JP2003273698A - Electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electronic equipment provided with a high-precision signal source for normally operating the functions of the electronic equipment composed of a display part and the signal source for driving the display part at least. <P>SOLUTION: The electronic equipment is composed of at least one oscillator composed of an amplifier circuit and a feedback circuit for obtaining a high- precision output signal for normally operating the respective functions of the electronic equipment, a CMOS inverter is used for the amplifier circuit, and a crystal vibrator is used for the feedback circuit. Besides, the vibrators of different vibration modes are used for the crystal vibrator. Further, an output signal has high frequency stability on the basis of the relation of the amplification factor of the amplifier circuit and the feedback rate of the feedback circuit and by using the output signal for the respective functions of the electronic equipment, the electronic equipment to be operated normally is realized. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device including at least a display section and an oscillator. In particular, the present invention relates to an electronic device having at least one crystal oscillator, which is an optimal oscillator as a clock source or a reference signal source.

[0002]

2. Description of the Related Art One of the conventional oscillators used in electronic equipment is often a crystal oscillator consisting of an amplifier, a capacitor, a resistance element, and a tuning fork-shaped bent crystal oscillator having electrodes on the upper and lower surfaces and side surfaces of a tuning fork arm. Are known. FIG. 11 is a schematic view of a tuning fork-shaped bent crystal unit 200 used in this conventional crystal oscillator. In FIG. 11, the crystal unit 200 includes two tuning fork arms 201 and 202 and a tuning fork base portion 2.
30 and. FIG. 12 shows a sectional view of the tuning fork arm of FIG. As shown in FIG. 12, the excitation electrodes are arranged on the upper and lower surfaces and side surfaces of the tuning fork arm. An electrode 203 is arranged on the upper surface and an electrode 204 is arranged on the lower surface of the cross section of one tuning fork arm. Electrodes 205 and 206 are provided on the side surface. Electrode 207 is on the upper surface of the other tuning fork arm and electrode 208 is on the lower surface.
However, electrodes 209 and 210 are further arranged on the side surface to form a two-electrode terminal H-H '. When a DC voltage is applied between H-H ', the electric field works in the direction of the arrow. As a result, when one tuning fork arm bends inward, the other tuning fork arm also bends inward. The reason is that the electric field components Ex in the x-axis direction are opposite in direction inside each tuning fork arm. Vibration can be sustained by applying an alternating voltage. Also, JP-A-56-
65517 and JP-A-2000-223992 (P2000
No. 223992A), a groove is provided on a tuning fork arm and an electrode structure is disclosed.

[0003]

In the tuning fork-shaped bent crystal oscillator, the larger the electric field component Ex, the more the equivalent series resistance R ₁
Becomes smaller and the quality factor Q value becomes larger. However, as shown in FIG. 12, the conventional tuning fork-shaped bent crystal oscillator has electrodes arranged on the upper and lower surfaces and side surfaces of each tuning fork arm. Therefore, the electric field does not act linearly, and when the tuning fork type bent crystal oscillator is downsized, the electric field component Ex becomes small, the equivalent series resistance R ₁ becomes large, and the quality factor Q value becomes small. There were challenges left. At the same time, highly accurate as a time reference,
That is, it has been left as an issue to obtain a bent crystal oscillator having high frequency stability and suppressing harmonic mode vibration. Further, as a method for solving the above-mentioned problems, for example, Japanese Patent Application Laid-Open No. 56-65517 discloses a groove in a tuning fork arm and a groove structure and an electrode structure. However,
Groove configuration, size, vibration mode, and equivalent series resistance R ₁ of fundamental mode vibration and equivalent series resistance R _n of harmonic mode vibration
And the Figer of Merit M, which is related to the relationship with the frequency stability and frequency stability, are not disclosed at all. Also, if a conventional crystal oscillator or oscillator with a groove is connected to a conventional circuit to configure a crystal oscillator circuit, the output signal of the fundamental mode vibration will be affected by shock or vibration, and the output signal will be a harmonic mode vibration. There is a problem that the frequency is changed or detected and the electronic device does not operate normally. For this reason, there has been a demand for a crystal oscillator having a tuning fork-shaped bent crystal oscillator that vibrates in a fundamental mode that suppresses harmonic mode vibration that is not affected by shock or vibration. . Further, if the load capacitance C _L is reduced in order to reduce the current consumption of the crystal oscillator, the harmonic mode vibration is likely to occur, and the problem that the output frequency of the fundamental wave mode vibration cannot be obtained remains. Therefore, it is equipped with a tuning fork-shaped bent crystal oscillator that vibrates in the fundamental wave mode, has a small equivalent series resistance R ₁ , and has a high quality factor Q value, and the output signal is high at the frequency of the fundamental wave mode vibration. A crystal oscillator having frequency stability (high time accuracy) and low current consumption has been desired. In addition, in particular, no report has been made on a crystal oscillator including a width vertical crystal resonator having a small equivalent series resistance R ₁ and a high Q value.

[0004]

The present invention comprises a tuning fork-shaped crystal resonator, a width-vertical crystal resonator, or a thickness-sliding crystal resonator that vibrates in a bending mode in which the conventional problems are advantageously solved by the following method. It is an object to provide an electronic device including a crystal oscillator.

That is, the first aspect of the electronic apparatus of the present invention is
An electronic device configured to include at least a display unit and an oscillator, wherein the electronic device is configured to include at least one oscillator, and the one oscillator is a crystal oscillator configured to include a crystal oscillator. The oscillator includes a crystal oscillator circuit including an amplifier circuit including at least an amplifier and a feedback circuit including at least a crystal oscillator and a capacitor, and the crystal oscillator of the feedback circuit forming the one crystal oscillator is bent. A tuning fork-shaped bent crystal resonator configured to include a tuning fork arm that vibrates in a mode and a tuning fork base, wherein the tuning fork arm has an upper surface, a lower surface, and a side surface, and an electrode is arranged on a side surface of the tuning fork arm. The electrodes arranged so as to face the inner side surface of the tuning fork arm are configured to have different polarities, and the electrodes are configured such that the tuning fork arm vibrates in a reverse phase, and Fundamental mode vibration of the full Iga of merit M ₁ is harmonic mode vibration of full Iga of merit M _n greater flexural crystal oscillator wherein one of the crystal oscillator comprises a bending quartz oscillator serial tuning fork is configured In addition, the absolute value of the negative resistance of the fundamental mode vibration of the amplifier circuit of the one crystal oscillator configured to include the amplifier circuit and the feedback circuit including the tuning fork-shaped bent crystal resonator | -RL
₁ | and the equivalent series resistance R ₁ of the fundamental mode vibration are the absolute value of the negative resistance of the harmonic mode vibration of the amplifier circuit | −RL _n
The one crystal oscillator is configured so as to be larger than the ratio of | and the equivalent series resistance R _n of the harmonic mode vibration.
An output signal of the one crystal oscillator configured to include the tuning fork-shaped bent crystal oscillator is a frequency of fundamental mode vibration, and the output signal is an electronic signal having a signal for displaying time on the display unit of an electronic device. Equipment.

