JP2013079498A - Backlight measure road sign board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that when the sun is located nearby an extension of a road sign board from a viewing point during reading of the road sign board on a vehicle during a travel, a sign board surface becomes dark owing to backlight and readability is too bad to maintain traffic safety, and uniform characters cannot be obtained at positions of ribs and a column by a method of improving the readability by making a hole and a slit in the center part of a character on the sign board and taking light in.SOLUTION: A photovoltaic power generation plate is fitted to the back of the sign board and electric power is generated. LEDs fitted to the signboard plate surface are made to emit light with the generated electric power to improve the visibility. The LEDs are fitted tracing the center position of white reflective sheet of characters and marks of the sign board to improve the readability. The photovoltaic power generation plate is set in the opposite direction from the sign board. A large current flows with intense backlight and the sign board plate surface illuminates intensely. A small current flows with weak backlight and weak illumination is obtained, so the LEDs automatically illuminate according to the intensity of the backlight to improve the visibility.

Description

  The present invention is an apparatus for improving visibility when a road sign board is backlit.

  The luminous efficiency of the LED has increased, and it has become possible to extract strong light with less power. This means that even with the power generated by a relatively small photovoltaic power generation board, it is possible to turn on a large number of LEDs, which can assist in the lack of illuminance of the display.

  The illumination angle of the LED is reduced to about 15 degrees, and light can reach far away. As a result, visibility from a distance has increased, and the use of road signs has expanded. If you use a lot of LEDs to display characters and marks, you can clearly see them from a distance, which is the best technique for road signs.

  The combination of the reflective sheet and LED is the best for the backlighting sign board. Electricity is generated by sunlight in the backlight, which turns on the LED and improves visibility. The stronger the backlight, the stronger the LED emits and raises the visibility of the sign board. The LED emits little light when the sun goes forward, but the visibility of the sign board is high. At night, the LED does not emit light at all, but the reflected light is generated by the headlight of the car to the reflective sheet, improving visibility. That is, the necessary light is generated when necessary and the purpose is achieved.

When embedding the LED to the reflective sheet, the area of LED 5mm diameter are removed, is the ratio of 0.4% when embedded one in about 40 cm ^2, visibility by the visibility or at night reflecting sheet of the forward light Without interfering with the nature, it emits light only in backlight and exhibits its function.

Japanese Patent Application No. 2008-284074 Japanese Patent Application No. 2002-66996

When reading a road sign while driving by car, if the sun is located near the extension line of the sign board from the viewing position, it will be backlit, the sign board surface will become dark and the legibility will become extremely bad, and it will be great for maintaining traffic safety It has become a challenge. As a countermeasure, there is a method of improving the legibility by introducing a light by making a hole or slit in the center of the character on the sign board.
However, it is difficult to match the position of the hole with the character when it overlaps with the position of the rib or the post fixed to the back surface.
Moreover, when the shadow of a rib or a support | pillar overlaps with the sunlight which inserts into a hole, it is difficult to maintain the point of a uniform light, and the legibility of a character and a mark cannot fully be improved.

Originally, an aluminum plate is used as the label plate, and a reflective sheet is pasted on the surface of the aluminum plate. As a countermeasure against backlight, there is a method of using a light-transmitting fiber sheet or a transparent acrylic plate instead of an aluminum plate, so that sunlight from the back reaches the sign plate surface, and the readability of the sign plate surface is improved even in backlight.
Even in this case, it is difficult to maintain uniform legibility due to the influence of the ribs on the back surface and the shadow of the support.

A photovoltaic power generation plate is attached to the back of the sign plate to generate electricity. The generated power emits an LED attached to the surface of the sign board to improve visibility.
The LED is mounted so that it follows the center position of the white reflective sheet portion of the sign and letters on the sign board, improving readability.

  As shown in FIG. 2, a letter box is used to attach the LED. A thin character box is attached to the sign board. If the box is not lit, leave it in the box. The LED is embedded in the center position of the letters and marks on the white reflective sheet displayed on the box, and this is turned on to improve the legibility of the other side of the sign even under backlight.

  The direction of the solar power generation plate is fixed so as to face the position where the sign plate is backlit. When the backlight is strong, a high current flows and the sign board surface emits light strongly. When the backlight is weak, a low current flows and weak light emission occurs. As if the solar power generation plate is an optical sensor, this means that light is emitted strongly when the backlight is strong, and weak light is emitted when the backlight is weak. Further, when the backlight changes to the forward light, the sign plate does not emit light and becomes a normal sign plate.

  The LED used is white and uses a radiation angle of 10 ° to 30 ° to ensure visibility from a long distance. Also, when attaching to the dial, the surface plate, LED and board are waterproofed and fixed with high fastness so as not to hinder long-term use.

  Naturally the LED does not emit light at night. As usual, the headlight of the car hits the reflective sheet affixed to the surface to ensure visibility. The area of the LED embedded in the reflective sheet is 0.4% or less and does not hinder visibility.

