JP2012100404A - Power generator and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generator for solving the problem of the conventional power generators in which generation efficiency depends largely on a distance between a fixed substrate and a movable substrate, too great a distance in between reduces the generation efficiency and makes sufficient power supply difficult, and too small a distance in between brings the fixed and movable substrates into contact with each other and makes it impossible to change relative positions of the substrates, thereby stopping a generating operation itself; and springs have been used to support the movable substrate, but the springs, which degrade with time, have difficulty in maintaining a small distance between the fixed substrate and the movable substrate.SOLUTION: A power generator includes: a first substrate having an electret layer that holds an electric charge; and a second substrate that, in a planar direction, overlaps a side of the electret layer of the first substrate, with a gap in between and that has an electrode provided on a side of the first substrate so as to face the electret layer. The power generator has a spacer that is sandwiched between the first substrate and the second substrate and is rotatable in a uniaxial direction.

Description

  The present invention relates to a power generation device and an electronic apparatus.

As a power generation device, there is known a device in which a static substrate and a movable substrate are arranged so as to overlap each other through a gap, and the movable substrate is vibrated to perform electrostatic induction power generation.
In this case, for example, the fixed substrate includes a fixed electrode that is processed into a comb shape by superposing a conductor and a charging member (electret) on a surface facing the movable substrate.
The movable substrate includes a movable electrode that overlaps the fixed electrode in a plan view of the fixed substrate on a surface facing the fixed electrode side of the fixed substrate. Here, the fixed substrate and the movable substrate are attracted to each other by Coulomb attractive force.

When the movable substrate is vibrated in the plane direction of the fixed substrate, the vibration energy applied to the movable substrate moves against the Coulomb attractive force between the movable electrode and the fixed electrode, thereby changing the capacitance. Electric energy can be obtained by collecting this change as electric power. That is, power generation is performed.
The power generation efficiency greatly depends on the distance between the fixed substrate and the movable substrate. If the distance is too long, the power generation efficiency decreases, and it becomes difficult to supply sufficient power. On the other hand, if the distance is too close, the fixed substrate and the movable substrate come into contact with each other and the position cannot be changed relatively, so that the power generation operation itself stops. For this reason, various techniques have been proposed to control the distance between the fixed substrate and the movable substrate.

Patent Document 1 describes a configuration in which a spring is used to support a movable substrate so that the movable substrate can be held in a movable state.
Patent Document 2 describes a configuration including a gap adjustment unit, a movable substrate, and a spring that supports the movable substrate. One end of the spring is connected to the movable substrate, and the other end is connected to the gap adjusting unit. And the distance of a fixed board | substrate and a movable board | substrate is controlled by adjusting the height of a gap adjustment part.
Japanese Patent Application Laid-Open No. 2004-228688 describes a configuration that is positioned so as to be sandwiched between a fixed substrate and a movable substrate, includes a gap adjustment unit that adjusts the gap, and can control the gap between the fixed substrate and the movable substrate. Even in this case, in order to hold the movable substrate in a movable state, a spring is used to support the movable substrate.

JP 2005-529574 A JP 2009-148124 A JP 2009-232615 A

However, in the configurations shown in Patent Documents 1, 2, and 3, a spring is used to support the movable substrate. Since the spring deteriorates with time, there is a problem in terms of reliability. In addition, the step of forming the spring has to perform a step such as a spin coating method for applying a resin material, which increases the number of manufacturing steps.
In addition, since the spring for supporting the movable substrate and the gap adjusting unit for adjusting the gap are formed of separate structures, there is a problem that the number of parts increases.
Furthermore, since a process for adjusting the gap is added, the number of manufacturing processes is further increased. And since it adjusts mechanically, it becomes difficult to control a gap narrowly in the state which maintained mass productivity. In addition, since it is necessary to adjust the gap in anticipation of the deterioration of the spring over time, there is a problem that it becomes more difficult to narrow the gap.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A power generation device according to this application example includes a spacer that is sandwiched between the first substrate and the second substrate and rotates with respect to one axial direction. The air gap between the substrate and the second substrate is arranged at a location apart from the electret layer and the electrode in a plane so as to keep a predetermined value.

  According to this, the size of the gap (gap) between the first substrate and the second substrate is controlled by the diameter of the spacer. Further, the first substrate and the second substrate are movable with respect to one axial direction by the rotation of the spacer. Therefore, it operates with a simple structure and adjustment method compared to the conventional configuration that uses an adjustment mechanism that adjusts the spring and the position of the spring and controls the size of the gap between the first substrate and the second substrate. It is possible to provide a power generation device that performs the operation.

  [Application Example 2] The power generation device according to this application example is located on one of the surfaces of the three or more substrates arranged in a plane direction with a gap and the substrates facing each other. An electret layer holding charge, an electrode facing the electret layer located on the other surface, a spacer in contact with both the one surface and the other surface, and rotating with respect to one axis direction; It is characterized by providing.

  According to this, three or more substrates are used. The power generation efficiency of the power generation apparatus is improved by using three or more substrates. For example, when three substrates are used, power generation is performed at two convenient locations between the first substrate and the second substrate and between the second substrate and the third substrate. This is about twice as much as when two substrates are used. In order to double the power generation amount, when two substrates are used, two sets of four substrates are required. That is, since power generation can be performed with a small number of substrates, power generation efficiency is improved. Note that the number of sheets added may be one or more.

