JP2011003499A - Lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To clearly display a character and figure of a display plate at high contrast while a light guide plate for irradiating light to the display plate is arranged on the surface of the display plate and light is irradiated to the display plate through the light guide plate.SOLUTION: A lighting system includes: a display plate 1 for displaying a character and figure; a light guide plate 2 comprising a transparent plate laminated to the surface of the display plate 1; and light emitting diodes 3 disposed in an outer peripheral surface of the light guide plate 2 and causing light to enter the light guide plate 2. The light guide plate 2 includes numerous light diffusion parts 4 for irradiating light transmitting through an inside of the light guide plate toward outside wherein the diffusion parts are formed in lines or dots. In the lighting system, light transmitting inside the light guide plate 2 while being reflected by total reflection is irradiated toward outside by the light diffusion parts 4 so as to irradiate the display plate 1, and light reflected from the display panel 1 is transmitted through the light guide plate 2 so as to be radiated toward outside. Further, the light guide plate 2 includes a light shielding layer 5 formed linearly or dotted on an outside of each light diffusion part 4, and light irradiated from each light diffusion part 4 toward outside is blocked by the light shielding layer 5.

Description

  The present invention mainly relates to a lighting device that irradiates light on the surface of a road sign or a signboard so that the surface can be easily seen.

  Signs and road signs that are visible at night have a built-in light source or irradiate light from the outside. Signboards and road signs that incorporate light sources such as fluorescent lamps and light bulbs have complicated structures and high manufacturing costs. Also, signboards and road signs that have already been installed cannot be remodeled into a structure that emits light so that they can be seen at night. A structure that irradiates with a light source from the outside is used for a road sign. However, this structure has a drawback in that the light source needs to be brightened and power consumption increases. In order to eliminate this drawback, an illuminating device has been developed in which a light guide plate is laminated on the surface of a road sign or the like, and light is irradiated on the surface of the road sign or the like with the light guide plate. (See Patent Document 1)

JP 2007-31365 A

  As shown in the cross-sectional view of FIG. 1, the lighting device described in Patent Document 1 includes a light guide plate 92 that irradiates light on the surface of a display plate 91 such as a road sign, and light is transmitted to the light guide plate 92 from an outer peripheral surface. A light source such as a light emitting diode 93 is provided. This illuminating device transmits light in the surface direction while totally reflecting light of the light emitting diode 93 on both surfaces of the light guide plate 92. An infinite number of light diffusion portions 94 are provided in order to radiate light that passes through the inside of the light guide plate 92 to the outside. The light diffusion portion 94 is a concave portion or a convex portion provided on the surface of the light guide plate 92 and radiates light to the outside without being totally reflected. Since the light guide plate 92 radiates light from the light diffusing unit 94 to the outside, the amount of light radiated to the outside can be controlled by the area and number of the light diffusing units 94. In order to make it easy to see the characters and figures provided on the display plate 91, the light diffusing portions 94 are arranged in the form of small dots, or are arranged in a grid or grid pattern.

  The lighting device described above turns off the light emitting diode when it is bright, and turns on the light emitting diode when it is dark at night. When it is bright, external light passes through the light guide plate, so that characters and figures on the display plate can be seen. When it is dark, the light emitting diode is turned on, the light of the light emitting diode is incident on the light guide plate, and this light is irradiated to the outside from the light diffusing portion to irradiate the display plate, so that it is easy to see characters and figures. The light diffusing unit illuminates the display plate by irradiating the back surface of the light guide plate with light from the light emitting diode. However, the light diffusing unit irradiates the surface of the light guide plate with the light of the light emitting diode. This light is irradiated outside without irradiating the display plate, reducing the contrast of the display plate and making it difficult to see characters and figures. Even in a bright state, external light incident on the light guide plate from the surface is reflected by the light diffusing portion and is irradiated on the surface side of the light guide plate. This light reduces the contrast of the display plate and makes it difficult to see characters and figures. In order to irradiate light uniformly to the display plate, the light diffusion portions are provided innumerably, or in a lattice shape or a grid shape. The infinite number of light diffusing portions have a drawback that light is irradiated on the surface side from innumerable points and lines on the surface of the display plate to reduce the contrast of the entire surface of the display plate and make it difficult to see characters and figures.

