JP7107813B2 - Electrostatic induction transducer, manufacturing method for electrostatic induction transducer, wristwatch - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrostatic induction transducer, a method for manufacturing an electrostatic induction transducer, and a wristwatch.

In Patent Document 1, a first electret film and a second electret film are provided on both surfaces of a rotating second substrate, respectively, and as the second substrate rotates, a first opposing film arranged to face the first electret film is formed. An electrostatic induction generator is described in which electric charges induced in an electrode and a second counter electrode arranged to face the second electret film are taken out through a rectifying circuit. In addition, the substrate on which the electret films are formed on both sides is provided so that the movement in the in-plane direction is permitted and the movement in the normal direction is restrained. In order to improve the operating efficiency and extend the life of the electrostatic induction transducer, it is desirable that the force acting in the normal direction of the substrate is small. Depends on membrane charge.

JP 2015-186424 A

Here, the substrate on which the electret films are formed on both sides is processed into a desired shape by stamping. A burr projecting in the punching direction is generated in the edge portion formed by the punching process. When charging treatment is performed by corona discharge machining, electric lines of force are concentrated on the burrs on the side of the substrate where the burrs protrude, and the amount of charge given to the electret film provided on the surface on the side where the burrs protrude. decreases. Therefore, in the substrate, the amount of charge applied to the electret film is different between the surface on which the burrs protrude and the surface on the opposite side. If the amount of electric charge differs between one surface and the other surface, resistance will occur in the operation of the substrate, which may reduce the energy conversion efficiency. Therefore, it is conceivable to apply different voltages in the charging process between the surface on which the burrs protrude and the surface on the opposite side so that the amount of charge applied to the electret film is the same on both surfaces. However, the amount of projection of the burrs may vary during the manufacturing process of each electrostatic induction transducer, making it difficult to adjust the applied voltage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide an electrostatic induction converter, a method for manufacturing the same, and a wristwatch that suppress a decrease in energy conversion efficiency.

The invention disclosed in the present application for solving the above problems has various aspects, and the outlines of typical aspects are as follows.

(1) A conductive substrate, a first electret film provided on a first surface of the conductive substrate and charged, and a second electret film provided on the second surface of the conductive substrate and charged. an electret substrate having a membrane; and a conductive supported member attached to the electret substrate so as to be electrically conductive to the conductive substrate and supported to allow in-plane movement of the electret substrate. , a first counter electrode arranged to face the first electret film, and a second counter electrode arranged to face the second electret film, the conductive substrate comprising: An edge of the supported member has a burr that protrudes toward the second surface, and the member to be supported is larger than the amount of protrusion on the first surface side in a direction perpendicular to the conductive substrate. An electrostatic induction transducer that is provided so that the amount of protrusion on the surface side of the is large.

(2) In (1), the electret substrate is disc-shaped and has a plurality of through-holes arranged at intervals in the circumferential direction, and the first electret film is formed between the plurality of through-holes. and the electrostatic induction transducer, wherein the second electret film is provided, and the edge portion having the burr projecting toward the second surface includes the edge portion of the through hole.

(3) In (1) or (2), the first counter electrode and the second counter electrode are disk-shaped and have a plurality of through-holes arranged at intervals in the circumferential direction. Electrostatic induction converter.

(4) In (1) or (2), a disc-shaped first counter substrate arranged to face the first electret film and a circle arranged to face the second electret film a plate-shaped second counter substrate, wherein a plurality of the first counter electrodes are provided on the first counter substrate so as to be spaced apart from each other in a circumferential direction; The electrostatic induction transducer, wherein a plurality of electrodes are provided on the second opposing substrate so as to be spaced apart from each other in the circumferential direction.

(5) In (4), at least one of the first opposing substrate and the second opposing substrate is a transparent substrate, and at least one of the first opposing electrode and the second opposing electrode is transparent. An electrostatic induction transducer, wherein the counter electrode provided on the substrate is a transparent electrode.

(6) In (1) to (5), the first counter electrode and the second counter electrode overlap each other at least partially in a plan view, and are out of phase with each other in the direction of motion of the electret substrate. Differently arranged electrostatic induction transducers.

(7) In (1) to (6), the supported member is the rotating shaft of the electret substrate, the conductive substrate has a shaft hole through which the rotating shaft is inserted, and the second surface The electrostatic induction transducer, wherein the edge having a burr protruding to the side includes the edge of the shaft hole.

(8) The electrostatic induction transducer according to (7), wherein a driving mechanism for driving the rotating shaft is provided on the second surface side.

(9) In (1), the supported member is attached to the electret substrate so as to allow translational motion of the electret substrate, and the electret substrates are spaced apart from each other in the direction of the translational motion. An edge portion having a plurality of through holes arranged side by side, the first electret film and the second electret film being provided between the plurality of through holes, and having a burr projecting toward the second surface side, , an electrostatic induction transducer, comprising an edge of said through-hole.

