Abstract: A quartz crystal tuning fork resonator has quartz crystal tuning fork tines for undergoing vibration in an inverse phase. Each of the quartz crystal tuning fork tines has a first main surface and a second main surface opposite the first main surface, each of the first and second main surfaces having a central linear portion. The quartz crystal tuning fork tines extend from a quartz crystal tuning fork base. At least one groove is formed in the central linear portion of each of the first and second main surfaces of each of the quartz crystal tuning fork tines. A width of the groove in the central linear portion of one of the first and second main surfaces of each of the quartz crystal tuning fork tines is greater than or equal to a distance in the width direction of the groove measured from an outer edge of the groove to an outer edge of the tuning fork tine.

Abstract: A piezoelectric crystal tuning fork resonator comprises a tuning fork base and a plurality of tuning fork tines connected to the tuning fork base, each of the tuning fork tines having opposite main surfaces and side surfaces, a groove having a plurality of stepped portions being formed in at least one of the opposite main surfaces of each of the tuning fork tines, a plurality of first electrodes being disposed on the stepped portions of the groove in at least one of the opposite main surfaces of each of the tuning fork tines, a plurality of second electrodes being disposed on the side surfaces of each of the tuning fork tines, the piezoelectric crystal tuning fork resonator comprising three electrode terminals and each of the three electrode terminals having a different electrical polarity.

Abstract: A quartz crystal unit has a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase. The quartz crystal tuning fork resonator has a fundamental mode of vibration, a second overtone mode of vibration, a quartz crystal tuning fork base, and a plurality of quartz crystal tuning fork tines connected to the quartz crystal tuning fork base. A merit value M2 for the second overtone mode of vibration of the quartz crystal tuning fork resonator is less than 30 so that the second overtone mode of vibration thereof is suppressed, the merit value M2 being defined by a ratio Q2/r2, where Q2 and r2 represent a quality factor and a capacitance ratio of the second overtone mode of vibration, respectively, of the quartz crystal tuning fork resonator capable of vibrating in the second overtone mode.

Abstract: In a method for manufacturing a quartz crystal unit, a quartz crystal tuning fork resonator is formed by etching a quartz crystal wafer to form a quartz crystal tuning fork base, quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, and a groove having stepped portions in at least one of opposite main surfaces of each of the quartz crystal tuning fork tines. A first electrode is disposed on at least one of the stepped portions of each of the grooves and a second electrode is disposed on each of side surfaces of each of the quartz crystal tuning fork tines. A frequency of oscillation of the quartz crystal tuning fork resonator is adjusted at least twice and in different steps. The quartz crystal tuning fork resonator is then mounted in a case and an open end of the case is covered with a lid.

Abstract: An electronic apparatus has a display portion and quartz crystal oscillators having different modes of vibration. Each of the quartz crystal oscillators has a quartz crystal oscillating circuit having a quartz crystal resonator. The quartz crystal resonator of one of the quartz crystal oscillating circuits is a width-extensional mode quartz crystal resonator capable of vibrating in a width-extensional mode. The width-extensional mode quartz crystal resonator has a vibrational portion, connecting portions disposed at ends of the vibrational portion, supporting portions connected to the vibrational portion through the connecting portions, and electrodes disposed on upper and lower surfaces of the vibrational portion. The quartz crystal oscillating circuit having the width-extensional mode quartz crystal resonator outputs a clock signal for operating the electronic apparatus to display time information at the display portion.

Abstract: A quartz crystal unit has a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase. The quartz crystal tuning fork resonator has a fundamental mode of vibration, a second overtone mode of vibration, a quartz crystal tuning fork base, and a plurality of quartz crystal tuning fork tines connected to the quartz crystal tuning fork base. A merit value M2 for the second overtone mode of vibration of the quartz crystal tuning fork resonator is less than 30 so that the second overtone mode of vibration thereof is suppressed, the merit value M2 being defined by a ratio Q2/r2, where Q2 and r2 represent a quality factor and a capacitance ratio of the second overtone mode of vibration, respectively, of the quartz crystal tuning fork resonator capable of vibrating in the second overtone mode.

Abstract: An electronic apparatus comprises a display portion and a plurality of oscillators, one of which is a quartz crystal oscillator comprising: a quartz crystal oscillating circuit comprising; an amplification circuit and a feedback circuit. For example, the feedback circuit is constructed by a quartz crystal resonator comprising vibrational arms and a base portion, and having novel shape and electrode construction. Also, the quartz crystal resonator is housed in a package. In addition, from a relationship of an amplification rate of the amplification circuit and a feedback rate of the feedback circuit, an output signal of the quartz crystal oscillating circuit having an oscillation frequency of a fundamental mode of vibration for the quartz crystal resonator can be provided with a frequency of high stability.

