Abstract: A displacement sensor includes a coil which is mounted on a board and which is formed to have less than one turn, an inverter electrically connected to the coil, the inverter being configured to generate an oscillation signal, and a frequency detector electrically connected to the inverter, the frequency detector being configured to detect an oscillation frequency of an oscillator circuit including the coil and the inverter in accordance with a distance between a measurement object and the coil.

Abstract: A displacement sensor includes a coil, an inverter electrically connected to the coil, the inverter being configured to generate an oscillation signal, a reducer electrically connected between the coil and an output terminal of the inverter, the reducer being configured to reduce the strength of the oscillation signal, and a frequency detector electrically connected to the inverter, the frequency detector being configured to detect an oscillation frequency of an oscillator circuit in response to a distance between a measurement target and the coil, the oscillator circuit including the coil, the inverter, and the reducer and having an oscillation frequency of 30 MHz or higher.

Abstract: A displacement sensor includes a coil, an inverter electrically connected to the coil, the inverter being configured to generate an oscillation signal, a reducer electrically connected between the coil and an output terminal of the inverter, the reducer being configured to reduce the strength of the oscillation signal, and a frequency detector electrically connected to the inverter, the frequency detector being configured to detect an oscillation frequency of an oscillator circuit in response to a distance between a measurement target and the coil, the oscillator circuit including the coil, the inverter, and the reducer and having an oscillation frequency of 30 MHz or higher.

Abstract: A pointed heat-generating device for molds of injection molding machines comprises a heat-generating body with a conical portion at its front end, a disc-shaped flange at its rear end, a metal casing therebetween, a plurality of first passages in the metal casing for passing a focused resin therethrough, and a plurality of second passage in said flange and communicating with the first passages.

Abstract: This invention relates to a pointed heat-generating device for molds of injection molding machines. It comprises a metal casing, a pointed projectile heat-generating means fixed with the metal casing, and a gate formed at the pointed heat-generating means and communicated to a cavity of the molds, characterized in that a heat-generating wire is penetrated wholly into a passage which is bored in a non-processed cylindrical material and an alloy portion is formed in an inert gas between an end of the heat-generating wire and the non-processed cylindrical material, thereby the alloy portion being formed as a pointed part of the heat-generating means by machining.