(10) preparing a conductive substrate; providing electret material films on a first surface and a second surface of the conductive substrate; forming a portion; allowing movement of the conductive substrate in the in-plane direction and attaching a conductive supported member to the conductive substrate so as to be electrically connected to the conductive substrate; grounding the conductive substrate; and applying an electric charge to the electret material film by an electrification process, and in the step of attaching the supported member to the conductive substrate, moving the supported member in a direction perpendicular to the conductive substrate, A method for manufacturing an electrostatic induction transducer, wherein the electrostatic induction transducer is attached so that the amount of protrusion on the side of the second surface is larger than the amount of protrusion on the side of the first surface.

(11) A wristwatch comprising the electrostatic induction transducer according to any one of (1) to (9) and a dial having a viewing area, wherein the electrostatic induction transducer is in which the watch overlaps with the visible region in and is arranged so that the second face side faces the dial.

According to aspects (1) to (11) of the present invention, a decrease in energy conversion efficiency can be suppressed.

1 is a schematic perspective view of an electrostatic induction transducer according to this embodiment; FIG. FIG. 3 is a schematic end view of an electret substrate and a rotary shaft included in the electrostatic induction transducer according to the present embodiment; FIG. 3 is a schematic circuit diagram explaining the operating principle when the electrostatic induction converter is used as a generator; FIG. 2 is a schematic circuit diagram for explaining the principle of operation when the electrostatic induction converter is used as an electric motor; It is a figure explaining the manufacturing process of an electret board. FIG. 5B is a partially enlarged view schematically showing a state of a cut end face immediately after the conductive substrate having electret material films provided on both sides thereof is subjected to the punching process shown in FIG. 5B. It is a figure explaining the influence which a burr and a rotating shaft have on electrification processing. It is a top view of the conductive substrate of this embodiment. It is a top view of the conductive substrate of the 1st modification of this embodiment. It is a top view of the conductive substrate of the 2nd modification of this embodiment. FIG. 11 is a cross-sectional view of a plane taken along the XI-XI cutting line in FIG. 10; FIG. 4 is a diagram showing an example in which the electrostatic induction transducer according to this embodiment is incorporated in a wristwatch; FIG. 11 is a schematic circuit diagram for explaining the principle of operation when the electrostatic induction converter is used as a power generator in a third modified example of the present embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention (hereinafter referred to as the present embodiment) will be described in detail below with reference to the drawings.

FIG. 1 is a schematic perspective view of an electrostatic induction transducer according to this embodiment. FIG. 2 is a schematic end view of the electret substrate and rotating shaft provided in the electrostatic induction transducer according to this embodiment. FIG. 2 shows an end surface cut along a plane passing through the edge of the electret substrate 3, and the outline of the electret substrate 3 is indicated by a chain double-dashed line.

Here, the electrostatic induction converter means a device that mutually converts kinetic energy and electrical energy using electrostatic induction, and refers to a generator or an electric motor. Although the principle will be described later, when an external force is applied to the electrostatic induction converter 100 to give kinetic energy, the energy can be converted into electrical energy and taken out, which is a generator. Also, when electric energy is applied to the electrostatic induction converter 100, the energy can be taken out as kinetic energy, which is an electric motor.

The electrostatic induction transducer 100 shown in FIG. 1 is an example of an electrostatic induction transducer that converts mechanical rotational motion into electrical energy or extracts electrical energy as mechanical rotational motion. The basic structure of the electrostatic induction transducer 100 of this example will be described below.

The electrostatic induction transducer 100 includes, as main components, a disk-shaped first counter electrode 1, a disk-shaped second counter electrode 2, and the first counter electrode 1 and the second counter electrode. It has an electret substrate 3 which is arranged so as to be sandwiched between 2 at a predetermined interval, and a rotating shaft 4 as a member to be supported. Here, the disc shape means that the member has a generally flat disc shape as a whole, and an appropriate through hole 33d as shown in FIG. 1 is provided in the plane. Also, it is permissible to apply notches, protrusions, or other processing to the outer peripheral portion.

As shown in FIG. 2, the electret substrate 3 includes a conductive substrate 33, a first electret film 31 provided on a first surface 33a of the conductive substrate 33, and a second electret film 31 provided on a second surface 33b of the conductive substrate 33. 2 electret films 32 .

In addition, the conductive substrate 33 has a plurality of through holes 33d that are arranged in the circumferential direction at intervals and have a substantially fan-shaped planar shape. The first electret film 31 and the second electret film 32 are provided in a region of the conductive substrate 33 where the through holes 33d are not formed. That is, the first electret films 31 are provided on the first surface 33a so as to be spaced apart from each other in the circumferential direction, and the second electret films 32 are provided so as to be spaced apart from each other in the circumferential direction. is provided on the second surface 33b.

The first counter electrode 1 is arranged so as to face the first electret film 31 provided on the first surface 33 a of the electret substrate 3 . The second counter electrode 2 is arranged so as to face the second electret film 32 provided on the second surface 33 b of the electret substrate 3 . The first counter electrode 1 and the second counter electrode 2 are preferably fixed to an appropriate housing (not shown).

