| 摘要 |
PURPOSE:To perform printing even when the number of pixels are increased, by counting the number of the pixels of an image signal to be printed and changing the frequency of a clock signal in accordance with the number of the pixels. CONSTITUTION:A receiving circuit 2b-1 receives the image signal of the next page from an external machinery 1 to start the storing to a video memory 2c. A counter 2b-2 counts the number of the pixels of the image signal at this time. A microprocessor 2a takes in the count value from the counter 2b-2 through an input/output port 2e and compares the same with the predetermined value preset to an ROM and, when the count value is smaller (larger) than the predetermined value, said microprocessor imparts a selection signal to multiplexers 2k, 8d so as to select the first (second) printing basic clock signal and a scanning cycle clock signal. A printing signal generating circuit 2f controls the video memory 2c and a parallel/serial converter 2i, and a scanner motor driving circuit 8a controls a scanner motor 9 to perform the reduction or magnification printing of the image signal. |
