JP3539043B2 - Power generation device and portable electronic device having the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generator for generating power by vibrating a vibrating reed having a piezoelectric body, and to a portable electronic device such as a timepiece containing the power generator.

[0002]

2. Description of the Related Art Several small devices for generating electric power using a piezoelectric material have been proposed, for example, Japanese Patent Publication No. Sho 51-173.
93 describes a device in which a spring lever is vibrated by the movement of a rotary weight, and a displacement is applied to a piezoelectric element directly fixed to the spring lever by this vibration to generate an electromotive force.

In Japanese Utility Model Application Laid-Open No. 63-72593, there is described a technique in which a piezoelectric element is housed inside a watch case, and a weight is vibrated by being inertially operated in a vertical direction to generate electric energy by the vibration. Have been.

[0004]

SUMMARY OF THE INVENTION A power generating device using these piezoelectric materials is intended to obtain electric power for operating a timepiece device by generating a power by applying a distortion to the piezoelectric material by capturing a movement of a user's arm or the like. However, it is necessary to develop a power generator with low power generation efficiency and high power generation efficiency.

[0005] In order to obtain kinetic energy from the movement of the arm and efficiently convert the electric energy into electric energy, the portable and small power generator first needs to efficiently convert the movement of the arm and the like to the rotating weight. It converts it into kinetic energy that is actually used for power generation, such as rotation, and secondly, efficiently applies the kinetic energy to the piezoelectric body as strain, and thirdly,
It is important to efficiently convert the strain applied to the piezoelectric body into electric energy.

[0006] Kinetic energy (input energy) applied to the piezoelectric body is stored in a storage device such as a capacitor by distortion energy of a support layer or the like that supports the piezoelectric body, distortion energy of the piezoelectric body itself, and power generation of the piezoelectric body. It is mainly divided into three types of electric energy. Of these, the most important electrical energy as a power generator varies depending on the electromechanical coupling coefficient of the piezoelectric body, the output voltage and capacitance when the piezoelectric element is not charged, the voltage of the power storage device, and the like. Only a few percent of energy. Therefore, it has been studied to generate power using a piezoelectric body that freely vibrates as a spring lever. This is because strain can be repeatedly generated by vibrating the piezoelectric body, and the strain energy generated by the input energy can be gradually converted into electric energy. Thus, the efficiency of the electric energy generated with respect to the input energy corresponding to the third factor is improved. In the wristwatch-type power generation device worn on the user's wrist, studies on the first factor described above, in which the movement of the user's arm is analyzed and the rotating weight efficiently rotates, are underway.

Therefore, in the present invention, the second
It is an object of the present invention to provide a device capable of efficiently transmitting the kinetic energy obtained as the rotational motion of the rotary weight, which corresponds to the above factor, to the piezoelectric body as input energy. By realizing such a device, an object is to provide a power generation device having a sufficient power supply capability to actually drive a portable device from movement of a user's arm or the like.

Particularly, as described above, the input energy can be efficiently converted into electric energy by vibrating the vibrating reed having the piezoelectric body as described above.
An object of the present invention is to provide a power generation device capable of transmitting kinetic energy of a rotary weight or the like to a resonator element with as little loss as possible. An object of the present invention is to provide a power generation device that improves the power generation efficiency by efficiently displacing a piezoelectric body, has a high power generation capability, and can secure a sufficient power generation amount by movement of an arm or the like.

[0009]

Means for Solving the Problems When the present inventors excite a vibrating piece by kinetic energy of a rotary weight or the like,
Considering that it is necessary to have a period during which the vibrating piece vibrates to generate power and a period to give kinetic energy, kinetic energy was transmitted using a part of the period when the rotating weight was moving. I found that it was not. That is, only a very small portion of the kinetic energy obtained by the oscillating weight, for example, about 10% is given to the vibrating piece as input energy, and most of the kinetic energy of the oscillating weight becomes a mechanical loss, or Entered and canceled, not used. Therefore, the power generation device of the present invention provides a plurality of vibrating reeds having a piezoelectric layer, a weight moving in a predetermined direction, and sequentially displacing the vibrating reed in conjunction with the weight, and thereafter, A vibrating device that opens to excite the vibrating piece to vibrate, and an output unit that outputs power generated in the vibrating piezoelectric layer, wherein the output unit includes:
A plurality of converters for converting AC output from the resonator element to DC.
Rectifying units, and these rectifying units are connected to the resonator element and
Connected one-to-one to store DC output from the rectifier
And the individual rectifiers correspond to the power storage units.
Connected in parallel, the vibrating device has a plurality of protrusions
The plurality of protrusions are different from the plurality of vibrating pieces.
Displacement is applied sequentially at the timing, and individual vibrations are
It is characterized in that the electromotive voltages generated on the pieces are different . Since the power generating device of the present invention can sequentially apply vibrations to the plurality of vibrating reeds by the vibrating device, it is possible to increase the chance of applying kinetic energy of a weight such as a rotary weight to the vibrating reed to improve energy transfer efficiency. . On the other hand, it is possible to secure a sufficient period for each of the resonator elements to vibrate for power generation.
Therefore, the kinetic energy of the weight can be transmitted to each vibrating piece continuously or in a state close to it, and the vibrating piece can sufficiently convert it into electric energy. A high power generation device can be provided. Furthermore, since the vibrating piece is released after giving a certain displacement to the vibrating piece by the vibrating device, the vibrating piece is vibrated, so that the output means is approximately five times as large as the specified voltage output to the secondary side such as the processing device. The amplitude of the initial vibration can be set so that the open-circuit voltage is generated frequently at the start of vibration in each vibrating piece. Therefore, it is possible to output electric power of a voltage with good charging efficiency to a power storage unit such as a capacitor.

