JP5126746B2 - Multipolar LCD motor - Google Patents

Description

The present invention relates to a multipolar liquid crystal motor. A liquid crystal refers to a state that has fluidity but is optically anisotropic, exhibits birefringence, has crystal-like properties, or exhibits such a state. When an electric field or magnetic field is applied to the liquid crystal, all liquid crystal molecules rotate around the center of gravity, and the axial direction is oriented at an angle unique to the liquid crystal with respect to the direction of the electric field or magnetic field.
The present invention relates to a multipolar liquid crystal motor utilizing the properties of the liquid crystal.

Conventionally, liquid crystals have been used in information display devices such as liquid crystal displays because their optical properties change as liquid crystal molecules are aligned.
The viscosity of the liquid crystal changes when the orientation direction of the liquid crystal molecules is changed by applying an electric field or a magnetic field. That is, since the liquid crystal also has a property as an electrorheological fluid, bearings, dampers, and the like using this property have been developed.

On the other hand, it is known that liquid crystal flow occurs when liquid crystal molecules are aligned, and a technique for industrially utilizing such liquid crystal flow has also been developed (Patent Document 1).
Patent Document 1 discloses an object moving mechanism that includes an outer member having a hollow space and an inner shaft rotatably disposed in the outer member, and that accommodates liquid crystal therebetween. In this object moving mechanism, liquid crystal molecule rotating means for rotating the liquid crystal molecules by applying an electric field from the radial direction of the inner axis is provided, and a pair of alignment films that restrict the rotation direction of the liquid crystal molecules are provided on the inner surface and the inner side of the outer member. It is provided on the outer surface of the shaft.
In this object movement mechanism, the liquid crystal molecules are constrained to rotate only in the plane intersecting the axial direction of the inner axis by the pair of alignment films, so if the liquid crystal molecules are rotated by the liquid crystal molecule rotating means, Liquid crystal flow is generated along the circumferential direction of the inner shaft. Then, if the outer member is fixed, the inner shaft can be rotated, so that the rotational force can be extracted from the inner shaft.

  By the way, although the technique of the said patent document 1 is an effective technique at the point which can generate | occur | produce industrially available rotational force from a liquid-crystal flow, it is a pair of alignment film on the inner surface of an outer member, and the outer surface of an inner side shaft. Must be provided. For this reason, since the manufacture becomes difficult when the object moving mechanism is downsized, development of a mechanism having a structure that is easier to manufacture is desired.

Japanese Patent No. 3586734

  In view of such circumstances, an object of the present invention is to provide a multipolar liquid crystal motor that can be easily manufactured even if it is downsized and that can efficiently generate a rotational force.

The multipolar liquid crystal motor of the first invention is a motor operated by liquid crystal flow caused by a velocity gradient generated around the liquid crystal molecules as the liquid crystal molecules rotate, and includes a hollow cylindrical member, A shaft-shaped member disposed in a hollow space of the tubular member, a liquid crystal disposed between an outer surface of the shaft-shaped member and an inner surface of the tubular member, and liquid crystal molecules of the liquid crystal It comprises liquid crystal molecule rotating means for applying an electric field or a magnetic field to rotate the liquid crystal molecules of the liquid crystal in a plane intersecting the axial direction of the shaft-shaped member, and the shaft-shaped member can rotate around its central axis. The liquid crystal molecule rotating means is arranged in a hollow space of the cylindrical member, and the liquid crystal molecule rotating means generates a plurality of rotations that generate an electric field or a magnetic field along a direction intersecting the axial direction of the axial member. A plurality of rotating means for generating an electric field generated or Direction of the magnetic field, characterized in that it is arranged so as to intersect with each other.
A multipolar liquid crystal motor according to a second invention is characterized in that, in the first invention, the multipolar liquid crystal motor comprises control means for sequentially switching the rotation means for generating an electric field or a magnetic field so that the liquid crystal molecules rotate in the same direction. To do.
According to a third aspect of the present invention, in the first or second aspect, the plurality of rotating means are arranged side by side along the circumferential direction with respect to a central axis of the shaft-shaped member. The control means sequentially switches the rotating means for generating an electric field or a magnetic field clockwise or counterclockwise.

