| 摘要 |
<p>Stable light emission at high luminance is obtained while suppressing power consumption, by specifying an on-period based on a peak current value of a light emitting element, making the maximum amplitude of the pulse in the on-period equivalent to a peak current value, and by varying the duty ratio between the on-period and an off-period variable. A light source driving device is provided with: a light source load section (12) having an LED (17) connected therewith; a load capacity detecting section (14) which detects a rated voltage value (VF) of the LED (17); a signal processing control section (15) which calculates a rated current value (IF) of the LED (17) from the value (VF) and a peak current value (IP); and a constant current pulse driving section (13), which generates a first drive pulse (P1) with a first on/off cycle wherein the on-period of the LED (17) is specified based on the value (IP), and generates a second drive pulse (P2) such that the maximum amplitude of the pulse is equivalent to the value (IP) by further switching the pulse during the on-period with the variable duty ratio between the on-period and the off-period.</p> |
