Electronic apparatus

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. In addition, from a relationship of an amplification rate and a feedback rate, an output signal of the quartz crystal oscillating circuit having an oscillation frequency of the fundamental mode vibration for the quartz crystal tuning fork resonator can be provided with the high frequency stability.

1 .- 23 . (canceled)  
   
   
       24 . An electronic apparatus comprising: 
 at least one quartz crystal oscillator comprised of a quartz crystal oscillating circuit having a quartz crystal resonator, an amplifier, at least one resistor, and a plurality of capacitors;    wherein the quartz crystal resonator comprises a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase, the quartz crystal tuning fork resonator having a quartz crystal tuning fork base, a plurality of quartz crystal tuning fork tines connected to the quartz crystal tuning fork base and each of the quartz crystal tuning fork tines having opposite main surfaces, and at least one groove formed in at least one of the opposite surfaces of at least one of the quartz crystal tuning fork tines; and    wherein a length of the at least one groove formed in at least one of the opposite main surfaces of at least one of the quartz crystal tuning fork tines is within a range of 40% to 80% of a length of the at least one of the quartz crystal tuning fork tines.    
   
   
       25 . An electronic apparatus according to  claim 24;  further comprising an electrode disposed on a surface of the at least one groove formed in at least one of the opposite main surfaces of at least one of the quartz crystal tuning fork tines so that a series resistance R 1  of a fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a series resistance R 2  of a second overtone mode of vibration thereof.  
   
   
       26 . An electronic apparatus according to  claim 24;  further comprising an electrode disposed on a surface of the at least one groove formed in at least one of the opposite main surfaces of at least one of the quartz crystal tuning fork tines so that a capacitance ratio r 1  of a fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a capacitance ratio r 2  of a second overtone mode of vibration thereof.  
   
   
       27 . An electronic apparatus according to  claim 24;  wherein the opposite main surfaces comprise a first main surface and a second main surface; wherein the quartz crystal tuning fork tines comprise a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine, each of the first and second quartz crystal tuning fork tines having a first side surface and a second side surface opposite the first side surface; wherein the at least one groove is formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein a first electrode is disposed on a surface of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines and a second electrode is disposed on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines; and wherein the first electrode of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the first electrode of the second quartz crystal tuning fork tine, and the second electrode of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the second electrode of the second quartz crystal tuning fork tine, the first and second quartz crystal tuning fork tines being formed before the at least one groove is formed.  
   
   
       28 . An electronic apparatus according to  claim 24;  wherein the opposite main surfaces have a first main surface and a second main surface; wherein the quartz crystal tuning fork tines have a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine, each of the first and second quartz crystal tuning fork tines having a first side surface and a second side surface opposite the first side surface; wherein the at least one groove is formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein a first electrode is disposed on a surface of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines and a second electrode is disposed on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines; and wherein the first electrode of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the first electrode of the second quartz crystal tuning fork tine, and the second electrode of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the second electrode of the second quartz crystal tuning fork tine, the at least one groove being formed before the first and second quartz crystal tuning fork tines are formed.  
   
   
       29 . An electronic apparatus according to  claim 24;  wherein the at least one quartz crystal oscillator comprises a first quartz crystal oscillator comprising a first quartz crystal oscillating circuit and a second quartz crystal oscillator comprising a second quartz crystal oscillating circuit, each of the first and second quartz crystal oscillating circuits having a quartz crystal resonator, an amplifier, at least one resistor, and a plurality of capacitors; wherein the quartz crystal resonator of one of the first and second quartz crystal oscillating circuits comprises one of a length-extensional mode quartz crystal resonator, a width-extensional mode quartz crystal resonator, a thickness shear mode quartz crystal resonator, a Lame mode quartz crystal resonator and a SAW resonator; wherein the quartz crystal resonator of one of the first and second quartz crystal oscillating circuits comprises a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase; and wherein the quartz crystal tuning fork resonator has a quartz crystal tuning fork base, first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first main surface and a second main surface opposite the first main surface, and at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines, an electrode being disposed on a surface of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines so that a series resistance R 1  of a fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a series resistance R 2  of a second overtone mode of vibration thereof.  
   
   
       30 . An electronic apparatus according to  claim 29;  wherein a length of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is within a range of 40% to 80% of a length of each of the first and second quartz crystal tuning fork tines.  
   