According to the first invention, the liquid crystal molecules can be swung around the center of gravity by controlling the rotating means for generating an electric field or a magnetic field, so that the liquid crystal molecules are swung around the shaft member. Liquid crystal flow can be generated. Then, since the shaft-like member can be rotated along the liquid crystal flow direction, the flow rate and flow direction of the generated liquid crystal flow can be controlled by controlling the timing and time at which each rotating means generates an electric field or magnetic field. And the rotational speed and direction of the shaft-like member can be controlled. Moreover, since the rotation of the liquid crystal molecules can be controlled without providing an alignment film that restricts the rotation of the liquid crystal molecules, the manufacture is facilitated even if the size is reduced. And since the alignment film which restrains a liquid crystal molecule is not provided, since the flow volume of the liquid crystal flow generate | occur | produced when a liquid crystal molecule rotates can be enlarged, a shaft-shaped member can be rotated efficiently.
According to the second aspect of the invention, since the operation of each rotating means is controlled so that the liquid crystal molecules rotate in the same direction by the control means, it is possible to generate a liquid crystal flow that flows in the same direction. Then, if the timing and time at which each rotating means generates an electric field or magnetic field is controlled by the control means, it is possible to generate a continuous liquid crystal flow in the same direction, so that the shaft-like member is continuously rotated in the same direction. be able to.
According to the third aspect of the present invention, if the rotating means for generating an electric field or a magnetic field is sequentially switched clockwise or counterclockwise, it is possible to generate a continuous liquid crystal flow clockwise or counterclockwise. It can be continuously rotated clockwise or counterclockwise.

It is a schematic explanatory drawing of the multipolar type liquid crystal motor 10 of this embodiment in the state in which the electric field ef is not applied with respect to liquid crystal LC. It is the figure which showed the arrangement | sequence of the liquid crystal molecule m when the electric field eaf is generated between the electrodes Ea and Ea. It is the figure which showed the arrangement | sequence of the liquid crystal molecule m when the electric field ebf was generated between the electrodes Eb and Eb from the state of FIG. It is the figure which showed the arrangement | sequence of the liquid crystal molecule m when the electric field ecf is generated between the electrodes Ec and Ec from the state of FIG. FIG. 5 is a diagram illustrating an arrangement of liquid crystal molecules m when an electric field edf is generated between electrodes Ed and Ed from the state of FIG. 4. It is the figure which showed the arrangement | sequence of the liquid crystal molecule m when the electric field eaf is generated between the electrodes Ea and Ea from the state of FIG. It is a schematic explanatory drawing of the state which rotates the shaft-shaped member 12 of the multipolar type liquid crystal motor 10 of this embodiment forward and backward. It is the figure which showed the condition of the liquid crystal flow which generate | occur | produces between the cylindrical member 11 and the shaft-shaped member 12, (A) is the figure shown in the condition where the clockwise flow generate | occur | produced, (B) is a counterclockwise. It is the figure which showed the condition where the surrounding flow generate | occur | produced. It is explanatory drawing of a motion of the liquid crystal molecule m when an electric field is applied. It is explanatory drawing of a motion of the liquid crystal molecule m when an electric field is applied to the liquid crystal LC mounted on the parallel plate P. It is a schematic explanatory drawing of the multipolar-type liquid crystal motor 10 of this embodiment in the state in which the electric field ef is applied from several electrode pairs E with respect to liquid crystal LC. It is a schematic explanatory drawing of the multipolar liquid crystal motor 10 from which the arrangement | positioning of the electrode pair E differs. It is a schematic explanatory drawing of the multipolar liquid crystal motor 10 from which the arrangement | positioning of the electrode pair E differs. It is a schematic explanatory drawing of the multipolar liquid crystal motor 10 from which the arrangement | positioning of the electrode pair E differs.

Next, an embodiment of the present invention will be described with reference to the drawings.
First, before describing the multipolar liquid crystal motor of the present invention, the principle of liquid crystal flow when an electric field or magnetic field is applied to the liquid crystal will be described.
In addition, when an electric field or a magnetic field is applied to the liquid crystal, the axial direction of the liquid crystal molecules is aligned at an angle unique to the liquid crystal with respect to the direction of the electric field or the magnetic field. Only the liquid crystal in which the axial direction of the liquid crystal molecules is parallel to the direction of the electric field or magnetic field will be described.
In addition, since the liquid crystal molecules are aligned when an electric field or a magnetic field is applied, only the case where an electric field is applied will be described below.

