JP2006194934A - Liquid transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumed for transferring a liquid by making the liquid transferred smoothly in a liquid transfer device. <P>SOLUTION: First and second liquids 23, 24 have dielectric constants different from each other, and further they are not miscible with each other. When voltages are applied to first to third electrode plates 4, 6, 12 under a first condition, the first liquid 23, composed of water and so on, is transferred via a first liquid transfer hole 15, from the inside of a front side space 21 to the inside of a rear side space 22, and concomitant therewith, the second liquid 24, composed of silicone oil and so on, is transferred via a second liquid transfer hole 16, from the inside of the rear side space 22 to the inside of the front side space 21. When voltages are applied to the first to third electrode plates 4, 6, 12 under a second condition, the first liquid 23 is transferred via the first liquid transfer hole 15 to the inside of the front side space 21, and concurrently, the second liquid 24 is transferred via the second liquid transfer hole 16 to the inside of the rear side space 22. In this case, both liquids are smoothly transferred, because the insides of both spaces 21, 22 and both liquid transfer holes 15, 16 are filled with both liquids 23, 24. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid moving apparatus, for example, a liquid moving apparatus such as a display apparatus that performs display by moving a liquid between electrodes.

  For example, in a conventional display device that performs display by moving a liquid between electrodes, a colored liquid (dielectric material) and bubbles are sealed in a container constituting one pixel, and face each other on the outer surface on one side of the container. When a voltage is applied to the pair of first electrodes provided, the colored liquid is moved to one side in the container by the electrostatic force, and the bubbles are moved to the other side in the container. When a voltage is applied to a pair of second electrodes provided opposite to each other on the outer surface, the colored liquid is moved to the other side in the container and the bubbles are moved to one side in the container by electrostatic force In some cases, display is performed by making only one side of the container a visible pixel (see, for example, Patent Document 1).

By the way, the phenomenon between the liquid and the solid surface (the inner wall surface of the container) can be simply explained by the so-called “static wetting” theory representing the degree of wetting of the liquid onto the solid surface. That is, regarding the contact angle representing the degree of wettability, that is, hydrophilicity and water repellency, as shown in FIG. 11, the surface energy of the solid is γ _S , the interface energy between the solid and the liquid is γ _LS , and the surface energy of the liquid is γ _{When L} and the contact angle are θ, the following Young's formula (1) is established.
γ _S = γ _LS + γ _L cos θ …… (1)
The wetting (drying) of the droplets is balanced in a state where this equation is satisfied, and a steady state is reached.

  However, when a liquid is moved on a non-ideal solid surface (the inner wall surface of the container), an adhesion force (frictional force) that cannot be explained only by the above-mentioned “static wetting” theory is generated, and there is a phenomenon that it is difficult to move. This must be taken into account (for example, see Non-Patent Document 1).

In the non-ideal solid surface S, when liquid is further added to the droplet L on the solid surface S in FIG. 11 from above, the droplet L swells, but the contact line (solid, gas, liquid triplet) The line does not move immediately, but the contact angle θ becomes larger than that given by Young's formula, and the contact line finally moves when the contact angle θ exceeds a certain angle (advance angle θ _A ). start. On the other hand, when the liquid is sucked out from the upper part of the droplet L on the solid surface S, the droplet L is deflated, but the contact line does not move immediately, and the contact angle θ is given by Young's formula. The contact line finally begins to move when the contact angle θ becomes less than a certain angle (retraction angle θ _R ).
Thus, the contact angle observed on the actual surface depends on how the system was prepared. Such a phenomenon is called a contact angle history (hysteresis).

  As a result, as shown in FIG. 12, for example, when the solid surface S is inclined, a phenomenon is observed in which the solid surface S does not start moving up to a certain angle (falling angle). With a slight inclination, the adhesion force (frictional force) of the droplet L to the solid surface S overcomes the gravity, and the droplet L does not move. When the inclination is inclined more than the falling angle, the gravity becomes the adhesion force (frictional force). It overcomes and the droplet L begins to move.

Also, in the liquid column model that stays in the vertical capillary as shown in FIG.
2γ _L (cosθ ₁ −cosθ ₂ ) / R = ρgH (2)
Holds. Here, ρ is the density of the liquid, g is the acceleration of gravity, R is the radius of the tube, and H is the height of the liquid column.
In order for the balance to be realized, the upper contact line needs to withstand not to retreat,
θ ₁ > θ _R (cos θ ₁ <cos θ _R ) is satisfied. Similarly, since the lower contact line needs to endure not to move forward, θ ₂ <θ _A (cos θ ₂ > cos θ _A ) is established. That means
2γ _L (cos θ _R −cos θ _A ) / R> ρgH (3)
In this case, the balance is realized and the liquid does not fall off due to gravity. If there is no history, that is, if the advance angle and the receding angle are equal, no balance can occur. (An ideal “good” interface has a small angle difference between the advance angle and the recede angle (˜ <5 degrees). This difference can be large (on the order of 50 degrees) on uneven or dirty surfaces.

