflecting surface 240 where the recess 250 does not exist. In the portion where the recess 250 is not provided, the tangent line in the extending direction of the optical path portion 220 of the reflecting surface 240 coincides with the extending direction of the groove portion 230. Since the path of the groove 230 is designed so that the angle of the incident light is lowered so that the light emitted to the outside of the optical path 220 as the refracted light is reduced, the reflecting surface is provided in the portion where the recess 250 is not provided. The amount of light reflected by 240 and reaching the light emitting ring 270 located on the inner circumference of the optical path portion 220 is small.

FIG. 11 shows the state of diffused reflection in the recess 250 having a small recess, which is provided in a portion where the distance from the incident portion 210 is short. When the recess 250 is provided, diffuse reflection occurs due to the effect of the curved surface of the boundary surface even if the vector through which the light travels is the same. The light diffusely reflected by the curved surface of the recess 250 recessed on the inner peripheral side (light emitting ring 270 side) is reflected in the inner direction of the optical path portion 220 (direction of the light emitting ring 270) at a higher rate than in the case where the diffused reflection is not performed. That is, due to diffused reflection by the recess 250, the light introduced into the incident portion 210 and transmitted through the optical path portion 220 reaches the light emitting ring 270 at a higher rate than when the recess 250 is not provided.

As shown in FIG. 12, in a portion far from the incident portion 210, the concave portion 250 having a larger concave amount (larger curved surface is curved inward) than in the case illustrated in FIG. 11 is the reflective surface 240. It is provided in. Therefore, even if the portion where the light reaches is slightly displaced, the light is reflected more diffusely than when the concave amount is small. By increasing the degree of diffuse reflection, the ratio of light reflected in the light emitting ring 270 direction can be increased for each recess 250 even in a portion where the distance from the incident portion 210 is long. In this embodiment, the diameter R of the recesses of the plurality of recesses 250 is common regardless of the distance from the incident portion 210.

The specific concave amount of the concave portion 250 is the inner peripheral side of the light emitting ring 270 where the light emitting amount is low, based on the result of the structural analysis in which the shapes of the optical path portion 220, the groove portion 230, and the light emitting ring 270 are variables. Determine to reflect more light towards. For example, in the reflective surface 240, the concave portion 250 provided in the region indicated by the double-headed arrow ARR in FIG. 9 has a concave amount of 1 mm, while the other portion has a concave amount of 0.5 mm. do.

As described above, in the light emitting ring 270, the portion having a long distance from the incident portion 210 tends to emit less light than the portion having a short distance. Therefore, in the portion of the reflecting surface 240 that is far from the incident portion 210, the degree of diffuse reflection is increased by increasing the number of recesses 250 as compared with the portion having a short distance. Further, in the present embodiment, the portion of the reflective surface 240 having a long distance from the incident portion 210 has a longer distance from the incident portion 210 by increasing the concave amount of the concave portion 250 as compared with the portion having a short distance. The degree of diffuse reflection at the site is increased. Therefore, the switch box 1 using the light guide body 20 of the present embodiment has less unevenness in light emission.

In the present embodiment, at least a part of the back surface of the light guide body 20 is subjected to rough surface treatment, for example, grain treatment so that the region far from the incident portion 210 is composed of a rough surface rather than the near region. .. Specifically, as shown in FIG. 13, when the light guide body 20 is viewed from the back surface (-z direction), a part of the surface (surface in the −Z direction) (texture processing region 280) is textured. It has been applied and a rough surface has been formed. The textured region 280 includes a region of the reflecting surface 240 that is distant from the incident portion 210 by a predetermined condition, and includes the back surface of the optical path portion 220, the front surface of the optical path portion 220, and the reflecting surface 260.

The grain treatment causes diffuse reflection of light on the reflecting surface 260. Therefore, it is possible to reduce the light emission unevenness in the light emitting ring 270 by performing the embossing treatment on the reflecting surface 240 at a portion far from the incident portion 210 by a predetermined condition.

The range of the grain processing region 280 is determined based on a structural analysis in which the shapes of the optical path portion 220, the groove portion 230, the light emitting ring 270, the recess 250, and the like are variables.

