| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a light source controlling circuit that can calibrate optical output of a light source automatically and direct exposure equipment having this light source controlling circuit. <P>SOLUTION: The light source controlling circuit 1 for a light source that has a laser diode 2 has a photo-diode 3 for outputting a photo-current in proportion to the power of light from the laser diode 2, an acquisition means 11 for acquiring a current value for the photo-current outputted by the photo-diode 3 when an acquisition order is received, a conversion means 12 for converting the current value into a first voltage value, a latching means 13 for retaining the first voltage value as a second voltage value until a rewrite order is received, a drive means 14 for supplying the laser diode 2 with a drive current according to the second voltage value, a comparing means 15 for comparing the first voltage value and the second voltage value, and a controlling means 16 for sending the acquisition means 11 an acquisition order for a current value and sending the latching means 13 a rewrite order about a retained content when the first and second voltage values do not agree. <P>COPYRIGHT: (C)2010,JPO&INPIT |
