| 摘要 |
PROBLEM TO BE SOLVED: To increase the quantity of light of a small spot without lowering the productivity of an exposure device and irrelevantly to secular changes of the device. SOLUTION: The ratio of the driving current setting resolution of 1st setting data determining a 1st level and 2nd setting data determining a 2nd level is previously stored, quantities of light emission of a light emitting element based upon the two specified pieces of setting data are measured respectively, and variation rates of the light emission quantities of the light emitting element corresponding to the setting data are calculated and stored; and 1st setting data are calculated from the variation rate of the light emission quantities so that the light emission quantity of the light emitting element corresponding to the 1st level matches a target value, and 2nd setting data are calculated from the ratio of the driving current setting resolution and the variation rates of the light emission quantities so that the light emission quantity of the light emitting element corresponding to the 2nd level matches a target value, thereby driving the light emitting element. COPYRIGHT: (C)2005,JPO&NCIPI |