  The present invention has been developed for the purpose of solving this drawback. An important object of the present invention is to arrange a light guide plate for irradiating light on the display plate on the surface of the display plate, and to illuminate the display plate with the light guide plate while clearly displaying characters and figures on the display plate with high contrast. It is in providing the illuminating device which can be displayed on.

Means for Solving the Problems and Effects of the Invention

  The illumination device of the present invention includes a display plate 1 that displays characters and figures, a light guide plate 2 that is a transparent plate laminated on the surface of the display plate 1, and a light guide plate on the outer peripheral surface of the light guide plate 2. 2 is provided with a light emitting diode 3 that enters light. The light guide plate 2 is provided with an infinite number of light diffusing portions 4 that irradiate the light transmitted through the inside to the outside in the form of dots or lines. The illuminating device irradiates the display plate 1 with the light diffusing unit 4 irradiating the light transmitted through the light guide plate 2 while totally reflecting the light inside the light guide plate 2, and transmits the reflected light of the display plate 1 to the light guide plate 2. And radiate to the outside. Further, the light guide plate 2 is provided with a light blocking layer 5 in the form of dots or lines on the outside of the light diffusing unit 4, and the light blocking layer 5 blocks light emitted from the light diffusing unit 4 to the outside. ing.

  The lighting device described above has a feature that a light guide plate is disposed on the surface of the display plate, and characters and figures on the display plate can be clearly and clearly displayed with high contrast while displaying the display plate brightly and easily on the light guide plate. This is because the light of the light emitting diode is irradiated only from the light guide plate toward the display plate, and not on the surface side of the light guide plate. When light is irradiated from the light diffusing part to the surface side of the light guide plate, the light guide plate is provided with innumerable light diffusing parts. The figure cannot be displayed clearly. The present invention is characterized in that since the light diffusing unit emits light only toward the display plate, the display plate can be brightly irradiated with light emitted from the light emitting diode, and characters and figures can be clearly displayed with high contrast. . Moreover, since the light diffusing part is arranged in a dot shape or a line shape on the light guide plate, this does not make it difficult to see characters and figures on the display plate.

Lighting apparatus of the present invention, the light diffusing portion 4 as a point-shaped, one of the area of the light diffusing portion 4 may be 0.1 mm ² to 5 mm ^2.
Since this illuminating device has a small light diffusing portion, it does not make it difficult to see characters and figures on the display plate.

In the illumination device of the present invention, the light blocking layer 5 can be provided with the reflective layer 6 on the surface facing the light diffusion portion 4.
In addition to being able to irradiate the display plate with light transmitted through the inside of the light guide plate, the illuminating device can irradiate the display plate with the light transmitted through the light diffusing portion reflected by the reflective layer. For this reason, there is a feature that the display plate can be efficiently illuminated brightly with the light emitting diode, and the characters and figures on the display plate can be displayed with high contrast and easy to see while reducing the power consumption of the light emitting diode.

In the lighting device of the present invention, the area of the light blocking layer 5 can be set to be 1 to 10 times the area of the light diffusion portion 4.
This illuminating device has a feature that can more reliably prevent light diffused by the light diffusing portion from leaking to the front side of the light guide plate and display characters and figures with high contrast.

In the lighting device of the present invention, the light guide plate 2 can be provided with the light diffusion portion 4 on the outer surface.
Since this illuminating device is provided with a light diffusing portion on the outer surface of the light guide plate, the distance between the light diffusing portion and the display plate is widened, and the display plate is made uniform with light diffused by the light diffusing portion. There is a feature that can be irradiated.

