Patent ID: 9071103
Filing Date: 2015-06-30
Classification: G02B,H02K,H04N

Abstract:
1. A color wheel driving motor, comprising: a shaft rotatable about a center axis, and the shaft extending along the center axis; a rotary body including a rotor holder indirectly or directly fixed to the shaft; and a stationary body including a magnetic position detector mechanism arranged near the rotor holder to detect a rotation position of the rotor holder, wherein the motor includes a ring-shaped magnet arranged radially outward of the rotor holder and configured to rotate together with the rotor holder; the ring-shaped magnet includes a first end surface and a second end surface arranged along the center axis in a substantially parallel relationship with each other; the ring-shaped magnet includes n number of N-pole and n number of S-pole alternately arranged along a circumferential direction and magnetic pole changeover portions arranged between the N-pole and the S-pole adjoining each other; the number of the magnetic pole changeover portions is 2n; the magnetic pole changeover portions adjoining each other are arranged at an angular interval of 360°/2n in the circumferential direction; the n is an integer equal to or larger than 1; on an imaginary plane perpendicular to the center axis, a first straight line passing through the center axis and at least one of the magnetic pole changeover portions makes a specified angle θ with respect to a second straight line extending from the center axis toward the ring-shaped magnet, a first mark being arranged in a region of a surface of the ring-shaped magnet where the second straight line overlaps with the ring-shaped magnet; and the specified angle θ is equal to or larger than 0° and equal to or smaller than 360°/2n.