Abstract: A pyroelectric infrared sensor includes a package having a light-receiving window, and at least two dual pyroelectric elements arranged in the package, each of the dual pyroelectric elements having first and second unit pyroelectric elements, the first and second unit pyroelectric elements being connected in series or parallel with each other so as to have opposite polarities, wherein the first and second light-receiving electrodes and the first and second back electrodes are formed such that an effective light-receiving electrode area of the first unit pyroelectric element opposing a central portion of the light-receiving window is smaller than an effective light-receiving electrode area of the second unit pyroelectric element opposing a peripheral portion of the light-receiving window.

Abstract: This invention concerns a pyroelectric infrared detector, comprising a substrate and polymeric pyroelectric elements mounted to both surfaces of the substrate, in which the electrode plates on one of the polymeric pyroelectric element are connected electrically to the electrode plates of opposite polarities on the other of the polymeric pyroelectric elements respectively.

Abstract: An infrared detector comprising a polymeric pyroelectric device and a field effect transistor as an impedance conversion circuit.