In the lighting device of the present invention, the protrusion or recess 2A can be provided on the outer surface of the light guide plate 2 to form the light diffusion portion 4, and the light blocking layer 5 can be provided on the surface of the protrusion or recess 2A.
This illuminating device has a feature that the display plate can be uniformly irradiated by the light diffusion portion provided on the outer surface of the light guide plate.

In the illumination device of the present invention, the light diffusion portion 4 of the recess 2A is provided on the outer surface of the light guide plate 2, and the reflection layer 6 and the light blocking layer 5 are provided in the recess 2A. It is possible to make the same plane as the region not provided with.
This illuminating device can be provided with a reflective layer and a light blocking layer without positional deviation with respect to the light diffusion portion of the light guide plate, and the outer surface of the glazed light guide plate can be a smooth surface.

The lighting device of the present invention includes a solar cell panel 7 disposed on the back surface of the display plate 1, a secondary battery 11 that charges the generated power of the solar cell panel 7, and the light emitting diode 3 is connected to the secondary battery 11. The lighting circuit 8 which lights up can be provided.
Since this lighting device has a solar cell panel on the back, energy is saved by charging the secondary battery with the solar cell panel using bright external light and lighting the light emitting diode with the secondary battery when it gets dark. There is a feature that can be.

It is sectional drawing of the conventional road sign. 1 is a schematic exploded perspective view of a road sign according to an embodiment of the present invention. It is the schematic which shows the use condition of the daytime of the road sign concerning one Example of this invention. It is the schematic which shows the use condition at night of the road sign concerning one Example of this invention. It is a top view which shows the light-diffusion part of the light-guide plate of the road sign shown in FIG. It is a top view which shows another example of the light-diffusion part of a light-guide plate. It is a top view which shows another example of the light-diffusion part of a light-guide plate. It is an expanded sectional view of the light guide plate of the road sign shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below exemplifies a lighting device for embodying the technical idea of the present invention, and the present invention does not specify the lighting device as follows.

  Further, in this specification, in order to facilitate understanding of the scope of claims, numbers corresponding to the members shown in the examples are indicated in the “claims” and “means for solving problems” sections. It is added to the members. However, the members shown in the claims are not limited to the members in the embodiments.

  The illumination device shown in FIGS. 2 to 4 includes a display plate 1 that displays characters and figures, a light guide plate 2 of a transparent plate laminated on the surface of the display plate 1, and an outer peripheral surface of the light guide plate 2. And a light emitting diode 3 that makes light incident on the light guide plate 2. The light guide plate 2 is provided with innumerable light diffusing portions 4 that irradiate the light transmitted through the inside to the outside in a dotted or linear shape, and the light diffusing portion 4 transmits the light while totally reflecting the inside of the light guide plate 2. The display plate 1 is irradiated to the outside and the reflected light of the display plate 1 is transmitted through the light guide plate 2 and radiated to the outside to make it easy to see characters and figures brightly.

  The display plate 1 displays on the surface characters and figures that are optimal for the application. The display plate 1 used for a road sign is a sign for displaying a main sign such as a regulation sign, a support sign, a warning sign, a guide sign, and various auxiliary signs, or a road condition, a traffic condition, a road guide, and the like. However, the display plate is not limited to a road sign, and any display plate that can be used outdoors or indoors and can be easily seen by irradiating light can be used. The display plate 1 is provided with a display pattern 10 made up of characters and figures on the surface of a metal plate or plastic plate that does not transmit light.

