| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting controller and a discharge lamp lighting control method, capable of controlling a duty of a chopper according to an electric power of a discharge lamp without detecting a primary current. SOLUTION: In this controller, a current detector 8 and a voltage detector 9 detect a discharge lamp voltage and a discharge lamp current, and a computing element 14 calculates a target current from a preset target electric power and a detection current value, and calculates a count number on the basis of equation (2). When zero detector 12 detects that a secondary current of a transformer T becomes zero, a switching element Q is turned on, and the counting is started by an on time timer 13. When the count number becomes the count number calculated by the computing element 14, the switching element Q is turned off. COPYRIGHT: (C)2004,JPO |
