| 摘要 |
PROBLEM TO BE SOLVED: To keep the installation span of street lamps at a value four times as large as apparatus height while keeping a uniformity ratio on road surface required in relation to direct light from a light source and reflected light. SOLUTION: The maximum luminous intensity value of a street lamp is available at a vertical angle (θ) between 60 and 65 degrees, and a horizontal angle (ϕ) between 70 and 80 degrees, and the value is between 600 and 650 cd/klm. The maximum luminous intensity value along a vertical plane (ϕ=0) is available at θbetween 20 and 30 degrees, and the value is between 320 and 380 cd/klm. At the same time, the ranges of vertical and horizontal angles for giving a luminous intensity value equal to or larger than 300 cd/klm are taken so that the horizontal angles are between 20 and 30 degrees at a vertical angle equal to 0, between 20 and 35 degrees at a vertical angle equal to 10 degrees, between 25 and 35 degrees at a vertical angle equal to 20 degrees, between 25 and 40 degrees at a vertical angle equal to 30 degrees, between 25 and 45 degrees at a vertical angle 40 degrees, between 35 and 60 degrees at a vertical angle equal to 60 degrees, between 40 and 70 degrees at a vertical angle equal to 70 degrees, and between 40 and 70 degrees at a vertical angle equal to 80 degrees, respectively. Also, the intensity is equal to or less than 10 cd/klm at a vertical angle equal to or above 85 degrees. |
