Quartz crystal tuning fork resonator

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.

1. A quartz crystal tuning fork resonator capable of vibrating in a flexural mode, the quartz crystal tuning fork resonator comprising:
 a plurality of quartz crystal tuning fork tines for undergoing vibration in an inverse phase, each of the quartz crystal tuning fork tines having 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;    a quartz crystal tuning fork base to which the quartz crystal tuning fork tines are attached; and    at least one groove 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 being 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.    
     
     
       2. A quartz crystal tuning fork resonator capable of vibrating in a flexural mode, the quartz crystal tuning fork resonator comprising:
 a plurality of quartz crystal tuning fork tines each having a plurality of stepped portions;    a quartz crystal tuning fork base to which the quartz crystal tuning fork tines are attached;    at least one first electrode disposed on each of two of the stepped portions of each of the quartz crystal tuning fork tines; and    at least one second electrode disposed on a side of each of the quartz crystal tuning fork tines, the second electrode of each of the quartz crystal tuning fork tines having an electrical polarity opposite to an electrical polarity of the first electrode of each of the quartz crystal tuning fork tines.    
     
     
       3. An integrated quartz crystal tuning fork resonator for undergoing vibration in a flexural mode, the integrated quartz crystal tuning fork comprising:
 a plurality of individual quartz crystal tuning fork resonators each capable of vibrating in a flexural mode, the plurality of individual quartz crystal tuning fork resonators being selected from the group consisting of: 
 (A) a quartz crystal tuning fork resonator having a plurality of quartz crystal tuning fork tines each having sides and a central linear portion, a quartz crystal tuning fork base to which the quartz crystal tuning fork tines are attached, at least one groove formed in the central linear portion of each of the quartz crystal tuning fork tines, at least one first electrode disposed in the at least one groove of each of the quartz crystal tuning fork tines, and at least one second electrode disposed on a side of each of the quartz crystal tuning fork tines, the second electrode of each of the quartz crystal tuning fork tines having an electrical polarity opposite to an electrical polarity of the first electrode of each of the quartz crystal tuning fork tines;  
 (B) a quartz crystal tuning fork resonator having a plurality of quartz crystal tuning fork tines, a quartz crystal tuning fork base to which the quartz crystal tuning fork tines are attached, a plurality of grooves formed in the quartz crystal tuning fork base, and at least one electrode disposed in each of the grooves;  
 (C) a quartz crystal tuning fork resonator having a plurality of quartz crystal tuning fork tines each having a plurality of stepped portions, a quartz crystal tuning fork base to which the quartz crystal tuning fork tines are attached, at least one first electrode disposed on each of two of the stepped portions of each of the quartz crystal tuning fork tines portions, at least one second electrode disposed on a side of each of the quartz crystal tuning fork tines, the second electrode of each of the quartz crystal tuning fork tines having an electrical polarity opposite to an electrical polarity of the first electrode of each of the quartz crystal tuning fork tines; and  
 (D) a combination of individual resonators according to at least two of (A), (B) and (C).  
   
     
     
       4. A quartz crystal tuning fork resonator according to  claim 1 ; wherein the plurality of quartz crystal tuning fork tines comprises a first quartz crystal tuning fork tine and a second quartz crystal tuning fork tine; and wherein the grooves in the first and second main surfaces of each of the first and second quartz crystal tuning fork tines are disposed opposite each other in a thickness direction of the first and second quartz crystal tuning fork tines. 
     
     
       5. A quartz crystal tuning fork resonator according to  claim 4 ; wherein each of the first and second quartz crystal tuning fork tines has side surfaces; and further comprising a plurality of first electrodes each disposed in a respective groove of the first and second quartz crystal tuning fork tines, and a plurality of second electrodes each disposed on a respective side surface of each of the first and second quartz crystal tuning fork tines, the second electrodes of each of the first and second quartz crystal tuning fork tines having an electrical polarity opposite to an electrical polarity of the first electrodes of each of the quartz crystal tuning fork tines. 
     