In the present invention, since vibrations are excited at different timings from the vibrating device to the plurality of vibrating pieces, the electromotive voltages generated in the respective vibrating pieces at the same time are different. Therefore, in order to extract power efficiently from the individual vibrating pieces, a plurality of rectifier for converting an AC output from the resonator element to a direct current provided in advance by connecting them to the resonator element and the one-to-one
This effectively converts input energy to electrical energy
Can be converted to Furthermore, by mounting the vibrating reed on a semiconductor substrate and forming a rectifying portion on the semiconductor substrate using photolithography technology or the like, a power generation device including a plurality of vibrating reeds and a rectifying portion can be reduced in size and weight. It can be mounted on small and portable electronic devices such as.

Further, by connecting the rectifier in parallel to the power storage unit for storing the DC output from the rectifier, the current density during charging can be increased.
Furthermore, a backflow prevention unit connected in series to the power storage unit is provided,
By connecting the rectifier in parallel with the backflow prevention unit,
Power loss due to reverse leakage from the power storage unit to the resonator element can be prevented.

In such a power generator, when the vibrating device moves together with the weight, it is desirable to dispose a plurality of vibrating reeds along the moving direction of the weight. For example, when the weight moves linearly, by arranging the vibrating reed on one or both sides of the moving direction, the vibrating reed can be sequentially excited in conjunction with the movement of the weight. Further, when the weight rotates or turns, the vibration can be sequentially excited by arranging the vibrating reed along the locus of the circle or the arc. When the vibrating device includes a rotating member having at least one projection for vibrating, a plurality of vibrating pieces are similarly arranged radially with respect to the center of rotation of the rotating member, whereby Vibration can be sequentially excited in the resonator element. In order to apply displacement to the tip of the vibrating reed by the rotating member, it is desirable to arrange a plurality of vibrating reeds in a comb-like shape along at least one of the inside and the outside of the rotating member, and of course, even if it is arranged on both sides good.

In portable electronic devices such as wristwatches,
It is possible to house the above-described power generation device inside the case together with the processing device operated by electric power. This portable electronic device can perform processing using electric power supplied from the power generation device of the present invention instead of the battery, so that the battery life is extended and the battery does not need to be replaced. For example, in the case where the power generator is stored in an arm-mounted case,
Kinetic energy can be transmitted by using a rotating weight that rotates in the case as a weight and using a vibration device having a rotating member formed with a plurality of vibration projections that move in conjunction with the rotating weight. If a timepiece with a display facing one side of the case is provided, a plurality of vibrating reeds
It is possible to provide a compact and thin portable electronic device including a power generation device having a high power generation capability, which can be disposed facing the other side of the case opposite to the display portion. In an electronic device in which a rotating member rotates together with a rotary weight, a plurality of vibrating pieces can be arranged radially with respect to the rotation center of the rotating member.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 shows an outline of a wristwatch device provided with a power generation device according to an embodiment of the present invention. FIG.
2 shows an enlarged cross section of a power generation device of the wristwatch device 10 of the present example. The wristwatch device 10 of the present embodiment includes a thin case 1 of a substantially circular arm-mounted type.
Is a back case 2 on the side in contact with the user's wrist, a dial (display unit) 7 of a timing device 6, and a display unit 7.
Is provided with a transparent cover (not shown). In the space between the back case 2 and the display unit 7, a driving system such as a power generator 20 having a plurality of vibrating reeds 21 and a rotary weight 13 for supplying energy to the vibrating reeds 21 are further provided. A large secondary battery or a capacitor 5 constituting a power generation device connected to the minus electrodes 37a and 37b, and a second hand 41 functioning as an electronic timepiece;
Various devices such as a fourth wheel 38 and a second wheel 39 for operating the minute hand 42 and the hour hand 43 are arranged. Rotating weight 1
3 is installed on the case 1 so as to turn around the center of the case 1 as a rotation center 13a.
A rotating member 31 that rotates together with the rotating weight 13 is attached to the rotating member 13. Further, a plurality of protrusions 32 projecting outward are formed on the outer peripheral portion of the rotating member 31. A plurality of vibrating reeds 21 are radially arranged around the rotating member 31, and the tip 2 of the vibrating reed 21 facing the inside of the case 1 is arranged.
3 comes into contact with the projection 32 of the rotating member 31. A donut-shaped thin semiconductor substrate 15 is arranged so as to surround the radially arranged vibrating reeds 21, and a base end 24 of the respective vibrating reeds 21 opposite to the distal end 23 is attached to the semiconductor substrate 15. Has been. A rectifier circuit for outputting electric power from each of the resonator elements 21 is formed on the semiconductor substrate 15 as described later.

