KR20130010333A - Power saving road sign board using a minority of led and light guide plate - Google Patents

Abstract

PURPOSE: A low-power variable road sign board using a small amount of LEDs and a light guide plate is provided to improve visibility by controlling the brightness of an LED module and a light guide plate. CONSTITUTION: A low-power variable road sign board using a small amount of LEDs and a light guide plate comprises a light guide plate(10), an LED module(20), side backlights(30), and a controller(90). The light guide plate is used as a base plate of the road sign board. The LED module is located at the rear surface of the light guide plate and comprises multiple LEDs for displaying traffic information. The side backlights are formed on one or more side surfaces of the light guide plate and emit light to the light guide plate. The controller selectively controls the lighting of the LEDs according to the traffic information displayed on the LED module. [Reference numerals] (10) Light guide plate; (20) LED module; (30) Side backlight; (40) Reflective plate; (50) Blocking plate; (60) Illuminance sensor; (70) Fog sensor; (80) Memory; (90) Controller

Description

Low power variable road sign using few LEDs and light guide plate {POWER SAVING ROAD SIGN BOARD USING A MINORITY OF LED AND LIGHT GUIDE PLATE}

The present invention relates to road signs, and more particularly, to road signs displaying variable traffic information.

Road signs are installed on the road for the convenience and safety of the driver, and are divided into direction signs, milestones, landmarks, and route signs. Road signs commonly seen around us include milestones installed at intersections of automobile roads as shown in FIG. 1.

Road signs require good visibility for driver safety. Therefore, most road signs are constructed by adhering a high brightness reflector in multiple layers on a prominent green or blue aluminum plate, and are designed to increase visibility by scattering light irradiated onto the road signs from street lights or automobile headlights.

However, since the reflector reflects light only when there is a light source, in the place where the street light is broken at night or where the street light is not installed, the above-mentioned reflection alone does not ensure sufficient visibility, and easily replaces the displayed traffic information. There is an inconvenience that cannot be done.

In order to improve this, road signs using LED backlights have been proposed. However, road signs using LED backlights only increase visibility by using the backlight on the back of a predetermined letter sign, and do not provide traffic information that changes every moment. That is, when an unexpected road situation such as an accident or flooding occurs, or when a road is changed and a need to change traffic information occurs, the changed traffic information cannot be provided without replacing a sign.

As a road sign for displaying variable traffic information, a system mainly using an electronic sign has been proposed.

The electric signboard is high power consumption, very expensive, and the size and weight are considerable, which puts a heavy burden on the prop.

In the case of LED signboards, which have recently been spotlighted, the device is expensive, there are disadvantages of devices that are difficult to provide sufficient visibility in fog areas, and in case of failure of any of the LEDs, the entire panel must be replaced. It is true that there is a great inconvenience in use due to the fact that the substrate is damaged on the back side due to high heat dissipation and the service life is limited.

Therefore, it is urgent to improve road signs to secure low power, low cost, and high visibility while utilizing the functionality of flexible information provision.

The present invention has been proposed in order to solve the above problems, to provide a road sign that is excellent in visibility even at night, and can respond to changes in the road situation by displaying variable traffic information.

In addition, an object of the present invention is to provide a road sign that can be implemented at low cost, consumes less power, and obtains excellent visibility by controlling according to changes in illuminance value and fog amount.

Road signs for achieving the above object, the light guide plate forming a base surface of the road sign; An LED module positioned on a rear surface of the light guide plate and including a plurality of LEDs, wherein the plurality of LEDs emit light to the front of the light guide plate to display traffic information composed of at least one of letters, numbers, and symbols; A side backlight disposed on at least one side of the light guide plate to emit light to the light guide plate; And a controller for selectively blinking and controlling the plurality of LEDs in response to the traffic information displayed on the LED module.

On the other hand, the light guide plate may further include a reflecting plate which converges to the light guide plate by reflecting the light emitted to the front of the light guide plate to the front.

Preferably, the side backlight may be a cold cathode fluorescent lamp (CCFL), a bright light source, and an LED.

In addition, at least one side of the road sign includes a variable guide display portion for displaying information using the LED, located between the variable guide display portion and the road sign portion displayed on the light guide plate and the LED module The display device may further include a blocking plate that separates the road marking portion and the variable guide display portion by blocking light flowing out from the light guide plate to the variable guide display portion.