According to a second aspect of the electronic apparatus of the present invention, the crystal oscillator of the feedback circuit which constitutes at least one crystal oscillator including the amplifier circuit and the feedback circuit is a width-vertical crystal oscillator or a thickness-sliding crystal. The electronic device according to the first aspect, wherein the output signal of a crystal oscillator that is a vibrator and is configured to include the crystal vibrator is used for other than the time display of the electronic device.

[0007]

As described above, the present invention relates to an electronic device equipped with a crystal oscillator including a bending crystal unit having a tuning fork shape, a width-direction crystal unit, or a thickness-shear crystal unit, and particularly, a relationship between an amplifier circuit and a feedback circuit. By indicating the shape and the cut angle of the crystal oscillator, it is possible to obtain an electronic device including a crystal oscillator having high frequency stability.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is an embodiment of an electronic apparatus of the present invention, which is an example of a block diagram of a facsimile. That is, it comprises a modem, a voice circuit, a clock circuit, a printing section, a loading section, an operating section and a display section. Further, according to this principle, first, the reflected light of the light projected on the document at the capturing portion is detected by the charge coupled device (CCD) and scanned. The reflected light and shade of the reflected light is converted into a digital signal, modulated by a modem and sent to a telephone line. On the receiving side, the received signal is demodulated by the modem and printed on the recording paper in synchronization with the transmitting side by the printing section. As shown in FIG. 1, the crystal oscillator is used for the CPU clock of the control unit and the printing unit, the clock of the voice synthesis IC of the voice circuit, the synchronous clock of the modem, the time reference of the clock circuit, and the like. That is, these constitute a crystal oscillator and the output signal thereof is used. For example, it is used as a signal for displaying time on the display unit of an electronic device. More specifically, in order for the facsimile, which is one of the electronic devices of this embodiment, to operate normally, an accurate output signal of the crystal oscillator used in this device is required. In this embodiment, the facsimile is shown as an example of the electronic device, but the electronic device of the present invention includes all devices including a crystal oscillator. For example, mobile phone, telephone, television, camera, video, video camera, pager, personal computer, printer, CD player, MD player, electronic musical instrument, car navigation, car electronics,
For example, a clock or an IC card. Hereinafter, the crystal oscillator used in the electronic device of the present invention will be described in detail.

FIG. 2 is an embodiment of a crystal oscillation circuit diagram constituting a crystal oscillator used in the electronic equipment of the present invention. In this embodiment, the crystal oscillation circuit 1 is composed of an amplifier (CMOS inverter) 2, a feedback resistor 4, a drain resistor 7, capacitors 5, 6 and a tuning fork-shaped bent crystal oscillator 3. That is, the crystal oscillation circuit 1 includes an amplifier circuit 8 including an amplifier 2 and a feedback resistor 4, a drain resistor 7, a capacitor 5,
6 and a feedback circuit 9 including a bent crystal unit 3. Further, the output signal of the crystal oscillating circuit 1 constituted by the tuning fork-shaped bent crystal oscillator 3 vibrating in the fundamental wave mode is output from the drain side through a buffer circuit (not shown). That is, the frequency of the fundamental wave mode vibration is output as an output signal through the buffer circuit.
In the present invention, the frequency of fundamental mode vibration is 10 kHz to
200 kHz is used. Further, in the present invention, the frequency of the fundamental wave mode vibration also includes the frequency obtained by dividing or multiplying the frequency of the output signal by the frequency dividing circuit or the frequency multiplying circuit. More specifically, the crystal oscillator of this embodiment is configured to include a crystal oscillation circuit and a buffer circuit. In other words, the crystal oscillation circuit is composed of an amplifier circuit and a feedback circuit, the amplifier circuit is composed of at least an amplifier, and the feedback circuit is composed of at least a tuning fork-shaped bent crystal oscillator and a capacitor. The tuning fork-shaped bent crystal unit used in the crystal oscillator of this embodiment will be described in detail with reference to FIGS.

FIG. 3 shows the feedback circuit diagram of FIG. The angular frequency of a tuning fork-shaped crystal unit that vibrates in the bending mode is now ω
_i , the resistance of the drain resistance 7 is R _d , and the capacitors 5 and 6 are
_Let C _{g be} the capacitance of C _d , C _{d be} the crystal impedance of the crystal be R _ei , be the input voltage be V ₁ and be the output voltage be V ₂ .
The feedback rate β _i is defined by β _i = | V ₂ | _i / | V ₁ | _i . However, i represents the vibration order of the bending mode vibration. For example, when i = 1, the fundamental mode vibration, and when i = 2,
Second harmonic mode vibration, when i = 3, third harmonic mode vibration. That is, when i = n, the vibration is n-th harmonic mode vibration, but hereinafter simply referred to as harmonic mode vibration. Further, the load capacitance C _L is given by C _L = C _g C _d / (C _g + C _d ), and when C _g = C _d = C _gs and Rd >> R _ei , the feedback ratio β _i is β _i = It is given by 1 / (1 + kC _L ² ). However, k is represented by a function of ω _i , R _d , and R _ei . Also, R _ei is approximately equal to the equivalent series resistance R _i .

As described above, from the relationship between the feedback ratio β _i and the load capacitance C _L , as the load capacitance C _L becomes smaller, the feedback ratios at the resonance frequencies of the fundamental vibration mode and the harmonic vibration mode may increase. I understand. Therefore, the load capacity C
_{When L} becomes smaller, the harmonic mode vibration is more likely to oscillate than the fundamental wave mode vibration. The reason is that the maximum vibration amplitude of the harmonic mode vibration is smaller than the maximum vibration amplitude of the fundamental mode vibration, so that the amplitude condition and the phase condition that are the oscillation continuation conditions are satisfied at the same time.