In the wristwatch device 10 of this embodiment, as shown in FIGS. 1 and 2, a rotating weight 13 whose outer peripheral direction is heavy and unbalanced surrounds a mechanism such as a timing device housed in a case 1. Are located. For this reason, when the acceleration applied to the wristwatch device 10 changes due to the movement of the user's arm or the like, the rotating weight 13 rotates around the center 13a, and the movement of the user or the like can be captured as the rotational energy of the rotating weight 13. . Accordingly, when the rotating weight 13 performs a rotating motion, the rotating member 31 attached to the back case 2 side of the rotating weight 13 rotates together with the rotating weight 13, and a plurality of projections 32 provided on the outer peripheral portion thereof respectively And contacts the tip 23 of the vibrating reed 21 to give a displacement. When the rotating member 31 further rotates, the tip 23 of the vibrating reed 21 is opened, and the vibrating reed 21 is vibrated. As a result, free vibration having a predetermined amplitude is excited in each vibrating piece 21 with the tip 23 as a free end. Since the resonator element 21 of this example is formed of the piezoelectric layer 22 of PZT or the like, an electromotive force is generated in the piezoelectric layer 22 by displacement due to vibration. The power generated by each of the vibrating bars 21 is collected at one output electrode 14a and 14b via a rectifying unit and wiring, which are output means formed on the semiconductor substrate 15, and is stored in the power storage unit from these output electrodes 14a and 14b. The signal is output to a time-measuring device 6 and the like via a condenser 5 constituting the device 4. Further, in the present example, the backflow prevention unit 8 is provided so as to suppress the reverse leak current flowing from the power storage unit 4 to the side of the resonator element 21. Thus, in the wristwatch device 10 of the present example, the vibrating reed 21, the semiconductor substrate 15, and the rotating member 31
The power generating device 20 is constituted by the rotary member 31, and functions as a vibrating device 30 for vibrating the vibrating reed 21 by moving the rotating member 31 in conjunction with the rotary weight 13.

FIGS. 3, 4 and 5 show one of the plurality of vibrating pieces 21 provided in the power generator 20 of this embodiment.
And its vicinity are enlarged. FIG. 3 shows a state in which the resonator element 21 attached to the semiconductor substrate 15 is viewed from below, FIG. 4 shows the resonator element 21 from the side, and FIG. 5 shows a cross section of the resonator element 21. . Vibrating piece 21 of this example
Is composed of a thin piezoelectric layer 22 made of PZT that is vertically polarized in the drawing as shown in FIGS. The vibrating reed 21 of the present example is a plate-shaped vibrating reed whose width gradually narrows from a fixed end (base end) 24 fixed to the semiconductor substrate 15 to a distal end 23 that performs free vibration. The electrode 25 is laminated on the surface. In the vibrating reed 21 of this example, the tip 23 has the protrusion 32 of the rotating member 31 to excite the vibration in the left and right direction X of FIG. 3, and as shown in FIG. The electromotive force in the opposite direction is generated on the upper and lower surfaces of. Therefore, the resonator element 21 of the present embodiment
In the above, the electrode 25a is provided on the entire surface of one surface 21a of the vibrating reed 21 to connect the left and right of the vibrating reed 21 in series, and two electrodes are provided on the opposite surface 21b so as to divide the surface 21 left and right. 25b and 25c are provided. Therefore, by connecting the electrodes 25b and 25c to the rectifying unit,
It is possible to extract electric power of a voltage in which electromotive forces generated on the left and right sides of the resonator element 21 are connected in series.

The semiconductor substrate 15 of this embodiment uses a PN junction formed near the base end 24 of each resonator element 21 by a known integrated circuit substrate manufacturing technique such as a photolithography technique or a diffusion technique. A rectifier circuit 50 is formed. Input terminals 51a and 5 of rectifier circuit 50
1b is connected to the electrodes 25b and 25c of the resonator element 21 by wire bonding 52, respectively.
The alternating current generated in each of the resonator elements 21 is rectified by the rectifier circuit 50, and the direct current is output to the output terminals 53a and 53b.
It can be supplied from. As described above, in the power generation device 20 of the present example, the resonator element 21 is attached to the semiconductor substrate 15.
The same number of rectifier circuits 50 are provided, and the power generated by each of the vibrating bars 21 is rectified by the rectifying circuits 50 corresponding to the vibrating bars 21 and output. In the semiconductor substrate 15 of the present example, two power lines 54a and 54b are formed in order to recover the DC power rectified by each rectifier circuit 50, and these power lines 54a and 54b Terminal 53a
And 53b. These two power lines 54 a and 54 b are connected to the output electrodes 14 a and 14 b of the power generator 20 shown in FIG. 1, so that the power generated by the individual vibrating reeds 21 can be supplied to the power storage unit 4. ing.