In addition, the first counter electrode 1 and the second counter electrode 2 have a plurality of through holes each having a generally fan-shaped planar shape, which are arranged in the circumferential direction at intervals. That is, the first counter electrode 1 and the second counter electrode 2 have a configuration in which regions where electrodes are provided and regions where electrodes are not provided are alternately arranged in the circumferential direction. However, the configuration of the first counter electrode 1 and the second counter electrode 2 is not limited to this. A plurality of first counter electrodes 1, which are conductive films, are provided so as to line up, and the conductive films are arranged on the surface of a disk-shaped second counter substrate so as to be spaced apart from each other in the circumferential direction. A configuration in which a plurality of second counter electrodes 2 are provided may be employed. Further, when adopting such a configuration, transparent substrates are used as the first counter substrate and the second counter substrate, and the first counter electrode 1 and the second counter electrode 2 are formed on the surfaces of the transparent substrates. A certain transparent conductive film may be formed. As a result, for example, when the electrostatic induction converter 100 is configured to be visible from the outside by forming a visible region composed of a transparent region or a through hole in a housing or the like that accommodates the electrostatic induction converter 100, A user can visually recognize the electret substrate 3 through the transparent substrate and the transparent conductive film. For example, when the electrostatic induction transducer 100 is incorporated in a wristwatch or the like, the user can enjoy the design by visually recognizing the shape and rotation of the electret substrate 3 .

The rotary shaft 4 is inserted through the shaft hole 33c of the conductive substrate 33 and attached to the conductive substrate 33 so as to be electrically connected to the conductive substrate 33 . Both ends of the rotating shaft 4 are supported by supporting portions formed in an appropriate housing (not shown) or the like so as to allow the electret substrate 3 to rotate. The rotating shaft 4 is supported and fixed to the electret substrate 3 so that the electret substrate 3 rotates as the rotating shaft 4 rotates. The motion of the electret substrate 3 in the extending direction of the rotating shaft 4 is restricted. That is, the distance between the electret substrate 3 and the first counter electrode 1 and the second counter electrode 2 is kept constant in the direction in which the rotating shaft 4 extends.

As shown in FIG. 1, a pinion 5 is attached to the rotary shaft 4, and kinetic energy is applied to the electrostatic induction converter 100 via a drive mechanism including gears (not shown) that mesh with the pinion 5. Alternatively, kinetic energy can be extracted from the electrostatic induction converter 100 . In this embodiment, the electrostatic induction transducer 100 is a generator, and rotation of a suspension weight provided via a gear meshing with the pinion 5 is input to the rotating shaft 4 .

The electrostatic induction converter 100 according to this embodiment can be used, for example, as a small and light generator built into a wristwatch. Alternatively, it may be used as an outdoor sensor to supply electric power, a generator for small lighting, or for other purposes.

FIG. 3 is a schematic circuit diagram explaining the operating principle when the electrostatic induction converter is used as a generator. As shown in FIG. 3, the electret substrate 3, the first counter electrode 1, and the second counter electrode 2 are arranged facing each other so as to be parallel to each other with a predetermined small gap therebetween.

In addition, as described above, the first counter electrode 1 and the second counter electrode 2 have a configuration in which regions where electrodes are present and regions where electrodes are not present are alternately arranged in the circumferential direction, and the electret substrate 3 is In this configuration, regions provided with the electret film and regions not provided with the electret film are alternately arranged in the circumferential direction. Furthermore, the electret substrate 3 is rotatably provided around a rotating shaft 4 . Therefore, as the electret substrate 3 rotates, the state in which the first electret film 31 and the second electret film 32 face the first counter electrode 1 and the second counter electrode 2 alternates with the state in which they do not.

The first electret film 31 and the second electret film 32 are formed to be in a predetermined charged state. In this embodiment, the first electret film 31 and the second electret film 32 are both charged to have negative charges.

In a state in which the first counter electrode 1 and the second counter electrode 2 face the first electret film 31 and the second electret film 32, the surfaces of the first electret film 31 and the second electret film 32 are Induced by the charges, charges of opposite polarities are accumulated in the first counter electrode 1 and the second counter electrode 2 (in this embodiment, positive charges are accumulated in the first counter electrode 1 and the second counter electrode 2). ). After that, when the electret substrate 3 moves and the first electret film 31 and the second electret film 32 do not face the first counter electrode 1 and the second counter electrode 2, the first counter electrode 1 And the charge induced and accumulated in the second counter electrode 2 is swept out, rectified by the rectifier circuit 6, and taken out as electric energy.

Note that FIG. 3 shows an example in which the first counter electrode 1 and the second counter electrode 2 are fixedly arranged so that the phases of the movement direction of the electret substrate 3 are different from each other. However, the invention is not limited to this, and as shown in FIG. may be placed.

