| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device of a bulb shape which can provide high light intensity in the lateral surface direction even when using an LED light source or the like, can provide visual quality like the conventional filament lamp capable of directly seeing a filament or a candle by using the LED light source.SOLUTION: A lighting device of a bulb shape includes: a substrate 2 having a top face 2a; a light source 4 arranged on a substrate top face; and a translucent cover 6 which is formed in a dome shape having a lower end opening 6a, has transparency, has the lower end opening side fixed to the substrate top face and covers a light source therewith. The translucent cover is formed such that a thickness of a wall part is smaller than the diameter of the lower end opening. The translucent cover 6 has a plurality of prisms 10 disposed on the whole region of a dome-shaped inner surface or outer surface, the prisms change a latitude direction of light beam made incident to the southern hemisphere direction of the translucent cover when the vertex of the dome-shaped translucent cover is set as north pole and emit the light and a virtual image of the light source is formed on a position floated up from the substrate top face when being viewed through the translucent cover. |
