| 摘要 |
PROBLEM TO BE SOLVED: To enhance the responsiveness of startup by supplying a proper bias current to a laser diode. SOLUTION: A laser exposure device includes a power control circuit S which supplies electric power corresponding to a grayscale value of image data to the laser diode LD. Furthermore, the laser exposure device includes a bias current setting module 70 which makes the power control circuit S sequentially increase a measured grayscale value and measures a value of a current flowing to the laser diode LD. The bias current setting module 70 determines an LD area threshold at which the measured current is changed to a decrease trend, sets a bias grayscale value obtained by adding an exposure adjustment value based upon the LD area threshold, and supplies it to a bias current supply section 67. Then the bias current supply section 67 supplies the bias current to the laser diode LD. COPYRIGHT: (C)2010,JPO&INPIT |