  Application Example 3 In the power generation device according to the application example described above, the spacer includes a sphere or a cylindrical shape that rotates in the one-axis direction.

  According to the application example described above, since the sphere and the cylinder are easy to roll, consumption of energy applied to the power generation device can be suppressed and the relative positions of the substrates can be changed. As a result, the power generation efficiency can be improved.

  Application Example 4 In the power generation device according to the application example described above, the spacer is provided in a guide disposed in a place apart from the electret layer and the electrode in a plane so as to be movable in the one-axis direction. It is contained.

  According to the application example described above, the spacer is housed in the guide in a planar manner. Therefore, the deviation of the spacer can be prevented, and the positional stability of the spacer can be kept high. Here, the guide includes a structure in which a region where the side surface of the spacer hits the substrate, or a structure in which a groove shape is provided in the substrate and the spacer is accommodated in the groove.

  Application Example 5 In the power generation device according to the application example described above, the value of the gap between the substrates is 1 μm or more and 500 μm or less.

  According to the application example described above, since there is a gap of 1 μm or more, collision between the first substrate and the second substrate can be avoided, and power generation can be performed if the gap is 500 μm or less. .

  Application Example 6 In the power generation device according to the application example described above, the value of the gap between the substrates is 10 μm or more and 300 μm or less.

  According to the application example described above, since there is a gap (gap) of 10 μm or more, it is possible to avoid a collision between the substrates including a deflection due to electrostatic force. Therefore, the strength of the substrate can be lowered. That is, the thickness can be reduced, and the amount of power generation per unit volume can be increased. And it becomes possible to raise electric power generation efficiency to a practical level because there is a gap of 300 micrometers or less.

  Application Example 7 In the power generation device according to the application example described above, the value of the gap between the substrates is 30 μm or more and 150 μm or less.

  According to the application example described above, since there is a gap (gap) of 30 μm or more, collision between the substrates can be avoided even if an impact is received. And the power generation efficiency is further improved due to the gap of 150 μm or less.

  Application Example 8 In the power generation device according to the application example described above, at least a part of the guide is inside the electret layer and the electrode in a plan view of the first substrate. To do.

  According to the application example described above, for example, a force attracting electrostatically is applied between the substrates. Therefore, the central part of the substrate may be bent. By arranging the guide inside the region that is attracted in plan view of the substrate, a spacer for controlling the distance between the substrates is accommodated in the guide. By arranging in this way, it becomes possible to suppress the bending of the central part of the substrate.

  Application Example 9 In the power generation device according to the application example described above, one of the substrates located on the outermost side in the thickness direction and every other substrate counted from the one side are fixed to each other, The spacer rotating in the uniaxial direction is provided on both surfaces of the movable first substrate located between the fixed substrates and the surface sandwiching the substrate, and the uniaxial Spacers that rotate in a direction crossing the direction are provided on at least one of the movable second substrates located between the fixed substrates and on a surface sandwiching the substrates. It is characterized by.

  According to the application example described above, since vibrations in different directions can be converted into electric energy, the improvement in power generation efficiency and the improvement in output power stability (reduction in vibration direction dependency of generated power) can be obtained together. Is possible.

  Application Example 10 An electronic apparatus according to this application example includes the above-described power generation device.

  According to this, since the power generation device that can control the size of the gap (gap) between the substrates by the diameter of the spacer is used, the power generation device formed in consideration of mechanical fatigue using a spring is used. Compared with the case where it was, it becomes possible to comprise the electronic device corresponding to reliability and high power.

(A) is a plan view of the fixed substrate, (b) is a plan view of the movable substrate, and (c) is a cross-sectional view taken along the line BB ′ in a state where the movable substrate and the fixed substrate are fixed via a bearing. (D) is the sectional view on the AA 'line in the state where a movable substrate and a fixed substrate were fixed via a bearing, and (e) is a partial enlarged view at the time of using a slot as a guide. (A)-(d) is the fragmentary sectional view of FIG.1 (d) which shows the electric power generation state of an electric power generation part, (e) is a graph which shows the electric power generation state in the state in (a)-(d). (A)-(d) is a top view for demonstrating 2nd Embodiment provided with the guide inside the electric power generation part. (A)-(d) is each top view at the time of using three board | substrates. FIG. 4E is a cross-sectional view taken along line B-B ′ in a state where three substrates are stacked, and FIG. 5F is a cross-sectional view taken along line A-A ′ in a state where three substrates are stacked. The perspective block diagram corresponding to the vibration of 2 directions. The top view of the board | substrate made to respond | correspond to the vibration of 2 directions. The schematic diagram which shows RF tag as an electronic device.

(First embodiment: power generation device)
Hereinafter, the first embodiment will be described with reference to the drawings.
1A is a plan view of a fixed substrate, FIG. 1B is a plan view of a movable substrate, and FIG. 1C is a cross-sectional view of a BB with a bearing held between the movable substrate and the fixed substrate. 'Line sectional view, FIG. 1 (d) is a sectional view taken along the line AA' with the bearing held between the movable substrate and the fixed substrate, FIG. 1 (e) shows the vicinity of the groove when the groove is used as a guide. FIG.
This power generation device 100 is movable in the X direction as a uniaxial direction, and converts vibration energy in the X direction into electric energy.
Here, “upper” is defined as a direction from the fixed substrate 101 toward the movable substrate 110 (Z direction: see FIG. 1D).