FIG. 9 is an explanatory diagram of the movement of the liquid crystal molecules m when an electric field is applied. FIG. 10 is an explanatory view of the movement of the liquid crystal molecules m when an electric field is applied to the liquid crystal LC placed on the fixed member P (hereinafter referred to as the fixed member P).
In FIG. 10, when the liquid crystal molecule m rotates around its center of gravity, the liquid crystal molecule m moves (translates) along the surface of the fixed member P. It has been described in a state that does not.

As shown in FIG. 9, when an electric field ef is applied to the liquid crystal LC so as to intersect the axial direction of the liquid crystal molecule m, the liquid crystal molecule m has a direction in which the rotation angle decreases (FIG. 9A).
(In the direction of the arrow) until the axis direction coincides with the electric field ef (FIG. 9B). Then, since a velocity gradient is generated around each liquid crystal molecule m, liquid crystal flow is generated (FIG. 9C).
).

Here, as shown in FIG. 10, in the liquid crystal LC in contact with the fixing member P, the liquid crystal molecules m located in the vicinity of the wall surface of the fixing member P are intermolecular interactions generated between the wall surface and the liquid crystal molecules m. As a result, the rotation and translation around the center of gravity of the liquid crystal molecules m located away from the wall surface are slightly limited. Then, even if the electric field ef is applied, the liquid crystal molecules m located in the vicinity of the fixing member P cannot rotate until the axial direction thereof coincides with the electric field ef, and the rotation amount becomes small, and the rotation of the liquid crystal molecules m. , The velocity gradient formed around it is also reduced (FIGS. 10B and 10C).
).
Therefore, in the liquid crystal LC arranged so as to be in contact with the fixing member P, a flow of liquid crystal molecules m having a velocity distribution as shown in FIG. 10D is generated in the liquid crystal LC when the electric field ef is applied. To do.

Now, the multipolar liquid crystal motor of the present invention will be described.
FIG. 1 is a schematic explanatory diagram of a multipolar liquid crystal motor 10 of the present embodiment in a state where an electric field ef is not applied to the liquid crystal LC. In FIG. 1, the code | symbol 11 has shown the cylindrical member. The cylindrical member 11 is provided with a hollow space 11h formed in a substantially circular cross section. And the alignment film is not provided in the inner surface of this cylindrical member 11, and the rubbing-less process is not performed. Alternatively, a weak anchoring process is performed on the inner surface of the cylindrical member 11. That is, the inner surface of the cylindrical member 11 is processed so that a liquid crystal LC (described later) is weakly anchored or not anchored at all.
In the following, the weak anchoring state including the state in which the liquid crystal LC is weakly anchored and the state in which the liquid crystal LC is not anchored at all (the state in which the alignment film is not provided and the rubbing-less process is not performed) Okay, processing to achieve this weak anchoring state is called weak anchoring processing.
Note that the anchoring process described in Japanese Patent No. 4053530 “Zero-plane anchoring liquid crystal alignment method and liquid crystal device thereof” is applied to the weak anchoring process, that is, horizontal or oblique alignment is forced, but in-plane (horizontal It also includes an anchoring process that does not force alignment in the direction (within the horizontal plane in which the axis of the molecule is located).

  1 illustrates the case where the cylindrical member 11 and the space 11h are concentric and have a circular cross section, the cross section of the cylindrical member 11 and the space 11h is not necessarily circular, but may be an ellipse, a rectangle, or the like. However, it does not have to be concentric.

As shown in FIG. 1, a shaft-like member 12 is disposed in the space 11 h of the tubular member 11. The shaft-like member 12 is disposed such that the center axis 12 a coincides with the center axis 11 a of the space 11 h of the cylindrical member 11. In addition, the shaft-like member 12 is supported so as to be rotatable around the central axis 11 a with respect to the tubular member 11.
In addition, the outer surface of the shaft-like member 12 is subjected to a weak anchoring process similarly to the inner surface of the tubular member 11.

  The shaft-shaped member 12 is not limited to a solid shaft as shown in FIG. 1 and may be a tubular member, and the shape is not particularly limited. 1 illustrates the case where the shaft-like member 12 has a circular cross section, the cross-section of the shaft-like member 12 does not necessarily have to be a circle, and may be an ellipse or a quadrangle.

A liquid crystal LC is accommodated between the outer surface of the shaft-shaped member 12 and the inner surface of the cylindrical member 11 in the space 11h. The liquid crystal LC is, for example, a nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal, a discotic liquid crystal, or the like, but is not particularly limited as long as the liquid crystal molecules rotate when an electric field is applied.
Needless to say, the liquid crystal molecules may rotate when a magnetic field is applied.