Abstract: A quartz crystal unit has a quartz crystal tuning fork resonator capable of vibrating in a flexural mode, a case for housing the quartz crystal tuning fork resonator, and a lid for covering an open end of the case. The quartz crystal tuning fork resonator has a tuning fork base, a pair of tuning fork tines connected to the tuning fork base, a series of grooves each formed on opposite main surfaces of each of the tuning fork tines, and a series of electrodes each disposed in a respective one of the grooves. When W and W2 represent a width of each tuning fork tine and a width of at least one of the grooves formed in the tuning fork tines, respectively, W2 is within a range of 0.03 mm to 0.12 mm, and a ratio (W2/W) is greater than 0.35 and less than 1.

Abstract: The electronic apparatus comprises a display portion and a quartz crystal oscillator at least, and said electronic apparatus comprises at least one quartz crystal oscillator. Also, the at least one oscillator comprises a quartz crystal oscillating circuit comprising an amplification circuit and a feedback circuit. The feedback circuit is constructed by a flexural mode, quartz crystal tuning fork resonator or a length-extensional mode quartz crystal resonator and for example, the quartz crystal tuning fork resonator comprising tuning fork tines and tuning fork base that are formed integrally, is shown with novel shape and electrode construction. Also, the quartz crystal tuning fork resonator, capable of vibrating in a fundamental mode and having a high frequency stability can be provided with a small series resistance and a high quality factor, even when the tuning fork resonator is miniaturized.

Abstract: A piezoelectric quartz crystal resonator has a vibrational portion, connecting portions integrally connected to respective ends of the vibrational portion, support portions integrally connected to the vibrational portion through the connecting portions, and electrodes disposed opposite each other on upper and lower surfaces of the vibrational portion. The piezoelectric quartz crystal resonator vibrates in a width-extensional mode and has a cutting angle in the range of one of xztw(−20° to +°)/(−10° to +10°) and xzwt(−10° to +10°)/(−20° to +20°).

Abstract: A quartz crystal unit, its manufacturing method and a quartz crystal oscillator are illustrated. In particular, the quartz crystal unit and the quartz crystal oscillator having a width-extensional mode quartz crystal resonator comprising a vibrational portion, connecting portions and supporting portions are illustrated with a cutting angle and electrode construction, which provides a high frequency and a high electro-mechanical transformation efficiency, even when the resonator is miniaturized. As a result of which the miniature quartz crystal unit and the quartz crystal oscillator may be provided with a zero temperature coefficient, a small series resistance R1 and a high quality factor Q. That is, these are accomplished by the cutting angle, the electrode construction and a large piezoelectric constant of the width-extensional mode quartz crystal resonator.

Abstract: A contour mode resonator such as a flexural mode, quartz crystal tuning fork resonator, a width-extensional mode quartz crystal resonator, a length-extensional mode quartz crystal resonator and a Lame mode quartz crystal resonator, a quartz crystal unit and a quartz crystal oscillator, and their manufacturing methods are described. As an example, a plurality of individual quartz crystal tuning fork resonators capable of vibrating in a flexural mode are formed in a quartz crystal wafer, with resonance frequency higher than 32.768 kHz, and are capable of vibrating in a fundamental mode, respectively, and also metal films are formed on said tuning fork tines in the quartz crystal wafer by a spattering method or an evaporation method to get said individual quartz crystal tuning fork resonators whose resonance frequency is lower than 32.

Abstract: The quartz crystal oscillator comprises a quartz crystal oscillating circuit having an amplification circuit and a feedback circuit. The feedback circuit is constructed by a flexural mode, quartz crystal tuning fork resonator and the quartz crystal resonator comprising tuning fork tines and tuning fork base that are formed integrally, is shown with novel shape and electrode construction. Also, the quartz crystal resonator, capable of vibrating in a fundamental mode and having a high frequency stability can be provided with a small series resistance and a high quality factor, even when said resonator is miniaturized. This is accomplished by grooves, groove dimensions and electrode construction on the tuning fork tines and/or tuning fork base of the quartz crystal resonator.

Abstract: The quartz crystal unit comprises a flexural mode, tuning fork, quartz crystal resonator, a case and a lid, and the tuning fork, quartz crystal resonator comprising of tuning fork tines and tuning fork base that are formed integrally, is shown with novel shape and electrode construction, which provides a high electromechanical transformation efficiency, a small series resistance and a high quality factor, even when said resonator is miniaturized. This is accomplished by grooves or a step difference and by electrode construction on the tuning fork tines and/or tuning fork base of the tuning fork, quartz crystal resonator.

