To provide a power supply device adapted to obtain a stage effect when an LED element in an on-state with optical output of some dimming degree is turned off, or when the LED element is turned on with optical output of some dimming degree from an off-state.
A control unit 21 exerts constant-current control by constant-current control means 19 in a region of dimming degree shallower than a preset degree of dimming, or exerts constant-voltage control by constant-voltage control means 20 in a region of dimming degree deeper than the preset degree of dimming. When a dimming signal of the deepest degree of dimming equivalent to the turn-off of an LED element 11 is inputted while in an on-state of the LED element 11, the control unit 21 gradually lowers the optical output of the LED element 11 from the immediately preceding degree of dimming until the LED element is turned off.
| JP2009110730 | ILLUMINATING DEVICE AND LIQUID CRYSTAL DISPLAY DEVICE |
| JP2013254005 | LIGHT EMISSION SIGN APPARATUS |
| WO/1993/021745 | APPARATUS FOR CONTROLLING ELECTRICAL LOADS |
TAKAHASHI KOJI
KUDO HIROYUKI
| JP2009232623A | 2009-10-08 | |||
| JP2011176911A | 2011-09-08 | |||
| JP2012054223A | 2012-03-15 | |||
| JP2011249174A | 2011-12-08 | |||
| JP2006041043A | 2006-02-09 | |||
| JP2006210836A | 2006-08-10 |
Satoshi Kabazawa
Tetsuya Yamada
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