US Patent 9415341 Air purifier

A wind direction plate of an air purifier includes a core member provided between an upper wall and a lower wall and extending in a substantially horizontal direction, and an infrared light highly scattering member provided on a side of the core member facing an infrared unit, the infrared light highly scattering member having a higher degree of scattered reflection of infrared light received by the infrared unit and/or infrared light transmitted from the infrared unit than a degree of scattered reflection on the core member.