Abstract: A meniscus lens has a dome shape and has a first surface facing a lens array and a second surface facing an infrared sensing element. The meniscus lens has a central portion and a peripheral portion. The central portion includes a top point that is an intersection between the optical axis of the meniscus lens and the first surface. The peripheral portion includes an end of the first surface of the meniscus lens. With respect to the central portion of the meniscus lens, an aplanatic point of the first surface is located at the focus of the lens array. With respect to the peripheral portion of the meniscus lens, an aplanatic point of the second surface is located at the focus of the lens array.

Abstract: A meniscus lens has a dome shape and has a first surface facing a lens array and a second surface facing an infrared sensing element. The meniscus lens has a central portion and a peripheral portion. The central portion includes a top point that is an intersection between the optical axis of the meniscus lens and the first surface. The peripheral portion includes an end of the first surface of the meniscus lens. With respect to the central portion of the meniscus lens, an aplanatic point of the first surface is located at the focus of the lens array. With respect to the peripheral portion of the meniscus lens, an aplanatic point of the second surface is located at the focus of the lens array.

Abstract: The infrared sensor in accordance with the present invention includes a pyroelectric element, an IC device, and a surface-mounted package. The IC device is configured to process an output signal of the pyroelectric element. The package houses the pyroelectric element and the IC device. The package includes a package body and a package lid configured to transmit infrared rays to be detected by the pyroelectric element, and has electrical conductivity. The package body is provided on its surface with plural recessed parts arranged in tiers. The IC device is mounted on a bottom of the lower recessed part. The package body includes an output wiring configured to electrically connect an output terminal of the IC device to an external connection terminal and a shielding member interposed between the pyroelectric element and the output wiring.

Abstract: A proximity sensor has an oscillation circuit, an amplitude measurement circuit, a control circuit and a signal processing circuit. The oscillation circuit has an LC resonant circuit and an oscillation control circuit that is configured to supply an electric current to the LC resonant circuit to generate oscillating voltage across the LC resonant circuit. The amplitude measurement circuit is configured to produce an amplitude signal corresponding to the amplitude of the oscillating voltage. The control circuit is configured to set the negative conductance of the oscillation control circuit to a critical value by which the LC resonant circuit can oscillate based on the amplitude signal. The signal processing circuit is configured to produce a distance signal corresponding to the distance between an object and the sensing coil based on a parameter associated with the negative conductance.

Abstract: The infrared sensor in accordance with the present invention includes a pyroelectric element, an IC device, and a surface-mounted package. The IC device is configured to process an output signal of the pyroelectric element. The package houses the pyroelectric element and the IC device. The package includes a package body and a package lid configured to transmit infrared rays to be detected by the pyroelectric element, and has electrical conductivity. The package body is provided on its surface with plural recessed parts arranged in tiers. The IC device is mounted on a bottom of the lower recessed part. The package body includes an output wiring configured to electrically connect an output terminal of the IC device to an external connection terminal and a shielding member interposed between the pyroelectric element and the output wiring.

Abstract: A detector for a proximity sensor, includes: a sensing portion including a pair of sensing coils which has central axes along a direction intersecting with a moving direction of a sensed object moving in a predetermined moving path and is provided so as to interpose the moving path; a circuit block including a capacitor composing an LC resonant circuit with the sensing coils of the sensing portion and provided with an oscillator which oscillates the LC resonant circuit; and an electric connector composed of first connection terminals and a first conductor pattern that connect the sensing coils of the sensing portion in series, and second connection terminals and a second conductor pattern that connect the sensing coils to the oscillator.

Abstract: A proximity sensor has an oscillation circuit, an amplitude measurement circuit, a control circuit and a signal processing circuit. The oscillation circuit has an LC resonant circuit and an oscillation control circuit that is configured to supply an electric current to the LC resonant circuit to generate oscillating voltage across the LC resonant circuit. The amplitude measurement circuit is configured to produce an amplitude signal corresponding to the amplitude of the oscillating voltage. The control circuit is configured to set the negative conductance of the oscillation control circuit to a critical value by which the LC resonant circuit can oscillate based on the amplitude signal. The signal processing circuit is configured to produce a distance signal corresponding to the distance between an object and the sensing coil based on a parameter associated with the negative conductance.

Abstract: An electrical quantity sensor includes, an oscillation circuit for producing a clock signal of predetermined frequency, a light-emitting element which blinks at a predetermined frequency in accordance with the clock signal output from the oscillation circuit, a switching element which is optically coupled to the light-emitting element and is brought into conduction when the light-emitting element illuminates, a transformer whose primary winding is connected, by way of the switching element, to input terminals which receive a d.c. electrical signal and a synchronization detecting circuit which synchronously detects an a.c. electric signal developing in a secondary winding of the transformer while the clock signal is taken as a reference, thereby producing a d.c. voltage signal corresponding to the amplitude of the d.c. electric signal.

Abstract: A sensor is configured to comprise a detection coil 1 into which a metallic shaft 2 to be detected, a reference coil 5 having the same specifications as those for the detection coil 1, drive oscillator circuits 3, 6 for generating high-frequency magnetic fields in the detection coil 1 and the reference coil 5, and a comparator 10 for outputting a detection signal, which indicates that the shaft 2 to be detected is detected, according to the difference between an oscillation signal, which is outputted from the detection coil 1 according to an inserted state of the shaft 2 to be detected, and an oscillation signal outputted from the reference coil 5.

Abstract: An electrical quantity sensor includes, an oscillation circuit for producing a clock signal of predetermined frequency, a light-emitting element which blinks at a predetermined frequency in accordance with the clock signal output from the oscillation circuit, a switching element which is optically coupled to the light-emitting element and is brought into conduction when the light-emitting element illuminates, a transformer whose primary winding is connected, by way of the switching element, to input terminals which receive a d.c. electrical signal and a synchronization detecting circuit which synchronously detects an a.c. electric signal developing in a secondary winding of the transformer while the clock signal is taken as a reference, thereby producing a d.c. voltage signal corresponding to the amplitude of the d.c. electric signal.