| 摘要 |
An infrared flame detector of the present invention has an infrared radiation receiving element accommodated in a package. In the infrared radiation receiving element, a set of two pyroelectric elements are arranged side by side and connected in anti-series on a pyroelectric element forming substrate. An infrared optical filter includes a filter forming substrate made of an infrared radiation transmitting material, a set of two narrowband transmission filter sections formed at positions respectively corresponding to positions of the pyroelectric elements on a first surface of the filter forming substrate and configured to transmit infrared radiation of a first selective wavelength and infrared radiation of a second selective wavelength, and a broadband blocking filter section formed on a second surface of the filter forming substrate and configured to absorb infrared radiation of a wavelength longer than an upper limit of an infrared reflection band. |