The crystal oscillator used in the electronic apparatus of the present invention provides a crystal oscillator having a fundamental mode vibration frequency with low current consumption and high frequency stability (high time accuracy). The purpose is to do. Therefore, in order to reduce the current consumption, the load capacitance C _L is 10 pF or less in this embodiment. In order to further reduce the current consumption, since the current consumption is proportional to the load capacitance, C _L = 8 pF or less is preferable. The capacitances C _g and C _d here are numerical values that do not include the stray capacitance of the circuit,
In reality, stray capacitance exists due to the circuit configuration. Therefore, in this embodiment, the load capacitance C _{L including the} stray capacitance of this circuit configuration is 18 pF or less. Further, in order to suppress the vibration of the harmonic mode and the output signal of the oscillator obtains the frequency of the fundamental mode vibration, α ₁ / α _n > β _n / β ₁ and α
The crystal oscillation circuit of the present embodiment is configured so as to satisfy ₁ β ₁ > 1. However, α ₁ and α _n are amplification factors of the amplification circuit for the fundamental wave mode vibration and the harmonic mode vibration, and β ₁ and β _n are the feedback factors of the feedback circuit for the fundamental wave mode vibration and the harmonic mode vibration. That is, when n = 2 and 3, it is the second and third harmonic mode vibration.

In other words, the ratio of the amplification factor α ₁ of the fundamental mode vibration of the amplifier circuit to the amplification factor α _n of the harmonic mode vibration is the feedback factor β _n of the harmonic mode vibration of the feedback circuit and the fundamental mode vibration. Is larger than the ratio of the feedback ratio β ₁ of the fundamental wave mode vibration, and the amplification factor α ₁ of the fundamental mode vibration and the feedback ratio β _{1 of the} fundamental mode vibration
The product of is greater than one. That is, it is possible to realize a crystal oscillator that consumes less current and whose output signal has a frequency of fundamental mode vibration. Further, high frequency stability will be described later.

Further, the amplifying portion of the amplifying circuit which constitutes the crystal oscillating circuit of this embodiment can exhibit its characteristic by the negative resistance -RL _i . When i = 1, it is a negative resistance of fundamental mode vibration, and when i = n, it is a negative resistance of harmonic mode vibration.
That is, when n = 2 and 3, it is the negative resistance of the second and third harmonic mode vibrations. In the crystal oscillator of the present embodiment, _the ratio of the absolute value of the negative resistance | -RL ₁ | of the fundamental mode vibration of the amplifier circuit to the equivalent series resistance R _{1 of} the fundamental mode vibration is the negative of the harmonic mode vibration of the amplifier circuit. The oscillating circuit is configured so as to be larger than the ratio of the absolute value | -RL _n | of the static resistance and the equivalent series resistance R _n of the harmonic mode vibration. That is, | -RL ₁ |
/ R ₁ > | −RL _n | / R _n . By configuring the crystal oscillating circuit in this manner, the oscillation start of the harmonic mode vibration is suppressed, and as a result, the oscillation start of the fundamental mode vibration is obtained, so that the frequency of the fundamental mode vibration is obtained as the output signal.

FIG. 4 is an external view of a tuning fork-shaped bent crystal oscillator 10 vibrating in a bending mode used in the crystal oscillator of the first embodiment constituting the electronic apparatus of the present invention and its coordinate system. Coordinate system O, electric axis x, mechanical axis y, optical axis z
O-xyz consisting of The tuning fork-shaped bent crystal oscillator 10 according to the present embodiment includes a tuning fork arm 20, a tuning fork arm 26, and a tuning fork base 40, and the tuning fork arm 20 and the tuning fork arm 26 are connected to the tuning fork base 40. The tuning fork arm 20 and the tuning fork arm 26 have an upper surface, a lower surface, and a side surface, respectively. Further, a groove 21 is provided on the upper surface of the tuning fork arm 20 so as to sandwich the neutral line, that is, so as to include the neutral line, and a groove 27 is provided on the upper surface of the tuning fork arm 26 as with the tuning fork arm 20. Further, the tuning fork base portion 40 is provided with a groove 32 and a groove 36. Further, grooves are provided on the lower surfaces of the tuning fork arms 20 and 26 as well as the upper surfaces.

FIG. 5 is a cross-sectional view of the tuning fork base portion 40 of the bending crystal unit 10 having the tuning fork shape shown in FIG. 5, the cross-sectional shape and electrode arrangement of the tuning fork base portion 40 of the crystal unit shown in FIG. 4 will be described in detail. Grooves 21 and 22 are provided in the tuning fork base portion 40 that is connected to the tuning fork arm 20. Similarly, the tuning fork base portion 40 connected to the tuning fork arm 26 is provided with grooves 27 and 28. Further, a groove 3 is further provided between the groove 21 and the groove 27.
2 and a groove 36 are provided. Further, a groove 33 and a groove 37 are also provided between the groove 22 and the groove 28. And
Electrodes 23 and 24 are provided in the grooves 21 and 22, and grooves 32 and 33,
Electrodes 34, 35, 38, 39 are provided on the grooves 36, 37 in the groove 27.
The electrodes 29 and 30 are arranged in the groove 28 and the groove 28, and the tuning fork base 40
Electrodes 25 and 31 are arranged on both side surfaces of. In detail, electrodes are arranged on the side surfaces of the groove, and electrodes having different polarities are arranged opposite to the electrodes. Further, electrodes are arranged also on the side surfaces of the tuning fork arm, and the counter electrodes arranged on the inner side surfaces of the tuning fork arm are constructed so as to have different polarities. In this embodiment, the opposing side surfaces of the tuning fork arm are referred to as inner side surfaces.

The tuning fork-shaped bent crystal oscillator 10 has a thickness t, and the groove has a thickness t ₁ . The thickness t _{1 mentioned} here means the thickness of the deepest part of the groove. The reason is that quartz is an anisotropic material, and therefore the etching speed differs depending on the direction of each crystal axis in the chemical etching method. Therefore, the chemical etching method causes variations in the depth of the groove, and it is extremely difficult to process into the uniform shape shown in FIG. In this embodiment, the ratio (t ₁ / t) between the thickness t _{1 of} the groove and the thickness t of the tuning fork arm or the tuning fork arm and the tuning fork base is 0.
It is preferably 0.01 to so as to be smaller than 79.
It is formed to be 0.79. In particular, in order to increase the distortion of the tuning fork base, it is preferable to set the ratio of the thickness of the groove of the tuning fork base to the thickness of the tuning fork base to 0.01 to 0.025. By forming in this way, the electric field Ex between the tuning fork arm or the tuning fork arm and the groove side surface electrode of the tuning fork base and the side surface electrode opposite thereto becomes large. That is, it is possible to obtain a bending oscillator having a high electromechanical conversion efficiency. That is, a tuning fork-shaped bent crystal oscillator having a small capacitance ratio can be obtained. Further, in this embodiment, the grooves 32, 33, 3 are further provided between the grooves of the tuning fork base.
Since 6, 37 are provided, the electric field strength thereof is further increased, and the electromechanical conversion efficiency is further improved. or,
In this embodiment, the grooves 32 and 36 are formed on the upper surface of the tuning fork base 40.
Although the grooves 33 and 37 are provided on the lower surface, they may be provided on only one surface.

