Common mode filter

1. A common mode filter comprising:

a winding core part including first, second, third, fourth, and fifth sections arranged in an axial direction in this order; and

first and second wires wound around the winding core part,

wherein the first and second wires cross each other once in each of the third and fifth sections,

wherein the first and second wires do not cross each other in each of the second and fourth sections, and

wherein the first and second wires cross each other twice in the first section.

2. The common mode filter as claimed in claim 1 ,

wherein the first and second wires constitute a double layer structure in each of the second and fourth sections, and

wherein the first and second wires constitute a single layer structure in the first section.

3. A common mode filter comprising:

a winding core part; and

first and second wires wound in a same direction around the winding core part,

wherein a predetermined one turn of the first wire crosses a predetermined one turn of the second wire a plurality of times,

wherein the winding core part includes a first winding area positioned on one axial end side thereof, a second winding area positioned on another axial end side thereof, and a third winding area positioned between the first and second winding areas,

wherein the first and second wires constitute a first winding block wound in the first winding area and a second winding block wound in the second winding area, the predetermined one turn of the first wire crossing the predetermined one turn of the second wire a plurality of times in order to suppress an unbalance caused by crossing the first wire and the second wire in the second winding block,

wherein the first and second wires cross each other in the third winding area,

wherein a space is formed between the first and second wires in the third winding area and the first and second wires in each of the first and second winding areas, and

wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire are included in the first winding block.

4. The common mode filter as claimed in claim 3 ,

wherein each of the first and second winding blocks includes a first winding layer positioned in a lower layer and a second winding layer positioned on an upper layer of the first winding layer,

wherein the first winding block includes a first layer part in which one of the first and second wires is positioned in the first winding layer and the other one thereof is positioned in the second winding layer and a non-layer part in which both the first and second wires are positioned in the first winding layer, and

wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire are included in the non-layer part.

5. The common mode filter as claimed in claim 4 , wherein the second winding block includes a second layer part in which one of the first and second wires is positioned in the first winding layer and the other one thereof is positioned in the second winding layer.

6. The common mode filter as claimed in claim 5 , wherein a number of turns in the first layer part and a number of turns in the second layer part are equal to each other.

7. The common mode filter as claimed in claim 5 ,

wherein the first and second wires are positioned in the first and second winding layers, respectively, in the first layer part, and

wherein the first and second wires are positioned in the second and first winding layers, respectively, in the second layer part.

8. The common mode filter as claimed in claim 5 , further comprising:

a first flange part provided at the one axial end of the winding core part;

a second flange part positioned at the another axial end of the winding core part;

first and second terminal electrodes provided on the first flange part and connected respectively with one ends of the first and second wires; and

third and fourth terminal electrodes provided on the second flange part and connected respectively with other ends of the first and second wires,

wherein the non-layer part is positioned between the one ends of the first and second wires and the first layer part.

9. The common mode filter as claimed in claim 8 ,

wherein the first and second wires cross each other an even number of times in the first winding block, and

wherein last turns which are closest to the other ends of the respective first and second wires in the second winding block cross each other once.

10. The common mode filter as claimed in claim 3 , wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire cross each other a plurality of times such that one of the first and second wires is positioned on an upper side, and the other one thereof is positioned on a lower side.

11. The common mode filter as claimed in claim 3 , wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire cross each other four times without crossing each other more than four times.

12. The common mode filter as claimed in claim 11 ,

wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire cross each other in first, second, third, and fourth cross points, and

wherein one of the first and second wires is positioned on an upper side, and other one thereof is positioned on a lower side in each of the first, second, third, and fourth cross points.

13. The common mode filter as claimed in claim 3 ,

wherein the winding core part has a plurality of surfaces including first and second surfaces, and

wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire cross each other once in each of the first and second surfaces without crossing each other more than once.

14. The common mode filter as claimed in claim 13 ,

wherein the plurality of surfaces further includes a third surface, and

wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire do not cross each other in the third surface.

15. The common mode filter as claimed in claim 3 , wherein the first and second wires do not cross each other in the second winding block.

16. The common mode filter as claimed in claim 3 , wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire cross each other twice without crossing each other more than twice.

17. The common mode filter as claimed in claim 16 ,

wherein the predetermined one turn of the first wire and the predetermined one turn of the second wire cross each other in first and second cross points, and

wherein one of the first and second wires is positioned on an upper side, and other one thereof is positioned on a lower side in each of the first and second cross points.

18. The common mode filter as claimed in claim 3 , wherein remaining turns of the first and second wires in the first winding block do not cross each other.

19. A common mode filter comprising:

a winding core part; and

first and second wires wound around the winding core part, the first and second wires including first and second turns,

wherein the first turn of the first and second wires cross each other an even number of times,

wherein the second turn of the first and second wires do not cross each other,

wherein the first and second wires further include a third turn, and

wherein the third turn of the first and second wires cross each other an odd number of times.