JP2000068132A - Inverter transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inverter transformer attachable even to the thin and long space of a narrow width. SOLUTION: The outer shape of the cross section of the winding shaft 12 of a bobbin 10 is turned to an almost elliptic shape, the side of the narrow width is turned to a side face to which the terminals 21 and 22 of the base part 11 of the bobbin 10 are attached, and the winding shaft 12 is integrally molded at the base part 11. Also, a center leg 62 whose cross section is elliptic is formed at the center part of one core 60, and outer legs 63 are formed at four corners, respectively. The center leg 62 is inserted to the hole of the winding shaft 12, and the outer legs 63 are abutted to the core 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small, thin, and narrow inverter transformer suitable for use in an inverter for lighting a cold-cathode tube for back lighting of a liquid crystal display device.

[0002]

2. Description of the Related Art Conventional inverter transformers include those shown in FIGS. A bobbin 2 made of an insulating material having terminals 1a and 1b attached to two opposing side surfaces, and a secondary winding 3 and a primary winding 4 wound around a bobbin 2a of the bobbin 2 are vertically butted against each other. A pair of cores 5 and 6 are provided and lead wires of the secondary winding 3 and the primary winding 4 are connected to terminals 1a and 1b, respectively.

[0003]

A circuit board of an inverter for illuminating the back of a liquid crystal display device is usually mounted inside a frame around a display screen. However,
While the dimensions of the main body of a notebook computer or the like do not change, the screen size of the liquid crystal display device tends to increase, and accordingly, the width of the frame around the screen decreases. The conventional inverter transformer has a problem that it cannot be mounted inside a narrow frame with a large size. SUMMARY OF THE INVENTION An object of the present invention is to provide an inverter transformer that can be mounted even in a narrow and narrow space.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a bobbin made of an insulating material having a base portion having terminals attached to two opposing side surfaces, a hollow winding shaft projecting upward from the center of the base portion, and a winding shaft. It has a secondary winding and a primary winding wound around, and a pair of cores that are butted up and down, and the lead wires of the primary winding and the secondary winding are respectively connected to terminals on different side surfaces of the bobbin. In the inverter transformer, the outer shape of the cross section of the bobbin bobbin is made substantially elliptical, and the narrow side is directed toward the side surface on which the terminals of the base are mounted, and the bobbin is integrally formed with the base. A central leg of at least one of the cores has a central leg having an oval cross section, outer legs at four corners, each of which is formed to protrude toward the other core, and the central leg is inserted into a hole of the winding shaft. I do.

[0005]

1 to 4 show an embodiment of an inverter transformer according to the present invention. The plastic bobbin 10 includes a base portion 11 having a plurality of terminals 21 and 22 implanted on two opposing side surfaces, and a hollow winding shaft 12 projecting upward from the center of the base portion 11. The winding shaft 12 has a substantially elliptical cross-sectional outer shape, and the narrow side is the base portion 11.
The base portion 11 faces the side where the terminals 21 and 22 are mounted.
It is integrally molded with. An oval flange 13 is provided at the upper end of the winding shaft 12.
Are provided at both ends of the flange 13, and upwardly projecting portions 14 are provided. The two terminals 21 provided on one side surface of the bobbin 10 are connected to a lead wire connecting portion 21a integrally connected inside the base portion 11.
Respectively.

As shown in FIG. 3, a high voltage side secondary winding 30 is wound around the winding shaft 12 of the bobbin 10, and a low voltage side primary winding 40 is further wound outside the secondary winding 30. is there. The secondary winding 30 is formed by winding a wire in multiple layers from the inside to the outside.
The lead wire (not shown) of the secondary winding 30 is pulled out from the slit 15 provided in the base portion 11 of the bobbin 10 to the lower surface of the base portion 11 and connected to the lead wire connection portion 21a of the terminal 21 by means such as soldering. I have.

A lead wire (not shown) of the primary winding 40 is also pulled out from the slit 16 provided in the base portion 11 to the lower surface of the base portion 11 and then connected to the terminal 22. As the primary winding 40, a feedback winding or the like may be wound together, or a tap may be taken out on the way. Since these secondary windings 30 and primary windings 40 are wound around the winding shaft 12 of the bobbin 10 having a substantially elliptical cross section, they are formed in a narrow oval shape as a whole.

A pair of cores 50 and 60 made of a magnetic material are opposed to each other with the bobbin 10 sandwiched from above and below to form a closed magnetic path. The upper core 50 has a flat plate shape as a whole, and is provided with a notch 51 that fits with the protrusion 14 of the bobbin 10 at the center of two opposing side surfaces. Bobbin with notch 51 in core 50
The core 50 is positioned with respect to the bobbin 10 by fitting the ten protrusions 14.

The lower core 60 has a central leg 62 having a substantially oval cross section integrally formed at the center of the flat plate portion 61 and outer legs 63 at four corners. The center leg 62 is inserted into the hollow portion of the winding shaft 12. The base 11 of the bobbin 10 has four cutouts 18 (FIG. 4) through which the outer legs 63 pass, and the four outer legs 63 are engaged with the cutouts 18, respectively.
Of the core 60 with respect to. Central leg 62 is the outer leg
It is slightly shorter than 63, so that a gap is formed between the core 50 and the butted core 50 so that magnetic saturation hardly occurs.

[0010]

According to the present invention, it is possible to obtain a thin inverter transformer which is narrow and can be mounted in a narrow space.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a front view of the transformer.

FIG. 3 is a front sectional view of the transformer.

FIG. 4 is an exploded perspective view of the transformer.

FIG. 5 is a plan view of a conventional transformer.

FIG. 6 is a front sectional view of the transformer.

[Explanation of symbols]

 10 bobbin 11 base 12 winding shaft 30 secondary winding 40 primary winding 50, 60 core 62 center leg 63 outer leg

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kunihiko Yamashita, 18 Gomigaya, Oaza, Tsurugashima-shi, Saitama Toko Co., Ltd. (72) Hideyuki Isobe 18 Gomigaya, Tsurugashima-shi, Saitama Toko Co., Ltd. Saitama Office F-term (reference) 2H091 FA42Z FD12 GA02 GA11 LA08 LA11 LA12 5B069 BA04 BB20

Claims (1)

[Claims] 1. A bobbin made of an insulating material having a base portion having terminals attached to two opposing side surfaces and a hollow winding shaft protruding upward from the center of the base portion, and wound around the winding shaft. In an inverter transformer including a secondary winding and a primary winding, and a pair of cores vertically abutted, and connecting the lead wires of the primary winding and the secondary winding to terminals on different side surfaces of the bobbin, respectively, The cross section of the winding shaft has a substantially elliptical outer shape, and the winding shaft is integrally formed on the base portion with the narrow side facing the side surface of the base portion to which the terminal is attached, and the center of at least one of the cores is formed. An inverter transformer, wherein a central leg having an oval cross section is formed at each of the portions, and outer legs are formed at four corners so as to protrude toward the other core, and the central leg is inserted into a hole of the winding shaft.