| 摘要 |
A copying machine wherein successive strip-shaped portions of an original are imaged onto a moving photosensitive carrier by a system which is mounted in part on a reciprocable carriage and includes one or more fluorescent or incandescent lamps and a mask having an elongated aperture through which light passes toward and is reflected on successive portions of the original when the carriage is in motion. The width of each strip-shaped portion is a whole multiple of the quotient of the speed of the carriage and the modulation frequency of light. The modulation frequency is twice the frequency of alternating current which is supplied to the lamp or lamps. Such selection of the width of illuminated portions of the original prevents the formation of lighter and darker transverse streaks between the marginal portions of the reproduction. The width of the aperture preferably increases stepwise from the center toward both ends to compensate for customary reduction of the brightness of lamp or lamps in the same direction. The width of each section of such aperture is also a whole multiple of the aforementioned quotient.
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