| 摘要 |
PURPOSE:To obtain uniform distribution of illuminance on the surface of the substance to be copied without elongating the length of a lamp by forming the triangular opening part on which phosphor is not yet applied symmetrically at right and left on the both end parts of a glass bulb. CONSTITUTION:At the both end parts of the glass bulb 1 of the fluorescent electric- discharge tube which is used as the light supply for a copier, the opening parts 8 on which fluorescent substance is not applied are formed symmetrically at right and left in the triangular form having the narrower width towards the center part from each end part. Therefore, the light from a point in the direction of length of a lamp comes as the light which is reflected in multiplicity in about 5cm between the right and the left of the point in the tube and is varied continuously according to the shape of the opening part 8, so the luminance at the both end parts can be increased by forming the opening part 8 into triangular form, and uniform distribution of illuminance on the surface of the substance to be copied which is exposure-light irradiated can be obtained without elongating the length of the lamp. |
