Patent ID: 8994252
Filing Date: 2015-03-31
Classification: H03H

Abstract:
1. A quartz plate having chamfered ridge portions and an almost rectangular shape in planar view, wherein a resonance frequency is equal to or larger than 7 MHz and equal to or smaller than 9 MHz, lengths of long and short sides of the rectangular shape are equal to or larger than 1.5 mm and equal to or smaller than 2.4 mm, sub-vibration is present in a range of frequencies higher than a range of frequencies of primary vibration by equal to or larger than 975 kHz and equal to or smaller than 1,015 kHz, and in ridges of the quartz plate in a direction of side thickness thereof (Y direction), first regions by ¼L from a center of the long sides toward ends of the long sides have a shape having a first curvature radius R