FIG. 4 is a schematic circuit diagram explaining the operating principle when the electrostatic induction converter is used as an electric motor. Also in this case, the electret substrate 3, the first counter electrode 1, and the second counter electrode 2 are arranged facing each other so as to be parallel to each other with a predetermined small gap therebetween. Further, as the electret substrate 3 rotates, the state in which the first electret film 31 and the second electret film 32 face the first counter electrode 1 and the second counter electrode 2 alternates with the state in which they do not. FIG. 4 shows an example in which the first counter electrode 1 and the second counter electrode 2 are fixed and arranged so that they are out of phase with respect to the motion direction of the electret substrate 3, but FIG. Thus, the first counter electrode 1 and the second counter electrode 2 may be fixedly arranged so that they are in the same phase with respect to the motion direction of the electret substrate 3 .

The first electret film 31 and the second electret film 32 are formed to be in a predetermined charged state. In this embodiment, the first electret film 31 and the second electret film 32 are both charged to have negative charges.

In addition, the first counter electrode 1 and the second counter electrode 2 are arranged so as to be out of phase with respect to the motion direction of the electret substrate 3, and the switch circuit 7 operates the first electret film 31 and the second counter electrode 2, respectively. 2 can be applied at a predetermined timing.

At this time, when the opposite charge of the charged state of the first electret film 31 and the second electret film 32 is applied to either one of the first counter electrode 1 and the second counter electrode 2, the electrostatic force causes the first electret film 31 and the second electret film 32 to The electret substrate 3 moves so that the second electret film 31 or the second electret film 32 faces the counter electrode to which the opposite charge is applied. By appropriately switching the switch circuit 7 to alternately switch between application and non-application of the opposite charge to the first counter electrode 1 and the second counter electrode 2 with good timing, continuous motion can be given to the electret substrate 3 and linear motion can be achieved. Motion, rotational motion, oscillatory motion and other motions are picked up.

Here, a material that is easily charged is used as the material of the electret film. For example, silicon oxide, fluorine resin, and the like are used as the material that is charged negatively. A specific example of such a material is CYTOP (registered trademark), which is a fluororesin manufactured by Asahi Glass Co., Ltd. Furthermore, other electret film materials include polymer materials such as polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, polytetrafluoroethylene, polyvinylidene difluoride, and polyvinyl fluoride, as well as the aforementioned silicon oxide, silicon nitride, Inorganic materials such as silicon oxynitride can also be used.

Of course, the circuit configuration for using the electrostatic induction converter 100 described above as a generator or a motor is an example, and other configurations including the arrangement of various members may be adopted.

As described above, the electret substrate 3 is provided so as to allow rotation, while restricting movement in the normal direction (perpendicular to the surface of the electret substrate 3). Also, the electrostatic force acting on the electret substrate 3 is an attractive force (or a repulsive force) acting between the first electret film 31 and the second electret film 32 and the first counter electrode 1 and the second counter electrode 2. , force acts on the electret substrate 3 in its normal direction.

This force is generated by forming the first electret film 31 and the second electret film 32 on both sides of the electret substrate 3, respectively, and the electrostatic forces acting on these electret films are directed in opposite directions with respect to the normal direction of the electret substrate 3. Therefore, if the forces acting on the first electret film 31 and the second electret film 32 are balanced, the forces in the normal direction cancel each other out. If the two are not balanced, the force in the normal direction will remain.

The force in the normal direction that is generated in the electret substrate 3 and remains is the force that acts in the direction in which the rotating shaft 4 extends. Therefore, the greater the remaining force in the normal direction, the greater the resistance to rotation of the electret substrate 3, which causes energy loss and reduces the conversion efficiency of the electrostatic induction converter 100. In addition, it causes wear of the rotating shaft 4 and the like. , may be a factor in reducing the life of the electrostatic induction transducer 100 . Therefore, it is desirable that the electrostatic forces acting on the first electret film 31 and the second electret film 32 are balanced.

In order to balance the electrostatic force acting on the first electret film 31 and the second electret film 32, the amount of charge held by each electret film should be balanced. However, this is simply not possible.

The reason for this will be described with reference to FIGS. 5 to 7. FIG. FIG. 5 is a diagram for explaining the manufacturing process of the electret substrate. First, a conductive substrate 33 is prepared, and electret material films 34 are provided on both surfaces thereof (FIG. 5(a)). The material of the conductive substrate 33 is not particularly limited as long as it has conductivity and sufficient rigidity against the generated electrostatic force, but in this embodiment, it is metal, and aluminum is used in particular. . The reason why the conductive substrate 33 is required to be conductive is that it is grounded in the step of charging the electret material film 34, which will be described later. The conductive substrate 33 may be configured to be grounded when incorporated into the electrostatic induction converter 100, or may be configured to be connected to a rectifying circuit.

The method of forming the electret material film 34 may be selected according to the material, and is not particularly limited. As such a method, for example, if the electret material is liquid and a so-called wet process can be used, an appropriate coating method such as dip coating, spin coating, curtain flow coating, spray coating, and gravure coating may be used. Other methods include PVD such as sputtering and ion plating, vapor deposition such as CVD, and a method of attaching a film of electret material to the conductive substrate 33 .

