Patent ID: 9585223
Date: 2017-02-28
CPC Classifications: H05B

Claim:
1. An illumination system comprising: a first light-emitting element column including one of a single first light-emitting element or a plurality of first light-emitting elements connected in series; a second light-emitting element column connected in parallel with the first light-emitting element column, and including one of a single second light-emitting element or a plurality of second light-emitting elements connected in series; a constant current supply that supplies a constant current to a light source unit that includes the first light-emitting element column and the second light-emitting element column; a first detector circuit that is connected in series with the first light-emitting element column, and detects a magnitude of current flowing through at least the first light-emitting element column; a current adjuster circuit that adjusts the magnitude of the current flowing through the first light-emitting element column, according to the magnitude of the current detected by the first detector circuit; and a bypass circuit that passes, to one of the first detector circuit or the current adjuster circuit, at least part of current flowing through the second light-emitting element column, when a predetermined condition is satisfied.