JPS63161879A - Electrostatic motor - Google Patents

Abstract

PURPOSE:To decrease the number of parts, and to lighten and miniaturize an electrostatic motor by constituting a rotor having dipole moment by using depletion charges generated in a P-N junction in a semiconductor. CONSTITUTION:In an electrostatic motor, a rotor is organized of an N-type semiconductor 1, a P-type semiconductor 2 and the junction scction (a P-N junction) 3 of both semiconductors. Space charge regions (depletion layers) are formed near the P-N junctions 3, and positive and negative charges in the space charge regions exist in each depletion layer in four P-N junctions 3 and function as dipoles. A center shaft 5 is penetrated and mounted at the central position of the rotor, and drive electrodes 4a-4h are arranged, shaping predetermined air gaps on the outer circumference of the rotor. Accordingly, when voltage is applied to the drive electrodes 4a-4h, electrostatic force is generated among the rotor and the drive electrodes 4a-4h, and said applied voltage is fluctuated with time, thus turning the motor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostatic motor, and particularly to a motor used in an electronic a2S such as a wristwatch that is required to be lightweight and compact.

[Summary of the invention]

The present invention forms one or more PN junctions in a half-body substrate,
The positive charges and IT charges generated in the depletion layer near this PN junction are used to create a rotor with a dipole moment, and a voltage is applied to the drive electrodes provided on the outer periphery of the rotor to generate electricity between the rotor and the drive electrodes. The rotor is rotated by the electrostatic force generated by the rotor.

[Conventional technology]

Conventionally, it is generally known that motors that perform electromechanical conversion use magnets in the rotor and use electromagnetic force to rotate the rotor by changing the polarity of an in-field applied to the rotor from the outside. There is.

[Problem that the invention seeks to solve]

However, the above-mentioned conventional conversion using electromagnetic force requires a coil, iron core, yoke, etc. as an external magnetic excavator due to its driving principle, and therefore has the problem that it is difficult to reduce weight and size. Another problem is that it is difficult to shield and eliminate magnetic noise, which is one of the disturbances that affect motor characteristics.

[Means for solving problems]

In order to solve the above problems, the present invention forms one or more PN junctions in a semiconductor substrate, and uses positive charges and negative charges generated in a depletion layer near the PN junctions to generate a rotation having a dipole moment. A voltage is applied to a plurality of drive electrodes provided on the outer periphery of the rotor, and the applied voltage is changed over time.

[Effect]

When a voltage is applied to the drive electrodes provided on the outer periphery of the rotor, electrostatic force is generated between the rotor and the drive electrodes.

When the applied voltage changes over time, the electrostatic force between the rotor and each drive electrode also changes, and as a result, rotational force is generated and the motor rotates.

〔Example〕

The present invention will be explained below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an electrostatic motor according to the present invention.

In the figure, the rotor includes an N-type semiconductor 1, a P-type semiconductor 2, and the N-type semiconductor 1.
It is composed of a junction 3 (hereinafter referred to as PN junction 3) between a type semiconductor 1 and a P type semiconductor 2. The rotor has a sector-shaped P
A type semiconductor 1 and an N type semiconductor 2 are alternately connected to form an endless state. In the figure, P-type semiconductor 1 and N-type semiconductor 2 are each
There are four PN junctions 3.

In the vicinity of the PN junction 3, holes move from the P-type region to the N-type region by diffusion, and electrons diffuse from the N-type region to the P-type region, creating a space charge region, that is, a depletion region, as shown in the figure. A layer is formed. The amounts of positive charges and negative charges existing in this depletion layer are equal, and the amount of charges is expressed by the following equation (2).

Charge amount Q=nt 2εqNφ −1−−−−−■
However, β is the junction length of the PN junction. In FIG. 1, 1 is the thickness of the bond, which is equal to the radius of the circle. In FIG. 1, it is the thickness of the semiconductor.