After that, the conductive substrate 33 is processed into a desired shape by punching with a press (FIGS. 5B and 5C). At this time, it is preferable that the conductive substrate 33 is simultaneously formed with a shaft hole 33c through which the rotating shaft 4 is inserted and a plurality of through holes 33d each having a substantially fan shape. However, it is not limited to this, and the plurality of through holes 33d and the shaft hole 33c may be formed sequentially by punching.

Furthermore, the rotating shaft 4 is attached so as to be electrically connected to the conductive substrate 33 . (Fig. 5(d)).

Finally, the conductive substrate 33 is grounded, the electret material films 34 on both sides are charged, and the electret material films 34 are charged. Although this charging treatment is not particularly limited, corona discharge treatment is used here. As a result, the electret material film 34 on the first surface 33 a and the electret material film 34 on the second surface 33 b of the conductive substrate 33 are charged to the same potential, forming the first electret film 31 and the second electret film 32 . Thus, the electret substrate 3 is manufactured (FIG. 5(e)). The figure schematically shows the corona discharge electrode 35 and how the charge is imparted by the corona discharge.

The manufactured electret substrate 3 further has a first electret film 31 facing the first counter electrode 1 fixedly provided in an appropriate housing, and a second electret film 32 in an appropriate housing. It is assembled to allow movement in the in-plane direction so as to face the second counter electrode 2 which is fixedly provided. In addition, the electrostatic induction transducer 100 is produced through processes such as wiring and connecting appropriate circuits and the like.

Through the above steps, the electret substrate 3 and the electrostatic induction transducer 100 incorporating the electret substrate 3 are produced. They may not be equal and may be unbalanced. The reason will be shown with reference to FIG.

FIG. 6 is a partially enlarged view schematically showing a state of a cut end face immediately after the conductive substrate having electret material films provided on both sides thereof is subjected to the punching process shown in FIG. 5(b). The drawing shows the shape of the end face when the conductive substrate 33 is punched by the blade of the punching die from the second surface 33b side toward the first surface 33a side. As shown in the drawing, a burr 36 projecting in the punching direction is generated at the edge of the conductive substrate 33 by punching.

FIG. 7 is a diagram for explaining the effects of burrs and a rotating shaft on charging processing.

When the conductive substrate 33 having the burrs 36 is grounded and subjected to electrification treatment, in this example, corona discharge machining, electric lines of force are concentrated on the burrs 36 on the surface on the side where the burrs 36 protrude, as shown in the figure. However, since the discharged charges flow to the conductive substrate 33, the amount of charges applied to the electret material film 34 near the burrs 36 is reduced. The dashed arrows in the figure indicate the lines of electric force and the movement of the charges emitted along the lines of electric force.

This phenomenon occurs on the surface on which the burrs 36 project (second surface 33b shown in FIG. 7) and does not occur on the opposite surface (first surface 33a shown in FIG. 7). Therefore, even if the same voltage is applied to the first surface 33a side and the second surface 33b side to charge the electret material film 34, the charge amount of the electret material film 34 above and below the surface of the conductive substrate 33 is imbalance occurs. In the example shown in FIG. 7, the charge amount of the electret material film 34 provided on the first surface 33a is greater than the charge amount of the electret material film 34 provided on the second surface 33b.

In order to make the electret material films 34 provided on both surfaces of the conductive substrate 33 equally charged, the voltage applied to the electret material films 34 provided on the first surface 33a of the conductive substrate 33 and the voltage applied to the electret material film 34 provided on the first surface 33a of the conductive substrate 33 It is conceivable that the voltage applied to the electret material film 34 provided on the second surface 33b of is different. For example, the voltage applied to the electret material film 34 provided on the second surface 33b of the conductive substrate 33 is set higher than the voltage applied to the electret material film 34 provided on the first surface 33a. However, the protrusion amount of the burr 36 may vary during the manufacturing process of each electrostatic induction transducer 100, and it is difficult to control how much the applied voltage should be varied.

Here, it is not only the burrs 36 that affect the amount of charge in the charging process. The rotating shaft 4 is a conductive member that protrudes in the normal direction of the conductive substrate 33 and is electrically connected to the grounded conductive substrate 33 . Therefore, the lines of electric force also concentrate on the rotating shaft 4 during the electrification process, preventing the electret material film 34 in the vicinity thereof from being electrified. Further, since the amount of protrusion of the rotating shaft 4 is larger than the amount of protrusion of the burrs 36 , the rotating shaft 4 has a greater influence on the charge amount in the charging process than the burrs 36 do. This effect becomes more pronounced as the length of the rotating shaft 4 protruding in the normal direction becomes longer, that is, as the rotating shaft 4 approaches the discharge electrode.