   
       31 . An electronic apparatus according to  claim 29;  further comprising a display portion; wherein one of the first and second quartz crystal oscillating circuits comprises an amplification circuit having a CMOS inverter, a feedback resistor, a negative resistance −RL 1  for the fundamental mode of vibration of the quartz crystal tuning fork resonator, and a negative resistance −RL 2  for the second overtone mode of vibration thereof; and a feedback circuit having the quartz crystal tuning fork resonator with the series resistance R 1  of the fundamental mode of vibration and the series resistance R 2  of the second overtone mode of vibration, a plurality of capacitors and a drain resistor, the quartz crystal tuning fork resonator being electrically connected to the CMOS inverter and the feedback resistor of the amplification circuit and to the capacitors and the drain resistor of the feedback circuit having the quartz crystal tuning fork resonator; and wherein a ratio |−RL 1 |/R 1  is greater than 2|−RL 2 |/R 2 -1, where |−RL 1 | represents an absolute value of the negative resistance for the fundamental mode of vibration of quartz crystal tuning fork resonator of the amplification circuit and |−RL 2 | represents an absolute value of the negative resistance for the second overtone mode of vibration of the quartz crystal tuning fork resonator of the amplification circuit, an output signal of the quartz crystal oscillating circuit comprising the quartz crystal tuning fork resonator being 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.  
   
   
       32 . An electronic apparatus according to  claim 31;  wherein the output signal output from the quartz crystal oscillating circuit comprising the quartz crystal tuning fork resonator has an oscillation frequency of about 32.768 kHz with a frequency deviation of −100 PPM to +100 PPM; and wherein the electrode is disposed on the surface of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines so that a capacitance ratio r 1  of the fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a capacitance ratio r 2  of the second overtone mode of vibration thereof.  
   
   
       33 . An electronic apparatus according to  claim 24;  wherein the opposite main surfaces comprise a first main surface and a second main surface; wherein the quartz crystal tuning fork tines comprise a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine, each of the first and second quartz crystal tuning fork tines having a first side surface and a second side surface opposite the first side surface; wherein the at least one groove is formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein a first electrode is disposed on a surface of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines and a second electrode is disposed on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines so that a series resistance R 1  of a fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a series resistance R 2  of a second overtone mode of vibration thereof and a capacitance ratio r 1  of the fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a capacitance ratio r 2  of the second overtone mode of vibration thereof; and wherein the first electrode of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the first electrode of the second quartz crystal tuning fork tine, and the second electrode of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the second electrode of the second quartz crystal tuning fork tine, the first and second quartz crystal tuning fork tines being formed simultaneously with the at least one groove.  
   
   
       34 . A method for manufacturing an electronic apparatus, comprising the steps of: 
 forming a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase by etching a quartz crystal wafer to form a quartz crystal tuning fork base and a plurality of quartz crystal tuning fork tines connected to the quartz crystal tuning fork base with each of the quartz crystal tuning fork tines having opposite main surfaces, and etching the quartz crystal wafer to form at least one groove in at least one of the opposite main surfaces of at least one of the quartz crystal tuning fork tines, a length of the at least one groove formed in at least one of the opposite main surfaces of at least one of the quartz crystal tuning fork tines being within a range of 40% to 80% of a length of the at least one of the quartz crystal tuning fork tines; and    providing at least one quartz crystal oscillator comprised of a quartz crystal oscillating circuit having a quartz crystal resonator, an amplifier, at least one resistor, and a plurality of capacitors, the quartz crystal resonator comprising the quartz crystal tuning fork resonator.    
   
   
       35 . A method according to  claim 34;  wherein the quartz crystal tuning fork tines have a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine, each of the first and second quartz crystal tuning fork tines having a first main and a second main surface opposite the first main surface; and wherein the at least one groove is formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines so that a length of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is within a range of 40% to 80% of a length of each of the first and second quartz crystal tuning fork tines.  
   
   
       36 . A method according to  claim 34;  further comprising the steps of providing a case having a mounting portion and providing a lid for covering an open end of the case; wherein the quartz crystal tuning fork tines have a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine connected to the quartz crystal tuning fork base; wherein the opposite main surfaces has a first main surface and a second main surface; and further comprising the sequential steps of forming the quartz crystal tuning fork base, and the first and second quartz crystal tuning fork tines in a first etching process, forming at least one groove in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines in a second etching process different from the first etching process, disposing an electrode on a surface of the at least one groove formed in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork base on the mounting portion of the case, and connecting the lid to the case to cover the open end thereof.  
   