A plurality of electrodes E are provided on the outer surface of the cylindrical member 11. The plurality of electrodes E are arranged along the outer surface of the cylindrical member 11 around the central axis of the space 11 h of the cylindrical member 11. In addition, the plurality of electrodes E are arranged so as to be arranged at equal angular intervals around the central axis of the space 11h of the cylindrical member 11, so that the angle θ formed by the adjacent electrodes E is an acute angle. Has been. In FIG. 1, a plurality of electrodes E are arranged so as to be arranged at intervals of 45 degrees.
The plurality of electrodes E are a plurality of rotating means referred to in the claims. The angle θ between the electrodes E means an angle between lines connecting the intermediate point of each electrode E in the direction along the outer surface of the cylindrical member 11 and the central axis 11a of the cylindrical member 11. Yes.

The plurality of electrodes E are all electrically connected to the control means 20. The control means 20 controls the voltage applied to the plurality of electrodes E to control the direction, intensity, and timing of the electric field generated in the space 11 h of the cylindrical member 11.
Specifically, the control means 20 applies a voltage to a pair of electrodes E, E (for example, electrode pairs Ea, Ea) facing each other across the central axis 11a of the space 11h of the cylindrical member 11 among the plurality of electrodes E. Is applied to generate an electric field ef between the electrode pair E and E. In addition, when the control unit 20 generates the electric field ef between the one electrode pair E and E and then generates the electric field ef at the other electrode pair E and E, the directions of both electric fields ef intersect each other. In this way, the electrode pair E, E that generates the electric field ef is controlled.

Next, operations and effects of the multipolar liquid crystal motor 10 of the present embodiment will be described with reference to FIGS.
In the following example, the case where the movement of the cylindrical member 11 is fixed and the shaft-shaped member 12 rotates will be described. However, the movement of the shaft-shaped member 12 is fixed and the cylindrical member 11 is rotated. Also good.

FIG. 2 is a diagram showing the arrangement of liquid crystal molecules m when an electric field eaf is generated between the electrodes Ea and Ea. FIG.
FIG. 3 is a diagram showing an arrangement of liquid crystal molecules m when an electric field ebf is generated between the electrode pair Eb and Eb from the state of FIG. FIG. 4 is a diagram showing the arrangement of the liquid crystal molecules m when the electric field ecf is generated between the electrode pair Ec and Ec from the state of FIG. FIG. 5 is a diagram showing the arrangement of the liquid crystal molecules m when the electric field edf is generated between the electrode pair Ed and Ed from the state of FIG. FIG. 6 is a diagram showing the arrangement of the liquid crystal molecules m when the electric field eaf is generated between the electrode pair Ea and Ea from the state of FIG.

First, when a voltage is applied between the pair of electrodes Ea and Ea by the control device 20, the cylindrical member 11 intersects the axial direction of the space 11h of the cylindrical member 11 (the direction perpendicular to the paper surface in FIG. 1). An electric field eaf is generated along the direction. Then, all the liquid crystal molecules m of the liquid crystal LC rotate so that the axial direction thereof is parallel to the electric field eaf (FIG. 2).
In a state before the voltage is applied, the inner surface of the cylindrical member 11 and the outer surface of the shaft-shaped member 12 are subjected to weak anchoring treatment. Therefore, until the electric field eaf is applied, the liquid crystal molecules m in the cylindrical member 11 The direction is in some arbitrary direction. For this reason, the direction of liquid crystal flow generated in the cylindrical member 11 when the liquid crystal molecules m rotate cannot be specified.

As shown in FIG. 2, the electric field eaf is not applied to all the liquid crystal molecules m. For this reason, the liquid crystal molecules m rotating due to the direct influence of the electric field eaf are limited to some liquid crystal molecules m to which the electric field eaf is applied. However, since the inner surface of the cylindrical member 11 and the outer surface of the shaft-shaped member 12 are subjected to weak anchoring treatment, the liquid crystal molecules m to which the electric field eaf is not applied can be aligned in an arbitrary direction. Then, in order to maintain the spatial continuity between the liquid crystal molecules m by the long-range order effect, the liquid crystal molecules m to which the electric field eaf is not applied also face the same direction as some liquid crystal molecules m to which the electric field eaf is applied. Rotate like so. Therefore, even if the electric field eaf is applied only to the liquid crystal molecules m in a part of the liquid crystal LC in the cylindrical member 11, all the liquid crystal molecules m are oriented in the same orientation, that is, in the direction of the electric field eaf. It rotates.
Note that, when the electric field ef is applied from any electrode pair E, E, all the liquid crystal molecules m are aligned in the direction of the electric field ef for the same reason as described above.

