| 摘要 |
PURPOSE:To prevent the ceiling from becoming dark by forming a fluorescent lamp having the triangular cross-section because it emits the light also to the upper area, different from a conventional reflection type fluorescent lamp. CONSTITUTION:The cross-section of glass tube 1 of a fluorescent lamp is triangular. In many cases, a distance up to the object to be illuminated is 10 times longer than the length of each side 4, 5, 6. Therefore, each side can be represented by a spot light source. The light is emitted to the spaces 12, 7, 8 from the side 4, while to the spaces 8, 9, 10 from the side 5 and to the spaces 10, 11, 12 from the side 6. In the spaces 8, 10, 12, the lights emitted from two sides are superimposed. When a fluorescent lamp is placed as shown in Fig. 2, two spaces among three where the lights are superimposed are located at the lower side and thereby the lower side becomes brighter than the upper side. For example, when this lamp is set at the ceiling as the lighting of a room, the entire corner of room becomes bright. Moreover, adequate lighting can be obtained by changing the form of vertical lighting curve to a certain degree in accordance with the degree of roundness at the corners of the triangle of a cross-section. |