In addition, an illuminance sensor for sensing the illuminance around the road sign; A fog sensor for collecting the road sign fog state information; And a memory unit which stores a reference luminance value of the LED module according to an illuminance value and a fog amount, wherein the controller receives an illuminance measurement value and a fog measurement amount from the illuminance sensor and the fog sensor, and measures the illuminance. The luminance of the LED module is controlled according to a reference luminance value corresponding to a value and a fog measurement amount.

Preferably, the memory unit further stores a reference luminance ratio of a predetermined allowable range for defining the luminance of the side backlight that is allowed for the luminance of the LED module, and the controller is configured to measure the illuminance measurement value and the fog measurement amount. The brightness of the side backlight is determined by applying the reference brightness ratio to the reference brightness value of the LED module determined according to the above, and the reference brightness ratio may be selected within the allowable range based on the fog measurement amount.

In addition, by attaching an optical film on the light guide plate can improve the uniformity and brightness of the light emitted from the light guide plate.

As described above, according to the present invention, the traffic information is displayed by using the LED, so that the visibility is excellent even at night. On the other hand, the road sign base surface is implemented by a light guide plate, and uses a lower power and lighter weight than the road sign that expresses the whole by the LED.

In addition, according to the present invention, by controlling the blinking of the LED according to the road conditions in the control unit can flexibly cope with the changing situation, and responds to changes in the illumination measurement value and the amount of fog and the LED module and the base surface forming the traffic information It provides excellent visibility by adjusting the brightness of the light guide plate.

1 is an image of a milestone installed at the intersection of an automobile road,
2 is a control block diagram of a road sign according to an embodiment of the present invention;
2 is an exploded perspective view of part of a road sign according to an embodiment of the present invention;
3 is a view showing a coupling of the light guide plate and the LED module in FIG.
4 is an exploded perspective view of part of a road sign according to another embodiment of the present invention;
5 is an exploded perspective view of part of a road sign according to another embodiment of the present invention;
6 is a flowchart illustrating a method of controlling luminance of an LED module and a side backlight by the controller of FIG. 1.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

2 is a control block diagram of a road sign according to an embodiment of the present invention.

Referring to FIG. 2, the road sign according to the present embodiment includes a light guide plate 10, an LED module 20, a side backlight 30, a reflection plate 40, a blocking plate 50, an illuminance sensor 60, and fog detection. The sensor 70 includes a memory unit 80 and a control unit 90.

The light guide plate 10 forms a base surface of the road sign plate, and the color of light emitted from the light guide plate 10 is determined by the color of the light source of the side backlight 30 described later. The light guide plate 10 is preferably made of a material having high mechanical strength and transparency. For example, the light guide plate 10 may be made of polymethyl methacrylate (PMMA), polycarbonate (PC), and aliphatic cyclic polyolefin (COP).

The LED module 20 is for displaying traffic information composed of at least one of letters, numbers, and symbols using a plurality of LEDs, and includes a plurality of LEDs and a driving circuit.

The side backlight 30 is a light source that emits light to the light guide plate 10 and is located on at least one side of the light guide plate 10. The side backlight 30 may be a light source capable of emitting light to the light guide plate 10, and the type of the side backlight 30 is not limited. In addition, the number or size of the side backlights 30 is determined according to the size of the light guide plate 10 and the required luminance.

The reflector 40 is positioned at the rear of the light guide plate 10 to converge the light emitted to the rear surface of the light guide plate 10 back to the light guide plate 10.

The blocking plate 50 includes a variable guide display portion, a light guide plate 10 and an LED module when the road sign according to the present invention includes a variable guide display portion for displaying traffic volume, weather information, warning phrases, etc. using the LED. Distinguish between the road direction and the road marking part of the street shown in 20).

Hereinafter, the structure and coupling relationship of the light guide plate 10, the LED module 20, the side backlight 30, the reflector 40, and the blocking plate 50 will be described in detail with reference to FIGS. 3 and 4. Shall be.

3 is an exploded perspective view of a part of the road sign according to an embodiment of the present invention, Figure 4 shows a combined view of the light guide plate and the LED module in FIG.