  When all the liquid crystal molecules m of the liquid crystal LC are parallel to the electric field eaf, the application of voltage between the pair of electrodes Ea and Ea is stopped. At this time, since the inner surface of the cylindrical member 11 and the outer surface of the shaft-shaped member 12 are subjected to weak anchoring, all the liquid crystal molecules are stopped when the voltage application between the pair of electrodes Ea and Ea is stopped. Since no force acts on m, all the liquid crystal molecules m are maintained in parallel with the electric field eaf.

Next, when a voltage is applied between the pair of electrodes Eb and Eb by the control device 20, an electric field ebf is generated between the pair of electrodes Eb and Eb. Then, since the electrode Eb is provided at a position rotated 45 degrees counterclockwise with respect to the electrode Ea, the direction of the electric field ebf is also a direction rotated 45 degrees counterclockwise with respect to the direction of the electric field eaf. Become. Then, the electric field ebf becomes a direction rotated 45 degrees counterclockwise with respect to the direction of all the liquid crystal molecules m when the electric field eaf is applied, so that all the liquid crystal molecules m are counterclockwise around the center of gravity. Rotate around (Fig. 3).
At this time, since the movement of the cylindrical member 11 is fixed, a surface orthogonal to the central axis 11a of the space 11h of the cylindrical member 11 between the inner surface of the cylindrical member 11 and the outer surface of the shaft member 12. In FIG. 8 (A)
The velocity distribution shown in is formed. Then, in the space 11h of the cylindrical member 11, a counterclockwise liquid crystal flow around the central axis 11a is generated.
When such a liquid crystal flow occurs, the shaft-like member 12 is supported so as to be rotatable around its central axis 11a with respect to the cylindrical member 11, so that the shaft-like member 12 is caused to rotate by counterclockwise liquid crystal flow. It is rotated counterclockwise.

  When all the liquid crystal molecules m of the liquid crystal LC are parallel to the electric field ebf, the application of voltage between the pair of electrodes Eb and Eb is stopped. Then, all the liquid crystal molecules m are maintained in parallel with the electric field ebf.

Next, when a voltage is applied between the pair of electrodes Ec and Ec by the control device 20, an electric field ecf is generated between the pair of electrodes Ec and Ec. Then, since the direction of the electric field ecf becomes a direction rotated 45 degrees counterclockwise with respect to the direction of the electric field ebf, all the liquid crystal molecules m rotate counterclockwise around the center of gravity (FIG. 4).
Also at this time, the velocity distribution shown in FIG. 8A is formed in the space 11h of the cylindrical member 11, and the liquid crystal flow around the central axis 11a of the space 11h is generated. The shaped member 12 is further rotated counterclockwise.

Further, when all the liquid crystal molecules m of the liquid crystal LC are parallel to the electric field ecf, the voltage application between the pair of electrode pairs Ec and Ec is stopped, and the control device 20 causes the voltage between the pair of electrode pairs Ed and Ed. Apply. Then, all the liquid crystal molecules m rotate counterclockwise around the center of gravity (FIG. 5), and FIG.
Is generated, and the liquid crystal flow around the central axis 11a of the space 11h of the cylindrical member 11 is generated in the counterclockwise direction. Therefore, the axial member 12 is further rotated counterclockwise.

Further, when all the liquid crystal molecules m of the liquid crystal LC are parallel to the electric field edf, the voltage application between the pair of electrode pairs Ed and Ed is stopped, and the voltage is applied between the pair of electrode pairs Ea and Ea by the controller 20. To do. Then, since the direction of the electric field edf is also a direction rotated 45 degrees counterclockwise with respect to the direction of the electric field ecf, all the liquid crystal molecules m rotate counterclockwise around the center of gravity (FIG. 6). At this time as well, the space 11h of the cylindrical member 11 is in FIG.
Is generated, and the liquid crystal flow around the central axis 11a of the space 11h is generated in the counterclockwise direction. Therefore, the shaft member 12 is further rotated counterclockwise.