     
       6. A quartz crystal tuning fork resonator according to  claim 5 ; wherein the first electrode disposed in one of the grooves of the first quartz crystal tuning fork tine is connected to the second electrode disposed on one of the side surfaces of the second quartz crystal tuning fork tine such that the first electrode of the first quartz crystal tuning fork tine and the second electrode of the second quartz crystal tuning fork tine define a first electrode terminal; and wherein the second electrode disposed on one of the side surfaces of the first quartz crystal tuning fork tine is connected to the first electrode disposed in one of the grooves of the second quartz crystal tuning fork tine such that the second electrode of the first quartz crystal tuning fork tine and the first electrode of the second quartz crystal tuning fork tine define a second electrode terminal. 
     
     
       7. A quartz crystal tuning fork resonator according to  claim 6 ; wherein two of the side surfaces of each of the first and second quartz crystal tuning fork tines comprises an inner side surface and an outer side surface opposite the inner side surface; wherein when a direct current voltage is applied between the first and second electrode terminals, a direction of an inner electric field generated between the second electrode disposed on the inner side of the first quartz crystal tuning fork tine and the first electrode disposed in one of the grooves opposite to the second electrode disposed on the inner side of the first quartz crystal tuning fork tine is the same as a direction of an inner electric field generated between the second electrode disposed on the inner side of the second quartz crystal tuning fork tine and the first electrode disposed in one of the grooves opposite to the second electrode disposed on the inner side of the second quartz crystal tuning fork tine, and a direction of an outer electric field generated between a second electrode disposed on the outer side of the first quartz crystal tuning fork tine and the first electrode disposed in one of the grooves opposite to the second electrode disposed on the outer side of the first quartz crystal tuning fork tine is the same as a direction of an outer electric field generated between the second electrode disposed on the outer side of the second quartz crystal tuning fork tine and the first electrode disposed in one of the grooves opposite to the second electrode disposed on the outer side of the second quartz crystal tuning fork tine, the direction of each of the inner electric fields being opposite to the direction of each of the outer electric fields. 
     
     
       8. A quartz crystal tuning fork resonator according to  claim 7 ; wherein the directions of the inner and outer electric fields of the first and second quartz crystal tuning fork tines are generally along an x-axis direction of the quartz crystal tuning fork resonator. 
     
     
       9. A quartz crystal tuning fork resonator according to  claim 8 ; wherein no electric field is generated between first electrodes disposed in opposite grooves of the first and second quartz crystal tuning fork tines when the direct current voltage is applied between the first and second electrode terminals. 
     
     
       10. A quartz crystal tuning fork resonator according to  claim 9 ; wherein the inner and outer sides of the first and second quartz crystal tuning fork tines undergo simultaneous deformation in opposite directions along a longitudinal axis of the first and second quartz crystal tuning fork tines. 
     
     
       11. A quartz crystal tuning fork resonator according to  claim 10 ; wherein when an alternating current voltage is applied between the first and second electrode terminals, the first and second quartz crystal tuning fork undergo vibration in a flexural mode of an inverse phase. 
     
     
       12. A quartz crystal tuning fork resonator according to  claim 2 ; wherein the quartz crystal tuning fork tines comprise first and second quartz crystal tuning fork tines each having a first main surface and a second main surface opposite the first main surface, each of the first and second main surfaces having one of the two stepped portions; wherein the first electrodes disposed in the two stepped portions of the first quartz crystal tuning fork tine are connected to the second electrode disposed on the side of the second quartz crystal tuning fork tine to define a first electrode terminal; and wherein the second electrode disposed on the side of the first quartz crystal tuning fork tine is connected to the first electrodes disposed in the two stepped portions of the second quartz crystal tuning fork tine to define a second electrode terminal. 
     
     
       13. A quartz crystal tuning fork resonator according to  claim 12 ; wherein each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a central linear portion; and wherein the two stepped portions corresponding to the first and second main surfaces of each of the first and second quartz crystal tuning fork tines are disposed on opposite sides of the central linear portion. 
     
     
       14. A quartz crystal tuning fork resonator according to  claim 13 ; wherein when an alternating current voltage is applied between the first and second electrode terminals, the first and second quartz crystal tuning fork undergo vibration in a flexural mode of an inverse phase. 
     
