JP4480510B2 - Object moving device using liquid crystal flow phenomenon - Google Patents

Description

  The present invention relates to an object moving device that moves an object arranged in a liquid crystal layer by utilizing a liquid crystal flow phenomenon. In particular, the present invention relates to an object moving apparatus that can change the moving direction of an object as well as linear motion.

Patent Documents 1 and 2 propose an apparatus for moving an object disposed in a liquid crystal layer by utilizing a liquid crystal flow phenomenon. These object moving devices have a structure in which a first electrode, a first rubbing layer, a liquid crystal layer, a second rubbing layer, and a second electrode are sequentially arranged. In Patent Document 1, the rubbing directions of the first rubbing layer and the second rubbing layer are adjusted in opposite directions. In Patent Document 2, the rubbing directions of the first rubbing layer and the second rubbing layer are adjusted to the same direction. In this case, the liquid crystal molecules exist in a state twisted by 180 ° between the pair of electrodes.
When a voltage is applied between the pair of electrodes, the liquid crystal molecules rotate until they coincide with the electric field direction. When the voltage is turned off, the liquid crystal molecules rotate until they return to their original state. As the liquid crystal molecules rotate, liquid crystal flows in the liquid crystal layer (also called backflow). In general, it is said that the liquid crystal flows in a direction opposite to the rubbing direction. If the rubbing directions of the first rubbing layer and the second rubbing layer are adjusted in the opposite directions, the liquid crystal flow in the vicinity of the first rubbing layer and the liquid crystal flow in the vicinity of the second rubbing layer are reversed.
In the technique of Patent Document 1, a rectangular wave alternating voltage is applied between a pair of electrodes. At that time, the state in which the positive pulse voltage is higher and lower than the voltage (absolute value) of the negative pulse is switched. Along with this switching, the object arranged in the liquid crystal layer is switched between a state located in the vicinity of the first rubbing layer and a state located in the vicinity of the second rubbing layer.
In the technique of Patent Document 1, an object arranged in the liquid crystal layer can be moved in the rubbing direction. The object can be reciprocated by switching the magnitude relationship between the positive pulse voltage and the negative pulse voltage (absolute value).
Japanese Patent Laid-Open No. 2001-13895 (see FIG. 7 of that publication) Japanese Patent Laid-Open No. 2003-113814 (see FIGS. 1 and 2 of the publication)

In the object moving apparatus, the moving direction of the object is limited to one dimension. Although it is not limited to one direction, an object can be reciprocated, but it is still limited to one dimension. If the direction in which the object can be moved is the X direction, the object cannot be moved in the Y direction that intersects the X direction.
Therefore, in the present invention, an object moving apparatus capable of moving an object in two dimensions is realized. An object moving device capable of moving an object in the X and Y directions that intersect (typically orthogonal) with each other is realized.

The object moving device of the present invention has a structure in which a first electrode, a first rubbing layer, a liquid crystal layer, a second rubbing layer, and a second electrode are sequentially arranged. The object moving device of the present invention is adjusted so that the rubbing directions of the first rubbing layer and the second rubbing layer intersect each other, and an object that is movably arranged in the liquid crystal layer is used as the first rubbing layer. It is characterized by comprising a plane direction moving means for moving between a position approaching and a position approaching the second rubbing layer.
The perpendicular movement means can employ any means that can move the object between a position approaching the first rubbing layer and a position approaching the second rubbing layer. Any means for moving the object in the direction perpendicular to the surface by applying an electrostatic force, a magnetic force, a laser trapping force, a force by sound waves, or the like can be employed. As will be described later, when a connecting member that moves integrally with the object and extends from the side surface of the liquid crystal layer to the outside of the liquid crystal layer is provided, means for moving the object in a direction perpendicular to the surface by applying a force to the connecting member Can also be configured.

According to the object moving device described above, a liquid crystal flow phenomenon facing the rubbing direction of the first rubbing layer (hereinafter referred to as the first direction) is obtained at a position close to the first rubbing layer, and at a position close to the second rubbing layer. A liquid crystal flow phenomenon that faces the rubbing direction of the second rubbing layer (hereinafter referred to as the second direction) is obtained. The first direction and the second direction are not parallel but intersect. In addition, a perpendicular direction moving means that can move the object between a position approaching the first rubbing layer and a position approaching the second rubbing layer is provided. When both are used in combination, the object can be moved in the first direction and the second direction, and the object can be moved two-dimensionally. That is, when the object is placed near the first rubbing layer by the plane direction moving means and an electric field is applied between the first electrode and the second electrode in this state, the object moves in the first direction. If the object is placed at a position approaching the second rubbing layer by the plane direction moving means and an electric field is applied between the first electrode and the second electrode in this state, the object moves in the second direction. When both are used in combination, the object can be moved two-dimensionally.
If the movement of the object is described accurately, the movement in the first direction, the movement in the second direction, and the movement in the perpendicular direction are combined, but the movement in the perpendicular direction is very small. Yes, since the movement direction is switched between the first direction and the second direction, it can be said that the movement is substantially two-dimensional.

The first rubbing layer and the second rubbing layer are not parallel to each other and the second rubbing direction is not parallel, and two-dimensional movement can be realized as long as they intersect, but the first rubbing direction and the second rubbing layer are It is preferable that they are orthogonal.
An object moving device incorporating a rectangular coordinate system can be realized.

As described above, magnetism, laser, sound wave, or the like can be used as the perpendicular direction moving means, but it can also be constituted by means for switching the polarity of the voltage applied between the first electrode and the second electrode. .
A normal object is naturally charged, and can move toward the first rubbing layer or move toward the second rubbing layer by switching the polarity of the voltage applied between the first electrode and the second electrode. To do. Utilizing this phenomenon, a plane direction moving means can be realized.
By using the electrodes and voltage necessary to move the object two-dimensionally, a plane direction moving means can be realized, and the apparatus configuration can be simplified.

