Piezoelectric transformer with patterns for recognizing node...

Details Piezoelectric transformer with patterns for recognizing node... Piezoelectric transformer with patterns for recognizing node...

2001-12-11

2002-07-09

Nguyen, Tran (Department: 2834)

Electrical generator or motor structure

Non-dynamoelectric

Piezoelectric elements and devices

C310S359000, C310S363000, C310S364000, C310S366000

Reexamination Certificate

active

06417603

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a piezoelectric transformer adapted as a high-voltage DC generating device, and more particularly to a piezoelectric transformer provided with node point recognition patterns for visually indicating respective node points, at which external electrical connection of input and output electrodes is made, thereby allowing the external electrical connection of the input and output electrodes to be easily achieved.
2. Description of the Related Art
Recently, piezoelectric transformers, which are adapted as high-voltage DC generating devices, have been used at an increased rate, as compared to coil transformers, because they have features of reduced size, high efficiency, high electrical insulation, and nonflammable, as compared to those coil transformers.
Piezoelectric transformers are mainly used in inverters for back light adapted to turn on and off color liquid crystal displays of notebooks, PDA (Personal Digital Assistant), DVC (Digital Video Camera), DSC (Digital Still Camera) and the like, and in high-voltage power supply devices equipped static brushes, air cleaners, and ozone generators.
Such a piezoelectric transformer basically consists of a piezoelectric member, an input electrode attached to the piezoelectric member and adapted to apply voltage of a certain level to the piezoelectric member, and an output electrode for outputting a voltage of a desired level from the piezoelectric member. When AC voltage having a frequency corresponding to the intrinsic vibration frequency of the piezoelectric member is applied to the piezoelectric member via the input electrode, the piezoelectric member vibrates mechanically. The mechanical vibration energy of the piezoelectric member is transformed into electrical energy, and then outputted via the output electrode. Thus, the piezoelectric transformer boosts the input voltage using piezoelectric vibrations.
FIG. 1
illustrates a general Rosen type piezoelectric transformer. As shown in
FIG. 1
, the Rosen type piezoelectric transformer, which is denoted by the reference numeral
10
, includes a piezoelectric member
11
having two opposite rectangular major surfaces, that is, first and second surfaces, and four side surfaces, that is, third through sixth surfaces, connecting the first and second surfaces. The piezoelectric transformer
10
also includes an input electrode
12
formed on a first one of two equal surface portions longitudinally divided on the first surface of the piezoelectric member
11
, an output electrode
13
formed on the third surface of the piezoelectric member
11
not contacting the input electrode
12
, and a ground electrode
14
formed on a first one of two equal surface portions longitudinally divided on the second surface of the piezoelectric member
11
while being arranged opposite to the input electrode
12
. That is, the piezoelectric member
11
is longitudinally divided into two portions, that is, a first portion provided with the input electrode
12
and ground electrode
13
, and a second portion provided with the output electrode
13
When AC voltage of a certain level from an AC power source S is applied between the input electrode
12
and the ground electrode
14
in the above mentioned conventional Rosen type piezoelectric transformer, mechanical vibrations are generated in vertical directions at the first portion of the piezoelectric member
11
in accordance with the electrical energy of the applied voltage. By virtue of the vibrations, the second portion of the piezoelectric member
11
vibrates in longitudinal directions. The longitudinal vibrations are transformed into electrical energy which is, in turn, outputted via the output electrode
13
. Such a piezoelectric effect provided in accordance with the application of AC voltage serves to generate a boosting effect.
The waveform diagram shown in the lower portion of
FIG. 1
illustrates the waveform of vibrations generated at the Rosen type piezoelectric transformer
10
. The first portion of the piezoelectric member
11
formed with the input electrode serves as a driving section (or an input section) for transforming electrical energy into mechanical vibration energy, whereas the second portion of the piezoelectric member
11
formed with the output electrode
13
serves as an electrical output generating section (or outputting section) for transforming vibration energy into electrical energy.
FIG. 2
illustrates an improved Rosen type piezoelectric transformer which has an output electrode structure improved over the above mentioned Rosen type piezoelectric transformer, in order to achieve easy external electrical connection of electrodes. As shown in
FIG. 2
, this piezoelectric transformer, which is denoted by the reference numeral
20
, includes a rectangular piezoelectric member
21
having the same structure as the piezoelectric member
11
of the conventional Rosen type piezoelectric transformer
10
. Similarly to the conventional Rosen type piezoelectric transformer
10
, the piezoelectric transformer
20
also includes an input electrode
22
formed on the first portion of the first surface of the piezoelectric member
21
, an output electrode
23
formed on the second surface portion of the first surface of the piezoelectric member
21
at the end of the second surface portion spaced away from the input electrode
22
, and ground electrodes
24
and
25
respectively formed on the second surface of the piezoelectric member
21
while being vertically symmetrical with the input and output electrodes
22
and
23
.
In order to implement an inverter or a high-voltage power supply device using the above mentioned piezoelectric transformer of
FIG. 1
or
2
, it is necessary to conduct a wire soldering process for the input, output, and ground electrodes of the piezoelectric transformer in order to achieve external electrical connection of those electrodes.
In the wire soldering process, a wire is soldered at a node point corresponding to the center of an associated electrode. Where wire is soldered at a portion of the electrode other than the node point, dispersion of characteristics may occur, thereby causing non-uniform vibration. As a result, the product exhibits a degraded reliability.
Furthermore, where the soldering positions on the upper and lower surfaces of the input section of the piezoelectric transformer are misaligned from each other, the piezoelectric transformer exhibits an increase in characteristic dispersion and a degradation in characteristics. In particular, where piezoelectric transformers are mass-produced, there is a problem involved with productivity. Where it is desired to conduct an automatic wire soldering process, it is necessary to install automatic equipment, in which the position of each node point is set for a particular size of piezoelectric transformers. For this reason, there is a problem in that it is necessary to modify the equipment to cope with a change of the size of piezoelectric transformers to be produced.
SUMMARY OF THE INVENTION
Therefore, the present invention has been made in view of the above mentioned problems involved with the related art, and an object of the invention is to provide a piezoelectric transformer provided with node point recognition patterns for visually indicating respective node points, at which external electrical connection of input and output electrodes is made, thereby allowing the external electrical connection of the input and output electrodes to be easily achieved in a manual wire soldering process, while allowing the wire soldering process to be automatically carried out irrespective of the size of the piezoelectric transformer.
In order to accomplish this object, the present invention provides A piezoelectric transformer comprising a piezoelectric member, an input electrode, an output electrode, and a ground electrode, the electrodes being printed on the piezoelectric member, further comprising: a plurality of node point recognition patterns extending radially about th

Affiliated with

Also associated with

Rating

Piezoelectric transformer with patterns for recognizing node... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Piezoelectric transformer with patterns for recognizing node..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Piezoelectric transformer with patterns for recognizing node... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2891082