LIGHT GUIDE FOR ADJUSTING LIGHT QUANTITY

PURPOSE:To vary the quantity of light continuously by a lightweight and inexpensive device which is free of variation in color temperature by arraying element wires of an optical fiber bundle at one end at random and arranging a shutter or filter at the other two-divided end side. CONSTITUTION:Light from a light source 1 is collimated by a lens 2 and cut off partially by the shutter 3 to enter the two-divided end part 4a of the optical fiber bundle 4, and the light is mixed in the fiber bundle and projected from the end part 4b where element wires are arrayed at random while the light is reduced in quantity uniformly. Therefore, the quantity of the irradiation light is varied by the movement of the shutter without varying the quantity of the light from the light source to adjust the quantity of light continuously, so that the lightweight and inexpensive device is constituted.