| 摘要 |
PROBLEM TO BE SOLVED: To reduce the radiated electromagnetic noise when forming an image added with a tracking pattern. SOLUTION: A tracking pattern forming control unit 54 added to an LD driving control unit 44 for forming an image of Y in an image forming apparatus operates synchronously with a clock for which spread spectrum frequency modulation is performed by a frequency modulating circuit 60. The tracking pattern data in which the information such as the model or serial number of the image forming apparatus is encoded are stored in a register 56, and are sequentially read from the register 56 in a timing synchronized with a line/page start signal and outputted to a data mask circuit 66. To prevent each pattern of the tracking patterns from being separated from a grid, the data mask circuit 66 generates a tracking pattern signal so that each pattern may have a length equivalent to at least two periods of the clock in a beam scanning direction. This tracking pattern signal is composited to an image signal by an image compositing circuit 86, thereby forming an image added with the tracking pattern. COPYRIGHT: (C)2005,JPO&NCIPI |