Further, the electrodes 25, 29, 30, 34, 35
Has electrodes 23, 24, 31, 37, 38, and
39 is arranged so as to have the same polarity as the other, and constitutes a two-electrode terminal structure E-E '. That is, the groove electrodes facing the z-axis direction have the same polarity, and the electrodes facing the x-axis direction have the different poles. Now, 2 electrode terminal E-
When a DC voltage is applied to E '(E terminal is positive and E'terminal is negative), the electric field Ex acts as shown by the arrow in FIG.
The electric field Ex is extracted perpendicularly to the electrodes, that is, linearly by the electrodes arranged on the side surface of the crystal unit and the side surface inside the groove, so that the electric field Ex becomes large, and as a result, the amount of strain generated is also large. Become. Therefore, even when the tuning fork-shaped bent crystal unit is downsized, the equivalent series resistance R ₁ is small.
A tuning fork-shaped crystal unit having a high quality factor Q value and vibrating in a bending mode is obtained.

FIG. 6 is a tuning fork-shaped bent crystal unit 1 of FIG.
0 is a top view of FIG. In FIG. 6, the arrangement and dimensions of the grooves 21 and 27 will be described in detail. The groove 21 is provided so as to sandwich the neutral line 41 of the tuning fork arm 20. The other tuning fork arm 26 is also provided with a groove 27 so as to sandwich the neutral line 42. Further, in the tuning fork-shaped bent crystal oscillator 10 of the present embodiment, the groove 32 and the groove 36 are also provided in the portion of the tuning fork base portion 40 sandwiched between the groove 21 and the groove 27. By providing the grooves 21 and 27 and the grooves 32 and 36, the electric field Ex acts on the tuning fork-shaped bent quartz crystal resonator 10 as shown by the arrow in FIG. Is drawn perpendicularly to the electrode, that is, linearly by the electrodes arranged on the side surface of the crystal unit and the side surface inside the groove, and especially the electric field Ex of the tuning fork base portion becomes large, and as a result, the amount of strain generated growing. As described above, the shape and electrode configuration of the tuning fork-shaped bent crystal resonator 10 of this embodiment have excellent electrical characteristics even when the tuning fork-shaped bent crystal resonator is downsized, that is, the equivalent series resistance R. _A crystal unit having a small value of ₁ and a high quality factor Q value can be realized.

Furthermore, if the partial width _W 1, _{W 3} and groove width _{W 2,} the arm width W of the tuning fork arms 20 and 26 W = It is configured such that W ₁ <W ₃ . The groove width W ₂ is W
It is configured under the condition of satisfying ₂ ≧ W ₁ and W ₃ . More specifically, in this embodiment, the ratio (W ₂ / W) of the groove width W ₂ to the tuning fork arm width W is larger than 0.35 and smaller than 1, preferably 0.35. It is preferable that the ratio (t ₁ / t) of the thickness t ₁ of the groove and the thickness t of the tuning fork arm or the thickness t of the tuning fork arm and the tuning fork base is less than 0.79 at .about.0.95. Grooves are formed in the tuning fork arm so as to be 01 to 0.79. By forming in this way,
The moment of inertia with respect to the neutral lines 41 and 42 of the tuning fork arm becomes large. That is, since the electromechanical conversion efficiency is improved, the equivalent series resistance R ₁ is small, the Q value is high, and
It is possible to obtain a tuning fork-shaped bent crystal unit having a small capacity ratio.

On the other hand, regarding the length l ₁ of the groove 21 and the groove 27, in this embodiment, the grooves 21 and 27 have the tuning fork arm 2
It is dimensioned to extend from 0, 26 to the length l ₂ of the tuning fork base 40 and to have the groove length l ₃ of the base. Therefore, the length of the groove provided in the tuning fork arms 20 and 26 is (l ₁ −
l ₃ ), to obtain an oscillator with a small R ₁ ,
_{(L 1 -l 3) / (} l-l 2) it has a value of 0.4 to 0.8. Further, the total length l of the tuning fork-shaped bent crystal unit 10
Is determined by the required frequency and the size of the storage container. At the same time, in order to obtain a bent quartz oscillator having a good tuning fork shape that vibrates in the fundamental mode, there is a close relationship between the groove length l ₁ and the groove length l ₁ .

That is, the tuning fork arm 20, 26 or the tuning fork arm 2
0, 26 and the length l _{1 of the} groove provided in the tuning fork base 40 and the total length 1 of the bending fork-shaped quartz crystal in the tuning fork shape (l ₁ / l) are set so that the ratio is 0.2 to 0.78. Is provided.
The reason for forming in this way is that it is possible to suppress harmonic mode vibration, which is unnecessary vibration, particularly second-order and third-order harmonic mode vibration, and to improve frequency stability of the fundamental wave mode vibration. Therefore, a good tuning fork-shaped bent crystal unit that easily vibrates in the fundamental mode can be realized. More specifically, the equivalent series resistance R _{1 of} the tuning fork-shaped bent quartz oscillator vibrating in the fundamental mode is smaller than the equivalent series resistance R _n of the harmonic mode vibration. That is, R ₁ <R
_n (equivalent series resistance of 2nd and 3rd harmonic mode vibrations when n = 2, 3), and is composed of an amplifier (CMOS inverter), a capacitor, a resistance element, a tuning fork-shaped bent crystal oscillator of this embodiment, and the like. In this crystal oscillator, a good crystal oscillator in which the oscillator easily vibrates in the fundamental wave mode can be realized. The length l _{1 of the} groove may be divided in the length direction of the tuning fork arm, and at least one of them may satisfy the side ratio (l ₁ / l) or is divided. The length of the added groove in the longitudinal direction of the groove is the side ratio (l ₁ /
It suffices to satisfy l).