FIG. 6 shows a schematic circuit configuration of the power generator 20 of the present embodiment. The power generation device 20 of the present example includes the rotating member 3
1 and a plurality of vibrating reeds 21.1 to 21. n is arranged. For this reason, the rotating member 31 rotates with the rotation of the rotating weight 13, and the vibrating pieces 21.1 to 21. n are sequentially displaced, and the vibrating bars 21.1 to 21. Vibration is excited at n. Thereby, each vibrating piece 21.1-2
1. n is output from each of the vibrating bars 21.1-2.
1. rectifier circuits 50.1 to 50.
n and rectified by the power lines 54a and 5
4b. In such a power generation device 20 of this example, the kinetic energy of the rotary weight 13 can be continuously input to the power generation device 20, and the kinetic energy of the rotary weight 13 can be used for power generation very efficiently. it can. On the other hand, as shown in FIG.
In a power generating device provided as an AC generator, one vibrating piece 2 is intermittently moved by the movement of the rotary weight 13.
Since only the vibration is excited at 1, only a small part of the kinetic energy of the rotary weight 13 can be used for power generation.

Referring to FIG. 8, the fact that the kinetic energy of the rotary weight 13 is effectively used in the power generator 20 of the present embodiment will be described in detail. First, FIG. 8A shows a model in which the single vibrating piece 21 shown in FIG. 7 is vibrated along with the movement of the rotary weight to generate power. Assuming that the total torque generated by the rotary weight 13 is A (N · m), a part of the total torque A, for example, about １ ／, is used as the torque T used to apply displacement to the resonator element. When the total torque A generated by the oscillating weight is required to displace the vibrating reed, the movement of the oscillating weight stops. On the other hand, if the torque T used for the displacement is too large, the opportunity for the rotary weight to move due to the movement of the arm or the like is reduced, so that kinetic energy cannot be efficiently obtained from the movement of the user. Therefore, the torque T required to displace one vibrating piece as in this example is about １ ／ of the total torque A (T = A
/ 3) is desirable.

In order to generate power by vibrating the resonator element,
A time for applying displacement to the vibrating piece and a time for generating power by free vibration are required. Since these times are proportional to the rotation angle of the rotary weight, FIG. 8 shows the above-mentioned times by the rotation angles θ1 and θ2. In order to increase the amount of power generated by one vibration, it is desirable to set the angle (time) θ2 at which power is generated as long as possible. However, if the angle θ2 at which free vibration is performed is increased, the chance of kinetic energy being input to the vibrating reed from the rotary weight is reduced, so that the energy of the rotary weight cannot be efficiently input to the vibrating reed. Therefore, it is assumed that the power generation device is set so that the angle θ1 required to apply displacement to the vibrating reed and the angle θ2 at which power is generated by free vibration are equal. In such a power generator, the energy e input to the vibrating reed from the rotary weight by one impact is as follows.

E = 1/2 × A / 3 × θ1 (1) Also, the number of times energy can be input to the vibrating reed while the rotary weight rotates 180 degrees (π) is as follows.

N = π / (θ1 + θ2) = π / (2θ1) (2) Accordingly, the energy E1 that can be input to the resonator element while the rotary weight rotates by π is as follows.

E1 = e × n = π · A / 12 (3) On the other hand, the kinetic energy E2 obtained during the rotation of the rotary weight by π is as follows.

E2 = ∫A · sin θdθ (θ = 0 to π) = 2A (4) Accordingly, of the kinetic energy E2 obtained by the rotating weight, the ratio of energy E1 that can be input to the vibrating element (energy transfer efficiency) η) is as follows.

Η = E1 / E2 = 0.13 (5) As described above, in the model using the single vibrating piece shown in FIG. 7, 13% of the kinetic energy obtained by the rotating weight is obtained. Only the degree is input to the resonator element. Therefore, the rotating weight continues rotating or turning by the remaining kinetic energy, and transmits the kinetic energy to the same vibrating piece. For this reason, it takes a very long time to transmit all of the kinetic energy of the oscillating weight to the vibrating piece, and during that time, much of the kinetic energy of the oscillating weight results in mechanical energy loss. In addition, the user's continuous movement, such as arm movement, is the energy input source to the oscillating weight. However, if it takes time to transfer energy from the oscillating weight to the vibrating element, there is an input that contradicts the movement of the oscillating weight. It is very likely that this will cause the oscillating weight to stop moving and the kinetic energy obtained by the oscillating weight to be unavailable for power generation. Therefore, in order to effectively utilize the kinetic energy of the rotating weight for power generation, it is desirable to perform energy transmission in a short time.

On the other hand, in order to effectively convert the input energy obtained by the resonator element into electric energy, it is desirable to secure a period during which free vibration is performed to some extent. Therefore, the angle θ2 at which free vibration can be performed is often larger than the angle θ1 at which a displacement is given. Therefore, in the model using a single vibrating reed, the time for transmitting kinetic energy from the rotating weight to the vibrating reed is reduced, that is, when the opportunity for the rotating weight to displace the vibrating reed is increased, the conversion efficiency of the vibrating reed is reduced. Therefore, the total energy transfer efficiency η tends to be lower.

