Lamp state detection device and lamp status detection method

摘要

PROBLEM TO BE SOLVED: To provide a device and method for detection of a lamp state, capable of sufficiently enlarging a recovery determination value and preventing erroneous detection when recovered from disconnection.;SOLUTION: A microcomputer detects disconnection of a main lamp when a current value detected at disconnection detection timing t1 during normal time is less than a determination value Ith1, and detects disconnection recovery of the main lamp when the current value detected at recovery detection timing t2 during disconnection detection is equal to or more than a recovery determination value Ith2. The determination value Ith1 is set to a value smaller than a drive current Iγ that is the sum of the currents flowing through the two main lamps and larger than a drive current Iβ that is the sum of the drive currents flowing through one main lamp and a sub lamp. The recovery determination value Ith2 is set to a value larger than the drive current Iγ that is the sum of the drive currents flowing through two main lamps and smaller than the drive current Iα that is the sum of the drive currents flowing through the two main lamps and the sub lamp.;COPYRIGHT: (C)2013,JPO&INPIT