JPH0722558U - On-board power supply - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a thin on-board power supply by taking advantage of the thinness of the piezoelectric transformer. [Structure] A transformer housing opening 11 is formed in a region where a piezoelectric transformer is arranged on a circuit board 2. The elastic node 5 of the vibration of the piezoelectric transformer 1 is held by the elastic holding member 12, the piezoelectric transformer 1 is arranged in the transformer housing opening 11 of the circuit board 2, and the fitting groove 13 of the elastic holding member 12 and the circuit board 2 are arranged. The piezoelectric recess 1 is fitted into the fitting recess 9 to connect the piezoelectric transformer 1 to the transformer housing opening 11 of the circuit board 2.
It will be suspended in the air. Next, the piezoelectric transformer 1 is conductively connected to a predetermined position of a power supply circuit formed on the circuit board 2 to produce an onboard power supply.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an on-board type power supply used for a backlight of a liquid crystal screen of a personal computer.

[0002]

[Prior art]

 FIG. 3 shows a main configuration of a conventional on-board type power supply for backlight. In the figure, a power supply circuit having circuits for oscillation, control, rectification, etc. is formed on the circuit board 2, and a U-shaped configuration for holding the piezoelectric transformer 1 is provided in an arrangement area E of the piezoelectric transformer 1 on the circuit board 2. The insulation holding fitting portions 4A and 4B are provided so as to face each other in the arrangement region E 1 of the piezoelectric transformer 1. Further, as shown in FIG. 3B, an insulating elastic body 3 such as rubber shown in FIG. 3C is fitted to a part of the piezoelectric transformer 1, that is, a vibration node 5 in the figure. The holes 8 are used for fitting. The elastic body 3 holding the piezoelectric transformer 1 is fitted between the U-shaped holding fitting portions 4A and 4B on the circuit board 2, and the driving side electrodes 15A and 15B of the piezoelectric transformer 1 are connected to the power circuit of the circuit board 2. The on-board power supply 10 is connected to the electrodes so that the output of the transformer is directly output from the output side electrode 16 of the piezoelectric transformer 1, or the electrode 16 is connected to a required circuit formed on the circuit board. Is formed.

The piezoelectric transformer 1 is formed by firing a ceramic material such as lead zirconate titanate or the like into a thin strip-shaped structure as shown in FIG. Electrodes 15A and 15B are formed on the front and back surfaces on the driving side of the piezoelectric transformer 1 by vapor deposition or baking, and electrodes 16 are also formed on the side surface of the tip on the output side. The extraction lead 17 is connected.

This piezoelectric transformer 1 converts the electric signal into mechanical vibration when an electric signal is applied to the driving portion of the piezoelectric transformer 1 as shown in FIG. 4, and further converts the mechanical vibration into an electric signal. It is taken out from the output part through an electrical → mechanical → electrical conversion system and performs impedance conversion during mechanical vibration to perform boosting action.

This piezoelectric transformer 1 is polarized in the thickness direction on the input side (driving side) and in the horizontal direction (length direction) on the output side. When mechanical vibration is boosted by impedance conversion. Since the magnitude of the output is proportional to the length and inversely proportional to the thickness, the piezoelectric transformer 1 is suitable for a thin on-board power supply for a backlight.

[0006]

[Problems to be solved by the device]

 However, the high-voltage power supply for the backlight of the LCD screen is formed by a U-shaped tube with a light (discharge tube) diameter of 3 mm, and the on-board power supply 10 installed in parallel with this U-shaped tube requires the same thickness. Has been done. However, since the conventional on-board type power supply 10 has the piezoelectric transformers 1 arranged in a layered manner on the circuit board 2, the on-board type power supply 10 becomes thicker and thinner. It was extremely difficult to make a power supply. Therefore, there is a problem that the thinness feature of the piezoelectric transformer 1 cannot be utilized. A transformer that uses windings as a backlight power transformer can be considered, but this transformer has a limit of 5 mm no matter how thin it is, so it is too thick for a backlight power transformer. There's a problem.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a thin on-board power supply by utilizing the thinness of the piezoelectric transformer.

