JP3240082B2 - Inverter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device in which an inverter circuit used for lighting a cold-cathode tube for illuminating the back of a liquid crystal display device is integrated as one composite part.

[0002]

2. Description of the Related Art A circuit configuration of a commonly used inverter device for lighting a cold cathode fluorescent lamp CFL is, for example, as shown in FIG. 5 and includes a primary winding 35, a feedback winding 36, and a secondary winding 50. , An output transformer T, a choke coil 60, transistors Q ₁ and Q ₂ , capacitors C ₁ and C ₂ , and resistors R ₁ and R ₂ . The conventional inverter device has a configuration in which these circuit components are mounted on a single printed circuit board, and the transformer T, the choke coil 60, and the like, which are completed as individual components in advance, are individually printed on the printed circuit board. It was fitted and assembled.

[0003]

The inverter device is required to be particularly thin because it is mounted in a narrow gap. However, in the conventional structure in which components such as the transformer T and the choke coil 60 are mounted on a printed circuit board, the entire inverter device becomes large, it is difficult to make the inverter device thin, and it takes time and effort to assemble. .

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inverter device which can be easily made thin and has good productivity.

[0005]

In order to achieve this object, the present invention relates to a circuit portion other than the cold-cathode tube CFL of the inverter device, or a circuit portion other than the cold-cathode tube CFL and the secondary side load current limiting capacitor C2. The circuit part is integrated into one small and thin block. That is, the inverter device according to the present invention has first and second magnetic plates having first and second winding shafts 11 and 12 and abutting each other to form a closed magnetic path.
10 and 40, a first through hole 31 into which the first winding shaft 11 is inserted, and a second through hole 32 into which the second winding shaft 12 is inserted. And a primary winding 35 formed by a conductor pattern at a position around the first winding shaft 11.
A secondary winding 50 disposed around the second winding shaft 12 and electromagnetically coupled to the primary winding 35, a magnetic core 70 forming a second closed magnetic path together with the first magnetic plate 10, A third magnetic member formed integrally with either the first magnetic plate 10 or the magnetic core 70
And a choke coil 60 attached around the third reel 13 to form terminals 37 and 38 made of a conductor pattern on both ends of the flexible printed circuit board 30.
Both ends of the flexible printed board 30 are wound around and fixed to the ends of the first magnetic plate 10 so that the 37 and 38 are exposed to the outside, and a circuit such as a transistor or a capacitor is formed on the conductor pattern of the flexible printed board 30. Part 90
Is characterized by the configuration in which.

[0006]

1 to 3 show an embodiment of an inverter device according to the present invention. The cold cathode fluorescent lamp CFL shown in FIG.
And it summarizes the circuit portions other than the capacitor C ₂ in one block. 1 is a front sectional view, FIG. 2 is a plan view,
FIG. 3 is a plan view of the main part of the inverter device, with the magnetic plate 40, the magnetic core 70, etc. removed. Insulating magnetic plate 10
Is integrally formed with three cylindrical winding shafts 11, 12, 13 projecting upward. On the magnetic plate 10, a flexible printed circuit board 30 having three through holes 31, 32, 33 as shown in FIG. The winding shaft 11 is inserted into the through hole 31 of the printed circuit board 30, and the through hole 32
, The winding shaft 12 is inserted, and the winding shaft 13 is inserted into the through hole 33. On the front and back surfaces of the printed circuit board 30 near the through hole 32, terminals 39 are provided to expose a part of the conductor pattern, and on the printed circuit board 30 near the through hole 33, a part of the conductor pattern is exposed. Two terminals
34 are provided. On the front and back of the printed circuit board 30, a primary winding 35 and a feedback winding 36 on the low voltage side of the transformer T are formed around the through-hole 31 by spiral conductive patterns connected through through holes (not shown). is there.
This feedback winding 36 may not be provided depending on the inverter device. Terminals 37 and 38 made of a conductor pattern are formed at both ends of the printed circuit board 30, respectively. The printed circuit board 30 is wound around and fixed to the ends of the magnetic plate 10 whose both ends are rounded so that the terminals 37 and 38 are exposed to the outside. The conductor pattern of the printed circuit board 30 includes a primary winding 35, a feedback winding 36, and an electrode on the upper surface side.
Illustration is omitted except for a part such as 37 and terminal 34.

