| 摘要 |
PURPOSE: To provide a lighting system with higher luminous efficiency than a high pressure sodium lamp, capable of discriminating a yellow road marking from a white one when it is used in road illumination or tunnel illumination, or capable of recognizing a red mark. CONSTITUTION: A lighting system uses mixed light of a low pressure sodium lamp and a fluorescent lamp. A three wavelength zone luminescent type fluorescent lamp having three kinds of fluorescent substance layers of blue luminescence, green luminescence, and red luminescence having luminescent peak wavelength in wavelength zones of 440-460nm, 540-560nm, and 600-620mm is used as the fluorescent lamp. The ratio of the luminous flux of the low pressure sodium lamp to that of the fluorescent lamp is specified to 10-40%. Thereby, the yellow road marking can be discriminated from the white one. |
