| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a power supply device which can drive a plurality of load circuits in a high efficiency. <P>SOLUTION: In the power supply device 100, a step-up circuit 10 supplies a drive voltage Vout to a plurality of light emitting diodes 300R-300B. A drive control unit 20 controls the drive states of the plurality of the light emitting diodes 300R-300B, that is, an emission luminance. The drive control unit 20 drives the plurality of the load circuits in a time sharing manner. The step-up circuit 10 has an enable terminal, and stops the switching operation during a non-emitting period which drives none of the light emitting diodes 300R to 300B by the drive control unit 20. A luminescence pattern generator 32 forms luminescence control signals SIG10R to SIG10B which direct the luminescence of each light emitting diode 300. The step-up circuit 10 performs the logical operation of this luminescence control signal SIG10R to SIG10B. Consequently, it stops the switching operation in the non-emitting periods in which neither of the light emitting diodes 300B to 300G emits. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
