Nec Corporation

Takashi Oota

Tadao Uchikawa

Naoto Okihara

Kazutoshi Wakamatsu

Yoshiki Aihara

In an ink jet recording head having a structure wherein grooves are formed on a piezo-electric ceramic substrate by a cutting work and the resulting side walls of the grooves are driven to thereby jet each ink in the grooves, fine cracks appears in the surface layer portion of the side wall during the time of the cutting work, accordingly the strength of the side walls is reduced, a long time driving of the side walls develops the cracks to end in the destruction and so on, which causes a problem of the reliability to be overcome. The cracks occurred in the surface layer portion of the side walls,are penetrated by an oxide,for being mended. The piezo-electric ceramic substrate with the grooves is coated with a solution obtained by solving the constituent elements of the oxide into a solvent and is fired so that the side walls are reinforced.

Ink jet recording head having mending layers between side walls and electrodes

In a printing hammer which is for use in a printer head and comprises a piezoelectric actuator (16) coupled to a base member (15) by a resilient coupler (23), an arm (19) carrying a printing wire (26), and a first resilient hinge (21) coupling the piezoelectric actuator to the arm, first and second resilient parts (221, 222) are used collectively as a second resilient hinge which couples the arm to the base member. The first and the second resilient parts are both sides of the first resilient hinge on a single plane which has a step of a predetermined size relative to the first resilient hinge in a direction of its thickness. The piezoelectric actuator may be fixed directly to the base member in order to give the printing hammer a high printing speed. Preferably, the first resilient hinge and the first and the second resilient parts are manufactured separately of the arm and/or the base member and brazed in grooves formed in a thick arm end with a spacing of the predetermined size, in a groove formed in an actuator block of the piezoelectric actuator, and in grooves formed in a pair of side legs of the base member. The first resilient hinge may have a T form with the top stroke of the T form brazed in the groove. The first and the second resilient parts may be both branches of a U form.

Printing hammer comprising two hinge parts coupling an arm to a base

Disclosed is a piezoelectric actuator comprising a pair of piezoelectric elements, bistable snap-action means, and projectile means attached to the snap-action means in an impact receiving relationship alternately with the piezoelectric elements. The projectile means has a mass sufficient to acquire an acceleration upon impact from each of the piezoelectric elements to cause the snap-action means to change state. The snap-action means may comprise an elongated bending element squeezed endwise between supports, the projectile means being carried by bending element at a point intermediate its ends.

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Tokyo, Japan

Takashi Oota