The light guide plate 2 irradiates the display plate 1 when it is dark to make the display pattern 10 of characters or figures easy to see. The light guide plate 2 is a transparent plate or glass plate made of plastic such as acrylic resin and has a thickness of 2 mm to 8 mm. The light guide plate 2 transmits the light of the light emitting diode 3 incident from the outer periphery while totally reflecting on both sides, and irradiates the display plate 1 by irradiating the back surface with the totally reflected transmitted light by the light diffusion unit 4. To do. Therefore, the light guide plate 2 is provided with the light diffusing portion 4 so as to irradiate the back surface with light totally reflected and transmitted inside. As shown in the plan view of FIG. 5, the light diffusing section 4 is provided innumerably in the form of dots, or as shown in FIGS. 6 and 7, it is provided innumerably in the form of a grid or a grid. If the light diffusing portion 4 is large, it is conspicuous on the surface of the display plate 1 and makes it difficult to see characters and figures, so it is provided locally as a small area. Area of one of the light diffusing portion 4, for example as a 0.1 mm ² to 5 mm ^2, is made inconspicuous. The light guide plate 2 can control the brightness with which the display plate 1 is irradiated with the density at which the light diffusion portions 4 are provided. This is because the light diffused by the light diffusing unit 4 is applied to the display plate 1. The light diffusing unit 4 is provided at a low density in a region close to the light emitting diode 3 and at a high density as the distance from the light emitting diode 3 increases, so that the entire surface of the display plate 1 can be uniformly irradiated. This is because in the vicinity of the light emitting diode 3, the intensity of the light transmitted through the inside of the light guide plate 2 is strong, and the light becomes weaker as the distance from the light emitting diode 3 increases.

  The light diffusing unit 4 diffuses the transmitted light while totally reflecting the inside, and irradiates the light to the outside. It can also be formed by innumerable irregularities provided inside the light guide plate. This is because by providing the concave portion and the convex portion, the incident angle α of the light becomes smaller than the critical angle and is not totally reflected and is emitted to the outside.

  The light guide plate 2 can be provided with the light diffusion portion 4 by providing a concave portion, a convex portion, or a concave-convex surface on the outer surface facing the display plate 1. The light guide plate 2 of FIG. 8 is provided with a concave portion 2A on the outer surface to form a light diffusion portion 4.

  The light diffusing unit 4 provided on the light guide plate 2 diffuses the light transmitted through the light guide plate 2 and irradiates the light from the surface to the outside. In the illumination device of the present invention, a light blocking layer 5 is provided outside the light diffusion portion 4 in order to irradiate light only from the light guide plate 2 toward the display plate 1. Since the light blocking layer 5 blocks the light diffused by the light diffusing portion 4 from being irradiated on the outer surface, the point-shaped light diffusing portion 4 has a dot-like shape and a linear shape on the outside thereof. The light diffusing portion 4 is linearly provided outside thereof. The light blocking layer 5 is a coating or metal layer that does not transmit light, blocks light emitted from the light diffusion portion 4 to the outside, and does not irradiate the light from the light emitting diode 3 on the outer surface of the light guide plate 2. I have to.

  The area of the light blocking layer 5 is at least one times the area of the light diffusing section 4 in order to reliably prevent the light diffused by the light diffusing section 4 from being irradiated on the surface side of the light guide plate 2. 10 times or less. As the area of the light blocking layer 5 is made larger than that of the light diffusion portion 4, the light diffused by the light diffusion portion 4 can be reliably prevented from being irradiated on the surface side of the light guide plate 2. However, if the light blocking layer becomes large, it becomes difficult to see the characters and figures on the display plate, so the area is 10 times or less, preferably 5 times or less, more preferably 3 times or less the area of the light diffusion portion. However, if the area of the light blocking layer is too small, it is impossible to reliably prevent the light diffused by the light diffusing part from being irradiated on the surface of the light guide plate.

  The light guide plate 2 of FIG. 8 is provided with a reflective layer 6 for reflecting the light diffused by the light diffusing unit 4 and irradiated to the outside of the light guide plate 2 to irradiate the display plate 1 more effectively. The reflection layer 6 is provided on the surface of the light blocking layer 5 that faces the light diffusion portion 4. The reflective layer 6 is a coating film or a metal film formed by applying a white paint that efficiently reflects the light of the light emitting diode 3. The metal film can be used in both the reflective layer 6 and the light blocking layer 5. In addition, a coating film in which a white paint that reflects light is applied thickly can be used for both the reflective layer 6 and the light blocking layer 5.