Referring to FIG. 3, an optical pattern is formed on the rear surface of the light guide plate 10 to induce diffused reflection to uniform the luminance of the entire light guide plate 10. The optical pattern may be formed by a printing method, a V-cutting method, an injection method, a laser method, or the like. In addition, the optical pattern has a large or small optical pattern density in consideration of the number of surfaces of the light guide plate 10 where the side backlight 30 is located, the distance to the side backlight 30, and the requirements of the light guide plate 10. Can be formed.

Meanwhile, the light guide plate 10 may have a flat shape or an inclination according to the position and shape of the side backlight 30.

The side backlight 30 is positioned at the side of the light guide plate 10 to irradiate light to the light guide plate 10. As long as light can be irradiated with the light guide plate 10, the specific form of a light source is irrespective. Thus, both forms of linear or point light sources are possible. For example, the side backlight 30 may be formed of a cold cathode fluorescent lamp (CCFL), a bright light source, or an LED.

The color of light emitted from the side backlight 30 is not limited, and the color of light emitted to the light guide plate 10 may be selected by changing the color of the light source of the side backlight 30 according to the location and purpose of the road sign plate installation. For example, it can be red, green, yellow, or blue. In addition, the side backlight cover may be further provided on the side surface so that light emitted from the side backlight 30 is not emitted to the outside.

When the side backlight 30 irradiates light from at least one side of the light guide plate 10, the irradiated light is diffused into the light guide plate 10 through total reflection, and is diffusely reflected by the pattern of the light guide plate 10 to guide the light guide plate 10. ) The whole will shine. As a result, the light of the light guide plate 10 forms the base surface of the road sign except for the traffic information displayed on the LED module 20.

On the other hand, some of the light emitted from the light guide plate 10 may be emitted to the back of the light guide plate 10 may be lost. The reflecting plate 40 reflects the lost light back to the front to converge to the light guide plate 10 to minimize the lost light. Therefore, the reflecting plate 40 is preferably formed to have a high reflectance. For example, the reflector 40 may be formed by coating silver on a base material such as polyethylene terephthalate (PET), stainless stainless (STS), brass, and aluminum, and applying titanium coating to prevent deformation due to prolonged endotherm. You may.

The LED module 20 is located at the rear of the light guide plate 10, and light is emitted from the LED to display traffic information. On the other hand, the light emitted from the LED should be emitted to the front of the light guide plate 10 so that the driver can recognize from the outside.

The reflector 40 may be omitted depending on the brightness of the color of the LED module 20 plate. For example, when the plate of the LED module 20 is white, since the reflectance is high, since the LED module 20 reflects the light emitted to the back of the light guide plate 10 to the front side, the reflection plate 40 may be omitted due to less loss of light. On the other hand, when the plate of the LED module 20 is a low index, such as black, since the reflectivity of the LED module 20 is low, it is preferable that there is a reflector 40 to increase the brightness of the light guide plate 10. .

The blocking plate 50 is located between the road sign portion and the variable guide display portion of the road sign according to the present invention to block the light flowing from the light guide plate 10 to the variable guide display portion. On the other hand, the blocking plate 50 is preferably employed in a color that does not interfere with the visibility of the road sign. For example, a color different from the background surface of the road sign and traffic information may be adopted.

Therefore, the blocking plate 50 may block the light diffused from the light guide plate 10 from the light guide plate 10 to the variable guide display panel when the ground surface of the road sign portion and the variable guide display portion have different colors, thereby preventing the visibility from being lowered. Can be.

Meanwhile, the road sign plate according to the present invention may further include an optical film attached to the light guide plate 10. The optical film is used to diffuse light to the front surface of the light guide plate 10 and to increase brightness, and is positioned on the front surface of the light guide plate 10. Therefore, the uniformity of the light diffused on the light guide plate 10 together with the pattern formed on the light guide plate 10 can be effectively increased.

For example, the optical film may be a diffusion plate or a prism sheet. Through this, light emitted to the front surface of the light guide plate 10 may be scattered and diffused to the entire light guide plate 10, and the diffused light may be collected to increase the overall brightness of the road sign.

The road sign plate may further include a housing for fixing and integrating the light guide plate 10, the LED module 20, the side backlight 30, the reflector 40, and the blocking plate 50.

Figure 4 shows an example in which the LED is displayed over the front of the LED module 20, the traffic information actually provided is limited, it is possible to limit the display area to a certain portion according to the purpose. For example, as shown in FIGS. 5 and 6, it is possible to display a background color so as to secure visibility where the LED is not installed while limiting an area where the LED is installed.