   
       37 . A method according to  claim 36;  wherein each of the first and second quartz crystal tuning fork tines has a first side surface and a second side surface opposite the first side surface; wherein the forming step comprises the step of forming the at least one groove in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; and wherein the disposing step comprises the step of disposing a first electrode on the surface of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines and a second electrode on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines.  
   
   
       38 . A method according to  claim 34;  further comprising the steps of providing a case having a mounting portion and providing a lid for covering an open end of the case; wherein the quartz crystal wafer has a first main surface and a second main surface opposite the first main surface; and further comprising the sequential steps of forming at least one groove in at least one of the first and second main surfaces of the quartz crystal wafer, forming a quartz crystal tuning fork base, and first and second quartz crystal tuning fork tines so that the at least one groove is formed in at least one of opposite main surfaces of at least one of the first and second quartz crystal tuning fork tines, each of the first and second quartz crystal tuning fork tines having a first side surface and a second side surface opposite the first side surface, disposing an electrode on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork base on the mounting portion of the case, and connecting the lid to the case to cover the open end thereof.  
   
   
       39 . A method according to  claim 34;  wherein the electronic apparatus comprises a display portion; wherein the at least one quartz crystal oscillator comprises a first quartz crystal oscillator comprising a first quartz crystal oscillating circuit and a second quartz crystal oscillator comprising a second quartz crystal oscillating circuit, each of the first and second quartz crystal oscillating circuits having a quartz crystal resonator, an amplifier, at least one resistor, and a plurality of capacitors; wherein the quartz crystal resonator of one of the first and second quartz crystal oscillating circuits comprises one of a length-extensional mode quartz crystal resonator, a width-extensional mode quartz crystal resonator, a thickness shear mode quartz crystal resonator, a Lame mode quartz crystal resonator and a SAW resonator; wherein the quartz crystal resonator of one of the first and second quartz crystal oscillating circuits comprises a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase; and further comprising the steps of providing an amplification circuit having a CMOS inverter, a feedback resistor, a negative resistance −RL 1  for a fundamental mode of vibration of the quartz crystal tuning fork resonator, and a negative resistance −RL 2  for a second overtone mode of vibration thereof, providing a feedback circuit having the quartz crystal tuning fork resonator with a series resistance R 1  of the fundamental mode of vibration and a series resistance R 2  of the second overtone mode of vibration, 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 having the quartz crystal tuning fork resonator; and wherein a ratio |−RL 1 |/R 1  is greater than 2|RL 2 |/R 2 −1, where |−RL 1 | represents an absolute value of the negative resistance for the fundamental mode of vibration of quartz crystal tuning fork resonator of the amplification circuit and |−RL 2 | represents an absolute value of the negative resistance for the second overtone mode of vibration of the quartz crystal tuning fork resonator of the amplification circuit, an output signal of the quartz crystal oscillating circuit comprising the quartz crystal tuning fork resonator being 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.  
   
   
       40 . A method according to  claim 39;  wherein the quartz crystal tuning fork resonator has a quartz crystal tuning fork base, first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first main surface and a second main surface opposite the first main surface, and at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines so that a length of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is within a range of 40% to 80% of a length of each of the first and second quartz crystal tuning fork tines.  
   
   
       41 . A method according to  claim 39;  further comprising the steps of providing a case having a mounting portion and providing a lid for covering an open end of the case; wherein the quartz crystal tuning fork resonator has a quartz crystal tuning fork base, first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first main surface and a second main surface opposite the first main surface, and a first side surface and a second side surface opposite the first side surface; and further comprising the steps of forming the quartz crystal tuning fork base, and the first and second quartz crystal tuning fork tines in a first etching process, forming at least one groove in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines in a second etching process different from the first etching process, disposing a first electrode on a surface of the at least one groove formed in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines and a second electrode on each of the first and second side surfaces of at least one of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork base on the mounting portion of the case, adjusting an oscillation frequency of the quartz crystal tuning fork resonator, and connecting the lid to the case to cover the open end thereof; and wherein the first and second quartz crystal tuning fork tines are formed before the at least one groove is formed.  
   
   
       42 . A method according to  claim 41;  wherein the forming step comprises the step of forming the at least one groove in each of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines; and wherein the at least one of first and second quartz crystal tuning fork tines is formed before the at least one groove in each of the first and second main surfaces is formed.  
   
