| 摘要 |
PROBLEM TO BE SOLVED: To prevent output reduction of a sensor with a temperature increase when driving a motor by assuring a light-shielding area of the sensor, while disposing the sensor positioning notch of a cup-like frame away from an external yoke to thereby avoid a direct contact therebetween. SOLUTION: When two or one coil bobbin is energized, a motor shaft 1 is forcibly rotated by the external source, and a slit plate 5 is thereby rotated. Then, the plate 5 passes through the light-shielding portion of a sensor 6, and thus the sensor generates its output. In order to prevent a direct contact between the yoke 2 and the sensor 6, a frame 17 having a sensor positioning/fixing notch is provided. As a result, an air gap is provided between the yoke 2 and the sensor 6 to thereby make them noncontact. Therefore, the rotation of a motor can be controlled by the output of the sensor, and the reduction in the output of the sensor section caused due to a temperature increase when driving the motor is also prevented. When the contact between the sensor positioning/ fixing portion of the frame 7 and the sensor 6 is made extremely smaller than the outside dimensions of the sensor 6, the output of the sensor section can be stabilized. |
