Patent ID: 7441316
Filing Date: 2008-10-28
Classification: H03B,H03H,H04R,Y10T

Abstract:
1. A method for manufacturing an electronic apparatus having a display portion for displaying time information and at least one quartz crystal oscillator comprised of a quartz crystal oscillating circuit having an amplification circuit and a feedback circuit, the method comprising the steps of: forming by at least one of a chemical etching method, a physical etching method, and a mechanical method a quartz crystal tuning fork resonator having a quartz crystal tuning fork base and first and second quartz crystal tuning fork tines each connected to the quartz crystal tuning fork base and having a first main surface and a second main surface opposite the first main surface, the quartz crystal tuning fork resonator having a fundamental mode of vibration and a second overtone mode of vibration each comprised of a flexural mode of an inverse phase, a series resistance R providing the amplification circuit having a CMOS inverter, a feedback resistor, a negative resistance −RL providing the feedback circuit having the quartz crystal tuning fork resonator, a plurality of capacitors and a drain resistor; and electrically connecting the quartz crystal tuning fork resonator to the CMOS inverter and the feedback resistor of the amplification circuit and to the capacitors and the drain resistor of the feedback circuit; wherein a ratio |−RL wherein a merit value M wherein an output signal of the quartz crystal oscillating circuit is a clock signal for use in operation of the electronic apparatus to display time information at the display portion, the clock signal having an oscillation frequency of the fundamental mode of vibration.