JPH0732972U - Power supply - Google Patents

Abstract

(57) [Summary] [Object] To provide a power supply device in which a rectangular piezoelectric element is fixed on a plane substantially the same as a printed circuit board by a fixture, and the overall thickness is thin. After mounting the fixture on the rectangular piezoelectric element, the rectangular piezoelectric element is attached by engaging with a recess provided on the long side of the printed circuit board opening provided on the short side surface of the fixture.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power supply device using a rectangular piezoelectric element.

[0002]

[Prior art]

 A power supply that uses a rectangular piezoelectric element does not require windings and can achieve a large boost ratio with a simple structure, and is particularly suitable for supplying a high voltage to a high impedance load. Further, since it uses a piezoelectric element made of ceramics, it is nonflammable and is useful for plane paper copy (PPC), laser beam printer (LBP), and backlight of liquid crystal device.

A conventional rectangular piezoelectric element is shown in FIG. The rectangular piezoelectric element 1 has a plate-like shape. One half of the rectangular piezoelectric element 1 in the longitudinal direction serves as the input portion 2 in the thickness direction (arrow P), and the other half of the rectangular piezoelectric element 1 protrudes. The force portion 3 is polarized in the longitudinal direction (arrow Q). A pair of input electrodes 4A and 4B are formed on two surfaces of the input section 2 facing each other in the thickness direction, and an output electrode 5 is formed on an end surface of the output section 3 in the longitudinal direction. The input electrodes 4A and 4B are connected to the drive signal source 6, and the output electrode 5 is connected to the lead wire 7. The boosted output voltage is taken out between the lead wire 7 and the ground.

Next, the operation of the rectangular piezoelectric element 1 will be described. When an AC voltage is applied between the input electrodes 4A and 4B by the drive signal power source 6, mechanical vibration occurs in the rectangular piezoelectric element 1 due to the piezoelectric effect. When the frequency of the alternating current applied to generate this mechanical vibration substantially matches the mechanical resonance frequency determined by the length and material of the rectangular piezoelectric element 1, resonance occurs and a standing wave is generated. As this condition, a vibration mode of full-wavelength resonance, a vibration mode of half-wavelength resonance, and the like are known. As a result, in the output section 3 of the rectangular piezoelectric element 1, an electric field distribution is created by the piezoelectric effect due to the amplified strain, and a boosted output voltage is obtained at the output electrode 5.

In the output section 3, the generated voltage linearly increases from the ends of the input electrodes 4 A and 4 B toward the output electrode 5, and reaches the maximum voltage at the output electrode 5.

Next, FIG. 4 shows a conventional holding method of the rectangular piezoelectric element 1. A rectangular parallelepiped fixture 8 is attached to the position of the vibration node of the rectangular piezoelectric element 1. The fixture 8 is provided with a through hole 9 into which the rectangular piezoelectric element 1 is fitted on opposite short side surfaces, has insulation, and does not hinder vibration of the rectangular piezoelectric element 1. Made of rubber with high elasticity. Further, on the substrate 10, which is a molded product, a pair of U-shaped standing portions 12 having grooves 11 on the side surfaces are integrally arranged so that the grooves 11 face each other. The groove 11 has the same width as the short side of the fixture 8. The fixture 8 is inserted between the facing grooves 11 to hold the rectangular piezoelectric element 1.

[0007]

[Problems to be solved by the device]

 In such a conventional holding method, since the rectangular piezoelectric element 1 is disposed on the substrate 10, the thickness of the entire power supply device becomes large, and the thinness of the rectangular piezoelectric element 1 is not utilized.

Therefore, an object of the present invention is to provide a power supply device having a small overall thickness.

[0009]

[Means for Solving the Problems]

 The present invention is configured as follows to achieve the above object. It consists of a rectangular piezoelectric element, a fixture that is attached to the rectangular piezoelectric element, and a printed circuit board that has a rectangular opening for arranging the rectangular piezoelectric element. A groove extending in the direction is provided, and at least one recess is provided facing each long side of the opening, and the fitting is mounted in the recess.

[0010]

After the mounting tool is mounted on the rectangular piezoelectric element, the groove provided on the short side surface of the mounting tool is engaged with the recess provided on the long side of the printed board opening to mount the rectangular piezoelectric element. .

[0011]

【Example】

 FIG. 1 shows an exploded perspective view of a power supply device using the rectangular piezoelectric element 1 of the present invention. Since the rectangular piezoelectric element 1 is the same as the conventional example, its description is omitted and the same numbers as those in the conventional example are used.