  The light guide plate 2 of FIG. 8 is provided with a concave portion 2A on the outer surface to form a light diffusing portion 4, and a concave layer 2a of the light diffusing portion 4 is provided by laminating a reflective layer 6 and a light blocking layer 5 on the concave portion 2A. Is the same plane as the region where the light diffusion portion 4 is not provided. That is, the concave portion 2A is filled with the coating material constituting the reflective layer 6 and the light blocking layer 5, and the surface thereof is made smooth. Since this light guide plate 2 can make the entire outer surface smooth, it can prevent foreign matters such as dust from adhering to the surface. Further, in the structure in which the reflection layer 6 and the light blocking layer 5 are provided in the light diffusion portion 4 of the recess 2A, the recess 2A is filled with the coating material of the reflection layer 6 and the coating material of the light blocking layer 5, so that the reflection layer 6 And the light blocking layer 5 can be provided so as not to be displaced with respect to the light diffusion portion 4.

  The light emitting diode 3 is on the outer periphery of the light guide plate 2 and irradiates light toward the inside of the light guide plate 2. The light emitting diode 3 irradiates the light condensed so that the light radiated to the inside of the light guide plate 2 can be uniformly transmitted to the entire surface while being efficiently totally reflected inside the light guide plate 2. A plurality of the light emitting diodes 3 are arranged at a predetermined interval and arranged on one side of the outer peripheral surface of the light guide plate 2 or provided on a plurality of sides so that light is uniformly incident on the inside of the light guide plate 2. Light incident on the light guide plate 2 from the light emitting diode 3 is diffused by the light diffusion portion 4 of the light guide plate 2 and is emitted toward the display plate 1. The light emitting diode 3 can increase the power consumption and illuminate the display plate 1 brightly. The power consumption of the light emitting diode 3 is adjusted by the power consumption of one light emitting diode 3 and the number of light emitting diodes 3. The power consumption of the light emitting diode 3 is set to an optimum value depending on the size of the display plate 1, and is set to, for example, 5 W to 100 W, preferably 10 W to 50 W.

  3 and 4, the solar cell panel 7 is disposed on the back surface of the display plate 1. This lighting device is most suitable for road signs installed outdoors. This is because the secondary battery 11 can be charged in the daytime with the solar battery panel 7 disposed on the back surface. The solar cell panel 7 is connected to the secondary battery 11 and charges the secondary battery 11 with the generated power. The secondary battery 11 lights the light emitting diode 3 with the charged electric power. In order to light the light emitting diode 3, the lighting device includes a lighting circuit 8.

  The secondary battery 11 is a rechargeable battery such as a lithium ion battery, a nickel metal hydride battery, or a nickel cadmium battery that is charged with the power generated by the solar battery panel 7. The secondary battery 11 has a capacity capable of charging power for 1 to 10 days generated by the solar battery panel 7. For example, the charging capacity of the secondary battery 11 connected to the solar battery panel 7 with the daily generated power of 300 Wh is 300 Wh to 3 kWh. When the secondary battery 11 is charged with power generated by the solar battery panel 7 and is fully charged, the light emitting diode 3 with power consumption of 10 W can be lit for 30 to 300 hours. The secondary battery 11 is charged via a charging circuit 9 connected between the solar battery panel 7. When the charging circuit 9 detects that the secondary battery 11 is fully charged, the charging circuit 9 stops charging the secondary battery 11. However, the charging circuit is not necessarily required. For example, a secondary battery such as a nickel metal hydride battery or a nickel cadmium battery can be always charged with the output of the solar battery panel. This road sign is set by optimizing the power generated by the solar panel, the capacity of the secondary battery, and the power consumption of the light-emitting diode, so that the deterioration due to the overcharge of the secondary battery without going through the charging circuit. Can be prevented.