     
       15. A quartz crystal tuning fork resonator according to  claim 3 ; wherein each of the plurality of individual resonators is connected to at least one other individual resonator of the plurality of resonators through a base portion. 
     
     
       16. A quartz crystal tuning fork resonator according to  claim 3 ; wherein each of the individual quartz crystal tuning fork resonators differs from another of the individual quartz crystal tuning fork resonators at least in one of the shape thereof and the configuration of the electrodes. 
     
     
       17. A quartz crystal tuning fork resonator according to  claim 3 ; wherein the individual quartz crystal tuning fork resonators are electrically connected together in parallel. 
     
     
       18. A quartz crystal tuning fork resonator comprising:
 a quartz crystal tuning fork base;    a plurality of quartz crystal tuning fork tines extending from the quartz crystal tuning fork base so that portions of the quartz crystal tuning fork base and portions of the quartz crystal tuning fork tines define opposite first and second main surfaces of the quartz crystal tuning fork resonator;    a first set of grooves formed in the first and second main surfaces of the quartz crystal tuning fork resonator;    a second set of grooves formed in the first and second main surfaces of the quartz crystal tuning fork resonator; and    a third set of grooves formed in the first and second main surfaces of the quartz crystal tuning fork resonator and between the first and second set of grooves.    
     
     
       19. A quartz crystal tuning fork resonator according to  claim 18 ; further comprising a first set of electrodes having the same polarity and each disposed in a respective one of the first set of grooves; and a second set of electrodes having the same polarity and each disposed in a respective one of the second set of grooves. 
     
     
       20. A quartz crystal tuning fork resonator according to  claim 19 ; wherein the polarity of the first set of electrodes is different from the polarity of the second set of electrodes. 
     
     
       21. A quartz crystal tuning fork resonator according to  claim 19 ; wherein the third set of grooves comprises a first pair of intermediate grooves each formed on a respective one of the first and second main surfaces and a second a second pair of intermediate grooves each formed on a respective one of the first and second main surfaces. 
     
     
       22. A quartz crystal tuning fork resonator according to  claim 21 ; further comprising a third set of electrodes having the same polarity and each disposed in a respective one of the first pair of intermediate grooves; and a fourth set of electrodes having the same polarity and each disposed in a respective one of the second pair of intermediate grooves. 
     
     
       23. A quartz crystal tuning fork resonator according to  claim 22 ; wherein portions of the quartz crystal tuning fork base and portions of the quartz crystal tuning fork tines define opposite first and second side surfaces of the quartz crystal tuning fork resonator; and further comprising a fifth electrode disposed on the first side surface and a sixth electrode disposed on the second side surface and having a different polarity than the fifth electrode. 
     
     
       24. A quartz crystal tuning fork resonator according to  claim 23 ; wherein the second and fourth sets of electrodes and the fifth electrode have the same polarity; and wherein the first and third sets of electrodes and the sixth electrode have the same polarity. 
     
     
       25. A quartz crystal tuning fork resonator according to  claim 24 ; wherein the quartz crystal tuning fork resonator is symmetrical about a central plane thereof. 
     
     
       26. A quartz crystal tuning fork resonator comprising:
   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, each of the first and second main surfaces having a central linear portion;        a groove formed in the central linear portion of at least one of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines, a width of the groove being greater than a distance in the width direction of the groove measured from an outer edge of the groove to an outer edge of the corresponding one of the first and second quartz crystal tuning fork tines; and        an electrode disposed in the groove so that the quartz crystal tuning fork resonator is capable of vibrating in a flexural mode of an inverse phase.     
     
     
       27. A quartz crystal tuning fork resonator according to  claim 26 ; wherein the groove formed in the central linear portion of the at least one of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines, the grooves in the central linear portions of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines being disposed opposite each other in a thickness direction of the first and second quartz crystal tuning fork tines. 
     
     
       28. A quartz crystal tuning fork resonator according to  claim 27 ; wherein at least one of the grooves formed in the central linear portions of each of the first and second quartz crystal tuning fork tines extends in the quartz crystal tuning fork base. 
     
