Invention Grant
- Patent Title: Electronic apparatus having quartz crystal oscillating circuits
- Patent Title (中): 具有石英晶体振荡电路的电子设备
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Application No.: US12220025Application Date: 2008-07-21
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Publication No.: US08127426B2Publication Date: 2012-03-06
- Inventor: Hirofumi Kawashima
- Applicant: Hirofumi Kawashima
- Applicant Address: JP
- Assignee: Piedek Technical Laboratory
- Current Assignee: Piedek Technical Laboratory
- Current Assignee Address: JP
- Agency: Adams & Wilks
- Priority: JP2002-060827 20020306
- Main IPC: H04R31/00
- IPC: H04R31/00

Abstract:
An electronic apparatus has a display portion, and first and second oscillating circuits each having a quartz crystal resonator, the quartz crystal resonator of each of the first and second oscillating circuits vibrating in a different mode from each other. One of the quartz crystal resonators is a quartz crystal tuning fork resonator having first and second tuning fork tines. Electrodes are disposed on side surfaces of each of the first and second tuning fork tines so that the electrodes of the first tuning fork tine have an electrical polarity opposite to an electrical polarity of the electrodes of the second tuning fork tine. The capacitance ratio r1 of a fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a capacitance ratio r2 of a second overtone mode of vibration thereof. An output signal of the oscillating circuit having the quartz crystal tuning fork resonator is a clock signal used to display time information at the display portion of the electronic apparatus.
Public/Granted literature
- US20080282520A1 Method for manufacturing quartz crystal unit and electronic apparatus having quartz crystal unit Public/Granted day:2008-11-20
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