In the light guide body 20 of the present embodiment, a plurality of recesses 250 for diffusely reflecting light are provided on the reflecting surface 240 formed on the outer peripheral portion of the optical path portion 220. Therefore, it is possible to illuminate the light emitting ring 270 with less unevenness. On the other hand, when the recess 250 is not provided, the portion of the light emitting ring 270 close to the incident portion 210 becomes brighter than the other portions, and light emission unevenness is strongly generated. As described above, according to the light guide body 20 of the present embodiment, it is possible to easily provide good-looking lighting. Further, the switch box 1 of the present embodiment has a good appearance because it illuminates the periphery of the keyhole 60 evenly. Further, since the portion of the front surface of the light guide body 20 other than the light emitting ring 270 is shielded from light by the panel 50, the illumination of the light emitting ring 270 stands out as compared with the other portions, and the appearance is better.

Further, in the present embodiment, the portion where the light of the light source is incident on the optical path portion 220 is limited to one location of the incident portion 210. Therefore, the cost is low as compared with the configuration in which light is incident from a plurality of incident portions 210. In addition, the degree of freedom in design is high. On the other hand, in a configuration in which light is incident from only one place, in order to make the entire light emitting ring 270 emit light, it is necessary to provide an optical path that bypasses the light emitting ring 270 in the optical path portion 220, so that light emission unevenness in the light emitting ring 270 occurs. Tends to grow. In the present embodiment, since a plurality of recesses 250 are provided in the reflective surface 240 formed on the outer peripheral portion of the optical path portion 220 to reduce the light emission unevenness in the light emitting ring 270, even a configuration in which light is incident from only one place looks good. Is small.

Further, in the light guide body 20 of the present embodiment, the number of recesses 250 formed on the reflecting surface 240 per unit length of the outer peripheral portion of the optical path portion 220 is located at a portion farther than the portion near the incident portion 210. many. Therefore, due to the diffused reflection by the concave portion 250, it is possible to increase the amount of light collected in the portion of the light emitting ring 270 where the light emission is originally small, and it is possible to reduce the light emission unevenness.

Further, the concave amount of the concave portion 250 formed on the reflective surface 240 is larger in the portion farther than the portion closer to the incident portion 210. Therefore, the amount of diffused reflection by the recess 250 can be increased at a portion farther than the portion near the incident portion 210, and the light can be collected at the portion of the light emitting ring 270 where the amount of light emission is originally small.

Further, the light guide body 20 of the present embodiment causes the light emitting ring 270, which is an annular portion, to emit light by the light incident on the incident portion 210. When the annular part with a large curve is made to emit light, the shape of the illumination is excellent and the aesthetic appearance is improved. However, as for the optical path from the light source, it is necessary to provide a curved optical path corresponding to the entire light emitting portion, so that light emission unevenness is likely to occur. According to the configuration of the present embodiment, the degree of light emission unevenness can be reduced even under such conditions due to diffused reflection by the recess 250.

Further, since the region of the reflecting surface 240 that is separated from the incident portion 210 by a predetermined condition is textured, at least a part of the region far from the incident portion 210 is composed of a rougher surface than the near region. .. Therefore, in addition to the diffused reflection by the concave portion 250, the occurrence of light emission unevenness can be reduced based on the diffused reflection by the rough surface (the portion subjected to the grain processing).

(Modification example)
Although the embodiment of the present invention has been described, the embodiment of the present invention is not limited to this, and various modifications are possible.

For example, in the above embodiment, the light emitting ring 270 has been described as an example as a portion that receives the light of the LED bulb 40 and emits light. However, the portion that receives the light of the light source and emits light is not limited to the ring shape, and can be applied when it has a light emitting surface that is continuous along the extending direction and curved by a predetermined degree or more. For example, the portion that receives the light of the LED bulb 40 as a light source and emits light may be an elliptical shape, a regular pentagonal shape, or an annular portion including a part of a straight line. It may be horseshoe-shaped. In this case, the optical path portion provided on the outer periphery of the light emitting portion is determined according to the shape of the light emitting portion. For example, if the light emitting portion is horseshoe-shaped, the shape of the optical path portion may be horseshoe-shaped according to the shape of the light emitting portion.