     
       29. A quartz crystal tuning fork resonator according to  claim 27 ; 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 electrode comprises a first electrode disposed in the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines and a second electrode disposed on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines so that the quartz crystal tuning fork resonator is capable of vibrating in a flexural mode of an inverse phase; wherein the first electrode disposed in the groove formed in the central linear portion of the first main surface of the first quartz crystal tuning fork tine has the same electrical polarity as the first electrode disposed in the groove formed in the central linear portion of the second main surface of the first quartz crystal tuning fork tine; wherein the first electrode disposed in the groove formed in the central linear portion of the first main surface of the second quartz crystal tuning fork tine has the same electrical polarity as the first electrode disposed in the groove formed in the central linear portion of the second main surface of the second quartz crystal tuning fork tine; and wherein the first electrodes of the first quartz crystal tuning fork tine have an electrical polarity opposite to an electrical polarity of the first electrodes of the second quartz crystal tuning fork tine. 
     
     
       30. A quartz crystal tuning fork resonator according to  claim 29 ; wherein the first electrode disposed in the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines extends on a surface adjacent to the groove; wherein the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a base portion and a stepped portion; wherein the first electrode is disposed on each of the base portion and the stepped portion of the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the first electrodes disposed on the base portions and the stepped portions of the grooves of the first quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine; wherein the first electrodes disposed on the base portions and the stepped portions of the grooves of the second quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine; and wherein a width of the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is greater than a distance in the width direction of the groove measured from an outer edge of the groove to an outer edge of the corresponding one of the first and second quartz crystal tuning fork tines. 
     
     
       31. A quartz crystal tuning fork resonator according to  claim 30 ; wherein the surface adjacent to the groove formed in the first main surface of each of the first and second quartz crystal tuning fork tines comprises the first main surface; and wherein the surface adjacent to the groove formed in the second main surface of each of the first and second quartz crystal tuning fork tines comprises the second main surface. 
     
     
       32. A quartz crystal tuning fork resonator according to  claim 29 ; wherein a third electrode is disposed on at least one of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a base portion; wherein the first electrode is disposed on the base portion of the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the first electrodes disposed on the base portions of the grooves of the first quartz crystal tuning fork tine are connected to the third electrode disposed on the at least one of the first and second main surfaces of the first quartz crystal tuning fork tine and the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine; and wherein the first electrodes disposed on the base portions of the grooves of the second quartz crystal tuning fork tine are connected to the third electrode disposed on the at least one of the first and second main surfaces of the second quartz crystal tuning fork tine and the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine. 
     
     
       33. A quartz crystal tuning fork resonator according to  claim 29 ; wherein the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a width W 2    greater than a distance W   1    extending between a first side of the groove and a first side of the corresponding one of the first and second quartz crystal tuning fork tines and a distance W   3    extending between a second side of the groove and a second side of the corresponding one of the first and second quartz crystal tuning fork tines; wherein each of the first and second quartz crystal tuning fork tines comprises a third main surface having W   1    and a fourth main surface having W   3   , a third electrode being disposed on at least one of the third and fourth main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the first electrodes disposed in the grooves of the first quartz crystal tuning fork tine are connected to the third electrode disposed on the at least one of the third and fourth main surfaces of the first quartz crystal tuning fork tine and the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine; and wherein the first electrodes disposed in the grooves of the second quartz crystal tuning fork tine are connected to the third electrode disposed on the at least one of the third and fourth main surfaces of the second quartz crystal tuning fork tine and the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine.   
     
     
       34. A quartz crystal tuning fork resonator according to  claim 33 ; wherein the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a base portion and a stepped portion; wherein the first electrode is disposed on each of the base portion and the stepped portion of the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the first electrodes disposed on the base portions and the stepped portions of the grooves of the first quartz crystal tuning fork tine are connected to the third electrode disposed on the at least one of the third and fourth main surfaces of the first quartz crystal tuning fork tine and the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine to form a first electrode terminal; wherein the first electrodes disposed on the base portions and the stepped portions of the grooves of the second quartz crystal tuning fork tine are connected to the third electrode disposed on the at least one of the third and fourth main surfaces of the second quartz crystal tuning fork tine and the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine to form a second electrode terminal; and wherein when an alternating current voltage is applied between the first and second electrode terminals, the quartz crystal tuning fork resonator is capable of vibrating in a flexural mode of an inverse phase. 
     