Around the winding shaft 12, a secondary winding 50 on the high voltage side which is wound into a ring shape is mounted. The secondary winding 50 is
In order to ensure a withstand voltage, the wires are aligned and wound in multiple layers from the inside to the outside. The inner lead wire of the secondary winding 50 is connected to a terminal (not shown) provided on the back surface of the printed circuit board 30 through the through hole 32, and the outer lead wire
51 is connected to the terminal 39 on the surface. Therefore, the inner lead wire is insulated by the printed circuit board 30 from the outer portion of the secondary winding 50 having a large potential difference. Between the secondary winding 50, the primary winding 35, and the feedback winding 36, the insulating paint 20 is applied so as to be thickly raised in order to ensure the withstand voltage. Further, the magnetic plate 40 is fixed by abutting on the winding shafts 11 and 12 of the magnetic plate 10 to form a closed magnetic path, and the primary winding 35 and the feedback winding 36 are connected to the secondary winding 50.
And electromagnetic coupling. Note that an insulating film 80 is attached below the magnetic plate 40 in order to reduce the possibility of magnetic saturation. A surface connection type choke coil 60 in which a wire is wound around a bobbin 65 and both ends are connected to an electrode (not shown) on the lower portion of the bobbin 65 is fitted into the winding shaft 13, and this electrode is soldered to a terminal 34. Then, a cap-shaped magnetic core 70 is covered. The conductor pattern (not shown) on the surface of the printed circuit board 30 includes circuit components such as transistors, capacitors, and resistors.
90 are installed. The terminal 37 is connected to the terminal 34 to which the choke coil 60 is connected and the circuit component 90 by a conductor pattern, and the terminal 38 is the terminal to which the secondary winding 50 is connected.
39 is connected by a conductor pattern.

The inverter device can be easily assembled, for example, as follows. First, the secondary winding 50 pre-wound and fixed on the flexible printed circuit board 30 is bonded and fixed, and the lead wire 51 is connected to the terminal 39. At this time, the lead wire inside the winding is drawn out to the back side of the printed circuit board 30 through the through hole 32 and connected to the terminal on the back surface of the printed circuit board 30, and the outer lead wire 51 is connected to the terminal 39 on the front surface of the printed circuit board 30. I do. Next, through holes 31, 32,
Place the printed circuit board 30 on the magnetic plate 10 while passing the winding shafts 11, 12 and 13 through 33 respectively.
Adhesively fix by winding around 10. Printed circuit board 30
The terminals 37 and 38 on the surface of the magnetic plate 10 are exposed on the side and lower surfaces of the magnetic plate 10. Next, the imposition type choke coil 60 wound around the bobbin 65 is fitted to the winding shaft 13, and the electrode provided on the bobbin 65 is connected to the terminal 34. Then, a transistor, a capacitor,
The circuit components 90 such as resistors are mounted. Further, the magnetic plate 40 having the insulating film 80 attached to the lower surface is adhered and fixed to the winding shafts 11 and 12, and the core 70 is fixed to the winding shaft 13 to complete the process.

The through-hole 33 for the choke coil 60 in the printed circuit board 30 is not a through-hole.
It may be formed in a notch shape cut from the side surface of 30.
In place of the insulating paint 20, a flat insulating ring having a hole that can be fitted into the winding shaft 11 may be used. Reel 11,1
Instead of forming the windings 2 and 13 on the magnetic plate 10, the winding shafts 11 and 12 may be provided on the magnetic plate 40 side and the winding shaft 13 may be provided on the core 70 side. Furthermore, it is also possible to implement the capacitor C ₂ to the printed circuit board 30 in FIG.

[0010]

According to the present invention, it is possible to obtain a small inverter device in which circuit components are assembled on a magnetic plate forming a core of a transformer and are integrated into one block. Since the thickness is about the thickness of the choke coil, the thickness can be extremely reduced. In addition, the lead wire inside the secondary winding can be easily insulated from the outside part of the secondary winding, and the number of parts is small, so that the components can be sequentially stacked and easily assembled.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the inverter device of the present invention.
AA line sectional view of

FIG. 2 is a plan view of the same.

FIG. 3 is a plan view of a main part of the inverter device.

FIG. 4 is a reduced plan view of a printed circuit board.

FIG. 5 is a circuit diagram of an inverter device.

[Explanation of symbols]

 10 ・ 40 Magnetic plate 11 ・ 12 ・ 13 Roller shaft 30 Printed circuit board 34 ・ 39 Terminal 35 Primary winding 37 Electrode 50 Secondary winding 60 Choke coil 70 Magnetic core

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H05B 41/24-41/29 H01F 30/00 H05K 1/18

Claims (1)

(57) [Claims] A first winding shaft having a first winding shaft and a second winding shaft facing each other;
First and second magnetic plates that are closed to form a closed magnetic circuit;
The first through hole into which the winding shaft is inserted and the second winding shaft are inserted
Conductor pattern is provided on both surfaces
Flexible print placed on the first magnetic plate
The conductor pattern is provided at a position around the substrate and the first winding axis.
And a primary winding formed around the second winding axis.
A secondary winding electromagnetically coupled to the primary winding;
A magnetic core forming a second closed magnetic path with the plate;
Formed integrally with either the magnetic plate or the magnetic core
A third reel formed and mounted around the third reel.
With flexible choke coil
Terminals formed of a conductor pattern at both ends of the
The flexible printed circuit board is exposed to the outside
Wrap both ends of the first magnetic body plate around the ends and fix them
And an inverter device having a circuit component mounted on the conductor pattern .