  Therefore, when trying to move the liquid on the actual solid surface S, the liquid cannot be moved over the adhesion force (friction force) unless an external force is applied to some extent.

Japanese Patent Laid-Open No. 8-254962 Degenne, Brossard-Viard, Kelle, Translated by Takeshi Okumura “Physics of surface tension” published by Yoshioka Shoten, September 2003, p. 67-68

  By the way, in the above conventional display device, the side opposite to the surface side on one side of the container is white and opaque, and when there are bubbles on one side in the container, white display is given, and the colored liquid is on one side in the container In some cases, since the color display of the colored liquid itself is used, the colored liquid is changed from one side of the container to the other side or in the opposite direction against the inner wall surface of the container due to the solid-gas-liquid contact angle history phenomenon. There is a problem in that the force required to move the colored liquid is increased and the power consumption is increased because it must be moved against the resulting adhesive force (frictional force).

  Therefore, an object of the present invention is to provide a liquid moving device that can reduce power consumption by reducing the force required to move the liquid.

  In order to achieve the above object, according to the present invention, the liquid movement path is filled with the first liquid and at least one second liquid that does not mix with the first liquid. With the wall surface wetted by the first liquid or the second liquid, the adhesive force due to the contact angle history phenomenon of the first liquid with respect to the inner wall surface of the liquid movement path is not generated. The liquid moving means moves at least the first liquid in the liquid moving path.

  According to the present invention, the liquid moving path is filled with the first liquid and the second liquid that does not mix with the first liquid, and the inner wall surface of the liquid moving path is filled with the first liquid or the second liquid. This liquid is prevented from causing an adhesion force (friction force) due to a contact angle history phenomenon with respect to the inner wall surface of the liquid movement path of the first liquid, so that it is necessary to move the first liquid. The force to be applied may be relatively small.

(First embodiment)
FIG. 1 is a sectional view showing a white display state of one pixel portion of a display device as a first embodiment of the present invention. This display device includes a space forming body 1 that forms a space divided in units of pixels, an intermediate layer forming body 11 that partitions a space corresponding to one pixel in the space forming body 1 into two spaces 21 and 22, and two spaces. The first liquid 23 provided in one of the spaces 21 and 22 and the second liquid 24 provided in the other space are provided.

  The space forming body 1 includes a front side transparent plate (substrate) 2 and a back side (transparent) plate (substrate) 3 made of a colorless and transparent material such as glass or resin. A first electrode plate 4 made of ITO or the like is provided on the inner surface of the front-side transparent plate 2, and an insulating film 5 made of silicon oxide or the like is provided on the inner surface. A second electrode plate 6 made of ITO or the like is provided on the inner surface of the back side (transparent) plate 3, and an insulating film 7 made of silicon oxide or the like is provided on the inner surface.

  The intermediate layer forming body 11 is provided with a front-side insulating film 13 and a back-side insulating film 14 on both front and back surfaces of a third electrode plate 12 made of copper foil or the like, and first and second liquid movements on both the left and right sides thereof. The structure is provided with holes 15 and 16 for use. In this case, the surface side insulating film 13 is formed of a white resin. The back side insulating film 14 may be formed of the same resin. The shape of the first and second liquid moving holes 15 and 16 may be any of a circular shape, a square shape, a rectangular shape, and the like.

  The insulating film 5 below the front surface side transparent plate 2 and the insulating film 7 on the back surface side (transparent) plate 3 are rectangular frame-shaped side walls 17 (surface side) made of an epoxy resin or the like disposed between them. The side wall 17a and the back side wall 17b) are bonded together. In this state, the 1st-3rd electrode plates 4, 6, and 12 are arrange | positioned so that it may mutually become parallel. The first and second electrode plates 4, 6 are provided in regions corresponding to the upper and lower portions of the first liquid movement hole 15, but are located above and below the second liquid movement hole 16. It is not provided in the area corresponding to the part.

  The space forming body 1 is mainly surrounded by the insulating film 5 below the front surface side transparent plate 2, the insulating film 7 on the back surface (transparent) plate 3, and the side wall 17 (front surface side wall 17a, back surface side wall 17b). The space corresponding to one pixel of the space forming body 1 is formed between the transparent plates 2 and 3, and the first and second spaces are formed between the transparent plates 2 and 3. Are divided into two spaces 21 and 22 by the intermediate layer forming body 11 having the liquid transfer holes 15 and 16.