The minute object placed in the liquid crystal may be a point-like minute object, for example. For example, if it is incorporated into a transmissive projector, a projection image in which the shadow position of the object can be controlled two-dimensionally can be realized.
In order to increase the moving force applied to the object, it is preferable to use a plate-like object on which a mesh is formed.
In this case, the contact area between the object and the liquid crystal increases, and the force applied to the object by the liquid crystal flow increases. An object can be moved with a strong force.

When the distance between the first rubbing layer and the second rubbing layer is very small, that is, when the liquid crystal layer is thin, the liquid crystal layer is confined to the distance between the first rubbing layer and the second rubbing layer by surface tension, and there is no side wall. It does not flow outside that interval. By utilizing this property, it is possible to transmit the movement of an object within the interval outside the interval.
For this purpose, a connecting member that extends outside the liquid crystal layer from the side surface of the liquid crystal layer that is prevented from flowing out by the first rubbing layer and the second rubbing layer is used. The connecting member only needs to move integrally with the object, and a part of the member may extend outside the interval, or the connecting member extending outside the interval and the object may be fixed.
The object moving apparatus of the above aspect can be used as an actuator that takes out the moving force of an object to the outside of the apparatus and drives other objects. An extremely flat two-dimensional actuator can be realized.

The structure in which the driving force is taken out from the device using the connecting member extending from the side surface of the liquid crystal layer to the outside of the device is suitable for stacking, and the connecting member extending outside the liquid crystal layer is stacked by stacking. Structure is obtained. In this case, it is preferable to integrate the connecting member that is extended and laminated outside the liquid crystal layer outside the liquid crystal.
According to the above, the driving force can be increased by increasing the number of stacked layers.

It is also possible to move the object in two dimensions by polar coordinates. In this case, the rubbing direction of the first rubbing layer is radial, and the rubbing direction of the second rubbing layer is concentric.
In the above moving device, the object can be moved in the radial direction by moving the object closer to the first rubbing layer, and the object can be moved in the circumferential direction by moving closer to the second rubbing layer. The object can be moved in two dimensions by polar coordinates.

When moving an object two-dimensionally, the surface is not limited to a flat surface, and may be a cylindrical surface. It may be necessary to move the object in two dimensions in the circumferential direction and the axial direction within the cylindrical surface. The above requirement can be realized by an object moving apparatus that satisfies the following conditions.
The first electrode has a cylindrical inner surface and is divided in the circumferential direction.
The first rubbing layer is disposed along the inner surface of the first electrode.
The second electrode has a cylindrical outer surface, is divided in the circumferential direction, and is arranged concentrically with the first electrode.
The second rubbing layer is disposed along the outer surface of the second electrode.
One of the rubbing directions of the first rubbing layer and the second rubbing layer is the circumferential direction, and the other is the axial direction.
The object preferably has an elliptical shape having a major axis substantially equal to the diameter of the first rubbing layer and a minor axis substantially equal to the diameter of the second rubbing layer. Alternatively, it may be formed of a soft material that can be deformed into the elliptical shape when a voltage is selectively applied to each of the divided electrodes of the first electrode and the second electrode. In the above moving device, the object approaches the first rubbing layer at the long diameter portion and approaches the second rubbing layer at the short diameter portion.
First, it is assumed that the first rubbing direction is the circumferential direction and the second rubbing direction is the axial direction. In this case, when a voltage is applied to the divided electrode corresponding to the long diameter portion of the object, the object moves and rotates in the circumferential direction. The object can be kept rotating by switching the divided electrodes to which the voltage is applied following the rotation of the object. When a voltage is applied to the divided electrodes corresponding to the short axis portion of the object, the object moves in the axial direction. When used in combination, it is possible to realize spiral movement in which circumferential rotation and axial movement are combined.
When the first rubbing direction is the axial direction and the second rubbing direction is the circumferential direction, the object moves in the axial direction when a voltage is applied to the divided electrode corresponding to the long diameter portion of the object. When a voltage is applied to the divided electrodes corresponding to the minor axis portion of the object, the object moves and rotates in the circumferential direction. The object can be kept rotating by switching the divided electrodes to which the voltage is applied following the rotation of the object. When used in combination, it is possible to realize spiral movement in which circumferential rotation and axial movement are combined.

Preferably, voltage applying means for applying a rectangular wave voltage is provided between the first electrode and the second electrode, and control means for controlling the duty ratio of the rectangular wave voltage is provided.
By adjusting the duty ratio, the liquid crystal flow speed can be increased or decreased, and the positive / negative of the flow direction can be reversed. With the former, it is possible to realize an object moving apparatus in which the moving speed of the object is variable. By the latter, it is possible to realize an object moving device that can move an object in an arbitrary direction spreading radially. Since the first moving direction can be moved in both positive and negative directions, and the second moving direction intersecting with the first moving direction can be moved in both positive and negative directions, it is possible to move the object in any direction out of the radial spread. .

  According to the present invention, an extremely flat object moving device capable of moving an object in two dimensions can be realized.

First, the main features of the embodiment are listed.
(First Form) The object moving device preferably further includes means for storing data relating to the direction and speed of liquid crystal flow when the polarity, duty ratio, voltage intensity, and frequency of the rectangular wave voltage are changed.
(2nd form) When the user of an object moving apparatus inputs the desired moving direction and moving speed, it has the means to select the polarity of the rectangular wave voltage, duty ratio, voltage intensity, and frequency which implement | achieve it.
(Third embodiment) When a user of an object moving device designates a position after the object has been moved, a rectangle that is necessary for determining the moving path with reference to the current position and moving the object along the path. Means are provided for calculating changes over time in the polarity, duty ratio, voltage intensity, and frequency of the wave voltage.
(Fourth Mode) At least the first electrode and the first rubbing layer are transparent, and a moving object can be observed from the outside.
(5th form) The 1st electrode, the 1st rubbing layer, the 2nd rubbing layer, and the 2nd electrode are transparent, and can project the shadow of the moving object outside.
(Sixth Mode) No opening is formed in the first electrode, the first rubbing layer, the second rubbing layer, and the second electrode. Nevertheless, the movement of the object arranged in the liquid crystal layer is taken out to the outside.
(7th form) The object arrange | positioned in a liquid-crystal layer is a film, and the film protrudes out of the space | interval from the side surface of the liquid-crystal layer confined between the 1st rubbing layer and the 2nd rubbing layer. The film moves in two dimensions in the plane.