  The lighting circuit 8 detects the brightness of the outside with a light sensor or determines nighttime with a 24-hour timer, and turns on the light emitting diode 3 with the secondary battery 11 at nighttime. A road sign that sufficiently increases the power generation capacity of the solar battery panel 7 and the charging capacity of the secondary battery 11 can turn on the light-emitting diode 3 at night using only the power of the secondary battery 11. However, the lighting circuit 8 may be provided with a commercial power supply circuit (not shown) for detecting that the secondary battery 11 is completely discharged and lighting the light emitting diode 3 with the commercial power supply 12. This road sign can be used with the commercial power source 12 at night even in a state where the amount of sunlight is small and the secondary battery 11 cannot be fully charged, or in a state where the secondary battery 11 is deteriorated and its capacity is reduced. The light emitting diode 3 can be turned on reliably. Even in the state where the light-emitting diode 3 is turned on by the commercial power supply 12, the lighting circuit 8 first turns on the light-emitting diode 3 by the secondary battery 11, and after the secondary battery 11 is completely discharged, The lighting is switched from the secondary battery 11 to the commercial power source 12.

DESCRIPTION OF SYMBOLS 1 ... Display plate 2 ... Light guide plate 2A ... Concave part
2a ... concave surface 3 ... light emitting diode 4 ... light diffusion part 5 ... light blocking layer 6 ... reflective layer 7 ... solar cell panel 8 ... lighting circuit 9 ... charging circuit 10 ... display pattern 11 ... secondary battery 12 ... commercial power supply 91 ... Display plate 92 ... Light guide plate 93 ... Light emitting diode 94 ... Light diffusion part

Claims (8)

A display plate (1) displaying characters and figures, a light guide plate (2) of a transparent plate laminated on the surface of the display plate (1), and an outer peripheral surface of the light guide plate (2) A light emitting diode (3) for entering light into the light plate (2),
The light guide plate (2) is provided with innumerable light diffusing portions (4) for irradiating the light transmitted through the inside to the outside in a dotted or linear shape,
The light diffusing unit (4) irradiates the display plate (1) by irradiating the light transmitted through the light guide plate (2) while totally reflecting the light, and guides the reflected light of the display plate (1). An illumination device configured to transmit to the light plate (2) and radiate to the outside,
The light guide plate (2) is provided with a light blocking layer (5) in the form of dots or lines on the outside of the light diffusion portion (4), and the light blocking layer (5) from the light diffusion portion (4). An illumination device configured to block light emitted to the outside. ^{2. The} lighting device according to claim 1, wherein the light diffusing portion (4) has a dot shape, and an area of one light diffusing portion (4) is 0.1 mm ^{2 to} 5 mm ² .   The lighting device according to claim 1, wherein the light blocking layer (5) is provided with a reflective layer (6) on a surface facing the light diffusion portion (4).   The lighting device according to claim 1, wherein the area of the light blocking layer (5) is not less than 1 and not more than 10 times the area of the light diffusion portion (4).   The illuminating device according to claim 1, wherein the light guide plate (2) is provided with a light diffusion portion (4) on an outer surface.   A projection or recess (2A) is provided on the outer surface of the light guide plate (2) to form a light diffusion portion (4), and a light blocking layer (5) is provided on the surface of the projection or recess (2A). 1. A lighting device according to 1.   A light diffusion part (4) of a recess (2A) is provided on the outer surface of the light guide plate (2), and a reflection layer (6) and a light blocking layer (5) are provided in the recess (2A). The lighting device according to claim 6, wherein the surface (2a) is flush with a region where the light diffusion portion (4) is not provided.   A solar battery panel (7) disposed on the back surface of the display plate (1), a secondary battery (11) for charging the generated power of the solar battery panel (7), and the secondary battery (11) The lighting device according to claim 1, further comprising a lighting circuit (8) for lighting the light emitting diode (3).

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