| 摘要 |
<p>PURPOSE:To eliminate the variance of the light quantity of every LED element by storing correction data concerning every LED element and outputting a pulse having a pulse length corresponding to the correction data to every LED element with printing data. CONSTITUTION:The printing data is inputted in a shift register 33 for storing printing data and a counter circuit 31 resets counting as soon as the data is transferred to a latch circuit 34. The counted value and output from a shift register for correction data are compared by a comparator circuit 32 and the pulse having the pulse length corresponding to the correction data is outputted. The outputted pulse is inputted in a logical element with the outputted pulse from the shift register 33, and the pulse having the pulse length corresponding to the correction data is outputted from the logical element to every LED element 37. Namely, the variance of the LED element 37 is eliminated by changing the pulse length of the pulse outputted to the LED element 37 with the aid of the correction data. Thus, the unevenness of the printing density of an LED head is reduced and the printing quality of an electrophotographic printer is improved.</p> |