On the other hand, in the power generator of the present embodiment shown in FIG. 6 which sequentially applies vibrations to the plurality of vibrating bars, the rotating weight is reduced without shortening the period during which the vibrating bars convert electric energy. The number of times that energy can be input to the resonator element can be dramatically improved, and the energy transmission time to the resonator element can be shortened. For example, in a model in which a plurality of vibrating pieces are sequentially vibrated as shown in FIG. 8B, the energy that can be input to the vibrating piece provided in the power generation device is double the above. Therefore, the energy transfer efficiency η is improved to about 26%. Further, since the time for generating power by free vibration can be set longer for each vibrating piece, input energy can be efficiently converted to electric energy.

Further, as shown in FIG.
A plurality of projections 32 are provided on a rotating member 31 that moves in conjunction with
When a plurality of vibrating pieces are excited by these projections 32,
As shown in FIG. 8C, the kinetic energy of the rotary weight can be almost continuously input to the vibrating reed provided as the power generation device.
In this case, the energy E1 ′ obtained while the entire vibrating reed provided in the power generating device rotates the rotating weight by π is as follows.

E1 ′ = A / 3 × π (6) Accordingly, the energy transfer efficiency η becomes η = E1 ′ / E2 = 0.52 (7), and the kinetic energy obtained by the rotating weight Is input to the vibrating reed to contribute to power generation.

The energy transmission efficiency η can be further improved by increasing the input torque T for displacing the resonator element. However, as described above, when the input torque T is increased, the opportunity for the rotating weight to move decreases, and the movement of the user or the like cannot be efficiently captured.

Next, the electromotive voltage will be described. As shown in FIG. 9, in order for the inventors of the present application to efficiently charge the power storage unit 4 using the vibrating reed having the piezoelectric layer as the power generation unit, the initial opening to start the free vibration is performed. Voltage V
It has been confirmed that it is preferable that of is about five times the output voltage (specified voltage) Ve supplied from the power storage unit 4 to the processing device such as the timekeeping device 6. In the power generation device of this example, each of the vibrating pieces 21 is applied with a substantially constant displacement by the projections 32 of the rotating member 31 that moves in conjunction with the rotary weight 13, and is thereafter opened. Since the open-circuit voltage Vof of the vibrating reed is almost proportional to the initial displacement, the power generating apparatus of this embodiment selects the combination of the vibrating reed 21 and the vibrating device 30, that is, the combination of the rotating member 31 and the projection 32, and the open-circuit voltage Vof is defined. 5 of voltage Ve
If it is set to be about twice as high, charging can be performed efficiently regardless of the speed of the rotary weight. Therefore, it is not necessary to analyze the movement of the user's arm and the movement of the rotating weight, and the charging efficiency can be increased irrespective of the user's own characteristics and the user's operation. Since the vibration of the plurality of vibrating pieces can be excited in conjunction with the movement of the rotary weight, it is possible to set the energy transmission efficiency to be the best under the condition of good charging efficiency. For this reason, the power generation device of the present example can efficiently input the kinetic energy obtained by the rotating weight to the vibrating reed and can efficiently charge the power storage unit with the electric energy obtained by the input energy, which is very efficient. Power generation equipment with high power generation capacity.

Further, in the power generating device of the present embodiment, a plurality of vibrating pieces are sequentially vibrated to generate power. For this reason,
As shown in FIG. 6, the vibration piece 21.
1-21. n, vibrations are excited at different timings, so that each vibrating piece 2
1.1 to 21. The voltage (electromotive voltage) output from n differs. Therefore, in the power generation device 20 of the present example, the individual vibrating pieces 21.1 to 21. rectifier circuit 50.1-
50. n is provided to prevent a current from flowing between the vibrating bars having different electromotive voltages to prevent the actually obtained voltage from decreasing.
In particular, since power cannot be obtained from the vibrating bars having opposite voltage phases, the individual vibrating bars 21.1 to 21. Rectifier circuit 5 for every n
0.1-50. By providing n, it is desirable to prevent backflow and to obtain power of a predetermined electromotive voltage from each vibrating piece.

Further, in the power generator 20 of this embodiment,
Rectifier circuits 50.1 to 50. n, a plurality of vibrating pieces 2
1.1 to 21. n are connected in parallel by the power lines 54a and 54b so that a large current can be obtained.
A power generator using a piezoelectric body can obtain a relatively high voltage, but the current density obtained from each piezoelectric body is very small. By connecting the vibrating reeds using a plurality of piezoelectric bodies in parallel as in this example, a large current can be obtained, so that a sufficient power supply for operating the clock device or other processing devices can be secured.

Further, in the power generator 20 of this embodiment,
A backflow prevention element such as a diode 9 is provided on one side of the capacitor 5 constituting the power storage unit 4 to prevent leakage current from the power storage unit 4. That is, the PN junction 59 used in the rectifier circuit 50 has a small reverse leakage current. Therefore, the plurality of rectifier circuits 50
Are connected in parallel, the reverse leak current increases in accordance with the number thereof, which may cause a loss of the power stored in the power storage unit 4. Therefore, in the wristwatch device 10 of the present example, a reverse current prevention unit 8 employing a backflow prevention element such as a diode 9 is provided on one side of the capacitor 5 constituting the power storage unit 4, and a plurality of rectification circuits 50 are connected in parallel. An increase in reverse leakage current, which is a problem when a connected circuit system is employed, is prevented.