Embodiments will be described in detail below with reference to the drawings.
First Embodiment FIG. 1 schematically shows a cross-sectional view of a main part of an object moving device 10.
The object moving device 10 includes a transparent lower glass substrate 12, a lower electrode 22 (an example of a first electrode), a lower rubbing layer 32 (an example of a first rubbing layer), and a nematic liquid crystal layer 42 (a liquid crystal). An example of the layer), an upper rubbing layer 34 (an example of the second rubbing layer), an upper electrode 24 (an example of the second electrode), and the transparent upper glass substrate 14 are sequentially laminated. The lower electrode 22 and the upper electrode 24 are formed by applying ITO (Indium Tin Oxide) to the inner surfaces of a pair of transparent glass substrates (12, 14). The distance between the pair of glass substrates (12, 14) is 20 μm, and both extend in parallel. When the pair of glass substrates (12, 14) and the pair of electrodes (22, 24) are viewed in plan, the shape thereof is formed in a rectangular shape spreading in a plane. In order to maintain a constant distance between the pair of glass substrates (12, 14), a spacer (not shown) may be interposed at a predetermined interval.
As a material of the nematic liquid crystal 42, 5CB (4-ciano-4'-n-pentylbiphenil) is used. Polyvinyl alcohol is used as the material for the rubbing layers (32, 34). The surface 32a of the lower rubbing layer 32 in contact with the nematic liquid crystal layer 42 and the surface 34a of the upper rubbing layer 34 in contact with the nematic liquid crystal layer 42 are rubbed. As shown in FIG. 2, the rubbing direction is processed so that the rubbing direction 32b of the surface 32a of the lower rubbing layer 32 and the rubbing direction 34b of the surface 34a of the upper rubbing layer 34 are orthogonal to each other.
As shown in FIG. 1, the object moving apparatus 10 further includes spherical polymer beads 52 (an example of an object to be moved) that are movably disposed in the nematic liquid crystal layer 42. The polymer beads 52 are negatively charged in a natural state and have a particle size of 10 μm.
A function generator 92 (an example of voltage application means) is connected to the pair of electrodes (22, 24). The function generator 92 applies a rectangular wave voltage between the pair of electrodes (22, 24). The function generator 92 receives an electrical signal from the CPU 94 (an example of a control unit). The CPU 94 may be incorporated as a part of the function generator 92. The CPU 94 includes a first memory 96 that stores the rubbing direction of the pair of rubbing layers (32, 34) and a second memory 98 that stores the movement destination of the polymer beads 52.

The liquid crystal molecules (5CB in this embodiment) constituting the nematic liquid crystal layer 42 are aligned along the rubbing direction (32b, 34b) of the upper and lower rubbing layer surfaces (32a, 34a). Therefore, the liquid crystal molecules constituting the nematic liquid crystal layer 42 are present in a state twisted by 90 ° between the pair of rubbing layers (32, 34) (generally, it is a state called TN type liquid crystal).
The liquid crystal molecules constituting the nematic liquid crystal layer 42 have both characteristics of fluidity as a liquid and dielectric anisotropy of crystals. Therefore, when a rectangular wave voltage is applied between the pair of electrodes (22, 24) using the function generator 92, the liquid crystal molecules of the nematic liquid crystal layer 42 are affected by the dielectric anisotropy when the rectangular wave voltage rises. It rotates until the long axis direction of the molecule coincides with the electric field direction (generally called Frederix transition). On the other hand, when the rectangular wave voltage falls, the liquid crystal molecules of the nematic liquid crystal layer 42 rotate to the original alignment state. Based on these rotations, a liquid crystal flow is generated in the nematic liquid crystal layer 42.

FIG. 3 shows the liquid crystal flow direction and flow velocity distribution in the nematic liquid crystal layer 42. Note that the origin of the Z axis coincides with the position of the contact interface between the lower rubbing layer 32 and the nematic liquid crystal layer 42, and the X axis, Y axis, and Z axis directions coincide with those in FIG. .
FIG. 3A shows the liquid crystal flow direction and the flow velocity distribution that occur when the rectangular wave voltage rises. As shown in the figure, the liquid crystal flow direction generated when the rectangular wave voltage rises occurs in the direction opposite to the rubbing direction 32 b of the lower rubbing layer 32 (−Y direction) on the lower rubbing layer 32 side. On the other hand, on the upper rubbing layer 34 side, it occurs in a direction opposite to the rubbing direction 34b of the upper rubbing layer 34 (−X direction). That is, the liquid crystal flow direction is orthogonal on the upper and lower sides between the pair of electrodes (22, 24).
FIG. 3B shows the flow direction and flow velocity distribution that occur when the rectangular wave voltage falls. As shown in the figure, the liquid crystal flow direction generated when the rectangular wave voltage falls is the direction (Y direction) that coincides with the rubbing direction 32b of the lower rubbing layer 32 on the lower rubbing layer 32 side. On the other hand, on the upper rubbing layer 34 side, the direction (X direction) coincides with the rubbing direction 34b of the upper rubbing layer 34. That is, the liquid crystal flow direction is orthogonal on the upper and lower sides between the pair of electrodes (22, 24).
The flow velocity distribution is generated in the Z-axis direction because liquid crystal molecules are constrained by rubbing treatment of the upper and lower rubbing layer surfaces (32a, 34a). This is because the rotation of the liquid crystal molecules at the time of rising or falling of the rectangular wave voltage is restricted. Therefore, the flow velocity is small in the vicinity of the rubbing layer surfaces (32a, 34a).

