Patent ID: 8228005
Filing Date: 2012-07-24
Classification: H05B

Abstract:
1. A light-emitting-element driving circuit which drives a light-emitting element, comprising: a voltage boosting circuit unit which boosts a voltage based on a feedback voltage and which supplies a boosted voltage to a first side terminal of the light-emitting element; a current circuit unit which drives the light-emitting element with a predetermined drive current; a first feedback loop path through which a voltage on a second side terminal of the light-emitting element is input as the feedback voltage to the voltage boosting circuit unit; a second feedback loop path which is provided as a backup feedback loop path through which a voltage on the first side terminal of the light-emitting element is input as the feedback voltage to the voltage boosting circuit unit; an abnormality detection circuit unit which compares the feedback voltage which is input to the voltage boosting circuit unit through the first feedback loop path and a predetermined determination voltage, to detect abnormality in the first feedback loop path; and a switching circuit unit which switches from the first feedback loop path to the second feedback loop path when the abnormality detection circuit unit has detected the abnormality.