If the electrode E to which the voltage is applied is sequentially changed counterclockwise by repeating the above procedure, the liquid crystal molecules m continuously rotate counterclockwise. Then, since the liquid crystal flow continuous in the counterclockwise direction can be generated in the space 11h of the cylindrical member 11, the shaft-shaped member 12 can be continuously rotated counterclockwise.
Therefore, in the multipolar liquid crystal motor 10 of this embodiment, the counterclockwise rotational force can be extracted from the shaft-like member 12.

Moreover, a continuous liquid crystal flow can be generated in the space 11h of the member 11 simply by switching the electrode pair E, E to which the voltage is applied. In other words, since the liquid crystal molecules m can be continuously rotated in the same direction simply by switching the electrode pair E, E to which the voltage is applied, an alignment film or the like that constrains the liquid crystal molecules m to rotate in a certain direction. There is no need to treat the inner surface of the cylindrical member 11 or the outer surface of the shaft-shaped member 12. Since the electrode pair E, E only needs to be provided on the outer surface of the cylindrical member 11, even if the cylindrical member 11 becomes smaller, the electrode pair E, E is relatively disposed on the cylindrical member 11. It can be done easily.
Therefore, since the multipolar liquid crystal motor 10 of this embodiment can be easily manufactured even if the cylindrical member 11 and the shaft-like member 12 become small, for example, even a very small liquid crystal motor having an outer diameter of 0.1 mm or less. It can be manufactured.
And since the alignment film which restrains the liquid crystal molecule m is not provided, the flow rate of the liquid crystal flow generated when the liquid crystal molecule m rotates can be increased, so that the shaft member 12 can be efficiently rotated.

Further, if the timing of switching the electrode pair E, E to which the voltage is applied is controlled by the control means 20, the flow rate of the liquid crystal flow can be controlled, so that the rotational speed of the shaft member 12 can be controlled.
Specifically, if the switching time from one electrode pair E, E to the adjacent electrode pair E, E (for example, the electrode pair Ea, Ea in FIG. 1 to the electrode pair Eb, Eb, etc.) is shortened, the liquid crystal molecules The liquid crystal flow generated by the rotation of m can be a more continuous flow, and the rotational speed of the shaft-like member 12 can be increased.
Conversely, if the switching time from one electrode pair E, E to another adjacent electrode pair E, E is increased, the liquid crystal flow generated by the rotation of the liquid crystal molecules m becomes an intermittent flow. The rotation speed of the member 12 can be decreased.

In the above description, the case where the electrode pair E, E to which the voltage is applied is switched from one electrode pair E, E to another adjacent electrode pair E, E has been described. It goes without saying that the electrode pair E, E to be applied may be switched by skipping or skipping two. As a result, driving in a wide speed range can be expected.
In particular, if the number of electrodes E provided on the cylindrical member 11 is increased, the degree of freedom in switching the applied electrode pair E, E increases, so that precise control can be expected.

In the above example, the case where a voltage is applied only to one electrode pair E has been described. In this case, the liquid crystal molecules m outside the electric field are aligned with the alignment of the liquid crystal molecules m positioned in the electric field. ing. For this reason, it is only the liquid crystal molecules m located in the electric field that give the rotational force to the shaft-shaped member 12, so that the rotational torque of the shaft-shaped member 12 is reduced.
Therefore, in each figure, if an electric field is formed by applying a voltage also to one electrode pair E and the electrode pair E sandwiching the electrode pair E, the liquid crystal molecules m that impart a rotational force to the shaft member 12. Therefore, the rotational torque of the shaft-like member 12 can be increased.
Specifically, as shown in FIG. 11, when a voltage is applied between the pair of electrodes Ea and Ea to form the electric field eaf, at the same time, the controller 20 causes the electrode pair Eb and the electrode Ed to be between Apply voltage. That is, a voltage is applied between the electrode pair Eb and the electrode Ed so that an electric field ebdf parallel to the electric field eaf is formed between the electrode pair Eb and the electrode Ed. Then, since an electric field parallel to the electric field eaf is formed in almost the entire cross section of the cylindrical member 11, a rotational force is generated in almost all liquid crystal molecules m in the cylindrical member 11. Therefore, since rotational force is applied to the shaft-like member 12 from almost all the liquid crystal molecules m, the rotational torque of the shaft-like member 12 can be increased.