Further, the shape and path of the groove portion 230 can be arbitrarily deformed according to the structure of the optical path portion. For example, the path of the groove may be circular or elliptical. Alternatively, if the light emitting portion and the optical path portion are horseshoe-shaped, the groove portion may also be provided in a horseshoe shape on the outer periphery of the optical path portion.

Further, in the above embodiment, the groove portion 230 is a recess provided in the light guide body 20 which is a light transmitting member, and the outer wall surface is also formed by the light guide body 20. However, the structure of the outer peripheral portion of the optical path portion 220 can be replaced with another structure on the condition that the reflectance of light can be secured to a certain level or more. For example, as shown in FIG. 14, in the light guide body 21 of the modified example, a step may be formed on the outer peripheral edge of the optical path portion 220, and the reflection surface 240 may be provided on the side wall of the step on the outer peripheral edge. In this case, the groove portion 231 may be formed on the outer edge of the optical path portion 220 so that the upper case 11 is arranged with a slight space for the reflecting surface 240 provided on the step of the outer edge portion of the optical path portion 220. .. Regardless of whether the groove portion 230 is provided or the groove portion 231 is provided, a reflective surface is formed on the outer periphery of the optical path portion 220 to reflect the light incident on the incident portion 210 toward the light emitting ring 270.

Further, the number and arrangement of the recesses 250 to be installed on the reflective surface 240, and the amount of the recesses in that case are not limited to the above-described embodiment, and by reducing the unintended light emission unevenness of the portion that emits light by receiving the light of the light source. It can be changed arbitrarily as long as the aesthetics are improved.

An example is shown in which a recess 250 having a shape in which the groove portion 230 projects into the optical path portion 220 is formed on the reflection surface 240 in order to diffusely reflect the light toward the light emitting ring 270. This also corresponds to the fact that the reflective surface 240 on the outer edge of the optical path portion 220 projects into the groove portion 230. Further, the shape is not limited to the recess 250, and any shape may be used as long as the reflection surface 240 causes reflection in various directions and the degree of light diffusion increases as the distance from the incident point increases. For example, the reflecting surface 240 may be formed in a wavy shape in a plan view, and the size, period, curvature, etc. of the wave may be changed according to the position. In either case, since some uneven shape is formed, it is included in the technical scope of the present invention. Further, the reflective surface 240 was divided into a portion far from the incident portion 210 and a portion close to the incident portion 210, and more recesses 250 were provided in the portion far from the incident portion 210 as compared with the portion close to the incident portion 210. Further, in the distant portion, the concave amount of the concave portion 250 was made larger than that in the near portion. Not limited to this, the number and amount of recesses 250 may be continuously changed according to the change in the distance from the incident portion 210. That is, the mode in which the degree of diffuse reflection changes may be continuous or gradual with respect to the distance.

Further, although an example of performing rough surface treatment so that one region far from the incident portion 210 of the light guide body 20 is composed of a rougher surface than a closer region is shown, roughening treatment is performed on a plurality of locations. The roughness of the rough surface may be changed depending on the application or the position. For example, a region far from the incident portion 210 or a region with less light wraparound, or a region determined by a predetermined standard (a region that becomes darker than others if nothing is done) may be subjected to a stronger roughening treatment.

Further, the configuration of integrally forming the light guide body 20 including the optical path portion 220, the light emitting ring 270, and the incident portion 210 has been described. However, the present invention is not limited to this, and as long as a certain degree of uniformness and high light transmittance can be ensured, a configuration may be adopted in which any portion is connected by means such as an adhesive, adhesion, and fusion.

Further, in the above embodiment, the configuration in which the light guide body 20 is used for the switch box 1 has been described. However, the usage of the light guide body 20 is not limited to this, and it can be used for any lighting equipment that guides a light source such as an LED to illuminate a predetermined portion. For example, it may be applied to a light guide body used for illuminating the periphery of a panel of a speed measuring instrument of a vehicle.

The number of light sources and the number of incident portions are preferably one, but are not limited to this, and may be two or more. When light is incident on the optical path portion from a plurality of light sources and an incident portion, the effect of providing the recess 250 can be obtained when the positions of the incident portions are relatively close to each other.

