Abstract: A crystal unit includes a crystal element, excitation electrodes, and a container. The crystal element vibrates in a thickness-shear mode. The excitation electrodes are disposed on front and back surfaces of the crystal element. The crystal element is mounted to the container. The excitation electrodes are disposed on the crystal element. When a thickness of the crystal element is expressed as T, and a total thickness of the excitation electrodes disposed on the front and back surfaces of the crystal element is expressed as t, a ratio t/T is from 0.026 to 0.030.

Abstract: An AT-cut crystal element includes a vibrator and a supporting portion. The vibrator has a planar shape with an approximately rectangular shape. The supporting portion is connected to one short side of the vibrator and has a thickness thicker than a thickness of the vibrator. The AT-cut crystal element has an oscillation frequency of approximately 76 Mhz. The vibrator has a distal end portion that is an end portion on a side opposite to the supporting portion. The distal end portion is formed to have a protrusion shape toward a distal end side thereof. The vibrator has both ends formed to have a protrusion shape toward an outside direction along the short side. The vibrator has a long side dimension L and a short side dimension W. A W/L is in a range of 0.74 to 0.79 or in a range of 0.81 to 0.93.

Abstract: An AT-cut crystal element includes a vibrator and a supporting portion. The vibrator has a planar shape with an approximately rectangular shape. The supporting portion is connected to one short side of the vibrator and has a thickness thicker than a thickness of the vibrator. The AT-cut crystal element has an oscillation frequency of approximately 76 Mhz. The vibrator has a distal end portion that is an end portion on a side opposite to the supporting portion. The distal end portion is formed to have a protrusion shape toward a distal end side thereof. The vibrator has both ends formed to have a protrusion shape toward an outside direction along the short side. The vibrator has a long side dimension L and a short side dimension W. A W/L is in a range of 0.74 to 0.79 or in a range of 0.81 to 0.93.

Abstract: A quartz-crystal unit comprises a container body having a recess, a quartz-crystal blank having a pair of excitation electrodes respectively disposed on one and the other principal surfaces, and a pair of extending electrodes respectively extended from the pair of excitation electrodes, and a cover for sealing an opening plane of the recess. The extending electrodes are led to both sides of one end of the crystal blank, and the one end is secured by a conductive adhesive to hold the crystal blank in the recess in parallel to the cover. The crystal unit satisfies 0<d/L<0.64, where L is the length from the one end to the other end opposing the one end in the crystal blank, and d is a gap between mutually opposing surfaces of the crystal blank and the cover.

Abstract: A quartz-crystal unit comprises a container body having a recess, a quartz-crystal blank having a pair of excitation electrodes respectively disposed on one and the other principal surfaces, and a pair of extending electrodes respectively extended from the pair of excitation electrodes, and a cover for sealing an opening plane of the recess. The extending electrodes are led to both sides of one end of the crystal blank, and the one end is secured by a conductive adhesive to hold the crystal blank in the recess in parallel to the cover. The crystal unit satisfies 0<d/L<0.64, where L is the length from the one end to the other end opposing the one end in the crystal blank, and d is a gap between mutually opposing surfaces of the crystal blank and the cover.