The movement of the polymer beads 52 is obtained as a phenomenon in which the liquid crystal flows generated when the rectangular wave voltage rises and falls as shown in FIGS. 3A and 3B are summed. If the liquid crystal flow generated at the rise of the rectangular wave voltage is dominant, the liquid crystal flow occurs in the liquid crystal flow direction. If the liquid crystal flow generated when the rectangular wave voltage falls is dominant, the liquid crystal flow occurs in the liquid crystal flow direction.
In this embodiment, by controlling the duty ratio of the rectangular wave voltage (ratio of the on-time of the rectangular wave voltage per cycle), either liquid crystal flow generated at the time of falling or falling is made dominant. Can do. Thereby, liquid crystal flow can be generated in a desired direction on the upper and lower sides of the pair of electrodes (22, 24).

  The polymer bead 52 of this embodiment is negatively charged. Accordingly, an electrostatic force acts on the polymer beads 52 based on the polarity of the applied rectangular wave voltage. For example, when a positive rectangular wave voltage is applied to the upper electrode 24, electrostatic attraction acts on the polymer beads 52, and the polymer beads 52 are attracted to the upper electrode 24 side (also the upper rubbing layer 34 side). On the other hand, when a negative rectangular wave voltage is applied to the upper electrode 24, a repulsive force acts on the polymer beads 52, and the polymer beads 52 are attracted to the lower electrode 22 side (also the lower rubbing layer 32 side). That is, the polymer beads 52 can move between a position approaching the upper rubbing layer 34 and a position approaching the lower rubbing layer 32 depending on the polarity of the applied rectangular wave voltage (moving in the Z-axis direction). Can do). As described above, the polymer beads 52 moved in the Z-axis direction move in the ± X direction (or ± Y direction) along the flow direction generated based on the duty ratio of the rectangular wave voltage. Using this phenomenon, the polymer beads 52 can be moved two-dimensionally in a plane orthogonal to the pair of electrodes (22, 24).

More specifically, the user of the object moving device 10 can move the polymer beads 52 according to the following procedure.
First, the user inputs the movement destination of the polymer beads 52 to the second memory 98 via an interface (not shown). The CPU 94 compares the rubbing processing direction stored in the first memory 96 (in this embodiment, the upper side is the X direction and the lower side is the Y direction) with the input destination and the rectangle to be applied. Determine the duty ratio, voltage, frequency, polarity, etc. of the wave voltage. Based on the determined value, the function generator 92 is operated to move the polymer beads 52 to a desired destination. Specifically, the polymer beads 52 are first drawn toward the upper rubbing layer 34 and moved to a desired position in the X direction. Next, the polymer beads 52 are drawn toward the lower rubbing layer 32 and moved to a desired position in the Y direction. Next, the polymer beads 52 are moved near the center between the electrodes (22, 24). In addition, since the polymer bead 52 uses a half size of the distance between the pair of glass substrates (12, 14), the movement in the Z-axis direction is very small. The movement in the Z-axis direction is for switching the movement in the X direction and the Y direction, and the movement in the Z-axis direction may not be substantially moved. Thereby, the polymer bead 52 can be moved two-dimensionally in a plane orthogonal to the pair of electrodes (22, 24).

Next, the relationship between the particle velocity of the polymer beads 52 and the rectangular wave voltage in the object moving device 10 of the present embodiment will be described with reference to FIGS. In addition, the particle velocity of each data measures the distance which the five polymer beads 52 move in 10 seconds, and calculates the average. Further, in this embodiment, a positive rectangular wave voltage is applied to the upper electrode 24 and only the observation result of the movement of the polymer beads 52 in the X-axis direction is shown, but the polarity of the rectangular wave voltage is changed to change the Y-axis direction. Note that similar results are obtained when the movement of the polymer beads 52 is observed.
FIG. 4 shows the relationship between the particle velocity of the polymer beads 52 and the duty ratio of the rectangular wave voltage. The frequency of the rectangular wave voltage is 100 Hz, and the voltage is 40V.
The particle velocity is maximum in the + X direction when the duty ratio is approximately 20%. When the duty ratio is greater than 20%, the particle velocity decreases gradually. This is because when the duty ratio is increased, the effect of liquid crystal flow generated at the time of rise (the liquid crystal flow direction is the −X direction as shown in FIG. 3A) increases, and conversely, the liquid crystal generated at the time of fall. This is thought to be because the flow effect (liquid crystal flow in the + X direction as shown in FIG. 3B) is reduced. When the duty ratio is approximately 55%, the particle velocity is zero. The reason why the duty ratio at which the particle velocity becomes 0 does not coincide with 50% is considered to be because the relaxation time of liquid crystal flow at the fall is longer than the relaxation time of liquid crystal flow at the rise. When the duty ratio exceeds 55%, the liquid crystal flow direction becomes the −X direction. When the duty ratio exceeded 70%, the flow became too strong and the motion of the particles became unstable.
From this result, it is understood that the liquid crystal flow direction can be easily reversed only by adjusting the duty ratio of the rectangular wave voltage.

FIG. 5 shows the relationship between the particle velocity of the polymer beads 52 and the voltage intensity of the rectangular wave voltage. The frequency of the rectangular wave voltage is 100 Hz, and the duty ratio is 20%.
Particle movement does not occur until the voltage intensity is 10V. This is because the liquid crystal molecules are constrained by the rubbing process, and therefore, the rotation of the liquid crystal molecules does not occur unless a voltage of a certain level is applied (that is, it has a threshold value). When the voltage intensity is further increased, the particle velocity becomes substantially constant at about 40 V or more. When the voltage intensity exceeds 60V, a turbulent phenomenon occurs and the particles do not move in only one direction. This reduces the apparent particle velocity.
From this result, it can be seen that the liquid crystal flow speed can be easily adjusted only by adjusting the voltage intensity of the rectangular wave voltage.

