Journal of the Horological Institute of Japan

[title in Japanese]

Article type: Cover
1979 Volume 89 Pages Cover1-
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_Cover1

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[title in Japanese]

Article type: Cover
1979 Volume 89 Pages Cover2-
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_Cover2

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A Highly Precise Wristwatch with Two Ouartz Oscillators : Twin Quartz

Yoshikazu Akahane, Tokumon Ogawa

Article type: Article
1979 Volume 89 Pages 1-19
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_1

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This paper describes the system and analysis of "Twin Ouartz", a highly precise wristwatch which we have recently developed. An improvement in time accuacy is an inevitable subject for technological development of wristwatches. To realize a highly precise wristwatch, it is necessary to obtain a quartz oscillator with an excellent temperature characteristic. With this aim, we focused our attention on the method in which two similar quartz osdillators in temperature characteristics and the logic circuit are adopted. Thus, a wristwatch displaying satisfactory performance including time accuracy has been brought to completion.

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MINIATURIZATON OF 4.19 MHz RECTANGULAR AT-CUT QUARTZ RESONATORS

S. Yamashita, N. Echigo, Y. Kawamura, A. Watanabe, K. Kubota

Article type: Article
1979 Volume 89 Pages 20-39
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_20

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Properties of 4.19 MHz miniaturized rectangular AT*-cut quartz resonators for practical use in wrist watches were investigated. The frequency spectra of resonators were obtained as a function of w/t and 1/t, where w : Width along the Z'-axis l : Length along the X-axis t : Thickness of the following three resonators:(a) Non-beveled rectangular resonator (b) Beveled rectangular resonator (c) Be veled rectangular resonator with its both side edge planes(X-Y planes) tilted. For the resonator (b), detailed frequency spectra were studied in the range of w/t=2.3 to 4.5. Temperature characteristics, coupling etc.,were investigated in the thicknes-shear mode and several unwanted modes. Thus, the trial production of resonators housed in the cases:9.0×3.7×1.8mm and 9.6×4.0×1.8mm was performed, proving their excellent temperature characteristics, great shock-resistance by l m-drop impact test, and so on. It is concluded that: (1) The secondary overtones in the width-shear mode and the width-extensional mode should be given special consideration. (2) The frequency spectra require careful investigations. (3) The inflection point of frequency-temperature curve varies with dimensions of the resonator. (4) The long-X rectangular AT-cut quartz resonator can be practically used in highly accurate quartz watch.

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On Q-Value of a Linear Oscillator : 1st Report

Masatoshi Tooyama, Chikashi Otani

Article type: Article
1979 Volume 89 Pages 40-51
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_40

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A Relation between Q-value of a linear oscillator and its frequency stability is described here. When an external force in Roexp iωt (ω=ω_0+ω_1 : ω_0 resonance frequency of the oscillator: ω_l : random variable frequency) exerts on the oscillator with the resistant force proportional to its velocity, and when σ, variation of ωl, is greater than Δω(=ω_0/2Q), a calculation is tried by aid of statistical method. Moreover in this report, correlation fu-function of ω_1 is assumed to be quasi-static, that is the power spectrum of the external force is Gaussian type. And the following result is obtained. S=√<1/(2Q)(√<2/π>σ/(ω_0)-1/Q> where s is fractional frequency stability of the oscillator.

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Temperature Characteristics of Rectangular AT-cut Quartz Plates

Toshitake Katoh

Article type: Article
1979 Volume 89 Pages 52-63
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_52

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In this paper the resonant frequency-temperature characteris-tics of coupled fundamental thickness-shear mode of rectangular AT-cut quartz plates are studied. In order to obtain useful frequency formulae for calculating frequency-temperature characteristics of rectangular AT-cut quartz plates, Mindlin's frequency equations in which piezoelectric terms are considered are employed. The calculations are performed in two cases; in one case, the values given by Bechmann, and in the other case, those by Zelenka are used. The calculated results are compared with experimental data given by A. E. Zumsteg, showing considerabIy good agreement with each other. As a result, it is proved that Mindlin's frequency equations are useful for estimating frequency-temperature characteristics of rectangular quartz resonators.

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[title in Japanese]

[in Japanese]

Article type: Article
1979 Volume 89 Pages 64-71
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_64

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[title in Japanese]

[in Japanese]

Article type: Article
1979 Volume 89 Pages 72-81
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_72

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[title in Japanese]

[in Japanese]

Article type: Article
1979 Volume 89 Pages 82-88
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_82

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[title in Japanese]

[in Japanese]

Article type: Article
1979 Volume 89 Pages 89-
Published: June 20, 1979
Released on J-STAGE: November 09, 2017

DOIhttps://doi.org/10.20805/tokeieafj.89.0_89

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