JP2010224876A - Clearly visible traffic sign board emitting light from whole surface - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure for emitting light from the whole surface of a traffic sign to make road guidance easily visible and legible in the night. <P>SOLUTION: A combination of an edge light 1 by a LED (light emitting diode) and a light guide plate 12 illuminates the whole surface of a sign board brightly. A translucent reflective sheet 5 is stuck to the surface of the light guide plate 2, and a colored translucent film 6, in which a character/sign is cut out, is stuck onto the translucent reflective sheet. When the edge light 1 is turned on, light is emitted from the whole surface of the sign board, and a contrast between the colored translucent film 6 part and the cut out character/sign makes the traffic sign bright and easily legible. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  It is an invention of a structure in which the entire surface of a road sign is illuminated to make it easy to see and read road guidance at night.

When the light of the edge light by LED comes out in front of the sign board, it is possible to manufacture a reflective sheet that does not prevent the light from being transmitted.

The practicality of edge lights has been increased by improving the brightness of LEDs, and it has become possible to brighten large areas of flat surfaces.

The technology that efficiently changes the direction of the light from the edge light and evenly removes it to the front of the signboard.

JP 2006-172843 A JP 2005-17573 A JP 2002-132192 A

Reflective sheet is usually pasted on the surface of the road sign. At night, it receives the headlight light from the car and reflects it back to the driver to obtain visibility. When the headlights are directed downward on the installed signboard, it is difficult for the light to reach and it is difficult to obtain reflected light, so that it is difficult to see the letters and symbols on the signboard.

There is a method of illuminating the surface of the sign board by providing a fluorescent lamp or the like on the upper part of the sign board. However, if the size of the sign board increases by 2 m or more, the light to the lower part is insufficient and it becomes difficult to read a part.

There is a method of obtaining brightness by providing a spotlight 20m to 30m in front of the sign board and illuminating the sign board surface. However, light leaks outside the sign board surface, and there may be complaints from the surroundings as light pollution.

The 0007 spotlight uses one or two metal halide lamps of about 150 W, which consumes a large amount of power, and a countermeasure is awaited.

  The combination of LED edge light and light guide plate emits light from the entire plate surface. Visibility can be maintained because it emits light even in high places where the vehicle's headlight does not reach.

The light obtained from the LED edge light and the light guide plate can be guided and taken out uniformly over the entire surface of the sign plate, so that the sign plate can achieve uniform brightness.

Since the edge light light passes through the inside of the plate surface, the light does not leak outside the necessary place. Therefore, no light pollution occurs.

The power consumption of the LED used as the light source is small, and the LED is about 10 W in half compared to 20 W per 1 m ^{2 of} the metal halide lamp, thus saving energy.

The road sign of the present invention can emit light on the entire large sign board with low power consumption by a combination of a light source using LED, an edge light and a light guide plate.
It helps to visually recognize characters and symbols that were difficult to see with conventional reflective sheets, and also helps traffic safety.
Even if the LED does not light due to a power failure or disconnection, the function of the reflective sheet is maintained, and although the visibility is somewhat reduced, the function as a road sign is maintained.

Front view of sign board Cross section of sign board Structure of translucent reflective sheet Structure of light redirecting part

  FIG. 1 is a front view of a road sign. Since the translucent reflective sheet 5 is not colored, it is bright white. The colored translucent film 6 is colored. With these contrasts, letters or symbols can be clearly identified.

In FIG. 2, the light of the LED 1 is guided to the plate surface by the light guide plate 2 and is uniformly emitted through the light diffusion plate 4. A translucent reflective sheet 5 is pasted on the surface of the light diffusing plate 4.
This means that the entire surface of the translucent reflective sheet 5 always emits light uniformly.

A colored translucent film 6 from which characters or symbols are cut is pasted on the surface of the translucent reflective sheet 5. The translucent reflective sheet 5 that is cut out and appears on the surface is white in its original brightness.
The colored translucent film 6 portion becomes colored light.

In the unlikely event that the LED does not turn on due to a power failure or disconnection, if the headlight light 15 of the car hits the translucent reflective sheet, the light becomes reflected light 16 and 17 to give the driver visibility.
That is, the minimum function as a road sign can be maintained.