Abstract: The electronic apparatus comprises a display portion and a quartz crystal oscillator at least, and said electronic apparatus comprises at least two quartz crystal oscillators. Also, each of two quartz crystal oscillators of the at least two oscillators comprises a quartz crystal oscillating circuit having an amplification circuit and a feedback circuit. The feedback circuit is constructed by a flexural mode, quartz crystal tuning fork resonator or a width-extensional mode quartz crystal resonator or a thickness shear mode quartz crystal resonator and for example, the quartz crystal tuning fork resonator comprising tuning fork tines and tuning fork base that are formed integrally, is shown with novel shape and electrode construction. Also, the quartz crystal tuning fork resonator, capable of vibrating in a fundamental mode and having a high frequency stability can be provided with a small series resistance and a high quality factor, even when the tuning fork resonator is miniaturized.

Abstract: The quartz crystal unit comprises a flexural mode, tuning fork, quartz crystal resonator, a case and a lid, and the tuning fork, quartz crystal resonator comprising of tuning fork tines and tuning fork base is shown with novel shape and electrode construction, which provides a high electromechanical transformation efficiency, even when said resonator is miniaturized. As a result of which the miniaturized quartz crystal unit may be provided with a small series resistance R1 and a high quality factor Q. This is accomplished by grooves or a step difference and by electrode construction on the tuning fork tines and/or tuning fork base of the tuning fork, quartz crystal resonator. In addition, an improvement of the frequency temperature behavior for the flexural mode, tuning fork, quartz crystal resonator is accomplished by connecting a plurality of resonators formed integrally at their respective tuning fork bases via connecting portion.

Abstract: The Lame mode quartz crystal resonator vibrating in overtone mode is formed of an X-plate quartz crystal obtained in a manner that a blank X-plate quartz crystal having a coordinate of x, y and z axes is rotated through 36.5° to 47° about its y-axis and further rotated through 65° to 85° about a new x′-axis corresponding to the x-axis produced by the rotation about the y-axis and the thus rotated blank X-plate quartz crystal is then cut out along planes parallel to x-y, y-z and z-x planes of the original coordinate system, respectively. The quartz crystal resonator includes a vibrating portion, a supporting frame and a mounting portion formed integrally. The vibrating portion is connected through two connecting portions to the supporting frame and the mounting portion, as a result of which the quartz crystal resonator has less series resistance R1 and exhibits minimum vibrational energy losses and minimum frequency change over a wide temperature range.

Abstract: The width-extensional mode piezoelectric crystal resonator comprising vibrational portion, connecting portions and supporting portion is shown with new cut angle and electrode construction, which provides a high frequency and a high electro-mechanical transformation, even when said resonator is miniaturized. As a result of which the miniature crystal resonator may be provided with a small series resistance and a high quality factor Q. This is accomplished by cut angle, electrode construction and a large piezoelectric constant of the width-extensional mode piezoelectric crystal resonator. In addition, an improvement of the frequency temperature behavior for the crystal resonator is accomplished by connecting a plurality of resonators integratedly through frame or supporting frame. Crystal resonators with different turn over temperature points are electrically connected in parallel.

Abstract: Quartz crystal tuning fork resonators, capable of vibrating in a flexural mode, having a plurality of tuning fork tines attached to a tuning fork base, and novel shapes, and electrode configurations, are disclosed. The resonators provides a high electro-mechanical transformation efficiency, even when miniaturized, because they have a small series resistance and a high quality factor, which are achieved by providing grooves or a step difference, and by electrode construction, on the tuning fork tines and/or tuning fork base. Improved frequency-temperature behaviour of the resonators of the present invention, over that of previously known resonators, is accomplished by integrally connecting a plurality of resonators at their respective tuning fork bases. Resonators having different peak temperature points are electrically connected in parallel.

Abstract: The Lame mode quartz crystal resonator vibrating in overtone mode is formed of an X-plate quartz crystal obtained in a manner that a blank X-plate quartz crystal having a coordinate of x, y and z axes is rotated through 36.5° to 47° about its y-axis and further rotated through 65° to 85° about a new x′-axis corresponding to the x-axis produced by the rotation about the y-axis and the thus rotated blank X-plate quartz crystal is then cut out along planes parallel to x-y, y-z and z-x planes of the original coordinate system, respectively. The quartz crystal resonator includes a vibrating portion, a supporting frame and a mounting portion formed integrally. The vibrating portion is connected through two connecting portions to the supporting frame and the mounting portion, as a result of which the quartz crystal resonator has less series resistance R1 and exhibits minimum vibrational energy losses and minimum frequency change over a wide temperature range.