Referring back to FIG. 2, the illuminance sensor 60 of the road sign according to the present embodiment detects the illuminance around the road sign, and the fog sensor 70 collects fog state information around the road sign. The illumination sensor 60 and the fog sensor 70 detect the illumination and fog conditions around the road signs in real time.

The memory unit 80 stores data provided to the controller 90, and stores a reference luminance value of the LED module 20 and a reference luminance ratio of the side backlight 30 with respect to the LED module 20 luminance. have.

Specifically, the reference luminance value is defined as an appropriate luminance value of the LED module 20 corresponding to the illuminance value and the fog amount. The brightness of the LED module 20 is greatly influenced by the ambient illumination and the amount of fog. For example, high brightness during the day can ensure sufficient visibility, while relatively low brightness can provide enough traffic information at night. Can be. In addition, the brightness of the device must be adjusted due to the characteristics of the device that the LED light can not be transmitted to the far distance in the foggy weather. Therefore, the reference luminance value is predetermined and stored in two factors, that is, a value corresponding to the illuminance value and the fog amount, thereby ensuring proper brightness of the LED module 20.

The reference luminance ratio is defined as the luminance ratio of the side backlight 30 to the luminance of the LED module 20. Here, the reference luminance ratio is fixed or variable according to the luminance of the LED module 20, and may be predetermined as a variable having a certain allowable range.

That is, the brightness of the LED module 20 for providing traffic information and the side backlight 30 constituting the background color have a certain ratio to ensure proper visibility, and the ratio may be given in a predetermined allowable range. Here, the reference luminance ratio actually applied reflecting the characteristics of the LED element is determined within the allowable range according to the amount of fog to be measured, and the relationship may be determined experimentally.

Meanwhile, the memory unit 80 may further store a monthly average of illuminance values and fog amounts. Through this, if the value measured by the illuminance sensor 60 or the fog sensor 70 is significantly different from the monthly average, the remote traffic management system is notified to indicate whether the illuminance sensor 60 or the fog sensor 70 is abnormal. Can be detected. In addition, the memory unit 80 may be designed to be updated to reflect new information.

Next, the controller 90 controls the operation of the overall traffic sign.

The controller 90 receives specific information or commands through communication with a remote traffic management system or through a remote control, and controls the LED module 20 and the side backlight 30 by reflecting them.

For example, a control is performed to selectively blink a plurality of LEDs according to traffic information to be displayed, and to control the brightness of the LED module 20 and the side backlight 30 to secure visibility according to the weather. Therefore, the controller 90 may include a power control circuit, a data processing processor, an LED driving circuit, a telecommunication means, and the like.

For example, in case of linking with a remote traffic management system, the remote traffic management system uses cameras and optical beacons installed on the roads to deal with accidents such as traffic, traffic, and accidents on major roads, construction work, and maintenance work. Understand the information in real time. The remote traffic management system analyzes the road situation and provides the control unit 90 through the remote communication means (not shown) when the situation in which the traffic information to be displayed on the road sign needs to be changed.

The controller 90 controls the traffic information displayed on the LED module 20 by operating the driving circuit of the LED module 20 based on the received information to blink the LED in response to the changed traffic information.

At this time, the brightness of the LED module 20 and the brightness of the side backlight 30 are appropriately determined and controlled. An embodiment thereof will be described in detail based on the flowchart of FIG. 7.

FIG. 7 is a flowchart illustrating a method of controlling the luminance of the LED module 20 and the side backlight 30 in the controller 90 of FIG. 2.

Referring to FIG. 7, the controller 90 receives a measurement value and a fog amount of the ambient illuminance measured in real time from the illumination sensor 60 and the fog sensor 70 (S10).

Accordingly, the controller 90 determines an appropriate luminance value of the LED module 20 corresponding to the illuminance measurement value and the fog measurement amount among the reference luminance values previously stored in the memory unit 80 (S11), and the current LED module 20. It is compared with the luminance value of (S13).

According to the comparison result, the controller 90 controls the power of the LED module 20 in real time so that the current luminance value of the LED module 20 is matched with the reference luminance value selected as an appropriate luminance value (S15, S17, S19). .

