LED application in traffic indication

High-power LEDs are used in high-value products such as automotive lighting, lighting fixtures, LCD backlights, and LED street lamps, and they can be used for considerable profits. However, with the arrival of old-fashioned ordinary traffic lights and led lights that were not mature enough in previous years, the new brightly-colored three-color LED traffic lights have been widely used. In fact, a complete set of high-quality, high-quality LED traffic lights are very expensive, but due to the important role of traffic lights in urban traffic, a large number of traffic lights need to be updated each year, leading to a comparison. The large market, after all, high profits are also conducive to the development of LED production and design companies, for the entire LED industry will also have a positive stimulus.

  The LED products used in the field of transportation mainly include red, green, and yellow signal indicators, digital timing displays, and arrow indications. When the product requires high-intensity ambient light during the day, it should be bright and the brightness at night should be reduced to avoid glare. The light source of the LED traffic signal command lamp is composed of a plurality of LEDs. When designing the light source, multiple focuses must be taken into consideration, and there is also a certain requirement for the installation of the LED. If the installation is inconsistent, the luminous efficiency uniformity of the light emitting surface will be affected. In the design, it is necessary to consider how to avoid such defects. If the optical design is too simple, the light distribution of the signal light is mainly ensured by the perspective of the LED itself, then the requirements of the light distribution of the LED itself and the installation requirements are relatively strict. This phenomenon will be very obvious.
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  LED traffic lights also differ from other signal lights (such as car headlights) in light distribution, although there are similar requirements for light intensity distribution. The requirements for automotive headlamps on the light cut-off line are even more stringent. The design of the car headlights only needs to dispose enough light to the corresponding place, do not need to consider where this light sends out, the designer can divide the area and divide the small block to design the light distribution area of the lens, but the traffic signal lamp also needs to take care of the whole The uniformity of the luminous efficacy of the luminous surface must satisfy the observation of the luminous surface of the signal from any working area used by the signal lamp. The pattern of the signal must be clear and the visual effects must be uniform. Although incandescent lamps and tungsten halogen light source signal lamps are stable and uniform, there are disadvantages such as high energy consumption, low lifetime, susceptibility to phantom signal display, color fading, and the like. If you can reduce the phenomenon of LED dead lights, reduce light failure so high brightness, low power LED applications in the signal, will definitely bring revolutionary changes in the signal lamp products.


  LED applications in the field of transportation mainly include the following aspects:
  First, traffic lights. LED traffic lights are favored by urban traffic management departments for their features such as high brightness, high reliability, low use cost and long life.
  Second, highway traffic guidance system. With the improvement of highway construction standards, LED traffic guidance system has become the standard configuration product, and the market demand is large.
  Third, urban road traffic guidance and signs. With the increasing traffic congestion in large and medium-sized cities, road traffic-induced LED displays are rapidly growing in all cities.

  The application advantages of LEDs in signal lights are as follows:
  1. Monochromatic light with divergence angle
  The light emitted by the LED is monochromatic light, and therefore there is no need to use color chips to generate red, yellow, and green signal colors; the light emitted by the LED is directional and has a certain divergence angle, thereby eliminating the use of the traditional signal lamp. Aspherical mirrors. This feature of the LED solves the illusion of the traditional signal lights (commonly known as false display) and color fading problems, improving the light efficiency.

  2, cold light source, low energy consumption
  The advantage of LED light source in energy saving is very obvious, one of its remarkable features is low energy consumption, which is very meaningful for the application of lighting.

  3, good reliability, long life
  The working environment of signal lights is relatively poor, with severe cold and heat, sun and rain, and thus the reliability of the lamps is relatively high. The average lifetime of incandescent bulbs for general signals is 1000 hours, and the average lifetime of low-voltage halogen tungsten bulbs is 2000 hours, resulting in high maintenance costs. In actual use, many LED traffic lights have been used for more than 5 years and LEDs have not been damaged. There is also a relatively large advantage that tungsten halogen bulbs and the like do not respond quickly enough to reduce the occurrence of accidents.

  LED traffic lights to be resolved several issues
  1. The application of high-power LEDs has the advantage of significantly reducing the number of LEDs, but the problem to be solved is heat dissipation and cost.
  2. Although the light intensity indicators, electrical indicators and electromagnetic compatibility requirements of LED traffic lights are gradually increasing, the optical design and circuit design of LED lights need to be further optimized in order to become the mainstream of traffic signal design.
  3. With the increase of energy-saving and environmental protection requirements, the signal lamp combining LED and solar energy will be popularized, but the problem of coordination with the traffic signal control machine needs to be solved.

  All in all, the application of LEDs in traffic signals has been developing very rapidly, and the market prospects for applications in the transportation sector have also been very good and have basically replaced traditional light sources. Although the traffic signal products on the market are nearly saturated, due to the advantages such as environmental protection, energy saving, and long-life of the LED itself, the application of LEDs in the transportation field still has a very large space.