Title:
VEHICLE LAMP FITTING, AND LIGHTING CIRCUIT
Document Type and Number:
WIPO Patent Application WO/2021/206145
Kind Code:
A1
Abstract:
A first constant current circuit (210) is provided in series with a plurality of light emitting elements (112) between an input terminal (IN) and a ground terminal (GND), and is capable of switching between ON and OFF states in accordance with a first enable signal (EN1). A second constant current circuit (210) is provided in series with some of the plurality of light emitting elements (112) between the input terminal (IN) and the ground terminal (GND), and is capable of switching between ON and OFF states in accordance with a second enable signal (EN2). In a third voltage range in which an input voltage (VIN) is lower than a first threshold (VTH1) and is higher than a second threshold (VTH2), a control circuit (220) reduces the duty cycle of the first enable signal (EN1) and increases the duty cycle of the second enable signal (EN2) the lower the input voltage (VIN).
Inventors:
ICHIKAWA TOMOYUKI (JP)
ITO TORU (JP)
OZAWA ATSUSHI (JP)
ITO TORU (JP)
OZAWA ATSUSHI (JP)
Application Number:
PCT/JP2021/014919
Publication Date:
October 14, 2021
Filing Date:
April 08, 2021
Export Citation:
Assignee:
KOITO MFG CO LTD (JP)
International Classes:
H05B45/30; B60Q1/00; B60Q1/44; B60Q11/00; F21S43/14; F21S43/19; F21S45/10; H05B45/10; H05B45/325; H05B45/345; H05B45/357; H05B45/375; H05B45/395; H05B45/48; H05B45/54; F21W103/00; F21W103/10; F21W103/35; F21W103/40; F21W103/55; F21Y115/10; F21Y115/15; F21Y115/30
Domestic Patent References:
| WO2020045271A1 | 2020-03-05 |
Foreign References:
| JP2016197711A | 2016-11-24 |
Attorney, Agent or Firm:
MORISHITA Sakaki (JP)
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