MOVEMENT FOR CLOCK AND CLOCK

To accurately detect a reference position of a hand.SOLUTION: A movement for a clock comprises: a first load change gear, of a plurality of gears, which makes one revolution in a number of steps according to the number of steps for one revolution of a hand whose rotational position is to be detected, in which magnitude of a rotational load received by a rotor at a predetermined rotational position is different from magnitude of the rotational load received by the rotor at other rotational position; a second load change gear, of the plurality of gears, which makes one revolution in a number of steps smaller than the number of steps in which the first load change gear makes one revolution, in which the magnitude of the rotational load received by the rotor at the predetermined rotational position is different from the magnitude of the rotational load received by the rotor at other rotational position, and a frequency of occurrence of change in a load due to its rotation is a natural number times of a frequency of occurrence of change in a load due to the rotation of the first load change gear; a load change detection unit that detects change in the rotational load occurring in the rotor; and a rotational position determination unit that determines the rotational position of the hand on the basis of the change in the rotational load detected by the load change detection unit.SELECTED DRAWING: Figure 7 【課題】指針の基準位置を精度よく検出する。【解決手段】時計用ムーブメントは、複数の歯車のうち、回転位置検出対象の指針の１周分のステップ数に応じたステップ数によって１周し、所定の回転位置におけるロータが受ける回転負荷の大きさが他の回転位置におけるロータが受ける回転負荷の大きさと異なる第１の負荷変動歯車と、複数の歯車のうち、第１の負荷変動歯車が１周するステップ数よりも少ないステップ数によって１周し、所定の回転位置におけるロータが受ける回転負荷の大きさが他の回転位置におけるロータが受ける回転負荷の大きさと異なり、回転による負荷変動の発生頻度が第１の負荷変動歯車の回転による負荷変動の発生頻度の自然数倍である第２の負荷変動歯車と、ロータに生じる回転負荷の変動を検出する負荷変動検出部と、負荷変動検出部が検出する回転負荷の変動に基づいて、指針の回転位置を判定する回転位置判定部とを備える。【選択図】図７