Patent ID: 7116201

Claim:
A high-voltage transformer comprising: an insulating secondary-side bobbin made up of a roll, around which a secondary winding electromagnetically coupled with a primary winding is wound, divided into a plurality of winding sections lined up in a direction in which a central axis of the roll extends by a plurality of partition flanges arranged separated from one another in said direction, wherein grooves are formed in said partition flanges for passing said secondary winding from a low-voltage side winding section adjacent to said partition flange to a high-voltage side winding section, wherein the roll surface of said high-voltage side winding section is constructed so as to be located outward in radial direction with respect to the roll surface of said low-voltage side winding section in the vicinity of said groove, and wherein at least one set of two winding sections out of said plurality of winding sections provided for said secondary-side bobbin are constructed in such a way that each roll surface within a surface crossing said central axis at right angles has a flat cross section and the respective axis lines corresponding to a major axis in the cross section of said each roll surface cross each other when viewed from a direction in which said central axis extends.