Patent ID: 7414238

Claim:
An optical encoder device for a small-sized motor including a motor shaft extending to the exterior of the motor through a bearing accommodated in a bearing-retaining section provided on an end bell of the motor and paired motor terminals extending from positions on radially opposite sides of the motor shaft to the exterior of the end bell, the optical encoder device including a code wheel attached to the motor shaft and a board on which a photosensor module is mounted and which is attached to the paired motor terminals such that an optical modulation track portion of the code wheel is positioned and disposed in a gap of the photosensor module, the optical encoder device comprising: the motor, a spacer, and the board being fixed together by soldering the paired motor terminals to a printed wiring portion of the board, while the spacer is sandwiched between the end bell and the board on which the photosensor module is mounted; and the spacer having a generally U-shaped structure having a center hole for positioning the bearing-retaining section, and an introduction path continuous to the center hole, so as to allow fitting in position thereof through the introduction path from a direction orthogonal to the motor shaft.