     
       35. A quartz crystal tuning fork resonator according to  claim 34 ; wherein each of the third and fourth main surfaces adjacent to the groove formed in the central linear portion of the first main surface of each of the first and second quartz crystal tuning fork tines comprises the first main surface; and wherein each of the third and fourth main surfaces adjacent to the groove formed in the central linear portion of the second main surface of each of the first and second quartz crystal tuning fork tines comprises the second main surface. 
     
     
       36. A quartz crystal tuning fork resonator according to  claim 29 ; wherein each of the first and second quartz crystal tuning fork tines has a third main surface and a fourth main surface opposite the third main surface; wherein each of the third and fourth main surfaces is located between outer edges of the groove and outer edges of corresponding one of the first and second quartz crystal tuning fork tines and has a distance in the width direction of the groove measured from one of the outer edges of the groove to one of the outer edges of the corresponding one of the first and second quartz crystal tuning fork tines; wherein a third electrode is disposed on each of the third and fourth main surfaces of each of the first and second quartz crystal tuning fork tines; and wherein the third electrode disposed on each of the third and fourth main surfaces of each of the first and second quartz crystal tuning fork tines is connected to the first electrode disposed in the groove adjacent to the third electrode. 
     
     
       37. A quartz crystal tuning fork resonator according to  claim 36 ; wherein the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a base portion and a stepped portion; wherein the first electrode is disposed on each of the base portion and the stepped portion of the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the first electrodes disposed on the base portions and the stepped portions of the grooves of the first quartz crystal tuning fork tine are connected to the third electrodes disposed on the third and fourth main surfaces of the first quartz crystal tuning fork tine and the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine; wherein the first electrodes disposed on the base portions and the stepped portions of the grooves of the second quartz crystal tuning fork tine are connected to the third electrodes disposed on the third and fourth main surfaces of the second quartz crystal tuning fork tine and the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine; and wherein a width of at least one of the grooves formed in the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is greater than the distance in the width direction of the groove measured from one of the outer edges of the groove to one of the outer edges of the corresponding one of the first and second quartz crystal tuning fork tines. 
     
     
       38. A quartz crystal tuning fork resonator according to  claim 37 ; wherein the third main surface of each of the first and second quartz crystal tuning fork tines comprises the first main surface; and wherein the fourth main surface of each of the first and second quartz crystal tuning fork tines comprises the second main surface. 
     
     
       39. A quartz crystal tuning fork resonator according to  claim 26 ; wherein the groove formed in the central linear portion of at least one of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a width W 2    greater than a distance W   1    extending between a first side of the groove and a first side of the corresponding one of the first and second quartz crystal tuning fork tines and a distance W   3    extending between a second side of the groove and a second side of the corresponding one of the first and second quartz crystal tuning fork tines; 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 a first electrode is disposed in the groove formed in the central linear portion of 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 the quartz crystal tuning fork resonator is capable of vibrating in a flexural mode of an inverse phase; and wherein the first electrodes of the first quartz crystal tuning fork tine have an electrical polarity opposite to an electrical polarity of the first electrodes of the second quartz crystal tuning fork tine.   
     
     
       40. A quartz crystal tuning fork resonator according to  claim 39 ; wherein the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a base portion and a stepped portion; wherein the first electrode is disposed on each of the base portion and the stepped portion of the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the first electrode disposed on the base portion of the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines extends on a surface adjacent to the groove; wherein the first electrodes disposed on the base portions of the grooves of the first quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine; and wherein the first electrodes disposed on the base portions of the grooves of the second quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine. 
     
     
       41. A quartz crystal tuning fork resonator according to  claim 39 ; wherein the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a base portion and a stepped portion; wherein the first electrode is disposed on each of the base portion and the stepped portion of the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines; wherein the first electrode disposed on each of the base portion and the stepped portion of the groove formed in the first main surface of each of the first and second quartz crystal tuning fork tines extends on the first main surface adjacent to the groove; wherein the first electrode disposed on each of the base portion and the stepped portion of the groove formed in the second main surface of each of the first and second quartz crystal tuning fork tines extends on the second main surface adjacent to the groove; wherein the first electrodes disposed on the base portions and the stepped portions of the grooves of the first quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine; and wherein the first electrodes disposed on the base portions and the stepped portions of the grooves of the second quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine. 
     