Further, in this embodiment, the tuning fork base 40 is the entire lower part of the length l ₂ of the vibrator 10 in FIG.
Further, the tuning fork arm 20 and the tuning fork arm 26 are the vibrator 10 in FIG.
From the length l ₂ portion to the entire upper portion. In the present embodiment, the tuning fork has a rectangular shape, but the present invention is not limited to the above-mentioned shape, and the tuning fork may have a U shape. In this case as well, similar to the rectangular shape, the dimensional relationship between the tuning fork arm and the tuning fork base is the same as the above relationship. Further, in the present embodiment, the groove is provided in the tuning fork arm and the tuning fork base, but the present invention is not limited to this, and the groove may be provided only in the tuning fork arm, and the same effect can be obtained. . In this case, the groove length l ₃ = 0. The groove length l ₁ in the present invention means the ratio of the groove width W ₂ to the tuning fork arm width W (W ₂ / when the groove is provided only on the tuning fork arm.
W) is the length of the groove formed so as to be larger than 0.35 and smaller than 1. Further, when the groove provided on the tuning fork arm extends to the tuning fork base, and further grooves are provided between the grooves extending to the tuning fork base, the length including the groove length l ₃ is It is l ₁ . However, if the groove of the tuning fork arm extends into the tuning fork base, but no further groove is provided between the grooves, the length l ₁ is the length of the groove of the tuning fork arm. In this embodiment, the tuning fork arm is provided with the groove and the electrode. However, in the present invention, only the electrode is provided on the tuning fork arm, and the ratio of the electrode length on the upper and lower surfaces of the tuning fork arm to the tuning fork arm length is 0.4 to. It includes those configured to be 0.8. Further, the length of the electrodes on the upper and lower surfaces is the length having an electric field component in the x-axis direction. With such a configuration, it is possible to realize a bending crystal resonator having a tuning fork shape that suppresses harmonic mode vibration, vibrates in fundamental mode vibration, and has a small equivalent series resistance R ₁ .

In other words, at least one groove is provided in the longitudinal direction on the upper and lower surfaces of the tuning fork arm sandwiching the neutral line of the tuning fork arm, that is, including the neutral line, and both sides of the groove are provided. An electrode is arranged on the surface, and the electrode on the side surface of the groove and the electrode on the side surface of the tuning fork arm that opposes the electrode are configured so as to have different polarities, and each of them is configured to increase the moment of inertia generated in the tuning fork arm. The ratio (W ₂ / W) of the groove width W ₂ of at least one of the at least one groove and the tuning fork arm width W is larger than 0.35 and smaller than 1, and the groove thickness t ₁ and the tuning fork are equal to or smaller than _1. The ratio (t ₁ / t) to the thickness t of the arm is 0.79
Grooves are formed to be smaller.

[0025] Is satisfied, and the distance W ₄ is 0.05 mm to
0.35 mm, groove width W ₂ is 0.03 mm to 0.12 m
has a value of m. The reason for configuring in this way is that it is a very small bending crystal oscillator, and the tuning fork shape and the groove of the tuning fork arm can be formed separately (separate steps) using photolithography technology. The stability can be made higher than the frequency stability of harmonic mode vibration. In this case, a crystal wafer having a thickness t of usually 0.05 mm to 0.12 mm is used.

[0026] If More specifically, the ratio of full Iga of merit M _i is the quality factor Q _i value and the capacitance ratio r _i representing the inductive electromechanical conversion efficiency and the quality factor of the flexural crystal resonator (Q _i
/ R _i ) (fundamental oscillation when i = 1,
(2nd harmonic vibration when i = 2, 3rd harmonic vibration when i = 3), mechanical series resonance frequency f _s that does not depend on the parallel capacitance of the bent crystal oscillator, and series resonance frequency f that depends on the parallel capacitance. The frequency difference Δf of _r is inversely proportional to the Figer-of-merit M _i , and the larger the value M _{i, the} smaller Δf. Therefore, as M _i is larger, the resonance frequency of the bent crystal unit is not affected by the parallel capacitance, and the frequency stability of the bent crystal unit is improved. That is, a tuning fork-shaped bent crystal oscillator with high time accuracy can be obtained.

More specifically, due to the configuration of the tuning fork shape, the groove, the electrode, and the dimensions thereof, the figurer-of-merit M ₁ of the fundamental mode vibration is larger than the figurer-of-merit M _n of the harmonic mode vibration. That is, M ₁ > M _n . However,
n represents the vibration order of the harmonic mode vibration, and is a finger of merit of the second and third harmonic mode vibration when n = 2 and 3. As an example, the frequency of the fundamental mode vibration is 32.768 kHz, W ₂ /W=0.5, t ₁ / t =
When 0.34, l ₁ /l=0.48, variations due to production occur, but M ₁ and M of the tuning fork-shaped bent crystal oscillator
₂ becomes M ₁ > 65 and M ₂ <30, respectively. That is,
High inductivity and good electromechanical conversion efficiency (equivalent series resistance R
It is possible to obtain a bent crystal oscillator that vibrates in a fundamental wave mode having a small quality factor of ₁ ) and a large quality coefficient. As a result, the frequency stability of the fundamental mode vibration is better than that of the second harmonic mode vibration, and the second harmonic mode vibration can be suppressed. Therefore, the crystal oscillator constituted by the bent crystal oscillator of the present embodiment can obtain the frequency of the fundamental mode vibration as an output signal and has high frequency stability (excellent time accuracy). Although the tuning fork arm is provided with a groove in this embodiment, the present invention is not limited to this embodiment, and the present invention does not need to provide a groove in the tuning fork arm. That is, even if there is no groove, M ₁ > M _n also holds according to the ratio of the length of the tuning fork arm electrode to the length of the tuning fork arm. In detail, even if electrodes are provided on the side surface of the tuning fork arm and the upper and lower surfaces without grooves, the relationship of M ₁ > M _n can be obtained. The reference frequency of the tuning fork-shaped fundamental mode vibration that vibrates in the bending mode is 10 kHz to 200 kHz. In particular, 32.
768 kHz is widely used.

FIG. 7 is a top view of a tuning fork-shaped crystal oscillator 45 that vibrates in a bending mode used in the crystal oscillator of the second embodiment constituting the electronic apparatus of the present invention. The tuning fork-shaped bent crystal unit 45 includes a tuning fork arm 46, 47 and a tuning fork base 48.
It is composed of and. That is, one end of each tuning fork arm 46, 47 is connected to the tuning fork base 48. In the present embodiment, the tuning fork base portion 48 is provided with cutout portions 53 and 54. Further, the tuning fork arms 46 and 47 are provided with grooves 49 and 50 sandwiching (including) the neutral lines 51 and 52. Further, in this embodiment, the grooves 49 and 50 are provided in a part of the tuning fork arms 46 and 47, and the grooves 49 and 50 have a width W ₂ and a length l, respectively.
_{Has 1} . Specifically, the area of the groove is shown by S = W ₂ × l ₁ , and S is configured to have a value of 0.025 to 0.12 mm ² . The reason for forming the groove area in this way is that the groove can be easily formed by the chemical etching method, the electromechanical conversion efficiency is improved, and the quality factor Q value of the fundamental mode vibration is high. A tuning fork-shaped crystal unit that vibrates in a bending mode is obtained. As a result, it is possible to realize a crystal oscillator in which the output signal is the frequency of fundamental mode vibration.