  In FIG. 1, the number of electrodes E provided on the cylindrical member 11 with four electrode pairs Ea to Ed is not particularly limited, and only three electrode pairs E may be provided (FIG. 12), and four or more electrode pairs may be provided. Even if provided (FIG. 13).

In particular, as shown in FIGS. 13 and 14, it is more preferable to arrange a large number of small electrode pairs E on the outer peripheral surface of the cylindrical member 11 because the angle change of the electric field applied to the liquid crystal L can be finely adjusted.
Specifically, in FIGS. 13 and 14, 24 electrodes E (E1 to E24 counterclockwise) are disposed on the outer peripheral surface of the cylindrical member 11. In order to prevent the drawings from becoming complicated, only some of the electrodes are denoted by reference numerals in FIGS.
In the case of such a configuration, as shown in FIG. 13, from the state where electric fields are formed between the electrode E1 and the electrode E12 and between the electrode E24 and the electrode E13, as shown in FIG. From the state in which the electric field is formed between the electrode E12 and between the electrode E24 and the electrode E13, the electrode E that forms the electric field is changed counterclockwise. That is, as shown in FIG. 14, if the electric field is changed between the electrode E1 and the electrode E14 and between the electrode E2 and the electrode E13, the direction of the electric field changes counterclockwise. Then, the liquid crystal molecules m rotate counterclockwise so as to align along the direction of the electric field. Therefore, if the electrodes E that form the electric field are sequentially moved in the counterclockwise direction, the liquid crystal flow in the counterclockwise direction is generated with the rotation of the liquid crystal molecules m, and the shaft-like member 12 is rotated in the counterclockwise direction. Can do. And when the electrode E which forms an electric field is changed counterclockwise, the angle change of the direction of the electric field formed can be finely adjusted, so that the liquid crystal molecules m can be rotated more continuously. Then, since the generated liquid crystal flow can be made to be a more continuous flow, the rotation of the shaft-like member 12 becomes more continuous and can be smoothly rotated.
13 and 14, the case where the electric field is formed only between the two electrode pairs has been described. However, the number of electrode pairs that form the electric field is not limited, and the axial shape increases as the number of electrode pairs increases. The rotational torque of the member 12 can be increased. In other words, the rotational torque of the shaft member 12 can be finely adjusted by changing the number of electrode pairs.

In the above example, the electrodes E to which the voltage is applied are sequentially changed counterclockwise, but may be sequentially changed clockwise. In this case, since the liquid crystal molecules m continuously rotate clockwise, a continuous liquid crystal flow in the clockwise direction can be generated in the space 11h of the cylindrical member 11 (see FIG. 8B). Therefore, the shaft-like member 12 can be continuously rotated clockwise, and the clockwise rotational force can be taken out from the shaft-like member 12.
That is, in the multipolar liquid crystal motor 10 of the present embodiment, the rotation direction of the liquid crystal molecules m can be controlled simply by controlling the electrode E to which a voltage is applied. Can do.

  Further, if the electrode E to which the voltage is applied is switched as described above, the shaft-like member 12 can be continuously rotated in the same direction. However, if the electrode E to which the voltage is applied is switched as follows, The shaped member 12 can be rotated forward and backward.

  FIG. 7 is a schematic explanatory diagram of a state in which the shaft-like member 12 of the multipolar liquid crystal motor 10 of the present embodiment is rotated forward and backward. In FIG. 7, the alignment direction of a plurality of liquid crystal molecules m positioned at a predetermined angle is represented by one liquid crystal molecule m.

  First, a voltage is applied between the pair of electrodes Ea and Ea by the control device 20 in a state where the directions of the liquid crystal molecules m are different. Then, all the liquid crystal molecules m of the liquid crystal LC rotate around the center of gravity, and all the liquid crystal molecules m are in the state of facing the electric field eaf (FIG. 7B).

  Next, from the state of FIG. 7B, the control device 20 switches the electrode pair E, E to which the voltage is applied between the pair of electrodes Ea, Ea to the pair of electrodes Eb, Eb. Then, an electric field ebf is generated between the pair of electrodes Eb and Eb, all the liquid crystal molecules m rotate counterclockwise around the center of gravity, and all the liquid crystal molecules m become parallel to the electric field ebf (FIG. 7A )). At this time, in the space 11h of the cylindrical member 11, a counterclockwise liquid crystal flow centered on the central axis 11a is generated (FIG. 8A), and this counterclockwise liquid crystal flow causes an axial shape. The member 12 is rotated counterclockwise.