FIG. 6 shows the relationship between the particle velocity of the polymer beads 52 and the frequency of the rectangular wave voltage. The voltage intensity of the rectangular wave voltage is 40V, and the duty ratio is 20%.
The particle velocity is maximized at a frequency of approximately 800 Hz. When the frequency is 50 Hz or less, the motion of the particles is unstable. When the frequency exceeded 2 kHz, no particle migration was observed. This is considered to be because the rotation of the liquid crystal molecules cannot follow the fluctuation of the rectangular wave voltage.
From this result, it can be seen that the liquid crystal flow speed can be easily adjusted only by adjusting the frequency of the rectangular wave voltage.
The results shown in FIGS. 4 to 6 are preferably stored in, for example, a separately provided memory (the first memory 96 or the second memory 98 may be used for this function). Based on these results, the duty ratio, voltage intensity, and frequency of the applied rectangular wave voltage are preferably determined. Allows more precise movement of the polymer beads 52.
The results shown in FIGS. 4 to 6 are the results in this example, and it is natural that different results can be obtained if the shape, material, and the like of the object moving device are different.

The above embodiment may be the following modification.
The polymer beads 52 of the above embodiment use a size that is half the distance between the pair of glass substrates (12, 14). Therefore, with respect to the movement destination, the Z-axis direction may not be substantially taken into consideration. The movement destination of the xy plane is set and the movement is realized. When the polymer beads 52 are sufficiently smaller than the distance between the pair of glass substrates (12, 14), the Z axis direction may be taken into consideration as necessary for the movement destination. In this case, three-dimensional movement of the polymer beads can be obtained. In this case, it is preferable to consider the flow velocity distribution in the Z-axis direction as necessary. In consideration of the existence of a flow velocity distribution in the direction of the electrodes (22, 24), it is preferable to set the duty ratio, voltage, frequency, etc. of the applied rectangular wave voltage. The flow velocity distribution in the Z-axis direction is preferably stored in a separately provided memory (the first memory 96 or the second memory 98 may also have this function). Considering this flow velocity distribution, the polymer beads 52 can be moved more accurately.
Further, the pair of rubbing directions (32b, 34b) applied to the pair of rubbing layers (32, 34) is not limited to the case of being orthogonal to each other. Two-dimensional movement or three-dimensional movement can be realized. If necessary, a pair of rubbing directions (32b, 34b) may be crossed.

Second Embodiment FIG. 7 is a schematic perspective view of the object moving device 100. FIG. 8 is a cross-sectional view corresponding to the line VIII-VIII in FIG. In this embodiment, the use as an actuator for taking out the moving force of an object to the outside and driving another object will be described. Accordingly, since the description will focus on a mechanism for extracting the moving force of the object to the outside, it should be noted that substantially the same components as the first embodiment such as the liquid crystal layer and the rubbing layer are omitted.
In this object moving device 100, a lower electrode 122 spreading in a planar shape, a lower rubbing layer (not shown), a nematic liquid crystal layer (not shown), an upper rubbing layer (not shown), and an upper electrode 124 are arranged in this order. The rubbing direction of the lower rubbing layer and the rubbing direction of the upper rubbing layer are orthogonal to each other.
A movable film 152 (an example of a moving member) is movably arranged in a nematic liquid crystal layer (not shown). As the material of the movable film 152, polystyrene or the like is preferably used. The distance between the electrodes (122, 124) in this embodiment is very small. Therefore, there is no side wall on the side surface of the nematic liquid crystal layer interposed therebetween, but it is prevented from flowing out due to surface tension. Thereby, it is realized that the movable film 152 extends from the side surface of the nematic liquid crystal layer to the outside of the nematic liquid crystal layer. In addition, you may evaluate the part extended outside this apparatus as a connection member.
A first elastic member 162 and a second elastic member 164 are connected to the movable film 152 so as to have a positional relationship in which the extending and contracting directions are orthogonal to each other. The other end of each elastic member (162, 164) is connected to a first outer wall 172 and a second outer wall 174 provided orthogonal to the periphery of the movable film 152. As the elastic members (162, 164), for example, a polymer material such as polystyrene or a tungsten fine wire is preferably used. The directions in which the first elastic member 162 and the second elastic member 164 expand and contract are parallel to the rubbing directions applied to the rubbing layer. The elastic members (162, 164) bias the movable film 152 to the initial position.
The elastic members (162, 164) may be omitted depending on the case. The main function of the elastic members (162, 164) is to prevent the movable film 252 from sagging. Therefore, even if this elastic member (162, 164) is omitted, in principle it can be moved in both directions.

The mechanism of the phenomenon that the movable film 152 moves along the liquid crystal flow is basically the same as that of the first embodiment. That is, according to the polarity of the rectangular wave voltage applied between the pair of electrodes (122, 124), the movable film 152 is moved to a position close to the upper and lower rubbing layers and applied between the pair of electrodes (122, 124). By controlling the duty ratio, voltage, frequency, etc. of the rectangular wave voltage, the direction and speed of the liquid crystal flow generated orthogonally at the position close to the lower rubbing layer side and the position close to the upper rubbing layer side To move the movable film 152 to a desired position.
In this embodiment, the movable film 152 protrudes out of the nematic liquid crystal layer from the side surface of the nematic liquid crystal layer. When a certain kind of object is placed on or connected to the upper side surface 154 of the protruding portion, the object is driven following the movement of the movable film 152. That is, the mounted or connected object can be driven using the moving force of the movable film 152. The object moving device 100 can function as an actuator. Since the movement of the movable film 152 can be controlled at an extremely small distance, the object can also be moved at a very small distance. In this embodiment, since the movable film 152 can move in a plane orthogonal to the direction between the pair of electrodes (122, 124), an object placed or connected can also be moved in the plane. That is, it is possible to move a mounted or connected object by a minute distance in two dimensions. The first elastic member 162 and the second elastic member 164 move the movable film 152 to the initial position and return the object moving device 100 to the initial state when the applied rectangular wave voltage is turned off.

