| 摘要 |
PURPOSE:To provide modulated light which has an extremely large dynamic range without being influenced by temperature change by controlling the subsequent light output based on the light output information of one or more previous control in case of controlling the light output repeatesdly. CONSTITUTION:The ambient temperature of a laser chip does not change greatly while forming one image and the chip temperature during the forming greatly depends on the electric power loss of the chip itself. The temperatures of the adjacent picture elements are permitted to have small difference by such power loss. Therefore, a delay time DELTAt, which is a period between a time that current is turned on at (e) and a time of laser emission at (f), is allowed to be almost the same as the delay time of the subsequent picture element 2. Namely, the timing of the emission start of a picture element can be predicted by the emission start timing of the one or more previous picture element. A timing for operating a delaying device for deciding picture element density is changed to be at a certain time prior to the emission start by using such timing. |
