A thin hybrid magnetized ring magnet comprising a plurality of magnetic poles each having a first magnetic pole boundary at a first end of said magnetic pole and a second magnetic pole boundary at a second end of said magnetic pole, wherein said ring magnet comprises: a plurality of main pole regions ( 11a, 11b, 11c) being radially aligned and radially magnetized; and a plurality of interface regions ( 12a, 12b) existing between adjacent two of said main pole regions ( 11a, 11b, 11c), each interface region having a left side region of said first magnetic pole boundary and a right side region of said first magnetic pole boundary, wherein said interface regions ( 12a, 12b) are polar anisotropically aligned and polar anisotropically magnetized such that each interface region comprises two poles both on the outer peripheral surface or the inner peripheral surface of the ring magnet, a pole of said left side region is the same polarity as the pole of said main pole region left-adjacent to the left side region and a pole of said right side region is the same polarity as the pole of said main pole region right-adjacent to the right side region on the same peripheral surface of the ring magnet, wherein the polar anisotropic magnetization is realized such that between the two poles of each interface region ( 12a, 12b) the alignment direction and the direction of the magnetization gradually change and invert along the circumferential direction; wherein said ring magnet is an anisotropic rare earth bonded magnet comprising anisotropic rare earth powders and resin; characterized in that W/h is greater than 4 and less than 20, and w/h is greater than 1 and less than 4, when the thickness in radial direction of said ring magnet is h, the width in a circumferential direction of said each magnetic pole is W and the width in a circumferential direction of said interface region ( 12a, 12b) is w. a plurality of main pole regions ( 11a, 11b, 11c) being radially aligned and radially magnetized; and a plurality of interface regions ( 12a, 12b) existing between adjacent two of said main pole regions ( 11a, 11b, 11c), each interface region having a left side region of said first magnetic pole boundary and a right side region of said first magnetic pole boundary, wherein said interface regions ( 12a, 12b) are polar anisotropically aligned and polar anisotropically magnetized such that each interface region comprises two poles both on the outer peripheral surface or the inner peripheral surface of the ring magnet, a pole of said left side region is the same polarity as the pole of said main pole region left-adjacent to the left side region and a pole of said right side region is the same polarity as the pole of said main pole region right-adjacent to the right side region on the same peripheral surface of the ring magnet, wherein the polar anisotropic magnetization is realized such that between the two poles of each interface region ( 12a, 12b) the alignment direction and the direction of the magnetization gradually change and invert along the circumferential direction; wherein said ring magnet is an anisotropic rare earth bonded magnet comprising anisotropic rare earth powders and resin; characterized in that W/h is greater than 4 and less than 20, and w/h is greater than 1 and less than 4, when the thickness in radial direction of said ring magnet is h, the width in a circumferential direction of said each magnetic pole is W and the width in a circumferential direction of said interface region ( 12a, 12b) is w.