The second embodiment has the following characteristics.
Since the movable film 152 is projected outside from the side surface of the nematic liquid crystal layer, the size of the object moving device 100 in the direction between the pair of electrodes (122, 124) is hardly increased. It can be suitably used in situations where a flat structure is desired.
Further, by causing the movable film 152 to protrude outward from the side surface of the nematic liquid crystal layer, it is possible to increase the range of movement of an object placed or connected outside.
The second embodiment may be the following modification.
When the thickness of the movable film 152 is sufficiently thin compared to the distance between the pair of electrodes (122, 124), movement in three dimensions can be realized. As a result, the mounted or connected object can be moved in three dimensions.
The rubbing directions of the pair of rubbing layers may be formed in opposite directions. In this case, the movable film has a linear reciprocating motion parallel to the rubbing direction. Even in this case, the merit of flattening the object moving device can be obtained.
Moreover, as shown in FIG. 9, you may utilize the movable film 252 in which many meshes 252a were formed. In this case, since the area where the nematic liquid crystal and the movable film 252 are in contact with each other increases, the force applied to the movable film 252 by the liquid crystal flow increases, and the movable film 252 can be moved with a strong force. Therefore, even when an object to be placed or connected is heavy, the object can be driven.

Next, an example of the device for obtaining a strong driving force is shown in FIG.
The object moving device 300 shown in FIG. 10 can be evaluated as a plurality of object moving devices 100 stacked with the object moving device 100 shown in FIG. 7 as a unit. Actually, in the object moving device 300 of this embodiment, the lower electrode and the upper electrode adjacent in the stacking direction are used in common. Also in this case, it is evaluated that a plurality of object moving devices as a unit are stacked.
The object moving device 300 includes a plurality of stacked electrodes (322, 323, 324, 325, 326, 327). Nematic liquid crystal is interposed between the electrodes (322, 323, 324, 325, 326, 327). A rubbing layer is interposed between each electrode (322, 323, 324, 325, 326, 327) and each nematic liquid crystal. The rubbing directions of the rubbing layer surfaces (322a, 324b, 324a, 326b, 326a) are the same. On the other hand, the rubbing directions of the rubbing layer surfaces (323b, 323a, 325b, 325a, 327b) are the same. And the rubbing directions of both groups are orthogonal. In each nematic liquid crystal layer, movable films (352a, 352b, 352c, 352d, 352e) are movably disposed. The movable films 352a, 352b, 352c, 352d, 352e) extend from the side surface of the nematic liquid crystal layer to the outside of the nematic liquid crystal layer and are integrated outside thereof. Thereby, the integral movable film group 352 is comprised. On the upper side 354 of the protruding portion of the movable film group 352, a certain kind of object can be placed or connected. An elastic member 362 is connected to the movable film group 352, and the other end of the elastic member 362 is connected to the outer wall 372. Note that another elastic member is provided in the depth direction of the drawing (not shown), and this elastic member connects the movable film group 352 and an outer wall (not shown). The elastic member 362 biases the movable film group 352 to a predetermined initial position.
Of the electrodes (322, 323, 324, 325, 326, 327), the electrode (322, 324, 326) is connected to one terminal of the function generator 392, and the electrodes (323, 325, 327) are connected to the function generator 392. The other terminal of the generator 392 is connected. The function generator 392 receives an electrical signal from the CPU 394 (an example of a control unit). The CPU 394 may be incorporated as a part of the function generator 392. The CPU 394 includes a first memory 396 that stores the rubbing direction of each rubbing layer, and a second memory 398 that stores a moving destination of the movable film group 352.

When a positive rectangular wave voltage is applied from the function generator 392 to the electrodes (323, 325, 327), electrostatic attraction acts on the movable films (352a, 352b, 352c, 352d, 352e), and the movable films (352a, 352b, 352c, 352d, 352e) are attracted to the electrodes (323, 325, 327) (depending on the material of the movable film, repulsive force may be applied). Since the movable film group 352 is made of a soft material, the movable film group 352 is deformed and attracted to the electrodes (323, 325, 327). The rubbing layer surfaces (323b, 323a, 325b, 325a, 327b) of the electrodes (323, 325, 327) are rubbed in the same direction. Therefore, the movable films 352a, 352b, 352c, 352d, 352e) move along the rubbing direction. Since the movable films 352a, 352b, 352c, 352d, 352e) are integrally formed, the driving force of the movable film group 352 as a whole is the sum of the movable films 352a, 352b, 352c, 352d, 352e). Can be obtained as A strong driving force can be obtained. As a result, even when an object placed or connected is heavy, the object can be moved.
Further, the movable film 352 can be freely moved in two dimensions or three dimensions by controlling the polarity, duty ratio, voltage intensity, frequency, and the like of the applied rectangular wave voltage. Therefore, even when the weight of a mounted or connected object is heavy, the object can be freely moved in two dimensions or three dimensions.

