Blue LEDs are now mass-produced, and road traffic signal heads using LED systems are being used. LED signal heads have advantages such as energy savings and a long life. However, newly proposed LED signal heads have difficulty reducing problems such as the washout phenomenon. In this paper, we have proposed reducing the washout phenomenon of LED signal heads by using LED element 192 and the low-reflection black plate called a“phantom board”on a blank area between the elements. On the basis of light intensity distribution and luminance uniformity measurements, it was confirmed that the LED signal head we proposed satisfies the conditions described in the traffic signal lighting specifications of the National Police Agency. The visibility of the signal head was improved, as apparent from the before and after improvement pictures taken in the morning and the evening when the sun was at a low altitude and as a result of the phantom ratio.
The authors have conducted a research on an Intelligent Lighting System with low power consumption, that achieves an appropriate illuminance and color temperature for individual office workers by using a chroma meter as a sensor. However, as these chroma meters are expensive, it is not easy to introduce them into offices. For this reason, we have proposed a new method for an Intelligent Lighting System that achieves individual illuminance and color temperature without using a chroma meter. To verify the effectiveness of the proposed method, we have performed a comparative experiment between the method using a chroma meter and the proposed method. From the experiment, it was possible to achive an appropriate illuminance and color temperature for individual office worker, when the sensors were separated.
This paper examined the role of the nighttime landscape of Kaneyama Town, Yamagata prefecture, which has tackled the production of rows of houses over 50 years thanks to the initiatives of residents. A concept for the lighting environment that involves controlling consumption energy was proposed in combination with the characteristics of each street determined in this investigation. Because of the strong requests from residents, the landscape lighting experiment was conducted at four places: the bridge, the town square, and two buildings. The lighting design took into consideration expressing the individuality of the town and promoting the ability to take a walk without fear at night. Lighting equipment was attached in cooperation with local residents. The affirmative effects of the landscape and feeling of safety while taking a walk were demonstrated from the results of a questionnaire. The landscape lighting of the town will be improved thanks to the further participation of residents.