Further, from the state of FIG. 7A, the control device 20 switches the electrode pair E, E to which the voltage is applied from the pair of electrodes Eb, Eb to the pair of electrodes Ea, Ea. Then, since the electric field eaf is generated again between the pair of electrodes Ea and Ea, all the liquid crystal molecules m rotate clockwise around the center of gravity, and all the liquid crystal molecules m become parallel to the electric field eaf (FIG. 7 ( B)).
At this time, a clockwise liquid crystal flow around the central axis 11a of the space 11h of the cylindrical member 11 is generated between the inner surface of the cylindrical member 11 and the outer surface of the shaft-shaped member 12 (FIG. 8 ( B)), the shaft-like member 12 is rotated clockwise.

Further, from the state of FIG. 7B, the control device 20 switches the electrode pair E, E to which the voltage is applied from the pair of electrodes Ea, Ea to the pair of electrodes Ed, Ed. Then, all the liquid crystal molecules m rotate clockwise, and all the liquid crystal molecules m become parallel to the electric field edf (FIG. 7C).
Also in this case, since the liquid crystal flow around the central axis 11a of the space 11h of the cylindrical member 11 is generated between the inner surface of the cylindrical member 11 and the outer surface of the shaft-shaped member 12, the shaft The shaped member 12 is further rotated clockwise.

Then, from the state of FIG. 7C, the control device 20 switches the electrode pair E, E to which the voltage is applied from the pair of electrodes Ed, Ed to the pair of electrodes Ea, Ea again. Then, all the liquid crystal molecules m rotate counterclockwise, and all the liquid crystal molecules m become parallel to the electric field eaf (FIG. 7B).
Then, again, a liquid crystal flow counterclockwise around the central axis 11a of the space 11h of the cylindrical member 11 is generated between the inner surface of the cylindrical member 11 and the outer surface of the shaft member 12. The shaped member 12 is again rotated counterclockwise.

  If the electrode E to which the voltage is applied is changed by repeating the above procedure, the liquid crystal molecules m repeat the normal rotation and the liquid crystal flow in the counterclockwise direction is generated alternately in the space 11h of the cylindrical member 11. Therefore, the shaft-like member 12 can be rotated so as to repeat normal rotation and reversal.

  That is, in the multipolar liquid crystal motor 10 of this embodiment, the flow direction of the liquid crystal flow generated in the space 11h of the cylindrical member 11 can be controlled by controlling the order of switching the electrodes E to which the voltage is applied. The rotational direction of the shaft-like member 12 can also be controlled.

10 Multipolar liquid crystal motor 11 Tubular member 11
11h space 11
12 Shaft-shaped member 12
20 Control means E electrode LC liquid crystal m liquid crystal molecule ef electric field

Claims (3)

A motor operated by liquid crystal flow caused by a velocity gradient generated around the liquid crystal molecules as the liquid crystal molecules rotate;
A hollow cylindrical member;
A shaft-shaped member disposed in a hollow space of the cylindrical member;
Liquid crystal disposed between the outer surface of the shaft-shaped member and the inner surface of the cylindrical member;
A liquid crystal molecule rotating means for applying an electric field or a magnetic field to the liquid crystal molecules of the liquid crystal to rotate the liquid crystal molecules of the liquid crystal in a plane intersecting the axial direction of the shaft-shaped member;
The shaft-shaped member is
It is arranged in the hollow space of the cylindrical member so that it can rotate around its central axis,
The liquid crystal molecule rotating means includes:
A plurality of rotating means for generating an electric field or a magnetic field along a direction intersecting the axial direction of the shaft-shaped member;
The plurality of rotating means includes:
A multipolar liquid crystal motor, characterized in that the directions of the generated electric field or magnetic field are arranged so as to intersect each other. The liquid crystal molecule rotating means includes:
2. The multipolar liquid crystal motor according to claim 1, further comprising control means for sequentially switching the rotating means for generating an electric field or a magnetic field so that the liquid crystal molecules rotate in the same direction. The plurality of rotating means include
With respect to the central axis of the shaft-shaped member, it is arranged along the circumferential direction,
The control means includes
3. The multipolar liquid crystal motor according to claim 1, wherein the rotating means for generating an electric field or a magnetic field is sequentially switched clockwise or counterclockwise.

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