As described above, the power generation device 20 of this embodiment is the same as that shown in FIG.
A plurality of vibrating reeds 21 are radially mounted inside a donut-shaped disc-shaped semiconductor substrate 15 shown in (1), and the kinetic energy of the rotary weight 13 is sequentially applied to these vibrating reeds 21 to increase the energy transfer efficiency. ing. A rotating weight 13 that performs a rotating motion as in the wristwatch device 10 of the present example.
In a portable device provided with a vibrating piece 21, a complicated transmission mechanism and bearings can be omitted by forming the vibrating device 30 that vibrates the vibrating piece 21 by the rotating member 31 that moves together with the rotary weight 13. Further, since a plurality of vibrating reeds 21 can be arranged along the periphery of the rotating member 31, it is easy to secure a space for disposing the vibrating reed in the case 1, and for example, a clock The vibrating reed 21 and the rotating member 31 can be stored in a very thin space facing the back case 2 on the opposite side of the display unit 7. Further, by disposing the vibrating reed 21 around the rotating member 31, the plurality of vibrating reeds 21 are sequentially vibrated from a plurality of locations at each of the plurality of projections 32 provided on the outer peripheral portion of the rotating member 31. , Energy can be input more continuously as shown in FIG.

Further, by disposing the vibrating reeds radially around the rotating member 31,
This makes it easier to dispose the vibrating reed 21 as in the present example having a wide width on the side of. By employing a wide vibrating reed on the side of the base end 24, a large number of power generating layers can be provided in a portion where the amount of displacement by vibration is large, so that the electromechanical coupling coefficient is high and the power generation efficiency is higher. It can be a power generator.

In the power generator 20 of this embodiment, the vibrating reeds 21 are attached to a donut-shaped semiconductor substrate 15 made of silicon or the like, and a plurality of the vibrating pieces 21 are mounted on the semiconductor substrate 15 by using an integrated circuit device manufacturing technique. A rectifier circuit 50 is formed. Therefore, the rectifier circuit 50 can be manufactured very compactly, and the power generation device integrated with the resonator element 21 and the rectifier circuit 15 can be installed in a thin space inside the case 1. For this reason, a sufficient space can be ensured inside the case 1 for installing the mechanism constituting the timekeeping device 6 and the condenser 5 constituting the power storage unit 4, and the large size can be accommodated inside the small wristwatch device 10. Thus, a large-capacity capacitor 5 can be arranged. Further, it is also possible to house a multifunctional timekeeping device 6 including a communication function and the like inside the case 1.

In the power generator 20 of this embodiment, as shown in FIGS.
Although the oscillating piece 21 and the rectifier circuit 50 are connected by
The connection method is not limited to this. For example, the +
Alternatively, a method of directly attaching the negative electrodes 25b and 25c to the input electrodes 51a and 51b of the rectifier circuit 50 can be adopted. Further, the vibrating reed 21 of this example is a unimorph type formed by a single piezoelectric layer 22, but may be a bimorph type in which two or more piezoelectric layers are laminated, and furthermore, a phosphor bronze or the like may be used. Needless to say, a vibrating reed may be sandwiched between the vibrating pieces.

In FIG. 10, the support layer 16 is formed by extending the inner peripheral portion of the semiconductor substrate 15 in a comb-like shape, and two piezoelectric layers 22a and 22b are laminated on both sides of the support layer 16. An example in which the vibrating reed 21 is formed is shown. It is possible to integrally manufacture the semiconductor substrate 15 and the resonator element 21 by a known technique for manufacturing an integrated circuit such as CVD. By employing such a manufacturing method, a thinner and more integrated power generation device can be formed, and a small and suitable power generation device for portable equipment can be provided.

In the rotary member 31 shown in FIG. 10, the projection 32 is provided upward of the rotary member 31.

Further, in FIG. 11, a disc-shaped semiconductor substrate 15 is employed, a plurality of vibrating reeds 21 are mounted around the periphery of the semiconductor substrate 15 in a comb shape, and the outer side of these vibrating reeds 21 is Is rotated, and the vibrating piece 2 is
1 shows an example of a power generating device in which a displacement is given to 1. FIG.
The power generating device shown in FIG.
By arranging 1 radially, a relatively expensive semiconductor substrate can be made small and disk-shaped, so that it is possible to manufacture at a lower cost. As described above, in the power generation device of the present invention, the rotating member 31 is not limited to the above example.
Various structures can also be adopted. Also,
The rotating member 31 constituting the vibrating device is not limited to the one directly connected to the rotating weight 13, but the speed of the movement of the rotating weight 13 is increased by using a wheel train and transmitted to the rotating member 31 to transmit the vibration piece. Can be shortened.

