Abstract: A compact position sensor with high operational reliability is provided. This sensor has a tubular detection coil, a magnetic core movable in the detection coil, a drive circuit for the detection coil, a signal processing circuit for converting a change in impedance of the detection coil into an electric signal, and a guide means for guiding a movement of the magnetic core in the detection coil. The guide means has a guide portion connected to the magnetic core and a support portion for slidably supporting the guide portion. The magnetic core can be smoothly displaced in the detection coil without contacting an inner surface of the detection coil by a sliding movement of the guide portion relative to the support portion.

Abstract: A position sensor with excellent linearity of coil impedance is provided. This position sensor is equipped with a tubular detection coil, a magnetic core movable in the detection coil, a drive circuit for the detection coil, a signal processing circuit for converting a change in impedance of the detection coil into an electric signal, and a shield member disposed around the detection coil. The shield member is a tubular member having a first inner surface for surrounding an axial region of the detection coil, and a second inner surface for surrounding another axial region of the detection coil. The tubular member is formed such that a distance between the second inner surface and the detection coil is smaller than the distance between the first inner surface and the detection coil.

Abstract: A position sensor with excellent linearity of coil impedance is provided. This position sensor is equipped with a tubular detection coil, a magnetic core movable in the detection coil, a drive circuit for the detection coil, a signal processing circuit for converting a change in impedance of the detection coil into an electric signal, and a shield member disposed around the detection coil. The shield member is a tubular member having a first inner surface for surrounding an axial region of the detection coil, and a second inner surface for surrounding another axial region of the detection coil. The tubular member is formed such that a distance between the second inner surface and the detection coil is smaller than the distance between the first inner surface and the detection coil.

Abstract: A compact position sensor with high operational reliability is provided. This sensor has a tubular detection coil, a magnetic core movable in the detection coil, a drive circuit for the detection coil, a signal processing circuit for converting a change in impedance of the detection coil into an electric signal, and a guide means for guiding a movement of the magnetic core in the detection coil. The guide means has a guide portion connected to the magnetic core and a support portion for slidably supporting the guide portion. The magnetic core can be smoothly displaced in the detection coil without contacting an inner surface of the detection coil by a sliding movement of the guide portion relative to the support portion.

Abstract: A plasma treatment apparatus and a plasma treatment method having the capability of uniformly treating an object with plasma at a high treatment speed. This apparatus includes a tubular vessel having a laterally elongated cross section, a pair of electrodes arranged such that electric flux lines develop substantially in an axial direction of the tubular vessel when one of an AC voltage and a pulse voltage is applied between the electrodes, a gas supply for supplying a streamer generation gas into the tubular vessel, a power source for applying the voltage between the electrodes to generate plural streamers of the gas in the tubular vessel, and a plasma uniformity mechanism for making the plural streamers uniform in a lateral direction of the laterally elongated cross section of the tubular vessel to provide the plasma from one end of the tubular vessel.

Abstract: A plasma treatment apparatus can generate atmospheric pressure plasma with reliability by help of an ignition electrode to facilitate starting the apparatus without using an expensive impedance matching device. The apparatus comprises a plasma-generation chamber having an aperture from which the plasma blows out, a gas supply unit for supplying a gas for plasma generation into the chamber, a pair of electrodes, a power source for applying an AC electric field between the electrodes to maintain the plasma in the chamber, a pulse generator for providing a pulse voltage, and the ignition electrode for applying the pulse voltage to the gas supplied in the chamber to generate the plasma.

Abstract: A plasma treatment apparatus having the capability of uniformly treating an object with plasma at a high treatment speed and a plasma treatment method are provided. This apparatus comprises a tubular vessel having a laterally elongated cross section, a pair of electrodes arranged such that electric flux lines develop substantially in an axial direction of the tubular vessel when one of an AC voltage and a pulse voltage is applied between the electrodes, a gas supply for supplying a streamer generation gas into the tubular vessel, a power source for applying the voltage between the electrodes to generate plural streamers of the gas in the tubular vessel, and a plasma uniform means for making the plural streamers uniform in a lateral direction of the laterally elongated cross section of the tubular vessel to provide the plasma from one end of the tubular vessel.