| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a solid state scanning type optical writing unit in which a streak noise occurring in the main scanning direction can be reduced or eliminated without causing increase of driving voltage or damage of image reproducibility. SOLUTION: A large number of optical shutter elements 41 corresponding to respective pixels forming one fine of image are arranged while being divided into odd rows and even rows at an interval of five lines in the sub-scanning direction Y wherein the odd rows and even rows are shifted (shift A) from each other by an integer times (5 times) of one line in the sub-scanning direction. After a drive pulse signal is applied to elements 41 in odd rows, a drive pulse signal is applied to elements 41 in even rows with a lag of five line periods thus forming an image of one line. Although the exposed position on the light receiving plane is shifted between adjacent pixels depending on the shift A, shift of each pixel is not conspicuous when it is observed by the naked eye or through a loupe and a streak noise is substantially not observed at each line period.</p> |