     
       42. A quartz crystal tuning fork resonator comprising:
   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, each of the first and second main surfaces having a central linear portion;        a groove having a base portion and a stepped portion and formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines so that a width of the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is greater than a distance in the width direction of the groove measured from an outer edge of the groove to an outer edge of the corresponding one of the first and second quartz crystal tuning fork tines;        a first electrode disposed on each of the base portion and the stepped portion of the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines;        a second electrode disposed on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines; and        a third electrode disposed on each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines;        wherein the first electrodes disposed on the base portions and the stepped portions of the first quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine and the third electrodes disposed on the first and second main surfaces of the first quartz crystal tuning fork tine to form a first electrode terminal, and the first electrodes disposed on the base portions and the stepped portions of the second quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine and the third electrodes disposed on the first and second main surfaces of the second quartz crystal tuning fork tine to form a second electrode terminal; and        wherein when an alternating current voltage is applied between the first and second electrode terminals, the quartz crystal tuning fork resonator is capable of vibrating in a flexural mode of an inverse phase.     
     
     
       43. A quartz crystal tuning fork resonator according to  claim 42 ; wherein the base portions of the grooves in the first and second main surfaces of each of the first and second quartz crystal tuning fork tines are disposed opposite each other in a thickness direction of the first and second quartz crystal tuning fork tines; wherein the first electrode disposed on the base portion of the groove is connected to the third electrode adjacent to the groove through the first electrode disposed on the stepped portion of the groove; and wherein the first electrodes disposed on the base portions of the grooves of the first quartz crystal tuning fork tine have an electrical polarity opposite to an electrical polarity of the first electrodes disposed on the base portions of the grooves of the second quartz crystal tuning fork tine. 
     
     
       44. A quartz crystal tuning fork resonator comprising:
   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, each of the first and second main surfaces having a central linear portion;        a groove having a width W   2    and a base portion and formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines so that the width W   2    of the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines is greater than a distance W   1    extending between a first side of the groove and a first side of the corresponding one of the first and second quartz crystal tuning fork tines and a distance W   3    extending between a second side of the groove and a second side of the corresponding one of the first and second quartz crystal tuning fork tines;        a first electrode disposed on the base portion of the groove formed in the central linear portion of each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines;        a second electrode disposed on each of the first and second side surfaces of each of the first and second quartz crystal tuning fork tines; and        a third electrode disposed on each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines;        wherein the first electrodes disposed on the base portions of the grooves of the first quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the second quartz crystal tuning fork tine and the third electrodes disposed on the first and second main surfaces of the first quartz crystal tuning fork tine to form a first electrode terminal, and the first electrodes disposed on the base portions of the grooves of the second quartz crystal tuning fork tine are connected to the second electrodes disposed on the first and second side surfaces of the first quartz crystal tuning fork tine and the third electrodes disposed on the first and second main surfaces of the second quartz crystal tuning fork tine to form a second electrode terminal; and        wherein when an alternating current voltage is applied between the first and second electrode terminals, the quartz crystal tuning fork resonator is capable of vibrating in a flexural mode of an inverse phase.     
     
     
       45. A quartz crystal tuning fork resonator according to  claim 44 ; wherein the groove formed in each of the first and second main surfaces of each of the first and second quartz crystal tuning fork tines has a stepped portion; wherein the first electrode is disposed on the stepped portion; wherein the first electrode disposed on the base portion of the groove is connected to the third electrode adjacent to the groove through the first electrode disposed on the stepped portion of the groove; and wherein the first electrodes disposed on the base portions of the grooves of the first quartz crystal tuning fork tine have an electrical polarity opposite to an electrical polarity of the first electrodes disposed on the base portions of the grooves of the second quartz crystal tuning fork tine.