| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To easily and quickly complete adjustment work for compensating the variation of a circuit constant. <P>SOLUTION: A power supply circuit (110) supplies a light source LA with lighting power for lighting the light source LA. A power measuring circuit (160) measures the lighting power and generates power measuring voltage proportional to the measured lighting power. A target voltage generating circuit (a lighting control degree computing circuit 213, a polarity reversing circuit 220 and an integrating circuit 230) generates target voltage proportional to a target value of lighting power. A voltage correcting circuit 250 generates correction voltage proportional to the target voltage generated by the target voltage generating circuit. The voltage correcting circuit 250 is variable in the ratio of correction voltage to the target voltage. A comparing circuit 260 compares power measuring voltage generated by the power measuring circuit 160, with the correction voltage generated by the voltage correcting circuit 250. A supply control circuit 270 controls the lighting power based on the compared result of the comparing circuit 260. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
