EP 1562406 A1 20050810 - Method and apparatus for monitoring the condition of LEDs
Title (en)
Method and apparatus for monitoring the condition of LEDs
Title (de)
Verfahren und Vorrichtung zur Zustandsüberwachung von LEDs
Title (fr)
Procédé et appareil pour la surveillance de l'état de DELs
Publication
Application
Priority
FI 20040165 A 20040203
Abstract (en)
The invention relates to a method and apparatus for monitoring the condition of a LED illuminator comprising one or more light emitting diodes. The invention comprises the steps of: controlling the LEDs by means of pulsed current, measuring the light outputs of the LEDs or the LED illuminator by means of one or more light sensors separately during a minimum and maximum level of the pulsed control current. On the basis of the light outputs measured separately during the minimum and maximum levels of the pulsed control current, two separate measurement signals are generated to compare the light output signals corresponding to the minimum and maximum levels with each other and to thereby make conclusions on the operating condition of the LEDs or the LED illuminator. <IMAGE>
IPC 1-7
IPC 8 full level
H05B 33/08 (2006.01); H05B 44/00 (2022.01)
CPC (source: EP US)
H05B 45/12 (2020.01 - US); H05B 45/58 (2020.01 - EP US)
Citation (search report)
- [XA] US 5783909 A 19980721 - HOCHSTEIN PETER A [US]
- [XA] WO 9849872 A1 19981105 - SIGNAL HOUSE LIMITED [GB], et al
- [XA] EP 0974947 A1 20000126 - SIEMENS AG [DE]
- [A] WO 03009647 A1 20030130 - POWER SIGNAL TECHNOLOGIES INC [US]
- [A] EP 1282102 A2 20030205 - EASTMAN KODAK CO [US]
Designated contracting state (EPC)
CH DE FR LI NL
DOCDB simple family (publication)
EP 1562406 A1 20050810; EP 1562406 B1 20080305; DE 602005005095 D1 20080417; DE 602005005095 T2 20090129; DE 602005005095 T8 20090520; FI 116356 B 20051031; FI 20040165 A0 20040203; FI 20040165 A 20050804
DOCDB simple family (application)
EP 05100565 A 20050128; DE 602005005095 T 20050128; FI 20040165 A 20040203