The light from the LED edge lights 1 arranged in a thin line travels through the light guide plate 2. A part of the light dispersed in four directions by the light redirecting unit 3 is directed to the light diffusion plate 4, a part is directed to the reflection sheet 7, and the light directed to the reflection sheet 7 is reflected and is reflected on the opposite side of the light diffusion plate 4. Head in the direction. As a result, almost the entire amount of light is emitted through the light diffusion plate toward the front surface of the sign plate.

In FIG. 2, the light of the light diffusing plate 4 comes out to the surface through the translucent reflective sheet 5 stuck on the surface of the light diffusing plate 4.
The colored translucent film 6 affixed to the surface of the translucent reflective sheet 5 becomes colored light, and illuminates the entire surface of the sign board.
When the colored translucent film is cut out into characters or symbols, the translucent reflective sheet comes out on the surface. This part is bright white with no color.
With the contrast between this bright white color and colored light, the characters or symbols on the sign board can be clearly recognized.

FIG. 3 shows the structure of the translucent reflective sheet. Usually, the vehicle's headlight light is received from the surface and efficiently reflected in the direction of the incident light to maintain the driver's visibility.
The translucent reflective sheet can transmit light emitted from the light diffusion plate of the base material and extract it to the front surface of the sign plate.
For this reason, the base material 22 and the adhesive 23 of the translucent reflective sheet 5 are made translucent.
It has a function of transmitting light from the back side and reflecting incident light coming from the front side.

FIG. 4 shows the structure of the light conversion part. The light traveling through the light guide plate passes through and escapes to the opposite side if nothing is done.
(A) is a light conversion part of dot printing. (B) is a light conversion part with a V-shaped groove.
By applying dot printing or V-shaped grooves on one side of the light guide plate, the light traveling inside the light guide plate hits it and diffusely reflects it. The irregularly reflected light is partially directed toward the light diffusing plate, partially directed toward the opposite reflecting sheet, and the light directed toward the opposite side is reflected by the reflecting sheet toward the light diffusing plate.
Thus, almost all light can be efficiently directed to the light diffusing plate.

When viewed from the front of the sign board, the one near the light source of the edge light is brighter and the farther away is darker. Adjust the density of the light conversion part to make the entire sign plate shine evenly. The amount of light coming toward the light diffusing plate can be made uniform by making the side closer to the light source rougher and the side farther dense.
Therefore, the front surface of the sign plate can be kept uniform.

The LED edge light is a method in which light is introduced from the side of a thin plastic plate and extracted to the front.
It is thin, lightweight, easy to install, and can be used as a lighting fixture.
In addition, it consumes very little power and meets social needs for CO2 reduction.
The power supply used is as low as DC12V to DC24V, and it is easy to handle and safe. Therefore, the usage can be varied.

1. LED
2, light guide plate 3, light direction changing unit 4, light diffusing plate 5, translucent reflective sheet 6, colored translucent film 7, reflective sheet 8, metal frame 9, light toward the reflective sheet 10, diffuse reflection 11, light conversion Reflected light 12, Light from light converting part 13, Light that has passed through colored translucent film (colored)
14. Light passing through the translucent sheet (white)
15. Car headlight incident light 16. Car headlight reflected light (white)
17. Car headlight reflected light (colored)
18, light traveling in the light guide plate 19, adhesive portion 20 that connects the prism sheet and the base material, prism sheet 21, air layer 22, translucent reflective sheet base material 23, translucent adhesive 24, translucent reflective sheet Cross section 25, light 26 from the light guide plate, light coming out of the front of the sign plate

Claims (4)

A road sign board that improves visibility at night by illuminating the entire sign board with a side light incident device (hereinafter referred to as edge light) that arranges LEDs in a narrow row and enters the side of the light guide plate. The road sign board according to claim 1, wherein a reflective sheet having translucency is pasted on the entire surface of the sign board, and does not prevent edge light from coming out on the front face of the sign board. A colored translucent film obtained by cutting out characters or symbols is pasted on the surface of the translucent reflective sheet, and the character and the illuminance difference between the surface of the translucent reflective sheet in the cut-out portion and the colored translucent film surface. The road sign board according to claim 1, wherein the sign can be clearly identified. The translucent reflective sheet affixed to the entire surface of the sign board can reflect the headlight light of the car and maintain visibility even if the edge light is not lit. Road sign board.

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