When the luminance of the LED module 20 is determined, the luminance of the side backlight 30 corresponding thereto is determined. The luminance of the side backlight 30 is adaptively determined according to the above-described reference luminance ratio and the reference luminance value of the LED module 20.

Therefore, the controller 90 reads from the memory unit 80 a reference luminance ratio having a predetermined range, which is variable according to the reference luminance value of the LED module 20 (S21).

Then, one of the predetermined range values of the reference luminance ratio is selected based on the amount of fog measured in real time (S23).

For example, when the amount of fog is large, the controller 90 selects a reference luminance ratio that can obtain higher luminance than when the amount of fog is small. That is, when the reference luminance ratio is defined as a value having the luminance value of the side backlight 30 as the numerator and the luminance value of the LED module 20 as the denominator, the reference luminance ratio is larger within the allowable range when the fog amount is large. The value of the reference brightness ratio may be determined in consideration of the lamp type of the side backlight 30, the media characteristics of the light guide plate and the reflecting plate, and the like.

The value of the specific reference luminance ratio determined as described above is applied to the reference luminance value of the LED module 20 to determine the luminance of the side backlight 30. Accordingly, the controller 90 controls the power of the side backlight 30. It is controlled (S25).

As described above, the present invention not only can variably control road traffic information in real time, but also improves power efficiency and various weather conditions by controlling brightness of a light guide plate forming a background with a few LEDs by reflecting light characteristics of LEDs. This ensures optimized visibility for your needs. In particular, the road signs of the present invention in riverside roads, coastal roads, fog areas, etc. can provide a low power high efficiency, high visibility effect.

While an embodiment of the present invention has been described so far, it will be understood that the present invention can be variously modified without departing from the spirit thereof.

For example, in the above-described embodiment, the reflecting plate 40 and the blocking plate 50 may be elements that can be omitted if necessary.

Accordingly, it should be understood that the scope of protection of the present invention is not limited to the technical ideas and equivalents defined in the following claims.

10: light guide plate 20: LED module
30: side backlight 40: reflector
50: blocking plate 60: light sensor
70: fog sensor 80: memory
90: control unit

Claims (7)

For road signs,
A light guide plate forming a base surface of the road sign;
An LED module positioned on a rear surface of the light guide plate and including a plurality of LEDs, wherein the plurality of LEDs emit light to the front of the light guide plate to display traffic information composed of at least one of letters, numbers, and symbols;
A side backlight disposed on at least one side of the light guide plate to emit light to the light guide plate; And
And a controller for selectively blinking and controlling the plurality of LEDs in response to the traffic information displayed on the LED module.
The method of claim 1,
Located on the rear of the light guide plate, the road sign further comprises a reflecting plate for converging to the light guide plate by reflecting the light emitted to the back of the light guide plate to the front.
The method of claim 1,
The side backlight may be any one of a cold cathode fluorescent lamp (CCFL), a bright light source and an LED.
4. The method according to any one of claims 1 to 3,
A variable guide display portion for displaying information using LEDs on at least one side of the road sign plate, and is located between the variable guide display portion and a road sign portion displayed on the light guide plate and the LED module; And a blocking plate that separates the road marking portion from the variable guide display portion by blocking light flowing out from the light guide plate to the variable guide display portion.
The method according to claim 1 or 2,
An illuminance sensor detecting an illuminance around the road sign;
A fog sensor for collecting fog state information around the road sign; And
Further comprising a memory unit for storing the reference luminance value of the LED module according to the illuminance value and the fog amount,
The control unit receives the illuminance measurement value and the fog measurement amount from the illuminance sensor and the fog sensor, and controls the brightness of the LED module according to the reference luminance value corresponding to the illuminance measurement value and the fog measurement amount. Road signs.
The method of claim 5,
The memory unit further stores a reference luminance ratio of a predetermined allowable range for defining the luminance of the side backlight allowed for the luminance of the LED module,
The controller determines the luminance of the side backlight by applying the reference luminance ratio to a reference luminance value of the LED module determined according to the illuminance measurement value and the fog measurement amount, but within the allowable range based on the fog measurement amount. The road sign, characterized in that for selecting the reference luminance ratio.
The method of claim 1,
And a optical film attached to a surface of the light guide plate to improve uniformity and brightness of light emitted from the light guide plate.

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