LED drive method and LED drive device

A voltage conversion unit including a coil and a first switch converts an AC voltage into a first voltage, which is a DC voltage, by controlling the first switch to be on in an on-pulse period of a first drive signal. A constant current drive unit is supplied with the first voltage and generates a d...

Ausführliche Beschreibung

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Bibliographische Detailangaben
Hauptverfasser:	Fukuda Keisuke, Nakamura Makoto, Kitamura Mamoru, Suzuki Motoaki
Format:	Patent
Sprache:	eng
Schlagworte:	ELECTRIC HEATING ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR ELECTRICITY
Online-Zugang:	Volltext bestellen
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Beschreibung
Zusammenfassung:	A voltage conversion unit including a coil and a first switch converts an AC voltage into a first voltage, which is a DC voltage, by controlling the first switch to be on in an on-pulse period of a first drive signal. A constant current drive unit is supplied with the first voltage and generates a drive current Id having a current value according to light control information. An LED control unit compares brightness based on the light control information and reference brightness, generates a first drive signal based on an error between the first voltage and a target voltage representing a target of the first voltage, when the brightness is higher than the reference brightness, and generates the first drive signal having a predetermined fixed on-pulse period when the brightness is lower than the reference brightness.