Abstract: A prepreg having high processability and laminating performance and a method to produce such a prepreg is described, the prepreg comprising at least the components [A] to [E] shown below, and having a structure incorporating a first layer composed mainly of the component [A] and a first epoxy resin composition that contains the components [B] to [D] but which is substantially free of the component [E], and a second layer composed mainly of a second epoxy resin composition that contains the components [B] to [E], [A] carbon fiber, [B] epoxy resin, [C] curing agent, [D] thermoplastic resin, and [E] particles containing a thermoplastic resin as primary component and having a volume-average particle diameter of 5 to 50 ?m.

Abstract: A surface electric potential sensor for detecting an electric potential on a surface of an object without contacting the surface. The sensor comprises a tuning fork having a base and legs formed of a single elastic body, piezoelectric vibrators respectively mounted on the legs, double-layer structure electrodes respectively provided on ends of the legs and each comprising an insulating substrate and a high conductive film, a supporting board, and a shield case which has a window for introducing therethrough lines of electric force radiated from the surface of the object. The tuning fork is mounted at the base on the upper surface of the supporting board. An electric circuit may be also mounted on the upper surface of the supporting board. As the tuning fork is vibrated by the piezoelectric vibrators, the electrodes moves so as to open and close the window of the shield case.

Abstract: A flickerless 3-D TV viewing system is designed to be used with a single TV receiver set and with a set of stereoscopic glasses composed of light shutters.The system includes a signal-distributor, a set of memory devices, a signal-selector, a synchronous signal separator, a discriminator and a timing circuit. The system is very comfortable for the user during 3-D TV viewing.

Abstract: This invention provides an elastic surface wave device utilizing Bluestein-Gulyaev wave and constructed by a unitary body of a piezoelectric plate having a plurality of transducers thereon, wherein the wave propagation surface being coated with an insulating rubber and being embedded in molding by an insulating powdered epoxy resin, or whose body is attached on a unitary supporting substrate via double adhesive layers; wherein one layer is composed of one kind of adhesive resin and the other is composed of another kind of adhesive resin different from the former in ultrasonic property. This device is advantageous because it has a low spurious signal level without increasing insertion loss, and is easy to manufacture and inexpensive. This invention also provides an effective method for making the device.

Abstract: This invention provides a surface elastic wave device constituted by a unitary body of a piezoelectric plate having a pair of transducers thereon, which unitary body is embedded in a casing, and wherein the wave propagation of a surface elastic wave generated on the surface of the piezoelectric plate during excitation of the device is prevented from being transferred to the casing by a thin film inserted between the casing and the wave propagation surface of the piezoelectric plate or by using as the casing a roll of flexible sheet which has the same function of wave propagation prevention as that of the thin film. This device is advantageous because it has a low spurious signal level without incrementing insertion loss, is easy to manufacture and is inexpensive. This invention also provides an effective method of making the device.