With the groove area S, the groove and the tuning fork arm can be processed in separate steps. However, in order to simultaneously process the tuning fork arm and the groove provided therein, it is necessary to optimize the thickness t of the tuning fork arm, the groove width W ₂ , the spacing W _{4 of the} tuning fork arm, and the area S. That is, the thickness t of the tuning fork arm is 0.06 mm to 0.15 m.
When m, the groove width W ₂ is within the range of 0.02 mm to 0.068 mm, and the area S is 0.023 mm ^{2 to} 0.08.
It is in the range of 8 mm ² , and the interval W ₄ is 0.05 mm to
It is configured to be 0.35 mm. The reason for configuring in this way is to utilize the crystallinity of quartz, and due to its crystallinity, a groove that is not a through hole (including a groove divided in the length direction of the tuning fork arm).
And the tuning fork shape can be formed at the same time. Also, FIG.
Although not shown in FIG. 3, grooves are also provided on the lower surfaces of the tuning fork arms 46 and 47 at positions facing the grooves 49 and 50.

Further, the width dimension of the notch portions 53, 54 provided on the tuning fork base portion 48 on the tuning fork portion side is given by W ₅ , and the dimension of the notch portions 53, 54 on the end portion side is given by W _6. . When the end portion of the tuning fork base portion 48 is fixed to a surface mounting type case or a cylindrical type case with solder or adhesive, in order to reduce the loss of vibration energy of the vibrator, The energy loss of the vibrating part can be reduced. The arm width W, partial widths W ₁ and W ₃ , of the tuning fork arm shown in FIG.
Since the relationship between the total length l of the groove width W ₂ and the spacing W ₄ and the length of the groove l ₁ and the tuning fork vibrator is described in FIG. 6, omitted here.

FIG. 8 is a top view (a) and a side view (b) of a width-vertical crystal oscillator used in the crystal oscillator of the third embodiment constituting the electronic equipment of the present invention. The width-vertical crystal oscillator 62 includes a vibrating portion 63, supporting portions 67 and 80 including connecting portions 66 and 69 and mount portions 68 and 81, respectively. Further, the support portion 67 and the support portion 80 respectively have holes 67.
a and a hole 80a are provided. In more detail,
The first connecting portion 66 and the second connecting portion 69 are provided at the end portions of the vibrating portion 63 which are located opposite to each other in the longitudinal direction. That is, the one first support portion 67 is connected to the vibrating portion 63 via the first connecting portion 66.
And the other second support portion 80 is connected to the vibrating portion 63 via the second connecting portion 69. Further, an electrode 64 and an electrode 65 are arranged so as to oppose each other on the upper surface and the lower surface of the vibrating portion 63, and these electrodes have different polarities. That is, a pair of electrodes is arranged. Further, the electrode 64 is connected to the second mount portion 8 via one of the second connecting portions 69.
It is arranged to extend to 1. Further, the electrode 65 is arranged so as to extend to the first mount portion 68 via the other first connection portion 66. In the present embodiment, the electrodes 64 and the electrodes 65 arranged in the vibrating portion 63 extend in different directions to the mount portion. However, even if they are arranged so as to extend in the same direction, the electrodes 64 and 65 function as a vibrator. The same characteristics are obtained. In the vibrator of this embodiment, the mount portions 68 and 81 are fixed to the fixing portion of the case or lid of the unit with an adhesive or solder.

Next, the relationship between the cut angle of the width-longitudinal crystal unit and its coordinate system will be described. The coordinate system is the origin O,
When the electrical axis x, the mechanical axis y, and the optical axis z are used, O-xyz is formed. First, consider a so-called X-plate crystal, which is a crystal plate perpendicular to the x-axis. At this time, the width W ₀ , the length L ₀ , and the thickness T ₀ , which are the respective dimensions of the X-plate crystal, match in the y-axis, z-axis, and x-axis directions, respectively. Further, this X plate crystal is rotated around the x axis by an angle θ _x = −25 ° to + 25 °, and further,
New angle _y -axis Around the y'-axis Angle θ _y = -30 ° to +30
° rotated. At this time, the new axis of the x-axis is rotated around the x'axis and the z-axis is rotated around the two axes, so that the new axis becomes z ". The electrical axis + x axis in this embodiment is defined in accordance with JIS standard, and the counterclockwise rotation angle is positive (plus).
Also, to set the apex temperature of the vibrator near room temperature,
The angle θ _x is θ _x = -12 ° to -13.5 °, -18.5.
° to -19.8 ° or the angles θ _x and θ _y are respectively θ _x
= −13 ° to −18 °, θ _y = + / − (0.5 ° to 30
°). In this example, the X-plate crystal is first rotated about the x-axis at an angle θ _x = −25 ° to + 25 °, and then about the y′-axis at an angle θy = −30 ° to +30.
It has been rotated, but first the angle θ _x = around the x-axis
It may be rotated by -25 ° to + 25 °, and then rotated by an angle θ _z = -15 ° to + 15 ° around the new z-axis of the z-axis.
In the present embodiment, the cut angle of the crystal plate used for forming the width-vertical crystal oscillator is described, but the cut angle of the oscillator of the present invention is not limited to this, and the formed width-vertical crystal oscillator May be a vibrator having the above-mentioned angle, and the present invention also includes those vibrators. For example,
The crystal plate is not rotated in-plane, but is rotated in-plane by a mask or the like used for forming the vibrator.

More specifically, the thickness direction of the width-longitudinal quartz crystal unit is aligned with the electric axis x-axis direction, the width direction is aligned with the mechanical axis y-axis direction, and the length direction is aligned with the optical axis z-axis direction. The width-longitudinal crystal unit is first rotated by an angle θ _x with the axis in the thickness direction (x axis) as the axis of rotation, and then the axis in the width direction (new axis y ′ axis after rotation of y axis) is the axis of rotation. or to angularly theta _y rotated, or first angle theta is _x as a rotation axis in the thickness direction of the axis (x-axis) the width longitudinal quartz crystal resonator, then the longitudinal axis (optical axis z axis The new axis z ′ axis after the rotation is rotated by an angle θ _z , and the angles θ _x , θ _y and θ _z are θ _x = −25 ° to + 25 ° and θ _y = −30 ° to +, respectively.
The width-wise crystal unit is formed so as to have 30 ° and θz = −15 ° to + 15 °. By combining these cutting angles, the peak temperature can be set over a wide temperature range.