  The power generation apparatus 100 includes a fixed substrate 101 as a first substrate and a movable substrate 110 as a second substrate. Note that the fixed substrate 101 may be replaced with the second substrate, and the movable substrate 110 may be replaced with the first substrate. In each cross-sectional view and plan view, an important configuration is illustrated on the front side of the drawing, and the orientation of the drawing (XYZ direction) varies from drawing to drawing. Therefore, the XYZ directions are added for each drawing as necessary.

The fixed substrate 101 includes a fixed substrate main body 101a, a guide 103, a first electrode 104, a charge holding layer 105 as an electret layer holding charges, and a stopper 107. The guide 103, the first electrode 104, the charge holding layer 105, and the stopper 107 are located on the surface of the fixed substrate body 101a on the movable substrate 110 side.
The movable substrate 110 includes a movable substrate main body 110a, a second electrode 111, and a guide 113. The second electrode 111 and the guide 113 are located on the surface of the movable substrate body 110a on the fixed substrate 101 side.

The fixed substrate 101 and the movable substrate 110 sandwich a bearing 102 as a spacer so that they can move in the plane direction. The bearing 102 ensures the mobility of the movable substrate 110 by rotating the bearing 102 in the X direction.
The bearing 102 does not belong to either the fixed substrate 101 or the movable substrate 110, but for convenience, the bearing 102 is illustrated using a dotted line at the position where the bearing 102 should be.
Although the bearing 102 is illustrated as an example of a spherical shape, a cylindrical roller that rotates in the moving direction (X direction) of the movable substrate 110 may be used. Then, the fixed substrate 101 and the movable substrate 110 are overlapped to vibrate the movable substrate 110, whereby power generation is performed by the power generation unit 115 including the first electrode 104, the charge retention layer 105, and the second electrode 111. Here, normally, the first electrode 104 and the charge retention layer 105 overlap each other. In general, the first electrode 104 and the second electrode 111 overlap in a planar manner at a steady position (a position where the movable substrate 110 is stabilized in a state where the movable substrate 110 is not vibrated). Here, it is not an essential requirement that the first electrode 104 and the charge retention layer 105 overlap each other, or that the first electrode 104 and the second electrode 111 overlap in a planar manner at a steady position. It only has to be in the relationship. The force to pull back to the steady position is generated by electrostatically attracting the fixed substrate 101 and the movable substrate 110 together. Further, the charge retention layer 105 may be disposed on the movable substrate 110 side.

  For example, glass or plastic is used as a constituent member of the fixed substrate body 101a. The surface of the fixed substrate body 101a on the movable substrate 110 side has a flat shape so that the movable substrate 110 does not collide with the fixed substrate 101 when the movable substrate 110 moves.

  The guide 103 defines a direction in which the bearing 102 rotates and defines an area where the bearing 102 is located. In this embodiment, the power generation apparatus 100 having a degree of freedom in the X direction is handled. Therefore, the guide 103 is arranged so that the bearing 102 can be rotated along the X direction and the guide 103 and the bearing 102 can be accommodated in a position apart from the charge retention layer 105 and the second electrode 111 in a plane.

The guide 103 is formed by a method of applying a resin (for example, using a dispenser) on the fixed substrate body 101a, a method of performing a photolithography process after forming a photosensitive resin layer, or the like. In this way, by energizing a region sandwiching the bearing 102 and placing the bearing 102 inside the region, the bearing 102 can be rotated along the X direction. Further, instead of a configuration in which the guide 103 is stacked, a groove may be formed as a guide so that the bearing 102 can rotate in one direction, and the bearing 102 may be accommodated inside the groove (see FIG. 1E). Further, a cylindrical roller may be accommodated in the groove.
The stopper 107 defines the vibration range of the movable substrate 110 so that the amplitude of the movable substrate 110 does not become excessive.

The movable substrate main body 110a is made of, for example, glass or plastic as a constituent member similarly to the fixed substrate main body 101a. The surface of the movable substrate main body 110a on the fixed substrate 101 side has a flat shape so that it does not collide with the fixed substrate 101 when the movable substrate 110 moves.
As will be described later, the second electrode 111 has a function of generating power in cooperation with the first electrode 104 and the charge retention layer 105.
The guide 113 defines the movement of the bearing 102 so that the bearing 102 rotates along the X direction, like the guide 103. Note that one of the guide 103 and the guide 113 can be omitted.

(Power generation mechanism)
Hereinafter, a mechanism for generating power with the power generation unit 115 including the first electrode 104, the charge retention layer 105, and the second electrode 111 will be described. FIGS. 2A to 2D are cross-sectional views when a part of the BB ′ cross-sectional view of FIG. 1D is enlarged and vibration is applied to the movable substrate 110. FIG.2 (e) is a graph which shows the electric power generation state in the state in Fig.2 (a)-(d). In FIG. 2E, the vertical axis indicates the current I.

  As shown in FIG. 2A, when the movable substrate 110 is not oscillating (step S1), the capacitance of the capacitor C does not fluctuate with time (represented by t), and no power is generated.

