| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high quality image at a low cost by preventing a longitudinal line from thinning due to isolated dots without using a high response laser diode thereby attaining a required density even for an image of low gray scale. SOLUTION: An isolation dot detecting circuit 4 detects isolation dots in image data inputted to an LD control section 2 and a pulse width modulation circuit 6 increases the width of an LD drive pulse at the time of forming an isolation dot as compared with the pulse width per dot at the time of forming continuous dots. Furthermore, the pulse width of minimum gray scale is set larger than the pulse width per gray scale of other gray scale. |
