US 11,719,574 B2
Indicator
Sean Patrick O'Kell, Cwmbran (GB); and Andrew Jon Hallett, Cwmbran (GB)
Assigned to SAF-T-GLO LIMITED, Cwmbrand (GB)
Filed by SAF-T-GLO LIMITED, Cwmbran (GB)
Filed on Apr. 14, 2022, as Appl. No. 17/721,090.
Claims priority of application No. 2105485 (GB), filed on Apr. 16, 2021.
Prior Publication US 2022/0333984 A1, Oct. 20, 2022
Int. Cl. G01J 1/58 (2006.01)
CPC G01J 1/58 (2013.01) 20 Claims
OG exemplary drawing
 
1. A marker arranged to indicate the presence of ultraviolet radiation, the marker comprising at least an emitting layer having a fluorescent material arranged to emit visible light in a first range of wavelengths in response to excitation by ultraviolet radiation in a second range of wavelengths, the emission of visible light being reversible and the marker being reusable.