  Next, as shown in FIG. 2B, when the movable substrate 110 is moved in the X-axis direction (step S2), the movable substrate 110 and the fixed substrate 101 are displaced, and the movable substrate 110 and the fixed substrate 101 are moved. The capacity of the capacitor C formed therebetween is reduced. As the capacitance decreases, the charge moves through the resistor R. That is, current i flows as shown in FIG. Then, when the movement is stopped in the −X direction, the movement of the charge is finished, and the movement of the charge, that is, the current i stops.

  Next, as shown in FIG. 2C, when returning to the steady position (step S3), the capacitance of the capacitor C formed between the movable substrate 110 and the fixed substrate 101 is increased. As the capacitance increases, the charge moves through the resistor R, and a current (-i) flows in a direction opposite to that in the case of FIG. 2B, that is, as shown in FIG. Then, when returning to a stationary position and making it stand still, the movement of electric charge ends, and the movement of electric charge, that is, the current i stops.

  Next, as shown in FIG. 2D, when the movable substrate 110 is moved in the X axis + direction (step S4), the movable substrate 110 and the fixed substrate 101 are displaced, and the movable substrate 110 and the fixed substrate 101 are moved. The capacity of the capacitor C formed therebetween is reduced. As the capacitance decreases, the charge moves through the resistor R. That is, current i flows as shown in FIG. Then, when moving in the X direction and resting, the movement of the charge is finished, and the movement of the charge, that is, the current i stops.

  By repeating this operation, it is possible to generate energy by converting vibration energy, that is, to generate power.

(Gap control)
Returning to FIG. Hereinafter, the gap control as the gap between the fixed substrate 101 and the movable substrate 110 will be described. As shown in FIG. 1C, the gap is basically determined by the diameter of the bearing 102 when the guide 103 and the guide 113 are used. Therefore, gap control can be easily performed. It is also easy to change the size of the gap. As the size of the gap, for example, a value of 1 μm or more and 500 μm or less can be provided. Since there is a gap of 1 μm or more, collision between the fixed substrate 101 and the movable substrate 110 can be avoided, and power generation can be performed if the gap is 500 μm or less.

  It is also desirable that the gap has a value of 10 μm or more and 300 μm or more. By having a gap of 10 μm or more, it is possible to avoid collision between the fixed substrate 101 and the movable substrate 110 including the amount of deflection due to electrostatic force. Therefore, the strength of the fixed substrate 101 and the movable substrate 110 can be reduced. That is, the thickness can be reduced, and the amount of power generation per unit volume can be increased. And it becomes possible to raise electric power generation efficiency to a practical level because there is a gap of 300 micrometers or less.

  And as a magnitude | size of a gap, it is suitable that they are 30 micrometers or more and 150 micrometers or less. Since there is a gap of 30 μm or more, collision between the fixed substrate 101 and the movable substrate 110 can be avoided even if an impact is received. And since there is a gap of 150 μm or less, the power generation efficiency is further increased. In the present embodiment, for example, the description is continued for the case where the bearing 102 corresponding to a gap of about 80 μm (having a diameter of about 80 μm) is used.

  Further, instead of the guide 103 and the guide 113, a groove G may be formed as shown in FIG. In this case, the size of the gap can be reduced while keeping the diameter of the bearing 102 large. Therefore, even when fine dust enters the moving path of the bearing 102, the bearing 102 can get over it and rotate. Therefore, even if dust enters, the relative mobility of the movable substrate 110 with respect to the fixed substrate 101 can be maintained. Alternatively, a groove may be disposed on one of the fixed substrate 101 and the movable substrate 110 and a shape in which a region sandwiching the bearing 102 in a plane is raised on the other.

  The power generation apparatus described above has the following effects.

  As shown in FIG. 1C, by providing the guide 103 and the guide 113, the moving direction of the bearing 102 can be determined in the X direction. For example, if it shifts in the Y direction, the region where the charge retention layer 105 and the second electrode 111 overlap in a planar manner becomes narrow, and the power generation efficiency decreases. Therefore, by restricting the movement of the movable substrate 110 other than in the X direction, a stable power generation operation can be performed.

  A description will be given with reference to FIG. When a cylindrical roller (not shown) is used instead of the spherical bearing 102, the pressure can be dispersed because the fixed substrate 101 and the movable substrate 110 are in contact with each other with a line instead of a point. Therefore, when a cylindrical roller is used, the reliability of the power generation device 100 can be improved.

  As shown in FIG. 1C, when the guide 103 and the guide 113 are provided, the diameter of the bearing 102 determines the gap between the fixed substrate 101 and the movable substrate 110. The bearing 102 also has a function of relatively moving the fixed substrate 101 and the movable substrate 110. Therefore, it is possible to define the positional relationship between the fixed substrate 101 and the movable substrate 110 with fewer parts and without adjustment.

  As shown in FIGS. 1C and 1E, the influence on dust can be reduced by forming a groove G in place of the guide 103 and the guide 113 and fitting the bearing 102 in the groove G. In particular, when the gap size is reduced, the diameter of the bearing 102 can be increased. For example, even if fine dust enters the moving path of the bearing 102, it is possible to rotate (for simplicity, assuming that the dust shape is a cube, when the bearing 102 having a diameter of 10 μm is used, the bearing 102 has a diameter of 5 μm or more. Therefore, it is possible to provide the power generation apparatus 100 that is resistant to dust.

