Title:
LAMP MODULE AND LIGHTING CIRCUIT THEREFOR
Document Type and Number:
WIPO Patent Application WO/2021/020538
Kind Code:
A1
Abstract:
A drive circuit (210) stabilizes the time-average of a drive current (ILED) flowing in a light-emitting string (110) to a first current amount (IREF1) when in a first lighting mode and stabilizes the time-average of the drive current (ILED) to a second current amount (IREF2) which is smaller than the first current amount (IREF1) when in a second lighting mode. The drive circuit (210), on detection of an abnormal state in which no current flows in the light-emitting string (110) while in the second lighting mode, changes the on and off states of each of a plurality of bypass switches (SW1 and SW2) to search for a state in which a current flows in the light-emitting string (110) and secures that state. Next, the drive circuit stabilizes the time-average of the drive current (ILED) flowing in the light-emitting string (110) to a third current amount (IREF3) which is larger than the second current amount (IREF2).
Inventors:
ICHIKAWA TOMOYUKI (JP)
Application Number:
PCT/JP2020/029348
Publication Date:
February 04, 2021
Filing Date:
July 30, 2020
Export Citation:
Assignee:
KOITO MFG CO LTD (JP)
International Classes:
H05B45/40; B60Q1/26
Foreign References:
| US20110148306A1 | 2011-06-23 | |||
| JP2016197711A | 2016-11-24 | |||
| JP2015110357A | 2015-06-18 |
Attorney, Agent or Firm:
MORISHITA Sakaki (JP)
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