If the length of the rotation shaft 4 protruding in the direction of the first surface 33a of the conductive substrate 33 and the length of protruding in the direction of the second surface 33b are equal, the effect of electrification on the electret material film 34 is the electret Both surfaces of the substrate 3 are substantially equal, and the charge amounts of the first electret film 31 and the second electret film 32 do not become unbalanced. However, the pinion 5 is assembled to the rotating shaft 4, and a driving mechanism including gears (not shown) that mesh with the pinion 5 is provided, so that the rotating shaft 4 protrudes greatly on one side. It will happen.

Therefore, in the present embodiment, the burrs 36 are formed on the side of the rotary shaft 4 where the amount of protrusion is large. That is, by providing the rotating shaft 4 so that the amount of protrusion on the side of the second surface 33b is larger than the amount of protrusion on the side of the first surface 33a in the direction perpendicular to the conductive substrate 33, the burr 36 is removed. The influence of manufacturing variations in the amount of protrusion is reduced. This is because even if there is a manufacturing variation in the amount of projection of the burrs 36, the influence of the burrs 36 on the amount of charge is relatively small because the influence of the rotating shaft 4 on the amount of charge dominates. That is, since the adjustment amount of the voltage to be applied can be determined by considering only the influence of the amount of protrusion of the rotating shaft 4 on the amount of charge, the first electret film can be produced regardless of the manufacturing variation in the amount of protrusion of the burrs 36. 31 and the voltage applied to the second electret film 32 can be easily adjusted. Then, the charge amount on both surfaces of the conductive substrate 33 can be balanced. That is, as a result, the rotational resistance in the electret substrate 3 is reduced, and energy loss is less likely to occur. That is, it is possible to suppress a decrease in energy conversion efficiency. Furthermore, since the rotational resistance is reduced, the wear of the rotary shaft 4 and the like is suppressed, and the reduction in the life of the electrostatic induction transducer 100 is also suppressed.

Furthermore, with reference to FIGS. 8 to 10, the pattern of the configuration of the conductive substrate of the electret substrate will be described. FIG. 8 is a plan view of the conductive substrate of this embodiment. The overall disc-shaped conductive substrate 33 has a wheel shape here, that is, a shape in which the vicinity of the center and the outer periphery are connected in the circumferential direction, and the two are connected by a large number of spokes. A shaft hole 33c for mounting the rotating shaft 4 is provided in the center of the conductive substrate 33. As shown in FIG.

FIG. 9 is a plan view of a conductive substrate of a first modified example of this embodiment. The conductive substrate 53 of the first modified example has a shape having a plurality of tongue portions 531 radially extending from the central portion while maintaining a disk shape as a whole.

In the conductive substrate 53, burrs occur at the edge 53d of the tongue portion 531 and the edge of the shaft hole 53c. Therefore, when the conductive substrate 53 is used, it is preferable to provide the rotating shaft 4 so that the protrusion amount is large on the side where the burrs protrude from the edge 53d of the tongue 531 and the edge of the shaft hole 53c.

FIG. 10 is a plan view of a conductive substrate of a second modified example of this embodiment. FIG. 11 is a cross-sectional view of a plane cut along the XI-XI cutting line in FIG. 10 is an imaginary line indicating the groove 60 formed in the housing or the like. In FIG. 11, the electret film, the burrs of the conductive substrate 63, and the counter electrode are omitted.

The motion of the electret substrate is not limited to the rotational motion described above, and may be reciprocating motion or translational motion. In that case, a rectangular conductive substrate 63 as shown in FIG. 10 may be used.

The conductive substrate 63 has a rectangular shape with a plurality of slits 63d formed therein, and is provided so as to allow movement in the direction in which the plurality of slits 63d are arranged (the X direction in the figure and the opposite direction). Specifically, the conductive substrate 63 has a hole 63c, and a shaft 64 as a supported member is inserted through the hole 63c. Further, the shaft 64 is supported and fixed to the conductive substrate 63 so that the conductive substrate 63 moves as the shaft 64 moves. Further, both ends of the shaft 64 are fitted in grooves 60 formed in a suitable housing or the like and extending in the X direction, so that the shaft 64 is preferably provided slidably in the X direction in the figure and in the opposite direction. It is preferable that the shaft 64 is provided so that the projection amount is large on the surface 63b (second surface) on the side where the burrs project from the edges of the slit 63d and the hole 63c.

The conductive substrate 63 having such a shape is suitable for a so-called vibration power generator in which the electrostatic induction converter 100 using this picks up vibration in a specific direction and converts it into electric power. Of course, you may use this for other uses.

In addition, in the above-described embodiment and its modification, a conductive shaft is shown as a member to be supported, but it is not limited to this. Anything that stands out is acceptable. Further, the supported member may be provided so that the amount of protrusion increases in either the upper or lower side in the housing, and at least the side where the burrs 36 protrude is provided so that the amount of protrusion increases. I wish I had.

