| 摘要 |
PROBLEM TO BE SOLVED: To provide a line width control method enabling good reproducibility of dot and linear image. SOLUTION: By using a line width detection sensor which is constituted by combining a pair of light emission element PS1 and light receiving element PS2 and provided with a condensing lens PS4 on the element PS1 side and a pin hole between the element PS1 and the lens PS4 and whose spot diameter is smaller than the width of a line on an image carrier, the oblique lines having included angle θ in a sub-scanning direction on the image carrier are formed. By scanning the oblique lines, the change of the width of the line in a main scanning direction and in the sub-scanning direction is detected. Besides, an exposure condition is controlled based on data obtained by averaging the changing quantity of the line width in the main scanning direction and in the sub- scanning direction from an initial time. |