  A description will be given with reference to FIG. The guide 103 and the guide 113 are formed by a method in which a resin is applied (for example, using a dispenser) or a method in which a photosensitive resin layer is formed and then formed using a photolithography process. Since it can be formed by an apparatus and a process, the guide 103 and the guide 113 can be formed without introducing a new manufacturing apparatus or developing a new process. Therefore, it is possible to reduce the cost of the apparatus and the load necessary for process development.

  A description will be given with reference to FIG. By omitting one of the guide 103 and the guide 113, the manufacturing process of the power generation apparatus 100 can be shortened.

  This will be described with reference to FIGS. By using substrates with flat surfaces facing each other as the fixed substrate main body 101a and the movable substrate main body 110a, it is possible to generate electric power while avoiding collision between the two substrates.

  This will be described with reference to FIGS. Since the gap between the fixed substrate 101 and the movable substrate 110 is 1 μm or more, collision between the fixed substrate 101 and the movable substrate 110 can be avoided. And since a gap is 500 micrometers or less, even if it is a low output, it becomes possible to generate electric power.

  This will be described with reference to FIGS. Since the gap between the fixed substrate 101 and the movable substrate 110 is 10 μm or more, it is possible to avoid collision between the fixed substrate 101 and the movable substrate 110 including a deflection due to electrostatic force. Therefore, the strength of the fixed substrate 101 and the movable substrate 110 can be reduced. That is, the thickness can be reduced, and the amount of power generation per unit volume can be increased. And since a gap is 300 micrometers or less, it becomes possible to raise electric power generation efficiency to a practical use level.

  This will be described with reference to FIGS. Since the gap between the substrates is 30 μm or more, collision between the fixed substrate 101 and the movable substrate 110 can be avoided even if an impact is applied. And it becomes possible to maintain electric power generation efficiency high enough because a gap is 150 micrometers or less.

(2nd Embodiment: The electric power generating apparatus provided with the guide inside the electric power generation part)
Hereinafter, the second embodiment will be described with reference to the drawings. 3A to 3D are plan views for explaining the second embodiment. The main difference from the first embodiment is that at least a part of the guides 203, 213, 223, and 233 is disposed inside the power generation unit 115 in a plan view of the fixed substrate 101. Here, components similar to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Further, illustration and description of the stopper and the like are omitted, and duplication of explanation is avoided. 3A to 3D can be expressed in the same coordinate system, they are collectively added as one coordinate system.

The power generation device 200 includes a fixed substrate 101 as a first substrate (second substrate) and a movable substrate 110 as a second substrate (first substrate). Since the power generation apparatus 200 is configured by the fixed substrate 101 and the movable substrate 110, 200 is appended to the fixed substrate 101 and the movable substrate 110 in parentheses.
The fixed substrate 101 includes a first electrode 104, a charge holding layer 105 as an electret layer holding charges, and a guide 203.
The movable substrate 110 includes a second electrode 111 and a guide 213.
A power generation unit 115 including the first electrode 104, the charge retention layer 105, and the second electrode 111 is provided.
The fixed substrate 101 and the movable substrate 110 are overlapped with each other via a bearing 102 as a spacer so that they can move in the plane direction. Then, the power generation unit 115 including the first electrode 104, the charge retention layer 105, and the second electrode 111 is formed. The bearing 102 does not belong to either the fixed substrate 101 or the movable substrate 110, but for convenience, the bearing 102 is illustrated using a dotted line at the position where the bearing 102 should be.

A part of the guide 203 is disposed inside the fixed substrate 101 of the power generation unit 115 divided into a plurality. A part of the guide 213 is also formed on the inner side in the plan view of the power generation unit 115 of the movable substrate 110. About another structure, it is comprised similarly to 1st Embodiment.
FIG. 3A is a plan view of the fixed substrate 101 in which the power generation unit 115 is divided into three and the guide 203 is disposed inside the power generation unit 115. FIG. 3B is a plan view of the movable substrate 110 used in an overlapping manner with FIG.
As shown in FIG. 3A, the guide 203 is disposed inside the power generation unit 115 including the charge retention layer 105 and the first electrode 104 in plan view. Similarly, as illustrated in FIG. 3B, a guide 213 is disposed inside the power generation unit 115 including the second electrode 111 in a plan view.
FIG. 3C is a plan view of the fixed substrate 101 in which the power generation unit 115 is divided into two and the guide 223 is disposed so as to be sandwiched between the power generation units 115. FIG. 3D is a plan view of the movable substrate 110 used in an overlapping manner with FIG.
As shown in FIG. 3C, a part of the guide 223 is disposed inside the power generation unit 115 including the charge retention layer 105 and the first electrode 104 in plan view. Similarly, as illustrated in FIG. 3D, a part of the guide 233 is disposed inside the power generation unit 115 including the second electrode 111 in a plan view.

  In addition to the effects of the above-described embodiments, the power generation device according to the present embodiment has the following effects.

  Since the guides 203, 213, 223, and 233 can be arranged according to the layout of the power generation unit 115, the degree of freedom in design can be improved.

