| 摘要 |
PURPOSE:To prevent the thermal breakdown of a lens effectively, by arranging a glass member having a high heat-resisting property, where a heat-ray absorbing coat is covered on the surface, and a glass member having a high heat-ray absorbing property in order from the side of a light source lamp between the light source lamp and a condenser lens group. CONSTITUTION:The overall system consists of a light source lamp 12 and a condenser lens group 20 which has the light focusing property as the whole. The condenser lens group 20 consists of the first condenser lens 14 which has a heat- ray absorbing coating on the surface and consists of materials having a high heat-resisting property, the second condenser lens 16 consisting of materials having a high heat-ray absorbing property, and the third condenser lens 18 consisting of a general optical glass which are arranged in order from the light source lamp 12. |
