| 摘要 |
<p>In the disclosed light-emitting device, when the power source voltage fluctuates (decreases), the drive voltage of the light source decreases. However, as the amount of fluctuation of the power source voltage (amount of decrease relative to the standard voltage) increases, a control means increases the number of light-emitting diodes selected (short circuited) by a selection means not to be supplied with a drive current, and reduces the number of light-emitting diodes selected to be supplied with a drive current. In other words, because the light-emitting device uses the resistance component in the light-emitting diodes as a current limiting element and the number of light-emitting diodes with a drive current is decreased in response to the fluctuation amount of the input voltage (power source voltage), changes (increases) in the loss due to fluctuation in power source voltage can be suppressed and the circuit configuration can be simplified.</p> |