FIG. 12 is a diagram showing an example in which the electrostatic induction transducer according to this embodiment is incorporated in a wristwatch. In the example shown in FIG. 12, two electrostatic induction generators with different functions are built into the wristwatch. Specifically, an electrostatic induction converter 200 as a generator and an electrostatic induction converter 300 as an electric motor are shown, but their configurations are similar to the electrostatic induction converter 100 described above. be. However, in FIG. 12, illustration of the counter electrode and the electret film is omitted. In FIG. 12, the direction indicated by arrow Z1 is defined as upward, and the direction indicated by arrow Z2 is defined as downward.

The wristwatch includes a dial 81, a pointer shaft 82, a pointer 83 attached to the pointer shaft 82, and a wheel train 84 that drives the pointer shaft 82 to rotate.

Further, in the wristwatch shown in FIG. 12, the dial 81 is formed with a visible area 81a. The visible area 81a is made of a through-hole or a transparent member, and preferably allows the user to visually recognize the inside of the wristwatch. In the example shown in FIG. 12, the electrostatic induction transducer 200 is arranged below the dial 81 so as to overlap the visible region 81a in plan view. As described above, the conductive substrate has a well-designed shape such as a wheel shape, and the user can enjoy the design of the wristwatch by visually recognizing the rotating conductive substrate.

In addition, in the case of adopting a configuration in which the user can visually recognize the electrostatic induction transducer 200 in this way, it is preferable that the counter electrode on the side of the visual recognition area 81a is a transparent electrode. Alternatively, a transparent substrate may be arranged on the visible region 81a side, and a transparent conductive film, which is a counter electrode, may be formed on the transparent substrate.

In the example shown in FIG. 12, the surface (second surface 33b) on which burrs are formed of the conductive substrate 33 included in the electrostatic induction transducer 200 is arranged downward. That is, the electrostatic induction transducer 200 was arranged so that the surface (first surface 33 a ) on the side on which no burrs were formed faced the dial 81 . As a result, the user can, through the visual recognition area 81a, view the surface on which the burrs are not formed (the first surface 33a), which looks better than the surface on which the burrs are formed (the second surface 33b). ) will be visually recognized.

In addition, FIG. 12 shows an example in which the rotating shaft 4 rotates with the rotation of the suspension weight 90 attached to the side of the rotating shaft 4 where the amount of protrusion is large, that is, the side where the burrs are formed. By adopting such a configuration, the user can visually recognize the planar shape of the electret substrate without using the suspension weight 90 or the like as a driving mechanism for driving the rotating shaft 4 .

Further, in the example shown in FIG. 12, the pinion 5 of the electrostatic induction converter 300 as the electric motor meshes with the gear included in the train wheel 84 that drives the pointer shaft 82 to rotate. Therefore, when the rotating shaft 4 included in the electrostatic induction transducer 300 rotates, the pointer 83 rotates.

Since the electrostatic induction converter 200 and the electrostatic induction converter 300 shown in FIG. 12 have the same configuration, either one may be used as a generator or a motor, or both may be used as a generator or a motor. you can

FIG. 13 is a schematic circuit diagram for explaining the principle of operation when the electrostatic induction converter is used as a power generator in the third modified example of this embodiment. The circuit configuration when using the electrostatic induction converter as a power generator is not limited to that shown in FIG. In the third modification, as shown in FIG. 13, a plurality of first counter electrodes 11 of the first counter electrodes 1 are arranged so as to be spaced apart from each other in the circumferential direction, and a plurality of electrodes are arranged between them. , the first counter electrode 12 is arranged. The first counter electrode 11 and the first counter electrode 12 are connected to a rectifying circuit 61 to extract electric energy from each electrode.

In addition, the plurality of second counter electrodes 21 of the second counter electrodes 2 are arranged to be out of phase with the first counter electrodes 1 and spaced apart from each other in the circumferential direction. , the second opposing electrode 22 is arranged. Then, the second opposing electrode 21 and the second opposing electrode 22 are connected to a rectifier circuit 62 so that electrical energy can be extracted from each electrode.

In the circuit configuration of the third modification, as the electret substrate 3 rotates, the second electret film 32 and the second counter electrode 21 face each other, so that charges are induced in the second counter electrode 21. While the second electret film 32 and the second counter electrode 22 face each other from the state to the state in which charges are induced in the second counter electrode 22, the first electret film 31 and the first Electric charges are induced in the first counter electrode 11 by facing the counter electrode 11 directly. Therefore, as the electret substrate 3 rotates, the frequency at which electric charges are induced in the first counter electrode 1 and the second counter electrode 2 increases, making it possible to extract electric energy more efficiently.

Note that FIG. 13 shows an example in which the first counter electrode 1 and the second counter electrode 2 are fixed and arranged so that the phases in the motion direction of the electret substrate 3 are different, but this is not the only case. Instead, as shown in FIG. 1, the first counter electrode 1 and the second counter electrode 2 may be fixedly arranged so that the phases in the direction of movement of the electret substrate 3 are the same. good.

