| 摘要 |
<p>PURPOSE:To realize various types of total lighting time, by splitting exposing time for single main scanning into a plurality of time sections, then selecting different lighting times for at least two time sections and selecting combination of lighting time sections so that optimal total tighting times corresponding to the strength of emitted light can be obtained for respective optical modulation elements. CONSTITUTION:Time Tr for single main scanning is splitted into four time sections N1-N4, for example. Upon finish of transfer of flickering data for the first time section N1, a lighting signal 28a of lighting time T1 is fed from a lighting signal generating circuit 28 to LED array 16. Similarly, lighting signals T2-T4 upto time section N4 are fed to finish exposure for a single main scanning. Lighting signals having four types of widths are combined in such a manner so as to set the lighting times of respective light emission elements for example, T1:T2:T3:T4 is 8:4:2:1. Consequently, light emission elements which have low light emission strength light for a long time, so as to irradiate a photo-sensitive material 23 with uniform total light energy within a single main scanning time.</p> |
