| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of restraining irregular density caused by partial lowering of density even when high-density images are continued in a compact high-speed printing machine. <P>SOLUTION: An original is read by a reader (step S11). Next, density data of every block is read from image data stored in a memory 12 (S12). A maximum value and a minimum value are obtained out of the density data of each block, and the minimum value is subtracted from the maximum value so as to obtain a difference DIFF (S13). Such processing is performed to all the originals (YES in S14). The printing speed in a printing part is divided to three stages "high", "middle" and "low" according to the difference DIFF. Namely, when the difference DIFF is larger than a predetermined threshold 2 (YES in S15 and S16), the printing speed is set to "low" (S17). When it is between the threshold 2 and a threshold 1 (YES in S15 and NO in S16), the printing speed is set to "middle" (S18) and when it is smaller than the threshold 1 (No in S15), the printing speed is set to "high" (S19). <P>COPYRIGHT: (C)2007,JPO&INPIT |