FIG. 12 shows an embodiment of the present invention in which a plurality of vibrating pieces 21 are arranged in parallel. In the power generating device of the present invention, the plurality of vibrating pieces 21 are linearly arranged along the moving direction of the vibration device 35 instead of being arranged in the circumferential direction. The vibrating bars are vibrated sequentially. Such a power generation device is suitable, for example, as a power generation device mounted on a vehicle or the like and mounted on a device in which a weight (not shown) vibrates up and down due to vibration of the vehicle. By operating the vibrating device in conjunction with the weight to sequentially vibrate the vibrating reeds 21 arranged vertically, a power generating device having high energy transmission efficiency and high power generating capability can be provided. Of course, the arrangement of the resonator element 21 is not limited to two rows as in this example,
The number of rows may be three or more. Similarly, when the vibrating reeds are arranged in a circular shape, the vibrating reeds may be arranged in two or three or more layers to increase the energy transfer efficiency.

In the above embodiment, PZT (trademark) is used as a material constituting the piezoelectric layer.
Of course, it may be a ceramic material such as barium titanate or lead titanate, a single crystal such as quartz or lithium niobate, or a polymer material such as PVDF.

The present invention is not limited to the timepiece described in the above embodiment. As a portable electronic device containing a processing device other than a clock, for example, a pager,
There are information terminals such as telephones, wireless devices, hearing aids, pedometers, calculators, electronic organizers, IC cards, radio receivers, etc., and the power generating device of the present invention is applied to these portable electronic devices, and these processing devices Can be supplied with sufficient power. By adopting the power generation device of the present invention in these portable electronic devices, power generation can be efficiently performed by capturing human movements, etc., and battery consumption can be suppressed or the battery itself can be made unnecessary. It is also possible. Therefore, the user can use these portable electronic devices without worrying about running out of battery, and it is possible to prevent troubles such as loss of contents stored in the memory due to running out of battery. Furthermore, the function of the portable electronic device can be exhibited even in a region or place where a battery or a charging device is not easily available, or in a situation where it is difficult to replenish the battery due to a disaster or the like.

[0045]

As described above, according to the present invention, in a power generator for generating electric power by vibrating a vibrating piece having a piezoelectric layer, a plurality of vibrating pieces are provided, and the vibrating piece is interlocked with a weight such as a rotary weight. A plurality of vibrating pieces are sequentially displaced by a vibrating device which moves and then released, and the vibrating pieces are opened to generate power by exciting vibration. Therefore, the frequency at which the vibrating reed is displaced by the kinetic energy of the weight is greatly increased, so that the opportunity to transmit the kinetic energy of the weight to the vibrating reed is increased, and the kinetic energy obtained by the weight such as the rotating weight is efficiently vibrated. It is possible to transmit to one piece. Therefore, according to the present invention, it is possible to prevent the mechanical loss of the gained energy and the situation where the weighted energy cancels each other, and increase the input energy transmitted from the kinetic energy of the weight to the resonator element. Can be done. Therefore, the power generation device according to the present invention can efficiently use the kinetic energy generated by the rotating weight or the like as the input energy of the vibrating reed, and can generate power using the piezoelectric body. Furthermore, since it is possible to generate an electric power by giving a substantially constant displacement to the resonator element, it is possible to tune the power generation device to an open voltage having the best charging efficiency or at the vicinity thereof.
A power generation device with high power generation efficiency and high power generation efficiency can be realized.
Therefore, it is possible to provide a portable electronic device such as a small and lightweight wrist-mounted device using a piezoelectric body and a power generation device suitable for the portable electronic device.

Further, in the present invention, a rotary member which moves together with the rotary weight is employed as a vibrator, and a plurality of vibrating reeds are radially formed on the semiconductor substrate on which the rectifying circuit is formed along the outside or inside of the rotary member. To realize a thin and compact power generator. Further, the power generation device of the present invention,
A rectifying unit corresponding to each vibrating piece is provided so that power can be efficiently extracted from each vibrating piece, and a piezoelectric body that adopts a configuration suitable for a power generation device that uses multiple vibrating pieces, such as preventing reverse leakage current. A small power generation device with high power generation capacity is realized. As described above, the power generation device of the present invention enables the kinetic energy obtained by capturing the movement of the user's arm and the like to be efficiently transmitted to the vibrating reed, so that sufficient power is supplied to the small and portable device. It is possible to provide a power generation device that can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a power generator and a wristwatch-type device having a plurality of vibrating reeds provided with a piezoelectric layer according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a schematic configuration of a power generation device and a wristwatch-type device illustrated in FIG.

FIG. 3 is a plan view showing an enlarged view of the power generator shown in FIG. 1 as viewed from below.

FIG. 4 is a side view showing an enlarged view of the power generation device shown in FIG. 1 from a side.

FIG. 5 is an enlarged view of the power generator shown in FIG.
FIG. 4 is a diagram including a partial cross section.

FIG. 6 is a diagram showing a power system of the power generator shown in FIG.

FIG. 7 is a diagram showing a power system of a power generation device employing a single vibrating piece.