ε is the dielectric constant of the half-four body q is the electron charge amount 1.6 Xl0-" Coulomb N is the impurity concentration φ is the barrier voltage of the PN junction It exists in each depletion layer of the junction and acts as a dipole.

The central shaft 5 is provided through the rotor at a central position of the rotor. The drive electrodes 4a to 4h are arranged with a certain gap provided around the outer periphery of the rotor. In the illustrated example, eight drive electrodes are arranged at a predetermined distance from each other.

FIG. 2 is a schematic diagram of an electrostatic motor according to the present invention. A pinion 6 is attached to the central shaft 5, and the rotation of the rotor is transmitted to the outside via the pinion 6. Portions with the same reference numerals as in FIG. 1 are the same as in FIG. 1, and their explanation will be omitted. Although the embodiment shown in FIGS. 1 and 2 shows a structure having four PN junctions, only one PN junction may be used, and the rotational force can be increased by increasing the number of PN junctions.

The rotor shown in Figure 1 can be manufactured by doping a P-type or N-type impurity into a semiconductor substrate such as silicon or GaAs by diffusion or ion implantation, or by connecting a discrete N-type semiconductor and a P-type semiconductor. It can also be manufactured.

When doping impurities into a semiconductor substrate, doping is performed so that the semiconductor substrate has the same polarity between the doped surface and the opposite surface.

FIG. 3 is a schematic diagram of another embodiment of the rotor according to the invention. The semicircular N-type semiconductor 11 and P-type semiconductor 12 are in surface contact with each other in the thickness direction of the rotor to form a PN junction. Similarly, the P-type semiconductor 13 and the N-type semiconductor 14 are brought into surface contact and P
Form an N junction. Furthermore, each end face of the straight portion of the N-type semiconductor 11 and the P-type semiconductor 12, and the P-type semiconductor 13 and the N
The end faces of the straight parts of the type semiconductor 14 are connected, and a PN
A rotor is formed by forming a joint.

According to the structure shown in FIG. 3, since the junction area of the PN junction is larger than that in FIG. 1, a large depletion charge (2) is obtained, and the rotational force is increased.

Although the illustrated embodiment shows a structure having two P-type semiconductors and two N-type semiconductors, increasing the number can increase the rotational force.

The rotor shown in Fig. 3 can be manufactured by doping P-type or N-type impurities into a base conductor substrate such as silicon or GaAs by diffusion or ion implantation. It can also be manufactured by connecting semiconductors.

FIG. 4 shows a general view (A) and a schematic cross-sectional view (B) of another embodiment of an electrostatic motor according to the present invention.

The central shaft 19 is provided through the rotor at the center of the rotor. The drive electrodes 15, 16, 17, and 18 have a U-shaped cross section, and rotors are inserted into the four parts of the U-shape. Further, as shown in FIG. 4(B), the drive electrode has a U-shaped cross section separated into upper and lower parts, and an insulator 21 is placed in between.
The upper and lower electrodes are electrically separated. In Ku's example, the number of drive electrodes is four, but
Change depending on the number of PN junctions.

FIG. 5 is a drive block diagram of the electrostatic motor shown in FIG. 1. Drive electrodes 4a to 4h are each connected to an output terminal of drive circuit 30.

FIG. 6 is a diagram illustrating the rotation state of the electrostatic motor of the present invention. The example in the figure shows the case where the rotor is rotated clockwise.The voltages applied to the drive electrodes 4a to 4h are
), change the positive and negative polarity of every second electrode. At the next timing, the applied voltage is changed as shown in Figure (B).

In this case, when focusing on one electrode, the voltage of the polarity that was applied to the electrode on the right at the previous timing is applied to the electrode being poured. As a result, the rotor rotates clockwise by 4
5″' rotation. Similarly, the applied voltage is changed from (A) to
Change as shown in (H) and rotate the rotor once. The rotation speed can be varied by changing the timing of the applied voltage, and the rotation direction can be made reversible by reversing the direction of change in the applied voltage.