Furthermore, the vibrating portion 63 has a width _{W 0,} has a length dimension _{L 0,} and the thickness _{T 0,} the width _{W 0,} length _{L 0,} and the thickness _{T 0} respectively y 'axis, z "axis , And the x′-axis direction, that is, the vibrating part 6 which is a plane perpendicular to the x′-axis.
Electrodes 64 and 65 are arranged on the upper and lower surfaces of 3, respectively. Further, the electrode 65 that opposes the electrode 64 is configured to have a different polarity. Further, the length L ₀ of the vibrating portion 63 is the width W
It is designed to be larger than ₀ and the thickness T ₀ smaller than the width W ₀ . That is, in order to obtain a width vertical crystal resonator having a small equivalent series resistance R ₁ by making the coupling between the width vertical vibration and the length vertical vibration negligible and increasing the electrode area of the vibrating portion, the ratio _W 0 / _{L 0} width _{W 0} and the length _{L 0} is 0.8
To obtain a width vertical crystal unit having a smaller equivalent series resistance R _{1 with} a smaller electric field _Ex and a larger electric field Ex, the thickness T
₀ and the ratio _T 0 / _{W 0} of the width _{W 0} is required to be smaller than 0.85. The actual determination of these dimensions depends on the characteristics required for the width-wise crystal unit. Usually, the thickness T ₀ is set to 250 μm or less.

More specifically, the resonance frequency of the width-wise crystal oscillator is inversely proportional to the width dimension W ₀ and hardly depends on other dimensions (length, thickness, connecting portion and supporting portion). Therefore, by reducing the width W ₀ , the size can be reduced and the frequency can be increased. In addition, from the above-mentioned dimensional relationship, a width-longitudinal crystal oscillator that vibrates in a single vibration mode without unnecessary vibration can be obtained. At the same time, by arranging the electrodes in the vibrating portion so that the electric field is applied in the thickness direction, the vibration orders of the fundamental wave mode vibration and the harmonic wave mode vibration of the width-longitudinal quartz crystal resonator do not depend on the piezoelectric constant. That is, the vibrating portion and the electrodes arranged on the vibrating portion are configured so that the vibration orders of the fundamental mode vibration and the harmonic mode vibration do not depend on the piezoelectric constant. Therefore, since the resonance frequency of the width-longitudinal quartz crystal resonator does not depend on the piezoelectric constant, there is a remarkable effect that the resonator design becomes very easy.

Next, the value of the piezoelectric constant e ₁₂ required to drive the width-vertical crystal oscillator of this embodiment will be described. The larger the value of this piezoelectric constant e _12, the higher the electromechanical conversion efficiency. Piezoelectric constant e of the width-wise crystal unit of this embodiment
The absolute value of ₁₂ has 0.095 to 0.18 C / m ² . That is, since the width-vertical crystal resonator of this embodiment has high electromechanical conversion efficiency, it is possible to obtain a micro-width crystal resonator having a small equivalent series resistance R ₁ and a high quality factor Q value. it can.

When an alternating voltage is applied between the electrode 64 and the electrode 65 in FIG. 8, the electric field _Ex is alternately applied in the thickness direction as shown by the solid line and dotted arrow in the side view (b) of FIG. work.
As a result, the vibrating portion 63 vibrates by expanding and contracting in the width direction.
That is, it is possible to obtain a so-called lateral effect type vertical-width crystal oscillator that vibrates in the direction perpendicular to the electric field direction. The resonance frequency of the main (width-longitudinal) vibration is a vibrator that does not depend on the piezoelectric constant. In addition, the width-vertical crystal oscillator according to the present embodiment is a vibrator different from the KT-cut width-vertical crystal oscillator that vibrates in parallel with the electric field direction. At the same time, the KT cut crystal oscillator is a so-called vertical effect oscillator in which the vibration order depends on the piezoelectric constant. That is, it is a vibrator whose resonance frequency depends on the piezoelectric constant. In this embodiment, the width-vertical crystal oscillator is described, but a thickness-sliding crystal oscillator whose frequency depends on the thickness of the oscillator may be used in the electronic device of the present invention instead of this oscillator.

FIG. 9 is a sectional view of a crystal unit used in the crystal oscillator of the fourth embodiment constituting the electronic equipment of the present invention. The crystal unit 170 includes a tuning fork-shaped bent crystal oscillator 70, a case 71, and a lid 72. Specifically, the vibrator 70 is the fixing portion 7 provided on the case 71.
It is fixed to the surface 4 by a conductive adhesive 76 or solder. or,
The case 71 and the lid 72 are joined via a joining member 73. In the present embodiment, the oscillator 70 is a tuning fork-shaped crystal oscillator 1 that vibrates in the bending mode described in detail in FIGS. 4 and 7.
It is the same oscillator as one of 0 and 45. In the crystal oscillator of this embodiment, the circuit element is connected to the outside of the crystal unit. That is, only the tuning fork-shaped bent crystal oscillator is stored in the unit. At this time, the bent crystal unit is housed in a unit in vacuum. Further, the width vertical crystal unit and the thickness sliding crystal unit described in FIG. 8 are also housed in the surface mount type crystal unit of this embodiment. Usually, the width-vertical crystal oscillator is fixed to both ends thereof, and the thickness-sliding crystal oscillator is fixed to the fixing portion at one end thereof.

Further, the case member is made of ceramics or glass, the lid member is made of metal or glass, and the joining member is made of metal or low melting point glass. Further, the relationship between the vibrator, the case, and the lid described in this embodiment is also applied to the crystal oscillator of FIG. 10 described below.

FIG. 10 shows a fifth embodiment of the electronic equipment of the present invention.
The sectional view of the crystal oscillator of an example is shown. Crystal oscillator 190
Comprises a crystal oscillator circuit, a case 91 and a lid 92. In this embodiment, the crystal oscillator circuit is housed in a crystal unit including a case 91 and a lid 92. Further, the crystal oscillation circuit is a tuning fork-shaped bent crystal oscillator 90, an amplifier 98 including a feedback resistor, and a condenser (not shown).
And a drain resistor (not shown), the amplifier 98 is a CMOS inverter.

Further, in this embodiment, the vibrator 90 is fixed to the fixing portion 94 provided on the case 91 with the adhesive 96 or solder. On the other hand, the amplifier 98 has a case 91.
It is fixed to. Further, the case 91 and the lid 92 are joined via a joining member 93. Transducer 90 of this embodiment
Is a vibration in the tuning fork-shaped bent crystal unit 10 or 45 described in detail in FIGS. 4 and 7, or in the width-longitudinal mode crystal unit 62 or the thickness shear mode crystal unit described in FIG. The child is used.