Third Embodiment FIG. 11 is a schematic plan view of an object moving device 400 according to a third embodiment. The object moving device 400 is a type that obtains a driving force by using the moving force of the movable film 452 from the direction between the electrodes. This type of type may be employed in situations where the thickness between the pair of electrodes does not matter so much.
424 shown is an upper electrode, and an opening 425 is formed at substantially the center thereof. The lower electrode (not shown) is provided at a position facing the upper electrode 424. Each of the lower electrode spreads in a planar shape, the lower rubbing layer, the nematic liquid crystal, the upper rubbing layer, and the upper electrode. 424 are arranged in this order. The rubbing directions of the pair of rubbing layers are orthogonal to each other. The movable film 452 is formed in a substantially rectangular plane shape, and an elastic member (462, 463, 464, 465) is connected to each corner. The other end of this elastic member (462, 463, 464, 465) is connected to the outer wall (472, 473, 474, 475). The elastic members (462, 463, 464, 465) bias the movable film 452 to a predetermined initial position. The number of elastic members (462, 463, 464, 465) may be increased or decreased as necessary. A connection member (not shown) connected to the movable film 452 extends out of the nematic liquid crystal layer through the opening 425 of the upper electrode 452.
The mechanism of the phenomenon that the movable film 452 moves along the liquid crystal flow is basically the same as that of the first embodiment. That is, according to the polarity of the rectangular wave voltage applied between the pair of electrodes, the movable film 452 is moved to a position close to the upper and lower rubbing layers, and the duty ratio, voltage, and frequency of the rectangular wave voltage applied between the pair of electrodes. By controlling the direction and speed of the liquid crystal flow generated orthogonally at a position close to the lower rubbing layer side and a position close to the upper rubbing layer side, thereby controlling the movable film 452 as desired. Move to the position of.
Thereby, the movable film 452 can move in two dimensions. The two-dimensional movement of the movable film 452 can drive a connecting member (not shown) through the opening 425 in two dimensions.
In addition, you may comprise a connection member using the part extended out of the nematic liquid crystal layer of the movable film 452 as needed. In this case, the opening 425 is unnecessary.

(Fourth Example) The fourth example is an example in which the movable film 552 is moved in two dimensions by polar coordinates. FIG. 12 shows rubbing directions (522b and 524b) applied to a pair of rubbing layer surfaces (522a and 524a) of the object moving device 500. FIG. 13 shows a schematic plan view of the object moving device 500. In addition, a pair of electrode of a present Example is circular shape.
As shown in FIG. 12, the rubbing direction 524b of the upper rubbing layer surface 524a is processed by extending radially. The rubbing direction 522b of the lower rubbing layer surface 522a is processed to extend concentrically. The radial center and the concentric center coincide with the direction between the pair of rubbing layer surfaces (522a, 524a) (hereinafter referred to as coordinate center). Therefore, the radial rubbing direction 524b and the concentric rubbing direction 522b are in a positional relationship orthogonal to each other. That is, liquid crystal molecules of a nematic liquid crystal (not shown) between the pair of rubbing layer surfaces (522a, 524a) are present in a state twisted by 90 °.
Although not shown, the upper electrode 552 is opposed to the lower electrode, and the lower electrode, the lower rubbing layer, the nematic liquid crystal layer, the upper rubbing layer, and the upper electrode 424 each spread in a planar shape. They are arranged in this order.

  The mechanism of the phenomenon that the movable film 552 moves along the liquid crystal flow is basically the same as that of the first embodiment. The liquid crystal flow in this example is generated radially from the coordinate center along the respective rubbing directions (522b, 524b) of the pair of rubbing layer surfaces (522a, 524a) at positions close to the upper rubbing layer, and lower rubbing. It occurs in a direction rotating around the coordinate center at a position close to the layer. When the movable film 524 is moved to a position close to the upper rubbing layer using the polarity of the applied rectangular wave voltage, the movable film 552 is moved on a straight line passing through the coordinate center as shown in FIG. Can do. A linear reciprocating motion extending from the coordinate center can be obtained. Further, when the movable film 524 is moved to the lower rubbing layer side using the polarity of the applied rectangular wave voltage, the movable film 552 is moved along the peripheral direction of the upper electrode 524 as shown in FIG. Can do. A rotational movement around the coordinate center can be obtained. By combining both movements, the movable film 552 can be moved in two dimensions by polar coordinates.

Fifth Example FIG. 14 is a schematic perspective view of an object moving device 600 according to a fifth example. Note that a cylindrical movable film 652 is shown on the right side of the paper surface of FIG. 14, but in actuality, this movable film 652 is disposed between a pair of electrodes (1620, 1640) on the left side of the paper surface. I want to be. In order to clarify the figure, it is shown separately. 15 and 16 are cross-sectional views corresponding to the XV-XV line and the XVI-XVI line of FIG.
As shown in FIG. 14, the object moving apparatus 600 has an inner surface that is cylindrical, and an outer cylindrical electrode 1620 (first electrode) divided into four electrodes (622, 623, 624, 625) in the circumferential direction. Example). An unillustrated outer rubbing layer (an example of the first rubbing layer) is disposed along the inner surface of the outer cylindrical electrode 1620. Furthermore, the outer surface is cylindrical, and is provided with an inner cylindrical electrode 1640 (an example of a second electrode) divided into four electrodes (626, 627, 628, 629) along the circumferential direction. An unillustrated inner rubbing layer (an example of the second rubbing layer) is disposed along the outer surface of the inner cylindrical electrode 1640.
Each divided electrode (622 to 629) is electrically separated by an insulating material (682, 684, 686). The split electrodes provided on the outer cylindrical electrode 1620 and the inner cylindrical electrode 1640 are opposed to each other in pairs. A nematic liquid crystal layer (not shown) is interposed between the outer cylindrical electrode 1620 and the inner cylindrical electrode 1640.
The outer rubbing layer is rubbed around the circumferential direction. On the other hand, the inner rubbing layer is rubbed along the axial direction of the cylinder. Therefore, the liquid crystal molecules of the nematic liquid crystal layer (not shown) between the pair of rubbing layers are present in a state twisted by 90 °.