7th UjJ shows a timing chart of drive electrodes corresponding to FIG. The horizontal axis is the time axis, and the timings shown in FIGS. 6(A) to (11) are taken, and the vertical axis is the driving electrodes 4a to 4a.
4h is shown. No. 13 may be changed to be positive or negative with respect to the base'/$ potential, or the reference potential may be made to match either a positive or negative voltage.

In addition, in the case of the embodiment shown in FIG. 4, the drive electrodes 15, 16, 17
18 is divided into upper and lower parts as described above, and voltages of different polarities are applied to the upper and lower electrodes.

FIG. 8 shows a timing chart of the drive electrodes in the embodiment of FIG. 4. The rotor rotates clockwise.

FIG. 9 shows a schematic diagram of another embodiment of a rotor for an electrostatic motor according to the present invention; a semiconductor substrate 4 doped with impurities;
0 (for example, N type), P type impurity regions 41, 42, 43, and 44 of the same shape are doped in multiple numbers symmetrically about the rotation axis.

Doping is performed by diffusion or ion implantation. Doping with P-type impurities is performed in the thickness direction of the substrate 40, and groups #Ii, 4
Do this to approximately the center depth of the 0.0mm thickness. As a result, the board 4
A PN junction is formed at the center of the thickness of 0, and depletion charges are generated in the vicinity of this. Driving is performed using a drive electrode having a U-shaped cross section as in FIG.

Further, the drive circuit and drive electrode of the electrostatic motor of the present invention can be integrated into an integrated IC together with other circuits. In this case, the number of parts can be reduced and adjustments such as alignment of drive electrodes are not required.

〔Effect of the invention〕

As described above, in the electrostatic motor of the present invention, the rotor has a dipole moment by using the depletion charge generated in the PN junction in the semiconductor, and the voltage is applied to the drive electrode provided on the outer periphery of the rotor. Since it is rotated by applying an electric force, it does not require coils, iron cores, yokes, etc., compared to conventional motors that use electric power, and it is possible to realize an extremely lightweight and compact motor.

Furthermore, the electrostatic motor of the present invention is not affected by magnetic fields, and the effects of electric fields can be easily shielded with metal, so that a motor that is resistant to external disturbances can be provided.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of the electrostatic motor of the present invention, FIG. 2 is an overview of the electrostatic motor of the present invention, and FIG. 3 is a schematic diagram of another embodiment of the rotor of the present invention. Figure 4 (A), (B)
5 is a driving block diagram of the electrostatic motor of the present invention. FIGS. FIG. 7 is a timing chart of the drive electrode, FIG. 8 is a timing chart of the moving TL pole of another embodiment of the invention, and FIG. 9 is a diagram explaining the rotational state of the electrostatic motor of the invention. FIG. 2 is a schematic diagram of another embodiment of the rotor of the present invention. ■... N-type semiconductor 2... P-type semiconductor 3... PN junction 4a to 4h... From the drive electrode Seiko Electronics Co., Ltd. 2 P7 size 1 electrostatic upper r : R surface formula diagram Figure 1 W electric motor's toning of the electric motor Figure 2
Diagrams (A) (B') Seven of the blue C electric motors! No Yasenkyo, No Gikazu and Town Ria 1
Figure 4 Figure 4 Stillness t So 9 Self-bending! ★η Bro, Figure 7 Figure 5 (A) (B) (C) (D
) About the 1,61st day of the lightning motor's rotation, Figure 6.
Figure it! -Example of Fgtn Beating Quimin 7”9-T Figure 8

Claims (1)

[Scope of Claims] A rotor made of a semiconductor having one or more PN junctions therein; a rotation shaft provided at the center of the rotor and perpendicular to the rotation surface of the rotor; An electrostatic motor comprising a plurality of drive electrodes provided close to a semiconductor substrate and facing the PN junction.