15 October 2015 Research on the high-brightness traffic variable message sign based on laser diodes
Author Affiliations +
Researches indicate that foggy weather is one of the most critical factors that restrict human’s traffic activities and cause traffic accidents. It will reduce the visibility of traffic message board, which could cause the insecurity of transportation. Commonly, light-emitting diodes (LEDs) were used as light source for variable message sign, which could not be seen clearly in the foggy low visibility condition. A high-brightness light source which could be used for variable information board was firstly put forward in this paper. And a new type of variable message sign used in low visibility condition was also introduced. Besides, the attenuation characteristics of laser diode (LD) and light-emitting diode (LED) were analyzed respectively. Calculation and simulation show that the attenuation of red light source is fastest, and the yellow LED light has the better transmittance property. In the experiment, LDs were used to make variable message board for verifying image definition. A 16*16 array structure composed of LDs was designed and could display Chinese characters. By comparing the display effect of LDs and LEDs driven with same power, they were placed in fog chamber of the visibility less than 5 meters. And experiment results show that the penetrability of red LD light is better than that of red LED. So traffic variable message sign based on LDs could improve the image definition and the information could be seen more clearly in the foggy weather. In addition to the high-brightness, good coherence, good direction, experimental results show that traffic variable message board based on LD has better visual effect in low visibility condition.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Li-li Feng, Li-li Feng, Hai-tao Huang, Hai-tao Huang, Chi Ruan, Chi Ruan, } "Research on the high-brightness traffic variable message sign based on laser diodes", Proc. SPIE 9672, AOPC 2015: Advanced Display Technology; and Micro/Nano Optical Imaging Technologies and Applications, 967202 (15 October 2015); doi: 10.1117/12.2196782; https://doi.org/10.1117/12.2196782


The fog influence on bit error ratio
Proceedings of SPIE (December 17 2012)
Synthetic fog as a non-lethal obscurant
Proceedings of SPIE (May 25 2006)
Laser transmissometer
Proceedings of SPIE (February 28 1995)
Mesopic vision characteristics at decreased contrast in fog
Proceedings of SPIE (November 09 2010)
Optical attenuation in fog and clouds
Proceedings of SPIE (November 26 2001)

Back to Top