The mechanism of the phenomenon that the movable film 652 moves along the liquid crystal flow is basically the same as that of the first embodiment. The liquid crystal flow of this example occurs along a direction that goes around the circumferential direction at a position close to the outer rubbing layer side of the outer cylindrical electrode 1620. On the other hand, at a position close to the inner rubbing layer of the inner cylindrical electrode 1640, the liquid crystal flow occurs along the axial direction of the cylinder.
When a positive rectangular wave voltage is applied to the divided electrodes (623, 625, 626, 628), as shown in FIGS. 15 and 16, an electrostatic attractive force acts on the movable film 652, and the movable film 652 is divided into the divided electrodes (623, 625, 626, 628). Note that the movable film 652 is formed of a soft material (for example, polystyrene or the like is preferably used as a material), and thus is drawn in a deformed state. In this state, the movable film 652 has an oval cross-sectional shape whose major axis is approximately equal to the diameter of the outer rubbing layer and whose minor axis is approximately equal to the diameter of the inner rubbing layer.
As shown in FIG. 15, the movable film 652 attracted to the divided electrodes (623, 625) on the outer cylindrical electrode 1620 side receives a force from the liquid crystal flow generated along the direction of making a round of the circumferential direction, Move and rotate around the direction. In FIG. 15, it moves in the direction perpendicular to the page. On the other hand, as shown in FIG. 16, the movable film 652 attracted to the divided electrodes (626, 628) on the inner cylindrical electrode 1640 side receives force from the liquid crystal flow generated along the axial direction of the cylinder, and the cylinder It moves along the axial direction. In FIG. 16, it moves along the vertical direction of the paper. When these moving directions of the movable film 652 are combined, a spiral movement can be obtained as shown in FIG.
Note that a movable film originally processed into an elliptical shape may be used for the movable film 652. Similar effects can be obtained.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
For example, the applied voltage may be an alternating voltage. Typical examples include a rectangular wave alternating voltage, a sine wave alternating voltage, a triangular wave alternating voltage, and a sawtooth alternating voltage.
In addition, the technology described in this specification is used for, for example, a biochip, μ-TAS (micro chemical analysis system), chromatography, a micro object positioning device for a microscope, a display that displays by moving internal particles, and the like. Can be done.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

The principal part sectional drawing of the object moving apparatus of 1st Example is shown. The rubbing direction of 1st Example is shown. The liquid crystal flow direction and flow velocity distribution when the rectangular wave voltage rises (A) and falls (B) in the liquid crystal of the first embodiment are shown. The relationship between the particle velocity of 1st Example and the duty ratio of a rectangular wave voltage is shown. The relationship between the particle velocity of 1st Example and the voltage intensity of a rectangular wave voltage is shown. The relationship between the particle velocity of 1st Example and the frequency of a rectangular wave voltage is shown. The perspective view of the object moving apparatus of 2nd Example is shown. Sectional drawing of the principal part of 2nd Example is shown. The modification of a movable film is shown. 1 shows an object moving device having a laminated structure. The top view of the object moving apparatus of 3rd Example is shown. The rubbing direction of 4th Example is shown. The top view of the object moving apparatus of 4th Example is shown. The perspective view of the object moving apparatus of 5th Example is shown. Sectional drawing of the principal part of the object moving apparatus of 5th Example is shown (1). Sectional drawing of the principal part of the object moving apparatus of 5th Example is shown (2).

Explanation of symbols

12, 14: Glass substrate 22: Lower electrode 24: Upper electrode 32: Lower rubbing layer 32a: Lower rubbing surface 32b: Lower rubbing direction 34: Upper rubbing layer 34a: Upper rubbing surface 34b: Upper rubbing direction 42: Nematic liquid crystal layer 52: polymer bead 92: function generator 94: CPU
96: First memory 98: Second memory 152: Movable film

Claims (9)

The first electrode and the first rubbing layer and the liquid crystal layer and the second rubbing layer and the second electrode are arranged in this order,
The rubbing directions of the first rubbing layer and the second rubbing layer are adjusted to cross each other,
An object moving device comprising a plane direction moving means for moving an object arranged in a liquid crystal layer so as to be movable between a position approaching the first rubbing layer and a position approaching the second rubbing layer.   2. The object moving device according to claim 1, wherein the rubbing directions of the first rubbing layer and the second rubbing layer are orthogonal to each other.   The perpendicular direction moving means moves the object between a position approaching the first rubbing layer and a position approaching the second rubbing layer by switching the polarity of the voltage applied between the first electrode and the second electrode. The object moving device according to claim 1 or 2, wherein   The object moving apparatus according to claim 1, wherein the object has a plate shape in which a mesh is formed.   The apparatus further comprises a connecting member that moves integrally with the object and extends out of the liquid crystal layer from a side surface of the liquid crystal layer that is prevented from flowing out by the first rubbing layer and the second rubbing layer. The object moving device according to any one of 4.   6. A plurality of object moving devices according to claim 5, wherein the connecting members extending from the respective liquid crystal layers of the object moving device as a unit are integrated outside the liquid crystal layer. apparatus.   The object moving device according to claim 1, wherein the rubbing direction of the first rubbing layer is radial, and the rubbing direction of the second rubbing layer is concentric. The first electrode has a cylindrical inner surface and is divided in the circumferential direction.
The first rubbing layer is disposed along the inner surface of the first electrode,
The second electrode has a cylindrical outer surface, is divided in the circumferential direction, and is arranged concentrically with the first electrode.
The second rubbing layer is disposed along the outer surface of the second electrode,
2. The object moving device according to claim 1, wherein one of the rubbing directions of the first rubbing layer and the second rubbing layer is a circumferential direction and the other is an axial direction. A voltage applying means for applying a rectangular wave voltage between the first electrode and the second electrode;
9. The object moving device according to claim 1, wherein the voltage applying means includes control means for controlling a duty ratio of the rectangular wave voltage.

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