  The bearings 102 are arranged inside the fixed substrate 101 and the movable substrate 110 by the guides 203, 213, 223, and 233. Therefore, it is possible to reduce the bending due to the electrostatic attractive force, and the gap between the fixed substrate 101 and the movable substrate 110 can be further narrowed. Since the power generation efficiency is increased by narrowing the gap, it is possible to provide the power generation apparatus 200 with higher performance.

(Third embodiment: a power generation apparatus including three or more substrates)
Hereinafter, the third embodiment will be described with reference to the drawings. 4A to 4D are plan views in the case of using three substrates for explaining the third embodiment, and FIG. 5E is a view of B in a state where the three substrates are stacked. -B 'sectional view, FIG.5 (f) is an AA' sectional view in the state which piled up the three board | substrates. In this case, if the substrate at the center is a movable substrate and the substrates on both sides are fixed substrates, the power generation apparatus 300 can be easily fixed. In order to facilitate the explanation of the structure, the scale of the constituent members is partially changed between the plan view and the sectional view.
In this embodiment, an example in which the number of substrates is three is described. However, by adding a fixed substrate and a movable substrate in the same manner as in this embodiment, it is possible to cope with the number of substrates exceeding three. is there.

  Since the main difference between the first and second embodiments is that there are three substrates and the structure of the guide, this guide will be described in detail below. Further, the description of the substrate body and the power generation unit described in the first and second embodiments is omitted. For example, for the charge holding layer 105 as an electret layer holding charges and the second electrode 111 (see FIG. 1) as an electrode shown in the first embodiment, refer to the first embodiment, Avoid duplication.

As shown in FIG. 5, the power generation apparatus 300 includes a fixed substrate 311 and a movable substrate 321 as substrates, a fixed substrate 331 as a substrate, and bearings 312 and 332 as spacers. The fixed substrate 311 includes a guide 313 on the surface on the movable substrate 321 side. Similarly, the fixed substrate 331 includes a guide 343 on the surface on the movable substrate 321 side.
The guides 313 and 323 define the movement of the bearing 312 so that the bearing 312 rotates in the X direction as one axis direction. Similarly, the guides 333 and 343 define the movement of the bearing 332 so that the bearing 332 rotates in the X direction. A gap between the fixed substrate 311, the movable substrate 321, and the fixed substrate 331 is determined by the bearings 312 and 332, and is overlapped in this order with respect to the thickness direction of each substrate through the gap.

Next, the configuration of each substrate will be described with reference to FIG.
As shown in FIG. 4A, the fixed substrate 311 includes a guide 313 on the surface of the movable substrate 321 side. Similarly, as shown in FIG. 4B, the fixed substrate 331 includes a guide 343 on the surface on the movable substrate 321 side. As shown in FIGS. 4C and 4D, the movable substrate 321 has the same shape on both sides, and the guide 323 provided on the surface on the fixed substrate 311 side and the surface on the fixed substrate 331 side. The guide 333 provided in the above is provided.

The guides 313 and 323 define the movement of the bearing 312 so that the bearing 312 rotates in the X direction as one axis direction. Similarly, the guides 333 and 343 define the movement of the bearing 332 so that the bearing 332 rotates in the X direction.
Note that the applications described in the first embodiment and the second embodiment, such as the omission of part of the guide and the use of grooves instead of the guide, can be handled in the same manner as in the above-described embodiment.

  In the present embodiment, power generation is performed between the fixed substrate 311 and the movable substrate 321 and between the fixed substrate 331 and the movable substrate 321.

  In addition to the effects of the above-described embodiments, the power generation device according to the present embodiment has the following effects.

  By using the power generation device 300 using three or more substrates, the power generation efficiency per volume is improved. For example, when three substrates are used, power generation is performed at two convenient locations between the fixed substrate 311 and the movable substrate 321 and between the movable substrate 321 and the fixed substrate 331. In particular, when the vibration is large and the loss of vibration energy due to power generation is small, the power generation efficiency is about twice that of the case where the vibration attenuation of the movable substrate 321 uses two substrates. In order to double the power generation amount, when two substrates are used, two sets of four substrates are required. That is, since the same power generation can be performed with a small number of substrates, the power generation efficiency per volume is improved.

  When three or more odd-numbered substrates are used, the outer substrate can be used for fixing. Therefore, the power generator 300 can be easily mounted.

  In the case where a structure such as a spring protruding outside the substrate is used as a support for the substrate, if three or more substrates are used in a stacked manner, these structures may collide with each other. As shown in FIG. 4, the movable substrate 321 is supported by the bearing 312 and the bearing 332, so that the substrate can be supported without a risk of collision. Therefore, it is possible to easily increase the number of substrates.

  When increasing the number of movable substrates, for example, the resonance frequency can be changed for each movable substrate by changing the thickness of the movable substrate. In this case, the generated power is stable even when used under conditions where the period of external vibration varies. As a result, the output power can be stabilized and taken out.

(4th Embodiment: The electric power generating apparatus corresponding to the vibration of 2 directions)
Hereinafter, the fourth embodiment will be described with reference to the drawings. 6 is a perspective configuration diagram corresponding to vibrations in two directions, and FIG. 7 is a plan view of each substrate. Here, an example in which the number of substrates is five has been described. However, by adding a fixed substrate and a movable substrate in the same manner as in this embodiment, it is possible to cope with the number of substrates exceeding five. Note that the applications described in the first embodiment and the second embodiment, such as the omission of part of the guide and the use of grooves instead of the guide, can be handled in the same manner as in the above-described embodiment. Since FIGS. 7A to 7D can be expressed in the same coordinate system, they are collectively added as one coordinate system.