[0008]

[Means for Solving the Problems]

 The present invention is configured as follows in order to achieve the above object. That is, in the on-board power supply of the present invention, the power supply circuit of the portion excluding the piezoelectric transformer is printed and formed on the circuit board, and the piezoelectric transformer is held by the elastic holding member at a part thereof, and the elastic holding member is used to hold the piezoelectric transformer. In an on-board power supply in which a piezoelectric transformer is mounted on a circuit board and the piezoelectric transformer and the power supply circuit are electrically connected to each other, a transformer accommodating opening is formed in the area where the piezoelectric transformer is arranged on the circuit board. The piezoelectric transformer is configured to be held in the accommodation opening by the elastic holding member and suspended in the air.

[0009]

[Action]

 A transformer accommodating opening is provided in the area where the piezoelectric transformer is arranged on the circuit board, and the power supply circuit is formed by printing on the portion excluding the transformer accommodating opening. An elastic holding member that holds a part of the piezoelectric transformer is fitted in the transformer housing opening, the piezoelectric transformer is suspended in the transformer housing opening of the circuit board, and the piezoelectric transformer and the circuit board are electrically connected to each other. Create an on-board power supply. As a result, the onboard power supply is made thinner.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In the description of the present embodiment, the same reference numerals will be given to the same names as those in the conventional example, and detailed description thereof will be omitted. FIG. 1 shows the main configuration of the on-board power supply of this embodiment. The on-board type power supply of this embodiment is used for the power supply of the backlight as in the conventional example.

The on-board type power supply of this embodiment is characterized in that a transformer accommodating opening 11 is formed in a region of the circuit board 2 where the piezoelectric transformer 1 is arranged, and the piezoelectric transformer 1 is elastic in the transformer accommodating opening 11. That is, it is suspended by the holding member 12.

In FIG. 1, a power supply circuit is formed by printing on a portion of the circuit board 2 excluding the region where the piezoelectric transformer 1 is arranged, and a transformer housing opening 11 is formed in the region where the piezoelectric transformer 1 is arranged. The transformer accommodating opening 11 is provided with a fitting concave portion 9 into which an elastic holding member 12 having a rubber elastic insulating property shown in FIG. 1C is fitted. The elastic holding member 12 is provided with a fitting groove 13 that fits into the fitting recess 9 of the transformer housing opening 11, and an insertion holding hole 14 for inserting the piezoelectric transformer 1 and holding the piezoelectric transformer.

As in the conventional example, the piezoelectric transformer 1 has electrodes 15A and 15B formed on both front and back surfaces of the drive unit, and an electrode 16 formed on the tip side of the output unit, and a lead 17 for each electrode. Direct solder connection.

Next, a method for manufacturing the on-board type power supply of this embodiment will be described with reference to FIG. First, the transformer housing opening 11 is formed in the area where the piezoelectric transformer 1 is arranged on the circuit board 2. A power supply circuit is formed by printing on the circuit board 2 excluding the transformer housing opening 11. Moreover, the piezoelectric transformer 1 shown in FIG. 1B is inserted into the elastic holding member 12 shown in FIG. 1C, and the elastic holding member 12 is used at the vibration node 5 of the piezoelectric transformer 1. Hold. Next, the piezoelectric transformer 1 held by the elastic holding member 12 is fitted into the transformer housing opening 11 of the circuit board 2 by the fitting recess 9 of the transformer housing opening 11 and the fitting groove 13 of the elastic holding member 12, and the piezoelectric transformer 1 is held by an elastic holding member 12 and suspended in the air at a substantially center position of the thickness of the circuit board 2. Next, the lead-out lead 17 soldered to the electrodes 15A and 15B of the driving portion of the piezoelectric transformer 1 is connected to the power supply circuit formed on the circuit board 2, and is not connected to the electrode 16 of the output portion of the piezoelectric transformer 1. The output of the transformer is directly taken out from the lead-out lead 17 which is connected, or the lead-out lead 17 is connected to a circuit formed on the circuit board 2 to produce an on-board type power supply.

