Abstract: A spin speed measuring device almost free of malfunction is provided at low cost. The spin speed measuring device includes a casing, a spinning body pivotally supported in the casing, a pinion gear configured to spin together with the spinning body, a belt having a rack and a plurality of indicators, the rack being configured to mesh with the pinion gear, and a detector attached to the casing to detect the indicator passing by. The spin speed measuring device measures the spin speed of the spinning body. A spin speed of the spinning body is calculated from a time period from when one of the indicators passes by to when another one of the indicators passes by, the time period being obtained using signals output from the detector.
Abstract: A spin speed measuring device almost free of malfunction is provided at low cost. The spin speed measuring device includes a casing, a spinning body pivotally supported in the casing, a pinion gear configured to spin together with the spinning body, a belt having a rack and a plurality of indicators, the rack being configured to mesh with the pinion gear, and a detector attached to the casing to detect the indicator passing by. The spin speed measuring device measures the spin speed of the spinning body. A spin speed of the spinning body is calculated from a time period from when one of the indicators passes by to when another one of the indicators passes by, the time period being obtained using signals output from the detector.