A pyroelectric type infrared sensor.

摘要

An object of the invention is to provide a pyroelectric type infrared sensor without external lens, made in a compact size, and having an improved sensibility. A pyroelectric element (1) for detecting infrared rays is provided in a seal tube (seal body) (2) having an opening (5), at said opening (5) is provided an incident infrared ray filter (3). A diffraction optical lens (diffraction optical element) (4) for focusing or imaging infrared rays is provided on the front or back surface of said incident infrared ray filter (3).