According to this embodiment, since the piezoelectric transformer 1 is suspended from the center of the thickness of the circuit board 2, the circuit board 2 is kept as it is, and the piezoelectric transformer 1 is interposed via the elastic holding member 12. Since it is used to support the piezoelectric transformer 1, it is not necessary to hold the piezoelectric transformer 1 by the holding and fitting portion 4 on the circuit board 2 as in the conventional case, and the piezoelectric transformers 1 are not stacked on the circuit board 2 in a hierarchical manner. The thickness of the on-board power supply can be significantly reduced compared to the conventional example.

Further, in the present embodiment, since the elastic holding member 12 having rubber elasticity is used to hold the piezoelectric transformer 1, even if vibration or the like is applied to the onboard type power source 10 from the outside, the piezoelectric transformer can be held by the rubber elasticity. The vibration applied to the piezoelectric transformer 1 can be moderated, and even when the piezoelectric transformer 1 is inserted into the elastic holding member 12 to hold the piezoelectric transformer, the elasticity of the rubber prevents the piezoelectric transformer 1 from chipping or cracking. it can.

Further, since the circuit board 2 is used as it is for supporting the elastic holding member 12, the holding fitting portions 4A and 4B having a U-shape unlike the conventional ones are not required, and the cost of parts can be reduced.

Furthermore, since the vibration node 5 of the piezoelectric transformer 1 is held, the vibration is not hindered.

The present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted. For example, in the above-described embodiment, the lead wire is directly soldered to the electrodes of the driving section and the output section of the piezoelectric transformer 1. However, a conductor is interposed between the elastic holding member 12 and the electrode, and the lead wire is connected to this conductor. Alternatively, as shown in FIG. 2, the elastic holding member 12 has a three-layer structure, the insulating layer 7 is sandwiched by the conductive layers 6, and the conductive layers 6 are directly used as electrodes. May be connected.

Further, in the above embodiment, the number of vibration nodes 5 of the piezoelectric transformer 1 is one, but it may be two or more, and the number is not limited. Further, it may be configured to hold a position slightly deviated from the vibration node 5.

Further, in the above embodiment, the piezoelectric transformer 1 is suspended in the air at a substantially center position of the thickness of the circuit board 2, but it may be slightly displaced from the center position. In this case as well, the thickness of the on-board power supply 10 can be made sufficiently thin as compared with the conventional example.

[0022]

[Effect of device]

 In the present invention, since the piezoelectric transformer is suspended in the transformer housing opening of the circuit board, the circuit board is used as it is for supporting the piezoelectric transformer through the elastic holding member. Since the piezoelectric transformers are not stacked in layers on the upper side of the substrate, the thickness of the on-board power supply can be significantly reduced compared to the conventional example.

Further, since the circuit board is used as it is for supporting the elastic holding member, the conventional U-shaped holding and fitting portion is not required, and the cost of parts can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a main part configuration of an on-board power supply according to an embodiment.

FIG. 2 is an explanatory diagram of an electrode connection system having another configuration of the on-board power supply according to the present embodiment.

FIG. 3 is an explanatory diagram of a main part configuration of a conventional on-board type power supply.

FIG. 4 is an explanatory diagram of a piezoelectric transformer.

[Explanation of symbols]

 1 Piezoelectric transformer 2 Circuit board 5 Vibration node 9 Fitting recess 10 On-board type power supply 11 Transformer housing opening 12 Elastic holding member 13 Fitting groove

Claims (1)

[Scope of utility model registration request] 1. A power supply circuit of a portion excluding the piezoelectric transformer is formed by printing on a circuit board, and the piezoelectric transformer is held by an elastic holding member at a part thereof, and the piezoelectric transformer is mounted on the circuit board via the elastic holding member. In an on-board power supply that is mounted and in which the piezoelectric transformer and the power supply circuit are electrically connected to each other, a transformer housing opening is formed in an area where the piezoelectric transformer is arranged in the circuit board, and the piezoelectric transformer is provided in the transformer housing opening. An on-board power supply, characterized in that it is held by an elastic holding member and is suspended in the air.