   
       43 . A method according to  claim 39;  further comprising the steps of providing a case having a mounting portion and providing a lid for covering an open end of the case; wherein the quartz crystal tuning fork resonator has a quartz crystal tuning fork base, first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first main surface and a second main surface opposite the first main surface, and a first side surface and a second side surface opposite the first side surface; and further comprising the steps of forming the quartz crystal tuning fork base and the first and second quartz crystal tuning fork tines in a first etching process, forming at least one groove in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines in a second etching process different from the first etching process, disposing a first electrode on a surface of the at least one groove formed in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines and a second electrode on each of the first and second side surfaces of at least one of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork base on the mounting portion of the case, adjusting an oscillation frequency of the quartz crystal tuning fork resonator, and connecting the lid to the case to cover the open end thereof; and wherein the first and second quartz crystal tuning fork tines are formed after the at least one groove is formed.  
   
   
       44 . A method according to  claim 34;  further comprising the steps of providing a case having a mounting portion and providing a lid for covering an open end of the case; wherein the quartz crystal tuning fork tines have a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first side surfaces and a second side surface opposite the first side surface; wherein the opposite main surfaces have a first main surface and a second main surface; and further comprising the sequential steps of forming simultaneously the quartz crystal tuning fork base, the first and second quartz crystal tuning fork tines and at least one groove in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines by etching the quartz crystal wafer so that a length of the at least one groove is within a range of 40% to 80% of a length of the at least one of the first and second quartz crystal tuning fork tines, disposing a first electrode on a surface of the at least one groove formed in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines and a second electrode on each of the first and second side surfaces of at least one of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork base on the mounting portion of the case, and connecting the lid to the case to cover the open end thereof.  
   
   
       45 . A method for manufacturing an electronic apparatus, comprising the steps of: 
 forming a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase by etching a quartz crystal wafer to form a quartz crystal tuning fork base and a plurality of quartz crystal tuning fork tines connected to the quartz crystal tuning fork base with each of the quartz crystal tuning fork tines having opposite main surfaces, and etching the quartz crystal wafer to form at least one groove in at least one of the opposite main surfaces of at least one of the quartz crystal tuning fork tines, a length of the at least one groove formed in at least one of the opposite main surfaces of at least one of the quartz crystal tuning fork tines being within a range of 40% to 80% of a length of the at least one of the quartz crystal tuning fork tines; and    providing a first quartz crystal oscillator comprised of a first quartz crystal oscillating circuit and a second quartz crystal oscillator comprised of a second quartz crystal oscillating circuit, each of the first and second quartz crystal oscillating circuits having a quartz crystal resonator, an amplifier, at least one resistor, and a plurality of capacitors, the quartz crystal resonator of one of the first and second quartz crystal oscillating circuits comprising one of a length-extensional mode quartz crystal resonator, a thickness shear mode quartz crystal resonator, and a Lame mode quartz crystal resonator, and the quartz crystal resonator of one of the first and second quartz crystal oscillating circuits comprising the quartz crystal tuning fork resonator.    
   
   
       46 . A method according to  claim 45;  further comprising the steps of providing a case having a mounting portion and providing a lid for covering an open end of the case; wherein the quartz crystal tuning fork tines have a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first side surface and a second side surface opposite the first side surface; wherein the opposite main surfaces has a first main surface and a second main surface; and further comprising the sequential steps of forming the quartz crystal tuning fork base, and the first and second quartz crystal tuning fork tines in a first etching process, forming at least one groove in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines in a second etching process different from the first etching process, disposing a first electrode on a surface of the at least one groove formed in at least one of the first and second main surfaces of at least one of the first and second quartz crystal tuning fork tines and a second electrode on each of the first and second side surfaces of at least one of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork base on the mounting portion of the case, and connecting the lid to the case to cover the open end thereof.  
   
   
       47 . A method according to  claim 46;  wherein the forming step comprises the step of forming the at least one groove in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; and wherein the disposing step comprises the step of disposing the first electrode on the surface of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines and the second electrode on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines.  
   
   
       48 . A method according to  claim 45;  wherein the quartz crystal tuning fork base has cut portions; and further comprising the step of etching the quartz crystal wafer to form the cut portions; and wherein the etching steps are performed simultaneously to form the first and second quartz crystal tuning fork tines and the cut portions at the same time.  
   