Although the embodiment according to the present invention has been described above, the specific configuration shown in this embodiment is shown as an example, and it is not intended to limit the technical scope of the present invention to this. Those skilled in the art may modify these disclosed embodiments as appropriate, and it should be understood that the technical scope of the invention disclosed herein includes such modifications.

REFERENCE SIGNS LIST 1 first counter electrode 2 second counter electrode 3 electret substrate 4 rotary shaft 5 pinion 6 rectifier circuit 7 switch circuit 31 first electret film 32 second electret film 33,53 , 63 conductive substrate 33a first surface 33b second surface 33c, 53c, 63c shaft hole 33d through hole 34 electret material film 35 corona discharge electrode 36 flash 100, 200, 300 electrostatic induction Type converter, 531 tongue, 53d edge, 60 groove, 63c hole, 63d slit, 64 shaft, 81 dial plate, 81a visual recognition area, 82 pointer shaft, 83 pointer, 84 wheel train, 90 suspension weight.

Claims (12)

a conductive substrate, a first charged electret film provided on a first surface of the conductive substrate, and a second charged electret film provided on a second surface of the conductive substrate; an electret substrate having
a conductive supported member attached to the electret substrate so as to be electrically connected to the conductive substrate and supported so as to allow in-plane movement of the electret substrate;
a first counter electrode arranged to face the first electret film;
a second counter electrode arranged to face the second electret film;
including
The conductive substrate has a burr on its edge that protrudes toward the second surface,
The supported member is provided so that the amount of protrusion on the second surface side is larger than the amount of protrusion on the first surface side in a direction perpendicular to the conductive substrate.
Electrostatic induction converter. The electret substrate is disc-shaped and has a plurality of through holes arranged in a circumferential direction at intervals, and the first electret film and the second electret film are arranged between the plurality of through holes. is provided,
The edge having a burr protruding toward the second surface includes the edge of the through hole,
An electrostatic induction transducer according to claim 1. The first counter electrode and the second counter electrode are disk-shaped and have a plurality of through holes arranged in a circumferential direction at intervals,
The electrostatic induction converter according to claim 1 or 2. a disk-shaped first opposing substrate arranged to face the first electret film;
a disk-shaped second opposing substrate arranged to face the second electret film;
including
a plurality of the first counter electrodes are provided on the first counter substrate so as to be spaced apart from each other in the circumferential direction;
A plurality of the second counter electrodes are provided on the second counter substrate so as to be spaced apart from each other in the circumferential direction.
The electrostatic induction converter according to claim 1 or 2. at least one of the first counter substrate and the second counter substrate is a transparent substrate;
Of the first counter electrode and the second counter electrode, at least the counter electrode provided on the transparent substrate is a transparent electrode.
An electrostatic induction transducer according to claim 4. The first counter electrode and the second counter electrode overlap each other at least partially in a plan view, and are arranged such that the phases of the movement directions of the electret substrates are different from each other.
The electrostatic induction converter according to any one of claims 1-5. The supported member is a rotating shaft of the electret substrate,
The conductive substrate has a shaft hole through which the rotating shaft is inserted,
The edge portion having a burr protruding toward the second surface includes the edge portion of the shaft hole,
The electrostatic induction converter according to any one of claims 1-6. A drive mechanism for driving the rotating shaft is provided on the second surface side,
An electrostatic induction transducer according to claim 7. The supported member is attached to the electret substrate so as to allow translational movement of the electret substrate,
The electret substrate has a plurality of through-holes spaced apart from each other in the translational direction, and the first electret film and the second electret film are provided between the plurality of through-holes. ,
The edge having a burr protruding toward the second surface includes the edge of the through hole,
An electrostatic induction transducer according to claim 1. providing a conductive substrate;
providing an electret material film on the first surface and the second surface of the conductive substrate;
forming an edge of the conductive substrate by punching from the first surface;
attaching a conductive supported member to the conductive substrate so as to permit in-plane movement of the conductive substrate and to be electrically connected to the conductive substrate;
A step of grounding the conductive substrate and applying an electric charge to the electret material film by a charging process;
including
In the step of attaching the supported member to the conductive substrate, the supported member protrudes on the second surface side more than the amount of protrusion on the first surface side in a direction perpendicular to the conductive substrate. Install so that the amount increases,
A method for manufacturing an electrostatic induction transducer. An electrostatic induction converter according to any one of claims 1 to 9;
a dial having a visible area;
A wristwatch comprising
The electrostatic induction transducer overlaps the visible region in plan view and is arranged such that the second surface side faces the dial,
watch. providing a conductive substrate;
providing a first electret material film on the first surface of the conductive substrate;
providing a second electret material film on the second surface of the conductive substrate;
forming a through-hole penetrating through the conductive substrate, the first electret material film, and the second electret material film;
allowing in-plane movement of the conductive substrate and attaching a conductive supported member to the conductive substrate;
applying an electric charge to the first electret material film and the second electret material film by charging;
A method of manufacturing an electrostatic induction transducer, comprising:

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