Abstract: A small-size copying machine has an image sensor and a print head for printing image information or visible data on copying paper. The copying machine is moved over an original document to read the visible data with the image sensor, and the visible data read by the image sensor is printed by the print head on the copying paper. The reading of the visible data with the image sensor is synchronized with the printing of the visible data onto the copying paper with the print head by fixing an end of the copying paper discharged from the copying machine and moving the copying machine with respect to the original document. The distance from the position where the visible data of the original document is read to an outlet slit for discharging the copying paper therethrough is equal to the distance from the position where the visible data is printed by the print head on the copying machine to the outlet slit, so that the data printed on the copying paper and the image of the original document will be overlapped.

Abstract: A portable copying machine has a thermal head printer for printing image information on a copy paper, a Charge Coupled Device for reading out the image information, and a time-limit device of which setting time is varied in response to the voltage of power source, whereby a copying shade of the copy paper is kept constant, even if the voltage of a power source is changed by controlling the strobe pulse of the thermal head printer by the time-limit device.