   
       49 . A method according to  claim 45;  further comprising the step of providing a display portion; wherein one of the first and second quartz crystal oscillating circuits comprises an amplification circuit having a CMOS inverter, a feedback resistor, a negative resistance −RL 1  for a fundamental mode of vibration of the quartz crystal tuning fork resonator, and a negative resistance −RL 2  for a second overtone mode of vibration thereof; and a feedback circuit having the quartz crystal tuning fork resonator with a series resistance R 1  of the fundamental mode of vibration and a series resistance R 2  of the second overtone mode of vibration, a plurality of capacitors and a drain resistor, the quartz crystal tuning fork resonator being electrically connected to the CMOS inverter and the feedback resistor of the amplification circuit and to the capacitors and the drain resistor of the feedback circuit having the quartz crystal tuning fork resonator; and wherein a ratio |−RL 1 |/R 1  is greater than 2|−RL 2 |/R 2 −1, where |−RL 1 | represents an absolute value of the negative resistance for the fundamental mode of vibration of quartz crystal tuning fork resonator of the amplification circuit and |−RL 2 | represents an absolute value of the negative resistance for the second overtone mode of vibration of the quartz crystal tuning fork resonator of the amplification circuit, an output signal of the quartz crystal oscillating circuit comprising the quartz crystal tuning fork resonator being 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.  
   
   
       50 . A method according to  claim 49;  further comprising the steps of providing a case having a mounting portion and providing a lid for covering an open end of the case; wherein the quartz crystal tuning fork tines have a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first side surface and a second side surface opposite the first side surface; wherein the opposite main surfaces has a first main surface and a second main surface; and further comprising the sequential steps of forming the quartz crystal tuning fork base, and the first and second quartz crystal tuning fork tines in a first etching process, forming at least one groove in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines in a second etching process different from the first etching process, disposing a first electrode on a surface of the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines and a second electrode on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork base on the mounting portion of the case, and connecting the lid to the case to cover the open end thereof.  
   
   
       51 . A method according to  claim 50;  further comprising the steps of connecting the first electrodes disposed on the surfaces of the grooves in the first and second main surfaces of the first quartz crystal tuning fork tine to the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine to define a first electrode terminal; and connecting the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine to the first electrodes disposed on the surfaces of the grooves in the first and second main surfaces of the second quartz crystal tuning fork tine to define a second electrode terminal.  
   
   
       52 . A method according to  claim 50;  wherein the first electrode is disposed on the surface of the at least one groove in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines so that the series resistance R 1  of the fundamental mode of vibration of the quartz crystal tuning fork resonator is less than the series resistance R 2  of the second overtone mode of vibration thereof, and a capacitance ratio r 1  of the fundamental mode of vibration of the quartz crystal tuning fork resonator is less than a capacitance ratio r 2  of the second overtone mode of vibration thereof.  
   
   
       53 . A method according to  claim 45;  further comprising the steps of providing a case having a mounting portion and providing a lid for covering an open end of the case; wherein the quartz crystal tuning fork tines have a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first side surface and a second side surface opposite the first side surface; wherein the opposite main surfaces has a first main surface and a second main surface; and further comprising the sequential steps of forming the quartz crystal tuning fork base, and the first and second quartz crystal tuning fork tines in a first etching process, forming at least one groove in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines in a second etching process different from the first etching process, disposing a first electrode in the at least one groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines and a second electrode on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork base on the mounting portion of the case, and connecting the lid to the case to cover the open end thereof.  
   
   
       54 . A method according to  claim 53;  wherein the quartz crystal wafer has opposite main surfaces; and further comprising the plurality of steps of forming at least one metal film on each of the opposite main surfaces; and forming a resist on the at least one metal film formed on each of the opposite main surfaces; and wherein the plurality of steps are performed before the step of forming the quartz crystal tuning fork base, and the first and second quartz crystal tuning fork tines in a first etching process.  
   
   
       55 . A method according to  claim 54;  further comprising the step of adjusting an oscillation frequency of the quartz crystal tuning fork resonator after the step of mounting the quartz crystal tuning fork base on the mounting portion of the case and before the step of connecting the lid to the case to cover the open end thereof.  
   
   
       56 . A method according to  claim 54;  further comprising the step of adjusting an oscillation frequency of the quartz crystal tuning fork resonator after the step of connecting the lid to the case to cover the open end thereof.