US 11,919,441 B2
Lamp control device
Masaaki Nakayama, Kyoto (JP)
Assigned to Rohm Co., Ltd., Kyoto (JP)
Appl. No. 17/298,807
Filed by Rohm Co., Ltd., Kyoto (JP)
PCT Filed Dec. 2, 2019, PCT No. PCT/JP2019/046996
§ 371(c)(1), (2) Date Jun. 1, 2021,
PCT Pub. No. WO2020/121864, PCT Pub. Date Jun. 18, 2020.
Claims priority of application No. 2018-234402 (JP), filed on Dec. 14, 2018; and application No. 2019-061305 (JP), filed on Mar. 27, 2019.
Prior Publication US 2022/0055538 A1, Feb. 24, 2022
Int. Cl. B60Q 11/00 (2006.01); B60Q 1/00 (2006.01); B60Q 1/38 (2006.01); B62J 6/056 (2020.01); H05B 45/58 (2020.01)
CPC B60Q 11/005 (2013.01) [B60Q 1/0094 (2013.01); B60Q 1/382 (2013.01); B62J 6/056 (2020.02); H05B 45/58 (2020.01)] 13 Claims
OG exemplary drawing
 
1. A lamp control device comprising:
a first input terminal;
a second input terminal;
an output terminal configured to be connectable to a lamp via an external switch, a driving current for the lamp being output via the output terminal;
an internal switch arranged on a first path connecting together the first input terminal and the output terminal;
a constant current circuit arranged on a second path connecting together the second input terminal and the output terminal;
a voltage monitor configured to monitor a voltage fed to the output terminal; and
a controller configured to control the internal switch based on a result of monitoring by the voltage monitor,
wherein the controller is configured to start switching alternately between first and second control modes when the voltage fed to the output terminal is lower than a first predetermined value.