| 摘要 |
A quartz crystal unit comprising a quartz crystal tuning fork resonator having a quartz crystal tuning fork base, and first and second quartz crystal tuning fork tines, at least one groove being formed in at least one of opposite main surfaces of each of the first and second quartz crystal tuning fork tines, each of a length of the at least one groove and an overall length of the quartz crystal tuning fork resonator being determined so that a series resistance R1 of a fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a series resistance R2 of a second overtone mode of vibration thereof, the quartz crystal tuning fork resonator being housed in a case, a lid being connected to the case to cover an open end of the case, a metal or a glass being disposed in a through-hole of the case. |
