JPH05236768A - Optical driving linear actuator - Google Patents

Abstract

PURPOSE:To obtain a miniature optical driving microactuator requiring no feeder wire nor battery for supplying energy in which the reduction of thrust due to miniaturization is low by employing Coulomb's force, functioning directly from a photoelectric conversion element, in a driving section and a floating force generating section. CONSTITUTION:A stator 1 comprises a floating force generating section 2 and a driving section 3 having a surface arranged with stripe protrusions 4 at a pitch lambda. A slider 6 comprises a floating force generating section 7 and a driving section 8 comprising unit drive sections 8a, 8b, 8c and having a surface arranged with stripe protrusions 11 at a pitch of lambda, wherein the last pitch of each unit drive section 8a, 8b, 8c is set at nlambda+lambda/3. The floating force generating sections 2 and 7 of the stator 1 and the slider 6 are then irradiated, on the back thereof, with light through light supply means 12 and 13 to float the slider 6 and then the unit drive section 8a (8b, 8C) is irradiated, on the back thereof, with light through a light supply means 14 to move the unit drive section 8a (8b, 8c). The operations are sequentially carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine actuator driven by light.

[0002]

2. Description of the Related Art As an application target of a microactuator, autonomous work in a minute space is required. However, currently considered driving sources are electromagnetic, electrostatic, piezoelectric, shape memory alloy, etc., but in any case, it is necessary to supply voltage or current, so connect a supply line for that or connect a battery. Must be installed.
In order to solve such a problem, a method of remotely supplying an energy source from the outside can be considered. As one example, an optically driven motor is disclosed (Japanese Patent Laid-Open No. 1-19).
0273). As shown in FIG. 4, this optical drive motor has a stator having a field permanent magnet and a light supply means, a magnetic pole, a photoelectric conversion element provided on the magnetic pole surface, and a winding wound around the magnetic pole. The rotor is connected to both ends of the electrodes of the photoelectric conversion element. Now, when light is incident on the photoelectric conversion element through the light supply means, the electricity generated in the photoelectric conversion element 44A flows into the winding, for example, the tip of the magnetic pole 42A becomes the N pole and the tips of the other magnetic poles become S poles. Become a pole. As a result, the magnetic pole 42A
And the field permanent magnet 51A, and the magnetic pole 42C and the field permanent magnet 51A.
When B is attracted, the rotor 4 of the optical drive motor rotates counterclockwise around the rotation shaft 41. When the next rotating magnetic pole is supplied with light, the same operation is repeated.

[0003]

However, the conventional method of driving a rotor using electromagnetic force cannot be made compact because windings for generating magnetic poles are required. Further, since the electromagnetic force is proportional to the volume, when the size is reduced, the force is greatly reduced as compared with, for example, the method using the electrostatic force. An object of the present invention is to provide an optical drive actuator that is small in size and has a small reduction in thrust due to size reduction.

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, there is provided a drive unit in which at least six strip-shaped projections having a width b are arranged on one side surface of a rectangular plate-shaped photoelectric conversion element at a pitch λ, and the strip-shaped projections. A stator having a levitation force generating portion made of a photoelectric conversion element that is coupled to both ends in the longitudinal direction via an insulator,
Opposite the drive part of the stator, strip-shaped projections having the same width as the projections of the stator are provided on one side surface of the rectangular plate-shaped photoelectric conversion element at a pitch λ, and only the last pitch is nλ + λ / 3.
(N is a positive integer), and at least two unit driving units arranged in series are coupled through an insulator, and both ends of the strip-shaped protrusion in the longitudinal direction are opposed to the levitation force generating unit of the stator. The structure is provided with a slider in which a levitation force generating portion formed of a photoelectric conversion element is coupled via an insulator, and means for supplying light to the stator, the drive portion of the slider, and the levitation force generating portion.

[0005]

[Function] When the light receiving portion of the levitation force generating portion is irradiated with light, electric charge is excited on the protrusion of the driving portion or the surface of the levitation force generating portion,
Coulomb force works between charges. Since charges having the same sign are excited in the levitation part, the slider and the stator repel each other in the levitation part and float. Next, when the slider drive unit is irradiated with light, electric charges of different signs are excited in the protrusions, and the protrusions attract each other and move by the amount of deviation between the slider and the stator protrusion. Since the Coulomb force acting between charges is used in this way, a compact microactuator that does not require windings or iron cores and has a small reduction in thrust becomes possible.

