ApplicationNo. 502400 filed on 03/30/1990
US Classes:250/237R, Hoods, grating, baffles, diaphragms, masks250/227.29With specific illumination or viewing orientation of light conductor relative to viewed object (e.g., light normal to, and detector at 45 degree angle to, viewed object)
ExaminersPrimary: Nelms, David C.
Assistant: Le, Que T.
Attorney, Agent or Firm
International ClassH01J 040/14
AbstractA mask for reducing a semiperiodic variation of an output signal produced in response to a semiperiodic temporal variation of a distribution of radiation incident on the input of a detector. The mask can have a transmitance that changes abruptly at an outer profile of an opaque region or can have a varation in transmittance that varies continuously.