| 摘要 |
PROBLEM TO BE SOLVED: To improve lighting efficiency by previously positioning a lighting prism at a rotational angle at the point of time when the altitude of the sun on the next day is about 0 deg. after sunset and tracking it in the morning on that day so that the lighting prism may be at an appropriate position in accordance with the altitude of the sun all over the section obtained from the time when the altitude of the sun is about 0 deg. till the sunset. SOLUTION: The prism 1 is previously moved and set at the rotational angle of the prism 1 at the time when the altitude of the sun in the next morning is about 0 deg. in a part interlocked with a clock in a setting device 4 at a specified time after the sunset. Therefore, the prism 1 follows the position of the sun from the point of time when the altitude of the sun exceeds about 0 deg. every morning, and is driven and controlled to be tracked to a prism position suitable for the current position of the sun on that day in the section till every sunset. Thus, lighting is performed by the sunlight intake device according to the prism position agreeing with the altitude of the sun all over the section from sunrise to the sunset. |
