| 摘要 |
PROBLEM TO BE SOLVED: To protect the circuit by detecting steadily the phenomena of the end of life of a discharge lamp by a simple structure. SOLUTION: This is a discharge lamp lighting device that stops or reduces the output of a discharge lamp lighting means by detecting abnormality when at least one detection value Vi has reached a first reference value Vref1-i. The device comprises a second detection circuit 2 which compares a plurality of detection values Vi with respectively a plurality of second reference values Vref2-i and, when all of the plural detection values Vi (i=1, 2, 3) have reached the second reference values Vref2-i, changes at least one of the plural first reference values Vref1-i to the direction of the second reference value Vref2-i. COPYRIGHT: (C)2003,JPO |
