Abstract: In a pyroelectric infrared detector in which a pyroelectric element and an integrated circuit performing processing of a detection signal from the pyroelectric element are housed in a package, the integrated circuit includes: a converter that performs analog-to-digital conversion of the detection signal; a signal processor that performs signal processing by a digital filter for the detection signal after the conversion; and an input-output controller that delivers the output data from the signal processor to an external device via serial data communication. A cut-off frequency of the digital filter is settable and changeable by voltage application to the integrated circuit or by a command supplied from the external device via the serial data communication.

Abstract: In a pyroelectric infrared detector in which a pyroelectric element and an integrated circuit performing processing of a detection signal from the pyroelectric element are housed in a package, the integrated circuit includes: a converter that performs analog-to-digital conversion of the detection signal; a signal processor that performs signal processing by a digital filter for the detection signal after the conversion; and an input-output controller that delivers the output data from the signal processor to an external device via serial data communication. A cut-off frequency of the digital filter is settable and changeable by voltage application to the integrated circuit or by a command supplied from the external device via the serial data communication.

Abstract: An infrared detector capable of surface-mounting and excellent in electromagnetic wave resistance performance includes: a metal can-type infrared detector configured by disposing a pyroelectric photoelectric conversion element inside a metal package including a plurality of leads; and an insulating spacer made of an electric insulating material and equipped with a one or more through-holes through which the plurality of leads can penetrate. The plurality of leads of the metal can-type infrared detector are inserted into the through-hole from an upper surface side of the insulating spacer and a tip side of the lead is bent toward an outer periphery of the insulating spacer on a lower surface of the insulating spacer, whereby the metal can-type infrared detector is mechanically fixed to the insulating spacer.

Abstract: An infrared human body detector has an infrared detector (PE) having at least one light-detecting surface and disposed in a plane, groups of divided infrared ray converging members (LR and LD) disposed in the plane about the infrared detector in surrounding relation thereto, a primary reflecting mirror member (M.sub.1 or M.sub.1 ') disposed inwardly of the groups of divided infrared ray converging members for reflecting, in a primary fashion, rays (B) applied inwardly through the respective groups of divided infrared ray converging members, and a secondary reflecting mirror member (M.sub.2) disposed inwardly of the groups of divided infrared ray converging members for introducing the reflected rays from the primary reflecting mirror member within a sensitive angle of the infrared detector to apply the rays to the light-detecting surfaces thereof, the secondary reflecting mirror member having a reflecting surface sufficiently small as compared with the surface areas of the infrared ray converging members.

Abstract: External noise in an infrared sensor for a ceiling type human detector is suppressed by increasing the conductivity between a conductive window and the can and improving the temperature compensation by offsetting any difference in the electromotive force per unit area of the inside and/or outside electrode of the sensitive element consisting of coaxial electrodes with different areas. In a pair of electrodes for ceiling mounting the electromotive force is larger than in a pair of lower electrodes for floor mounting. The sensor improves a total sensitivity for use in the infrared sensor for a wall installation type human detector, on account of improving performance and reliability of the pyroelectric infrared sensor for use as a human detector.