The power generation device 400 includes a fixed substrate 411 as one of the outermost substrates, at least one movable substrate 421 as a movable first substrate positioned between the fixed substrates, and a fixed substrate 411. A fixed substrate 431 is provided as every other substrate counted from the (one side of the substrate) side.
At least one movable substrate 441 as a second substrate having mobility, a stationary substrate 411 (one side of the substrate) is positioned between the fixed substrates. ), Fixed substrates 451 as alternate substrates, bearings 412 and 422 as spacers, and bearings 432 and 442 as spacers that rotate in a direction crossing the axial direction.

  The fixed substrate 411 includes a guide 413. Since the main difference from the first, second, and third embodiments is the structure of a guide that accommodates a spacer or another spacer, this guide will be described in detail below. In order to avoid complication of the drawings, the illustration and description of the substrate main body and the like described in the first, second, and third embodiments are omitted.

As shown in FIG. 6, the fixed substrate 411, the movable substrate 421, the fixed substrate 431, the movable substrate 441, and the fixed substrate 451 are separated from each other through gaps formed by the bearing 412, the bearing 422, the bearing 432, and the bearing 442. Are arranged so as to overlap in the thickness direction (Z direction) of the substrate in this order.
The fixed substrate 411 is fixed to a housing or the like (not shown). The fixed substrate 431 and the fixed substrate 451 are also fixed to the fixed substrate 411 through a housing or the like.

As shown in FIG. 7A, the fixed substrate 411 is provided with a guide 413 for defining the movement of the bearing 412 on the surface of the movable substrate 421 so that the bearing 412 rotates in the X direction as one axis direction. ing.
Similarly, a guide 443 that regulates the movement of the bearing 422 is disposed on the surface of the fixed substrate 431 on the movable substrate 421 side so that the bearing 422 rotates in the X direction. In FIG. 6, the guide 443 is described only with reference numerals because it is hidden behind the fixed substrate 431.
The surface of the fixed substrate 411 on the movable substrate 421 side and the surface of the fixed substrate 431 on the movable substrate 421 side have the same structure. Therefore, in order to avoid duplication of drawings, only the reference numerals are duplicated.
As shown in FIG. 7B, a guide 423 is provided on the surface of the movable substrate 421 on the fixed substrate 411 side so that the bearing 412 rotates in the X direction.
Similarly, a guide 433 is provided on the surface of the movable substrate 421 on the fixed substrate 431 side so that the bearing 422 rotates in the X direction.
The movable substrate 421 has the same structure on both sides. Therefore, in order to avoid duplication of drawings, only the reference numerals are duplicated. In FIG. 6, only the reference numerals are shown for the guide 423 because it is hidden by the movable substrate 421.

As shown in FIG. 7C, a guide 453 is provided on the surface of the fixed substrate 431 on the movable substrate 441 side so that the bearing 432 rotates in the Y direction as a direction intersecting the one axis direction.
Similarly, a guide 483 for defining the movement of the bearing 442 is disposed on the movable substrate 441 side of the fixed substrate 451 so that the bearing 442 rotates in the Y direction.
The surface of the fixed substrate 431 on the movable substrate 441 side and the surface of the fixed substrate 451 on the movable substrate 441 side have the same structure. Therefore, in order to avoid duplication of drawings, the reference numerals are duplicated. In FIG. 6, only the reference numerals are shown for the guide 483 because it is hidden behind the fixed substrate 451.
As shown in FIG. 7D, a guide 463 is provided on the surface of the movable substrate 441 on the fixed substrate 431 side so that the bearing 432 rotates in the Y direction.
Similarly, a guide 473 is provided on the surface of the movable substrate 441 on the fixed substrate 451 side so that the bearing 442 rotates in the Y direction.
The movable substrate 441 has the same structure on both sides. Therefore, in order to avoid duplication of drawings, only the reference numerals are duplicated. In FIG. 6, since only the guide 463 is hidden because it is hidden behind the movable substrate 441, only a reference numeral is shown.

  By arranging the guides 413 to 483 and the bearings 412 to 442 in this way, it is possible to obtain the power generation apparatus 400 that can generate power by receiving vibration in the X direction and vibration in the Y direction.

  In addition to the effects of the above-described embodiments, the power generation device according to the present embodiment has the following effects.

  Since power generation can be performed in response to vibration in two directions, it is possible to increase the conversion efficiency from vibration to power and provide stable power compared to a power generation device that can generate power only in vibration in one axis direction. it can.

  If the vibration is in the plane direction, power generation can be performed by separating the vibration into the X component and the Y component, and therefore power generation can be performed in the vibration direction of any direction.

  Even in this case, since the power generation area is conveniently four places, the power generation efficiency per volume can be increased. For example, when the vibration is particularly large and the loss of vibration energy due to power generation is small, the power generation efficiency is about four times as compared with the case where two substrates are used. In order to increase the amount of power generation by four, when two substrates are used, four sets, that is, eight substrates are required. That is, since the same power generation can be performed with a small number of substrates, the power generation efficiency per volume is improved.

