Abstract: A multi-electron beam source comprises an electron emitting element part including: a plurality of electron emitting elements provided two-dimensionally in a matrix-like arrangement on a substrate; opposing terminals of electron emitting elements arranged adjacently in the column direction thereof being electrically connected to each other; terminals on the same side of all the electron emitting elements in the same row being electrically connected; and the plurality of electron emitting elements being arranged in "m" rows, "m" representing a number of two or more, and a driving circuit part for driving said electron emitting element part. The multi-electron beam source has means for removing a spike noise superposed onto the driving pulse generated by said driving circuit part.

Abstract: In a piezoelectric filter, two vibrating element parts are arranged on longitudinal side portions of a rectangular flat plate shaped piezoelectric substrate, and a capacitor is arranged therebetween. Each of the vibrating element parts comprises a pair of vibrating electrodes which are arranged on an upper surface of the piezoelectric substrate at a distance, and an opposite electrode which is arranged on a back surface of the piezoelectric substrate to be opposed to the vibrating electrodes. The pair of vibrating electrodes of each Vibrating element part is arranged along an electrode arrangement direction which is inclined with respect to side surfaces of the rectangular piezoelectric substrate. The electrode arrangement direction for the vibrating electrodes is inclined with respect to the side surfaces of the piezoelectric substrate at an angle .theta. of inclination which is preferably in excess of 0.degree. and not more than 45.degree..