Patent ID: 8228548

Claim:
A multiplex system, comprising: a scanning device to read a manuscript and generate an image data, the scanning device comprising: a storing section for storing the image data; and a printing device to print the image data generated by the scanning device, the printing device comprising: a transfer ability calculating section that calculates an image data transfer ability between the printing device and the scanning device; a data size calculating section that calculates an image data size of one page part read by the scanning device according to a read condition; a read ability calculating section that calculates an image data read ability of the scanning device according to the read condition; a capacity calculating section that calculates an empty capacity of the storing section; a threshold value calculating section that calculates a threshold value on the basis of the image data transfer ability, the image data size and the image data read ability; and a scanner controlling section that outputs a read instruction of the manuscript to the scanning device in the case that the empty capacity of the storing section is larger than the threshold value, wherein the threshold value calculating section calculates the threshold value according to the formula: threshold value=image data size×(1−(image data transfer ability/image data read ability)).