(Electronics)
Hereinafter, with reference to the drawings, an electronic device in which the power generation device 100 (or 200, 300, 400) according to the above embodiment is mounted will be described. FIG. 8 is a schematic diagram illustrating an RF tag as an electronic device. The RF tag 500 includes the power generation device 100 (or 200, 300, 400), a diode bridge 510, an electric double layer capacitor 520, and an RF output unit 530.

  The AC power generated by the power generation apparatus 100 (200, 300, 400) is rectified by passing through the diode bridge 510 and an electric double layer capacitor 520 (a capacitor having a different structure, a secondary battery, or the like may be used). Is stored and output as direct current. The power generation apparatus 100 (200, 300, 400) using electrostatic induction power generation generates power with an output voltage of about 10 to 30 V as a peak value, although the power generation voltage varies depending on the structure. When a normal silicon diode is used for the diode bridge 510, a forward voltage drop of about 1.2V occurs. However, since the output voltage is high, it is possible to rectify while suppressing power loss. Based on the electric power stored in the electric double layer capacitor 520, a signal is output from the RF output unit 530 in the form of a radio wave.

  This electronic apparatus has the following effects in addition to the effects of the above-described embodiment.

  A power generation device (see FIGS. 1, 3, 4, and 5: 100) with a gap controlled by bearings that are resistant to fatigue deterioration (see FIGS. 1, 3, 4, and 6: 102, 312, 332, 412, 422, 432, and 442). , 200, 300, 400), for example, the RF tag 500 shown in FIG. 8 as an electronic device having high reliability compared to a case where a power generation device supported by a spring is used. Therefore, for example, it is possible to cope with an application in which the RF tag 500 is embedded in a place where replacement is difficult, and because the gap accuracy is high, the power generation efficiency can be increased and the vibration intensity is low. However, communication can be performed.

  DESCRIPTION OF SYMBOLS 100 ... Power generation device, 101 ... Fixed substrate, 101a ... Fixed substrate main body, 102 ... Bearing, 103 ... Guide, 104 ... First electrode, 105 ... Charge holding layer, 107 ... Stopper, 110 ... Movable substrate, 110a ... Movable substrate main body , 111 ... second electrode, 113 ... guide, 115 ... power generation unit, 200 ... power generation device, 203 ... guide, 213 ... guide, 223 ... guide, 233 ... guide, 300 ... power generation device, 311 ... fixed substrate, 312 ... bearing 313 ... Guide, 321 ... Moving substrate, 323 ... Guide, 331 ... Fixed substrate, 332 ... Bearing, 333 ... Guide, 343 ... Guide, 400 ... Power generation device, 411 ... Fixed substrate, 412 ... Bearing, 413 ... Guide, 421 ... movable substrate, 422 ... bearing, 423 ... guide, 431 ... fixed substrate, 432 ... bearing 433 ... Guide, 441 ... Movable board, 442 ... Bearing, 443 ... Guide, 451 ... Fixed board, 453 ... Guide, 463 ... Guide, 473 ... Guide, 483 ... Guide, 500 ... RF tag, 510 ... Diode bridge, 520 ... Electric double layer capacitor, 530... RF output section.

Claims (10)

A first substrate comprising an electret layer holding a charge;
A power generation device including the electret layer and a second substrate provided with electrodes facing each other with a gap therebetween,
Sandwiched between the first substrate and the second substrate;
It has a spacer that rotates in the direction of one axis,
The spacer is disposed at a location apart from the electret layer and the electrode in a plane so as to keep a gap between the first substrate and the second substrate at a predetermined value. Power generator. Three or more substrates arranged in a plane direction through a gap; and
An electret layer holding an electric charge located on one of the faces of the substrates facing each other;
An electrode facing the electret layer located on the other surface;
A power generator comprising: a spacer that contacts both the one surface and the other surface and rotates with respect to one axial direction.   3. The power generation device according to claim 1, wherein the spacer includes a sphere or a columnar shape that rotates in the one-axis direction.   4. The power generation device according to claim 1, wherein the spacer is arranged at a location that is planarly separated from the electret layer and the electrode, which provides mobility in the one-axis direction. A power generator characterized by being housed in a guide.   5. The power generation device according to claim 1, wherein a value of a gap between the substrates is 1 μm or more and 500 μm or less.   5. The power generation device according to claim 1, wherein a value of a gap between the substrates is 10 μm or more and 300 μm or less.   5. The power generation device according to claim 1, wherein a value of a gap between the substrates is not less than 30 μm and not more than 150 μm.   5. The power generation device according to claim 4, wherein at least a part of the guide is inside the electret layer and the electrode in a plan view of the first substrate. It is an electric power generating apparatus as described in any one of Claims 2-8,
One of the substrates located on the outermost side with respect to the thickness direction, and every other substrate counted from the one side are fixed to each other,
The spacer rotating in the one-axis direction is provided on at least one of the movable first substrates located between the fixed substrates and a surface sandwiching the substrates,
Spacers that rotate in a direction crossing the one axial direction are provided on at least one of the movable second substrates positioned between the fixed substrates and on a surface sandwiching the substrates. A power generation device characterized by that.   An electronic apparatus comprising the power generation device according to claim 1.

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