ROTATION ANGLE SENSOR

To provide a rotation angle detection sensor that is inexpensive and has high accuracy.SOLUTION: A rotation angle sensor 100 comprises: a ring-shaped metal rotating panel 3; and a print circuit board 5 on which a primary coil S supplied with a high-frequency current and a secondary coil group R outputting an induction current to a detection IC for detecting the induction current are arranged with the rings of these coils being along a surface. The rotating panel 3 has a target part 30 in which an outer peripheral edge part of the rotating panel 3 is formed into a sine waveform shape. The primary coil S is arranged to overlap the target part 30 in plan view of the print circuit board 5, and is formed into an arc shape along a direction of rotation of the rotating panel 3. The secondary coil group R has 4n (where n is a natural number) secondary coils 20 that are arranged in one line along the rotation direction on an inner peripheral side of the primary coil S, and the number of windings of the secondary coils 20 at the ends of the line is made smaller than the number of windings of the secondary coils 20 on the inside of the line.SELECTED DRAWING: Figure 6 【課題】安価で精度の高い回転角度検出センサを提供する。【解決手段】回転角度センサ１００は、環状で金属製の回転板３と、高周波電流を供給される一次コイルＳ、及び、誘導電流を検知する検知ＩＣに当該誘導電流を出力する二次コイル群Ｒ、がそれらコイルの環を面に沿わせて配置されたプリント基板５と、を備え、回転板３は、回転板３の外周縁部が正弦波形状に形成されたターゲット部３０を有し、一次コイルＳは、プリント基板５の平面視において、ターゲット部３０と重複して配置されており、回転板３の回転方向に沿う円弧状に形成され、二次コイル群Ｒは、一次コイルＳの内周側において、回転方向に沿って一列に配列された４ｎ個（ただし、ｎは自然数）の二次コイル２０を有し、列の端部側の二次コイル２０の巻数が、当該列の内側の二次コイル２０の巻数よりも少なくされている。【選択図】図６