[0006]

Embodiments of the present invention will be described in detail with reference to the drawings. Figure 1
FIG. 3 is a model diagram for explaining a photoelectric effect used in the present invention. First, in (a), when the surface of the photoelectric conversion element (semiconductor) is irradiated with intense light, holes and electrons are excited on the surface. At this time, since a carrier density difference occurs between the irradiated surface and the inside of the crystal, holes and electrons move to the opposite surface as shown in (b). Generally, electron mobility is higher than hole mobility, so that electrons arrive at the opposite surface first. as a result,
As shown in (c), the surface exposed to light is positively charged and the opposite surface is negatively charged, so electromotive force is generated. FIG. 2 is a model diagram of the light-driven linear actuator according to the present invention, in which the facing surface is open. In the figure, the stator 1 is
It is composed of a floating part 2 and a driving part 3, and 2 and 3 are electrically insulated by an insulator 5. On the surface of the drive unit 3, strip-shaped projections 4 having a minute width are arranged at a pitch λ by fine processing or the like. The slider 6 facing the stator 1 is composed of a levitation force generator 7 and a drive unit 8 and is electrically insulated by an insulator 9. The drive unit 8 is composed of unit drive units 8a, 8b, and 8c with an insulator 10 interposed therebetween. On the surfaces of the unit drive parts 8a, 8b, 8c, three strip-shaped projections 11 similar to the projections 4 of the stator drive part are arranged at a pitch λ by three, respectively, by fine processing or the like. However, 8a,
The final pitch of the protrusions 8b and 8c is 1 + 1 / 3λ. The last pitch of the unit driving part is generally nλ + λ
/ 3 (n is a positive integer of 1 or more). Next, the driving principle will be described with reference to FIG. FIG. 3 is a sectional view taken along line AA of FIG. Now, when light is applied to the back surface of the levitation force generation portion 2 of the stator 1 and the back surface of the levitation force generation portion 7 of the slider 6 by the light supply means 12 and 13, the levitation force generation portion 2 of the stator and the levitation force generation portion of the slider are irradiated. Negative charges are excited on the facing surface of 7. As a result, a repulsive force is generated and the slider 6 floats. Next, when light is applied to the back surface of the unit driving portion 8a of the slider by the light supply means 14, negative charges are concentrated on the surface of the protrusion of 8a. At that time, negative charges are attracted to the surfaces of the opposing stator projections, and positive charges concentrate. Therefore, the surface of the protrusion 11 of the unit driving portion 8a of the slider and the surface of the protrusion 4 of the stator are attracted and aligned by the Coulomb force (FIG. 3A). Next, after stopping the light irradiation to the levitation force generating portion and landing the slider, the light irradiation to the levitation force generating portion is performed again to levitate the slider, and this time when the unit driving portion 8b is irradiated with light, Since the protrusion of 8b and the protrusion of the stator are aligned, the slider moves to the left by 1/3 pitch (FIG. 3 (b)). By repeating this cycle in sequence, the slider repeats the operations of floating, moving and landing. Regarding the moving direction, 8a → 8b → 8c → 8
The slider moves to the right when light is irradiated in the order of a → 8b → 8c5, and to the left when light is irradiated in the order of 8c → 8b → 8a → 8c → 8b → 8a. In addition, in order to increase the moving distance of the slider, it is sufficient to increase the light supply means to the slider driving section. In this embodiment, a semiconductor is used as the stator material. However, for example, a dielectric having a remanent polarization such as an electret can charge the surface of the slider drive unit negatively and the surface of the protrusion of the stator drive unit positively. The same effect can be obtained.

[0007]

As described above, according to the present invention, since the Coulomb force directly acting on the photoelectric conversion element is used for the driving section and the levitation force generating section, the connection line for supplying the voltage and the energy can be reduced. There is an effect that it is possible to provide a microactuator that does not require a battery to be supplied and has a small thrust reduction due to miniaturization.

[Brief description of drawings]

FIG. 1 is an explanatory model diagram of a photoelectric effect used in the present invention.

FIG. 2 is a perspective view showing a model of an optically driven linear actuator of the present invention.

FIG. 3 is a cross-sectional view showing the driving principle of the light-driven linear actuator of the present invention.

FIG. 4 is a sectional view of a conventional optical drive motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 2 Stator levitation force generation part 3 Stator drive part 4 Stator protrusion 5 Stator insulator 6 Slider 7 Slider levitation force generation part 8 Slider drive part 9 Slider drive part and light supply means insulator 10 Insulator of slider 11 Protrusion of slider 12 Light supply means of stator 13 Light supply means to levitation force generating part of slider 14-16 Light supply means to drive part of slider

Claims (1)

[Claims] 1. A drive unit in which at least six strip-shaped projections having a width b are arranged on one side surface of a rectangular plate-shaped photoelectric conversion element at a pitch λ, and an insulator is interposed at both ends in the longitudinal direction of the strip-shaped projections. Having a levitation force generating portion formed of photoelectric conversion elements coupled together, and a strip-shaped protrusion having the same width as the protrusion of the stator on one side of the rectangular plate-shaped photoelectric conversion element facing the drive portion of the stator. With a pitch λ, and only the last pitch is nλ + λ / 3 (n is a positive integer), and at least 2
Three unit driving sections arranged in series are coupled through an insulator, and a levitation force generating section composed of a photoelectric conversion element is provided at both ends of the strip-shaped projection in the longitudinal direction so as to face the levitation force generating section of the stator. An optically driven linear actuator comprising: a slider coupled via an insulator; and a means for supplying light to the stator, a drive unit and a levitation force generation unit of the slider.