DIFF Subgroup
F21S 9/037 Full Title
Lighting devices with a built-in power supply; Systems employing lighting devices with a built-in power supply > the power supply being a battery or accumulator > rechargeable by exposure to light
F21S 9/037 Lighting devices with a built-in power supply; Systems employing lighting devices with a built-in power supply > the power supply being a battery or accumulator > rechargeable by exposure to light