LED road lighting: safety and comfort is the first demand

The industry believes that, after several years of exploration and development of LED road lighting, after the application of the process of accumulation of technology and product improvement, the current market continues to grow steadily, the development of its re emergence. Many technical experts from the use of the environment, design and optimization of the feelings of consumers and how to scientifically evaluate the LED light source and other aspects of how to better explore the application of LED in road lighting, road lighting environment, how to obtain more safe and more comfortable. It can be seen from the LED road lighting technology and product applications to a deeper, more humane direction of a big step forward.

Taiwan optoelectronic optoelectronic components and system application of group leader Zhu Mudao

Optimize the design to meet the requirements of human comfort

LED road lighting products need to comply with the relevant technical specifications for road lighting to meet the relevant requirements of the ground illumination and regional brightness. LED manufacturer is concerned with light efficiency, but for users, the ultimate concern is the quality of lighting the eyes in the specific environment feel, in the existence of a conversion coefficient between the light efficiency and light quality, the coefficient is related with the environment, so before the road lighting products need to be installed a large number of specific research work, can not get a standard everywhere use.

LED lighting products should be integrated with the user in the basic physical properties of a deep understanding of LED source on demand, such as the combination of light and human feelings, combined with the use of the environment, the development of lighting products really humanized, and reasonable optical design is an important aspect of.

Several commonly used optical design methods are as follows: (1) use the structure to adjust the type of light, the light source will be arranged into a single plate array, and then tilt the lamp plate device to adjust the required light distribution. The optical design is the biggest advantage of low cost, but to meet the light quality high is not easy to achieve, but also can put the monomer between each tilt in different degrees, the light of street lamp needs superposition. (2) using the optical design of a single optical element, such as a reflector or lens, using a two optical design, the light beam is distributed to the desired light type. In this way, the monomer can be standardized and has high elasticity, and the LED monomer can be separated from the optical design, which makes the design more flexible, so as to meet the environmental requirements of different roads. (3) using a primary optical element, a single lens is used to directly guide the output form of the light output of the monomer on the LED monomer. The asymmetric distribution in the direction of the road can be achieved by using the tilt of the lamp plate or the design of the light source lens, so that the integration can be simplified, but the design cost and the manufacturing cost are high. (4) the use of optical devices, only in the patent, but the product has not been used, the design of light loss but easy to repair, to meet the higher quality requirements of light. Future road lighting needs to integrate these technologies, but also the introduction of command and control technology and network management technology.

PHILPS (China) Investment Co., Ltd. PHILPS Shanghai Institute of lighting systems and applications senior researcher Zhu Xiaoyan

The investigation shows that the 3000K warm white LED street lamp is more comfortable

When it comes to facing LED road lighting challenges, we usually refer to product quality challenges, such as life, reliability, and low rate of investment return. But the product is for lighting services, the end users are concerned about whether there is glare, the sidewalk is not too dark, white light is comfortable, whether the problem is high enough. Energy saving is not only the energy saving of the product itself, but also the energy saving effect of the application, which is based on the safe and comfortable lighting environment.

Road lighting is for road safety services, first of all need to meet the basic needs of safety. Security is related to visual function, visual function involves reaction time, detection rate, disability glare (TI) and face recognition and other factors. Second, we need to further consider the comfort, visual comfort related to color temperature, average brightness / illuminance, brightness (illumination) uniformity, glare, environmental factors and other factors.

PHILPS done a lot of research on LED road lighting visual comfort, such as the evaluation experiment in street lighting LED Holland ApELdoorm feeling, in the French city of Lyon do outdoor warm white lighting effect of the user sensory evaluation test in Suzhou, Chinese do outdoor warm white lighting effect user sensory evaluation test, in Shanghai to do the color of road lighting discomfort glare effect.

According to the survey feedback, LED street lighting can be positive to accept, because LED is such, the source of sustainable development, LED is expected to vision and sense of security can be improved lighting, new products with innovative design are always welcome. On the whole, when the contrast between the street surface illumination and the sidewalk illumination is small, the lighting fixtures and the effect are very easy to be positively recognized. Generally speaking, the warm color LED is considered to be comfortable. Of course, LED road lighting is also faced with some criticism: such as the lighting source is too bright, severe glare, the light is too strong glare, will interfere with vision and sight.

The experimental results show that the warm white light (3000K) is more comfortable and less comfortable than the cold white light (6500K). LED road lighting warm white light is preferred, but just consider it is not enough. The low contrast of sidewalk and driveway is more popular