The power supply device includes a rectangular piezoelectric element 1, a printed circuit board 13, and a mounting tool 14 for mounting the rectangular piezoelectric element 1 on the printed circuit board 13.

The printed circuit board 13 has a rectangular opening 15, and a plurality of recesses 16 are provided on both long sides of the opening 15 so as to face each other. At other places on the printed circuit board 13, components (not shown) constituting, for example, an oscillation circuit, a control circuit, a rectification circuit, etc. are mounted.

The fixture 14 has a rectangular parallelepiped shape, and grooves 17 for engaging the printed circuit board 13 are provided on both sides of the long side in the direction of the short side of the fixture 14. In addition, for example, through holes 18 are provided on both sides of the short side for mounting the rectangular piezoelectric element 1. The thickness L1 of the groove 17 is the same as the thickness L2 of the printed circuit board 13. Further, the short side length L3 of the fixture 14 is the same as the width L4 of the recess 16. Further, the length L5 between the grooves 16 provided on both sides of the long side of the fixture 14 is the same as the distance L6 between the recesses 16 of the opening 15. The fixture 14 is made of rubber or the like having an insulating property and a high elastic modulus so as not to disturb the vibration of the rectangular piezoelectric element 1.

FIG. 2 shows a case where the fixture 14 is attached to two vibration node portions in the vibration mode of all wavelengths in which the rectangular piezoelectric element 1 has two vibration node portions.

After attaching the fixture 14 to the vibration node of the rectangular piezoelectric element 1, the ends of the fixture 14 in the long side direction are inserted into the concave portions 16 of the printed circuit board 13 facing each other. The groove 17 engages with the printed board 13. Further, both ends of the short side of the fixture 14 are sandwiched by the convex portions 19 to prevent displacement of the opening 15 in the long side direction. In this way, the rectangular piezoelectric element 1 is held in the opening 15 of the printed board 13 without contacting the printed board 13.

When a lead wire is soldered to the electrodes 4A and 4B, or when the fixture 14 is fitted in the vibration node position of the input section 2, a conductor is provided between the fixture 14 and the electrodes 4A and 4B. To connect the lead wire to the conductor.

The output voltage is taken out by soldering a lead wire to the end portion 5 of the output portion 3 of the rectangular piezoelectric element 1. When the mounting tool 14 is mounted at the vibration node position of the output section 3, a conductive mounting tool 14 is used, and the mounting tool 14 is connected to the printed wiring formed in the recess 16 of the printed circuit board 13. You may take it out. In this case, as the material of the fixture 14, a conductive rubber or the like having a high elastic modulus is used so as not to hinder the movement of the rectangular piezoelectric element 1 when resonating.

Further, when a plurality of output voltages are to be taken out, the lead wire is twisted to an output voltage take-out tool (not shown) made of conductive rubber and attached to the output section 3 of the rectangular piezoelectric element 1. You can take it out. The output voltage extracting device is in the shape of a rectangular parallelepiped, and the length of the long side is shorter than the distance L7 between the convex portions 19 facing each other because the long side does not contact the long side of the opening 15. Further, through holes for attaching to the output unit 13 are provided on both side surfaces of the long side.

[0020]

[Effect of device]

 Since the present invention is configured as described above, the rectangular-shaped piezoelectric element 1 is fixed on the substantially same plane as the printed board 13 by the fixture 14. Therefore, the power supply device using the rectangular piezoelectric element 1 can be thinned. Further, when the vibration mode is changed and used, the fixing jig 14 is moved to the vibration node position of the rectangular piezoelectric element 1 and locked using the concave portion of the plurality of concave portions 16 at the optimum position. be able to.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an onboard high voltage generator according to the present invention.

FIG. 2 is an assembly view of an onboard high voltage generator according to the present invention.

FIG. 3 is a schematic view of a conventional piezoelectric transformer.

FIG. 4 is an exploded perspective view of a conventional piezoelectric transformer power supply.

[Explanation of Codes] 1 rectangular piezoelectric element 2 input part 3 output part 4A, 4B input electrode 5 output electrode 8 mounting tool 10 board 11 groove 12 standing part 13 printed board 14 mounting tool 15 opening 16 recess 17 groove 18 penetrating Hole 19 convex

Claims (1)

[Scope of utility model registration request] 1. A rectangular piezoelectric element, a fixture attached to the rectangular piezoelectric element, and a printed circuit board having a rectangular opening for arranging the rectangular piezoelectric element,
Grooves extending in the short side direction are provided at both ends of the fixture in the long side direction, at least one recess is provided facing each long side of the opening, and the fixture is mounted in the recess. Power supply.