| 摘要 |
<p>PURPOSE: To provide a light bulb uniform illuminating optical device excellent in energy efficiency at a low cost. CONSTITUTION: This light bulb uniform illuminating device is provided with a light source 4 and a light transmission tunnel 2, and the inner face of its wall section reflects light. The interior of the tunnel 2 is made rectangular, the length of the short side is N, and the length of the tunnel 2 is L. The tunnel 2 has an incidence end and an outgoing end. This device is provided with a focusing mirror 6 and a focusing lens 8 focusing the light from a light source 4 into a light spot on the incidence end. The maximum cross sectional size D of the light spot is equal to or smaller than the length N of the short side. The length L, the length N of the short side in the tunnel 2, and the opening angle (u) of the focusing lens 8 are expressed by the expression L=k*N/tan(u), where (k) is a constant in the range of about 1.5-3. A light bulb 12 is arranged at the outgoing end. An effective region where the light transmitting the light transmission tunnel 2 enters is formed on the light bulb 12.</p> |
