| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable the correction of luminescence irregularity due to a change with time elapse by detecting the brightness of luminescence of plural LED elements on an LED array arranged in the main scan direction and controlling the LED elements based on the detected brightness of luminescence so that the brightness of each of the LED elements is set to the specified value. SOLUTION: A quantity of light correction part 518 sequentially turns ON plural LED elements in the process of warming-up at a specific drive current and a specific duty ratio to seek a correction amount by detecting each of the luminescence brightnesses, and further, update and store the correction results. In addition, the quantity of light correction part 518 has a comparision circuit for determining a quantity of light measuring signal detected and outputs an LED abnormality signal to a printer CPU, if the measured quantity of light is below the specified value. The printer GPU connects this LED abnormality signal to a system control part to display it on a control panel. A quantity of light control part 517 corrects a quantity of light of luminescence based on a signal for setting a quantity of light of luminescence from the printer CPU and a quantity of light correction signal per LED element from the quantity of light correction part 518 to output a luminescence enable signal.</p> |
