| 摘要 |
PURPOSE:To reduce the price of a printing head and to improve picture quality by checking the mean density of a print sample area and by performing printing operation with a difference in density according to the check result. CONSTITUTION:An original signal, read in time series, is inputted to terminal 31, sampled by clock 32 for many samples and then inputted to counter 33. Counter 33 counts up only the black ''1'' signal of the sampled original signal and, after counting up to 16, the total of the black ''1'' signal is regarded as the mean density of a print dot space. The output of counter 33 is written in RAM35 by way of two-way driver 34. The address of RAM35 is assigned by counter 39, which is put into operation by the clock obtained by frequency-dividing clock of 1/16 of clock 32. Gradation information written in RAM35 is read out as required and compared with a value assigned from terminal 40 by comparator 37 to pick up dots to be printed at that time. Thus, even if gradation print operation is performed with a rough-density head, the deterioration of the picture quality can be prevented. |
