Nec Corporation

Naoto Taihaku

Takayuki Inoi

Hiromi Suzuki

Mitsuhiro Sugimoto

Yuko Sato

A piezoelectric transformer element includes electrodes formed on a maximum-area of the front surface and rear surface of a long-plate shaped piezoelectric body. A case in which the piezoelectric transformer element is housed includes first lead terminals and second lead terminals. The first lead terminals press the electrodes on the front surface of the piezoelectric transformer element and are electrically connected to the electrodes. The second lead terminals press the electrodes on the rear surface of the piezoelectric transformer element and are electrically connected to the electrodes. The piezoelectric transformer element is held within the case by the first and second lead terminals and ring-shaped elastic bodies in which the piezoelectric transformer element is inserted. Thus, inhibition of vibration of the piezoelectric transformer element is suppressed and energy conversion efficiency of the piezoelectric transformer element is improved.

Transformer with the piezoelectric transformer element held by lead

In order to achieve the above and other objects, a piezoelectric transformer unit is provided. The unit contains a piezoelectric transformer element, a first upper electrode, a first lower electrode, an insulator casing, a first lead terminal, and an insulator elastic member. The piezoelectric transformer element has a upper element surface, a lower element surface, and a first side element surface. The first upper electrode is formed on the upper element surface of the piezoelectric transformer element, and the first lower electrode is formed on the lower element surface of the piezoelectric transformer element. The insulator casing houses the piezoelectric transformer element. The first lead terminal protrudes from an inner surface of the insulator casing, supports the piezoelectric transformer element within the insulator casing, and vertically presses the an oscillation nodal point of the piezoelectric transformer element. The insulator elastic member is arranged between an oscillation nodal point on one of the upper, lower, and first side element surfaces of the piezoelectric transformer element and the insulator casing.

Piezoelectric transformer unit

A piezoelectric transformer having a structure where an electrode on a side of a transformer element and a lead terminal made of a leaf spring on a side of a package are brought into pressural contact with each other by an elastic spring performance of the lead terminal. An angle of inclination is given to a terminal portion of the lead terminal in respect of a base portion, whereby the terminal portion of the lead terminal is opened in a direction of extending the base portion, when the base portion is bent, with a side wall of a case being a fulcrum for the bending, by receiving a static pressing force from a transformer element on the terminal portion. An angle of rotation caused at the terminal portion by bending the base portion is counteracted by this angle of inclination, by which the terminal portion and the electrode of the transformer element are always kept in parallel with each other.

Piezoelectric transformer

A piezoelectric transformer element 1 is supported by a plurality of contact pins 5b provided on a printed wiring board 6. The contact pins are directly contacted to lower electrodes of the piezoelectric transformer element at its nodal points. An insulating case 4 accommodating the piezoelectric transformer element 1 is provided with a plurality of leads 3 which contact upper electrodes of the piezoelectric transformer element 1 at its nodal points. The insulating case 4 and the printed wiring board are combined together to provide electrical connection between the leads and wirings of the printed wiring board.

Growing community of inventors

Tokyo, Japan

Naoto Taihaku