Mask

摘要

[Problem] To provide a structure for a mask for dual-type pyroelectric sensors capable of accurately detecting movement of a moving body in the direction of the array of two pyroelectric elements and in a direction perpendicular to the direction of the array. [Solution] The structure for a mask applied to a detection face of a dual-type pyroelectric sensor for improving detection sensitivity of moving bodies comprises a sheet portion obstructing infrared light and an aperture pattern made from through-holes formed in the sheet portion. Using the direction of disposition of the two pyroelectric elements of the pyroelectric sensor on the detection face as the x-direction and the direction perpendicular to the x-direction on the detection face as the y-direction, the aperture pattern is formed so that ratio of the infrared light irradiation range with respect to the two pyroelectric elements changes in accordance with movement of a moving body in the x-direction and y-direction respectively.