Further, in the above embodiment, the light guide body 20 made of acrylic resin is used as the light guide body. However, the light guide body may be formed by using other known light-transmitting materials as long as the light-transmitting material can be sufficiently ensured. For example, as the light guide body, a configuration in which an insert glass made of light transmissive glass is inserted into the upper case 10 may be adopted.

Further, as a definition of perspective from the incident portion 210, the length of the outer circumference of the optical path portion 220 in the extending direction was used for the change in the number of recesses 250 and the amount of recesses. On the other hand, for the region to be textured, a straight line passing through the center of the light emitting ring 270 and the center of the incident portion 210 on the xy plane (the surface formed by the optical path portion 220 which is a plate member) and the incident portion passing through the textured region 280. The perspective is expressed using the straight line closest to 210 and the angle formed by. Not limited to this, regarding changes in the number or amount of recesses 250, a straight line passing through the center of the light emitting ring 270 and the center of the incident portion 210, and a straight line passing through the outer peripheral portion of the optical path portion 220 and the central portion of the light emitting ring 270. Perspective may be defined using the angle formed by. Further, the region to be textured may be determined based on the length of the outer peripheral portion of the optical path portion 220. Alternatively, another index that can define the perspective in the optical path portion 220 may be used, such as defining the perspective from the incident portion 210 by using the linear distance from the center of the incident portion 210.

In the above embodiment, the switch box 1 has three members, an upper case 10, a middle case 30, and a lower case 80, as case members. Not limited to this, two or three of the upper case 10, the middle case 30, and the lower case 80 may be integrally formed. Alternatively, the outer shell and the inside of the switch box 1 may be configured by four or more case members within a range in which the light guide body 20 and the LED bulb 40 can be held. In any case, it is desirable that the case member holding the light guide body 20 and the LED bulb 40 is made of a light-impermeable material (at least a material having a light transmission smaller than that of the light guide body 20) for light shielding. ..

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment. The present invention includes the inventions described in the claims and the equivalent scope thereof.

1 ... Switch boxes 10, 11 ... Upper case 10a ... Recessed portion 20 ... Light guide body 21 ... Light guide body 210 ... Incident portion 210a, 210b ... Reflective surface 220 ... Optical path portion 230 ... Groove portion 231 ... Groove portion 240 ... Reflective surface 250, 250a ~ 250c ... Recessed portion 260 ... Reflective surface 270 ... Light emitting ring 280 ... Texture processing area 30 ... Medium case 40 ... LED valve 50 ... Panel 60 ... Keyhole 80 ... Lower case

Claims (7)

It is a light guide body made of a light-transmitting material.
The light input part where the light from the light source is incident, and
A light emitting unit that emits light incident on the light input unit to the outside, and a light emitting unit.
An optical path portion provided on the outer peripheral portion of the light emitting portion to transmit light incident on the light input portion to the light emitting portion.
A single depression surrounding the outer edge of the optical path,
Equipped with
The inner side wall of the single recess on the light emitting portion side functions as a reflecting surface that reflects the light incident on the light entering portion toward the light emitting portion.
A plurality of recesses for diffusely reflecting the light incident on the light entering portion are formed on the reflecting surface so as to bite into the optical path portion.
Light guide body. Light is incident on the optical path portion from one of the incoming light portions.
The light guide according to claim 1. With respect to the unit length of the outer peripheral portion of the optical path portion, the number of the recesses formed on the reflective surface is larger in the portion farther than the portion near the light entrance portion.
The light guide according to claim 1 or 2. The concave amount of the concave portion formed on the reflective surface is larger at a portion farther than the portion near the light entering portion.
The light guide according to any one of claims 1 to 3. The light emitting portion is an annular portion.
The light guide according to any one of claims 1 to 4. Of the reflecting surface, at least a part of the region far from the light entering portion is composed of a rougher surface than the region near.
The light guide according to any one of claims 1 to 5. The light guide according to any one of claims 1 to 6 and the light guide body.
A case that holds the light guide body, which is made of a light-impermeable material, and a case that holds the light guide body.
Light source and
A panel formed of a light-impermeable member attached to at least a part of the surface of the light guide body other than the light emitting portion.
Equipment equipped with.

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