FIG. 8 is a diagram schematically showing how the kinetic energy of the rotating weight is transmitted in the power generation device of the present invention.
8A shows a model that gives kinetic energy to a single vibrating piece, FIG. 8B shows a model that gives kinetic energy to a plurality of vibrating pieces, and FIG. 2 shows a model that gives kinetic energy.

FIG. 9 is a graph showing how the charging efficiency changes depending on the ratio between the open-circuit voltage at the beginning of vibration and the specified voltage of the power storage unit in the power generating device using the resonator element.

FIG. 10 is a diagram showing a power generating device according to another embodiment of the present invention, FIG. 10 (a) is a side view, and FIG. 10 (b).
Is a plan view seen from below.

FIG. 11 is a view showing a power generating device according to another embodiment of the present invention in which a resonator element is installed inside a rotating member.

FIG. 12 is a view showing a power generating device according to another embodiment of the present invention in which vibrating pieces are linearly arranged.

[Explanation of symbols]

1. Case 2. Back case 4 ·· Storage circuit 5. Condenser 6. Processing unit (timer) 7 ··· Display part (character board) 8. Backflow prevention circuit 9. Diode 10. Wristwatch device 13. Rotating weight 14. Output electrode 15. Semiconductor substrate 16..Support layer protruding inward from semiconductor substrate 20 .. Power generator 21 ・ ・ Vibrating bar 22..Piezoelectric layer 23 Free end of tip (tip) 24. ・ Fixed end of resonator element (base end) 25 ·· Electrode laminated on resonator element 30, 35 ・ ・ Vibration device 31 Rotating members 32 ... Projection 50 rectifier circuit

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Makoto Furuhata 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Hajime Miyazaki 3-5-35, Yamato, Suwa-shi, Nagano Say (56) References JP-A-7-245970 (JP, A) JP-A-5-39661 (JP, A) JP-A-55-102283 (JP, A) JP-A-8-140369 ( JP, A) JP-A 63-58001 (JP, U) JP-A 6-76894 (JP, U) JP-A 7-30558 (JP, U) JP-A 63-72593 (JP, U) 60-60328 (JP, B2) JP 7-69440 (JP, B2) JP 51-17393 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02N 2 / 00 H01L 41/113 G04C 10/00

Claims (12)

(57) [Claims] 1. A plurality of vibrating reeds provided with a piezoelectric layer, a weight moving in a predetermined direction, and a displacement sequentially applied to the vibrating reed in conjunction with the weight, and thereafter released to release the vibrating reed. A vibrating element for exciting vibration to the vibrating reed; and output means for outputting electric power generated in the vibrating piezoelectric layer, wherein the output means converts an alternating current output from the vibrating reed into a direct current.
Rectifiers that convert the
Is connected to the vibrating reed one-to-one, and output from the rectifying unit.
Having a power storage unit for storing the rectified DC,
Is connected in parallel to the power storage unit, the vibrating device has a plurality of protrusions, and the plurality of protrusions
To sequentially apply vibrations to the individual vibrating bars at the same time.
A power generator characterized by different generated electromotive voltages . 2. The resonator element according to claim 1, wherein the vibrating reed is a semiconductor.
The rectifier is mounted on a substrate, and
A power generating device, characterized by forming: 3. The power storage unit according to claim 2, wherein
A backflow prevention unit connected thereto, wherein the rectification unit includes the backflow prevention unit.
Power generation characterized by being connected in parallel to the stop
Equipment . 4. The apparatus according to claim 1, wherein said output means is a secondary
Voltage is approximately 5 times the specified voltage
The open circuit voltage of the plurality of vibrating pieces is
Oscillation characterized by high frequency occurrence in the vibrating reed
Electrical equipment. 5. The apparatus according to claim 1, wherein the vibrating device is
Move with the weight, and the plurality of vibrating pieces move
A power generator characterized by being arranged along a direction. 6. The vibrating apparatus according to claim 1, wherein
A rotating member having at least one projection formed therein.
And the plurality of vibrating bars are at the center of rotation of the rotating member.
A power generation device characterized by being radially arranged
Place. 7. The inside of the rotating member according to claim 6,
Or comb teeth along at least one of the outer
Characterized in that a plurality of the resonator elements are arranged in
Power generator. 8. The power generating device according to claim 1, and the power generating device
Processing that can perform processing using the power output from the device
A portable electronic device having a device. 9. A power generation apparatus according to claim 1,
An arm-mounted case for housing the device, wherein the weight is
A rotary weight that rotates in the case;
The device includes a rotating member having the plurality of projections for excitation.
A portable electronic device characterized by the following: 10. The case according to claim 9, wherein one of the cases is provided.
Has a timing device with a display facing the side of
The plurality of vibrating bars are opposite to the display unit with respect to the rotating weight.
Being located facing the other side of the case on the side
A portable electronic device characterized by the following. 11. The rotating member according to claim 10, wherein
The vibrating piece rotates together with the rotating weight, and the vibrating piece
It is characterized by being radially arranged with respect to the center of rotation.
Portable electronic devices. 12. The rotating member according to claim 11, wherein
Comb along the inside and / or outside
A plurality of the resonator elements are arranged in a tooth shape;
Portable electronic devices.