Figure 1 shows the overall picture of the sign board, sunlight, and the location of the viewer Figure 2 shows the position of the sign board and the text light emitting box. Fig. 3 shows a structure for attaching a light-emitting box to a sign board Figure 4 shows a light emitting box Fig. 5 is a cross-sectional view of a character luminous box Figure 6 is a cross-sectional view of the LED fixing part

  A thin light-emitting box with LEDs embedded in the display part of a normal road sign is attached, and the appearance is a normal sign board. Only when the signboard is backlit, the letters and marks on the signboard emit light to improve visibility. When the backlight is backlit, the back of the sign board is exposed to strong sunlight. The light is generated by that light and the LED emits light on the face of the sign board to improve visibility. When the position of the sun moves to the front of the sign board, the light becomes forward and the LED does not emit light, but the sign board surface becomes bright and visibility is enhanced. At night, the LED naturally does not emit light, but the headlight of the car hits the reflective sheet and the reflected light is generated, improving visibility.

  FIG. 1 shows the position of the sun, the photovoltaic power generation board, the sign board, and the position of the viewer. From the person who looks at the sign board, when the sun is located behind the sign board, it becomes backlit and the visibility of the sign board surface becomes worse. At this time, the visibility is improved by the light emission of the LED attached to the sign board surface.

  When the sun comes in front of the sign board, the light comes forward and the sign board surface becomes bright and the visibility is enhanced. At this time, the photovoltaic power generation board is exposed to weak light, so the amount of power generation is small, and the LED on the sign board does not emit light. In other words, the LED emits light only when there is strong backlight, improving visibility. When the backlight is weak, the amount of power generation is small, and the LED light emission automatically weakens, but the visibility is maintained as such.

  FIG. 2 is a drawing of a character portion that is difficult to read during backlighting in a sign board. The LED embedded in the white reflective sheet part of the character part emits light and displays the character. The stronger the backlight, the stronger the LED emits light, so you can read text even in backlight.

  FIG. 4 shows a character light emitting box. A reflective sheet with the same color as that of the sign board is pasted on the entire box, and a white reflective sheet cut into letters is pasted thereon. Install the LED heads at regular intervals along the center line of the letters. Install the wiring in the box so that all LEDs are lit. The character luminous box is fixed to the sign board.

  FIG. 5 is a cross-sectional view of the character light emitting box. The LED is fixed so as to penetrate the reflective sheet attached to the face plate of the box. Connect all LEDs with wiring and connect to an external power supply. A plate is provided on the back of the box, and the periphery is in close contact with waterproofing. The protruding part of the LED is also in close contact, blocking water and dust from the outside.

  FIG. 6 is a cross-sectional view of the protruding portion of the box front plate and the LED. Adhesion with waterproofing of the front panel and LED is important, and it has a great impact on the durability of the light emitting box, because road signs are used for a long time and at the same time it is difficult to repair easily if it breaks down during use. The utmost attention must be paid to its durability.

  The backlighting display board has many uses other than road signs. For example, a guide signboard or a guidance display board. Also, storage devices and conversions between power generation and lighting, such as equipment that starts when the sun reaches a certain position, equipment that starts from a certain darkness, or lighting equipment that lights only when there is sunlight There is a low-cost and simple lighting device that does not involve a machine.

1 Sun position (backlight)
2 Sun position (backlight)
3 Sun position (backlight)
4 Sun position (forward light)
5 Sun position (adjacent light)
6 Position on the sun (front light)
7 Photovoltaic power generation plate 8 Marking plate 9 Marking column 10 Direction seen by person 11 Character light emitting box 12 White reflective sheet 13 Colored reflective sheet 14 LED
15 Bolt hole 16 Printed circuit board 17 In-box wiring 18 External connection lead wire 19 Character box surface plate 20 Waterproof adhesive 21 Character box surface plate 22 Character box back plate

Claims (4)

  The combination of photovoltaic power generation and LED improves road sign readability. The light receiving surface of the photovoltaic power generation plate and the radiated light surface of the LED are opposite to each other. Backlit road sign board that improves the legibility of signs.   The LED is embedded in the center line of the white reflective sheet characters and marks displayed on the road signs, and the light lines that can distinguish the characters and marks by displaying the LEDs are displayed, so that the display contents can be read even under backlight. The road sign board for counter light according to 1 above.   When incorporating LEDs into letters and marks displayed on road signs, create a thin box-like wiring box that creates the gap necessary for LED wiring, paste a reflective sheet on the surface, and the LED light emitting part on the surface of the reflective sheet 2. The counter-light countermeasure sign board according to 1 above, wherein the thin light-emitting box is attached to a surface of a road sign board so that the light is emitted while being fixed to be exposed.   The electricity generated by solar power generation is not stored, but the LED mounted on the road sign board is lighted as it is to improve the legibility of the sign board, and the amount of light emitted from the LED changes in proportion to the amount of light received and when it is low. In other words, the backlight anti-labeling plate as described in 1 above, wherein the light emission of the LED is automatically changed to strong or weak according to the amount of received light.