Although the present invention has been described above based on the illustrated example, the present invention is not limited to the above example. In the above embodiment, the tuning fork arm is composed of two, but the present invention is three or more. It includes the tuning fork arm. In this case, the electrodes may be configured so that at least two tuning fork arms vibrate in opposite phases.

Further, in this embodiment, the groove is provided on the tuning fork arm so as to sandwich (include) the neutral line, but the present invention is not limited to this, and the neutral line is left and both sides thereof are left. You may form a groove | channel in it. In this case, the partial width W ₇ including the neutral line of the tuning fork arm is configured to be smaller than 0.05 mm. The width of each groove is smaller than 0.04 mm, and the ratio of the groove thickness t ₁ to the tuning fork arm thickness t is 0.79 or less. With such a configuration, M ₁ can be made larger than M _n .

Furthermore, the shape of the tuning fork and the groove and width longitudinal mode crystal oscillator or the thickness shear mode crystal oscillator of the bent crystal oscillator of this embodiment is at least one of chemical, physical and mechanical methods. Processed using the method. In the physical method, for example, ionized atoms and molecules are scattered and processed. In the mechanical method, for example, particles for blast processing are scattered and processed.
Therefore, in the present invention, the processing method by the physical method and the mechanical method is called the processing by the particle method. Of course, the mechanical method includes processing by wire saw.

[0045]

As described above, by providing the electronic device of the present invention, many effects can be obtained. Among them, the following remarkable effects can be obtained. (1) Using a tuning fork-shaped bent crystal unit for the crystal oscillator,
The crystal oscillator is configured with a vibrator whose figure of merit M ₁ of fundamental mode vibration is larger than that of harmonic mode vibration M _n , and further, a negative resistance of fundamental mode vibration of the amplifier circuit. the absolute value of | -RL 1 _| and harmonic mode absolute value of the negative resistance of the oscillation of the ratio of the equivalent series resistance R ₁ is an amplifier circuit of the fundamental mode vibration | -RL n _| equivalent series resistance of the harmonic mode vibration Since the crystal oscillator is configured so as to be larger than the ratio of R _n , the output signal of the crystal oscillator has the frequency of fundamental mode vibration and has high frequency stability. As a result, a highly accurate electronic device using the output signal can be realized. (2) The crystal oscillator uses a width-vertical crystal oscillator or a thickness-slip crystal oscillator, so that a compact and highly accurate output signal can be obtained. Further, the electronic signal operates with this output signal, which is highly reliable. Electronic device having the property can be realized.

[Brief description of drawings]

FIG. 1 is an example of a block diagram of a facsimile according to an embodiment of an electronic device of the present invention.

FIG. 2 is an embodiment of a crystal oscillation circuit diagram constituting a crystal oscillator used in the electronic device of the invention.

FIG. 3 shows a feedback circuit diagram of FIG.

FIG. 4 shows an external view and a coordinate system of a tuning fork-shaped bent crystal oscillator that vibrates in a bending mode used in the crystal oscillator of the first embodiment constituting the electronic device of the present invention.

5 is a cross-sectional view of the tuning fork base portion of the tuning fork-shaped bent crystal resonator shown in FIG.

FIG. 6 shows a top view of the tuning fork-shaped bent crystal unit of FIG.

FIG. 7 is a top view of a tuning fork-shaped crystal resonator that vibrates in a bending mode used in a crystal oscillator of a second embodiment constituting the electronic device of the invention.

FIG. 8 is a top view (a) and a side view (b) of a width-longitudinal mode crystal unit used in the crystal oscillator of the third embodiment constituting the electronic device of the invention.

FIG. 9 is a cross-sectional view of a crystal unit used in a crystal oscillator according to a fourth embodiment of the electronic device of the present invention.

FIG. 10 is a sectional view of a crystal oscillator according to a fifth embodiment of the electronic device of the present invention.

FIG. 11 is a perspective view of a tuning fork-shaped bent crystal oscillator used in a crystal oscillator that constitutes a conventional electronic device, and its coordinate system.

12 is a cross-sectional view of a tuning fork arm of the tuning fork-shaped crystal unit shown in FIG.

[Description of Reference Signs] 1 amplifier circuit 9 feedback circuit V ₁ input voltage V ₂ output voltage W ₂ , t ₁ groove width, groove thickness W, W ₄ tuning fork arm width, tuning fork arm spacing W ₁ , W ₃ tuning fork Arm widths l ₁ , l ₂ Groove length, tuning fork base length t Tuning fork arm or tuning fork arm and tuning fork base thickness l Overall length of tuning fork-shaped bent crystal unit

Claims (2)

[Claims] 1. A crystal device comprising at least a display unit and an oscillator, wherein the electronic device comprises at least one oscillator, and the one oscillator comprises a crystal oscillator. In the oscillator, the crystal oscillator comprises a crystal oscillation circuit composed of an amplifier circuit composed of at least an amplifier and a feedback circuit composed of at least a crystal oscillator and a capacitor. The crystal unit is a tuning-fork-shaped bent crystal unit including a tuning fork arm that vibrates in a bending mode and a tuning fork base. The tuning fork arm has an upper surface, a lower surface, and a side surface, and an electrode is provided on a side surface of the tuning fork arm. Are arranged so as to face the inner side surface of the tuning fork arm and have different polarities, and the electrodes are arranged so that the tuning fork arm vibrates in the opposite phase. In addition, the figurine of merit M of the fundamental mode vibration of the tuning fork-shaped bent crystal oscillator
_{The one} crystal oscillator is configured with a bending crystal oscillator 1 of which is larger than the Figuer of Merit _Mn of harmonic mode oscillation, and a feedback circuit including an amplifier circuit and the tuning fork-shaped bending crystal oscillator is provided. The ratio of the absolute value of the negative resistance | -RL ₁ | of the fundamental mode vibration of the amplifier circuit of the crystal oscillator configured as described above to the equivalent series resistance R ₁ of the fundamental mode vibration is the harmonic mode vibration of the amplifier circuit. Absolute value of negative resistance | -RL _n | and equivalent series resistance R of harmonic mode vibration
_The one crystal oscillator is configured to be larger than the ratio of _n , and the output signal of the one crystal oscillator configured to include the tuning fork-shaped bent crystal oscillator is the frequency of fundamental mode vibration, The electronic device, wherein the output signal is a signal for displaying time on the display unit of the electronic device. 2. A crystal oscillator of a feedback circuit that constitutes at least one crystal oscillator including an amplifier circuit and a feedback circuit is a width-vertical crystal oscillator or a thickness-slip crystal oscillator,
The electronic device according to claim 1, wherein an output signal of a crystal oscillator configured to include the crystal oscillator is used for other than the time display of the electronic device.