  That is, a surface-side space 21 is formed by a space surrounded by the insulating film 5 under the front-side transparent plate 2, the surface-side insulating film 13 on the intermediate layer forming body 11, and the front-side side wall 17a, and the back side (transparent) plate 3, a back surface side space 22 is formed by a space surrounded by the back surface side insulating film 14 below the intermediate layer forming body 11 and the back surface side wall 17 b, and both the spaces 21, 22 are the first and second spaces. The liquid movement holes 15 and 16 communicate with each other.

  In this case, the volume of the front surface side space 21 and the volume of the back surface side space 22 are substantially the same. As will be described later, in the white display state shown in FIG. 1, the first liquid 23 made of a colored liquid dielectric is formed in the back side space 22 and in the first and second liquid moving holes 15 and 16. Filled and the surface side space 21 is filled with a second liquid 24 made of a colorless and transparent liquid dielectric. Here, both the spaces 21 and 22 and the both liquid moving holes 15 and 16 constitute a liquid moving path through which both the liquids 23 and 24 move.

  The first and second liquids 23 and 24 are not mixed with each other. The second liquid 24 is made of a material having a dielectric constant lower than that of the first liquid so that a difference in force due to an electric field described later is generated.

  For example, water (relative dielectric constant of about 78 (25 ° C.)) may be used as the first liquid 23, and silicone oil (relative dielectric constant of about 2 to 3) may be used as the second liquid 24. In addition, ethanol (relative dielectric constant of about 25) is used as the first gas 23, and fluorine-based non-crystalline liquid such as Fluorinert (manufactured by 3M Corporation, relative dielectric constant of about 1.7 to 2.0) is used as the second liquid 24. An active liquid may be used. As will be described later, as the force due to the electric field, the portion corresponding to the second liquid works in substantially the same manner as when air (or vacuum) (relative permittivity is 1). The surface tension of silicone oil is 16-22 mN / m, which is lower than the surface tension of water about 73 mN / m (20 ° C.), the surface tension of fluorinate is 9-18 mN / m, and the surface tension of ethanol is about 22 mN. / M (20 ° C) lower. That is, in the case of the above combination, as will be described later, if the influence of the force due to the electric field is not considered, the inner walls of both the spaces 21 and 22 and the two liquid moving holes 15 and 16 (that is, the inner wall of the liquid moving path) ), The second liquid 24 having a lower surface tension adheres to the inner wall surface of the side wall 10 and becomes stable.

  Further, the coloring material for coloring the first liquid 23 does not dissolve in the second liquid 24 but dissolves only in the first liquid 23, and is an aqueous pigment ink or an aqueous dye ink. When water and silicone oil are used as the first and second liquids 23 and 24, for example, water-based pigment ink is dissolved in water. When ethanol and fluorinate are used as the first and second liquids 23 and 24, for example, an aqueous dye ink (for example, sodium fluorescein) is dissolved in ethanol. In the first embodiment, a case where water and silicone oil are used as the first and second liquids 23 and 24 and black aqueous pigment ink is dissolved in water will be described.

  Next, an operation with force by an electric field in this display device will be described. The first liquid 23 and the second liquid 24 that are dielectrics are polarized when an electric field is applied. Where the electric field applied to the polarized liquid is not uniform (spatially changing), the liquid receives a force from the electric field according to the relationship between the polarization direction and the partial differential of the electric field component. The magnitude and direction of the force applied to each part of the liquid is considered from the polarization of each part of the liquid approximated by the dipole moment, and from the component of each dipole moment and the partial differentiation of the electric field component at the position of each dipole. can do.

The force F received by the dipole can be obtained from the following equation (4), where P is the dipole moment and E is the electric field. However, P, E, and F are vectors, and ▽ is Nabula.
F = (P ・ ▽) E …… (4)

  The force F received by this dipole increases when the gradient of the square of the electric field strength is large. For this reason, by generating an appropriate electric field (change in potential) in the space 12, power for moving the liquid can be obtained. In this case, since the first liquid 23 having a large dielectric constant is polarized more than the second liquid 24 having a small dielectric constant, the force acting on the first liquid 23 is increased. (This can be considered from the energy of the system as described later.)

  In other words, in the state shown in FIG. 1, when a voltage of 0 V is applied to the second electrode plate 6 and the third electrode plate 12, and a positive voltage of 10 V, for example, is applied to the first electrode plate 4 (first The force due to the electric field is generated. This force acts on both the first and second liquids 23 and 24, but may be considered to be applied to the first liquid 23 having the higher dielectric constant as a difference. Further, this force is applied as a strong upward force to the first liquid 23 in the first liquid moving hole 15 provided in the region facing the first and second electrode plates 4, 6, Then, an upward weak force is applied to the first liquid 23 in the second liquid moving hole 16 provided in a region not facing the second electrode plates 4 and 6. This is because the electric field in the vicinity of the liquid movement hole 15 is larger than the electric field in the vicinity of the liquid movement hole 16. That is, by arranging the electrode shape arrangement in the vicinity of the liquid movement hole 15 and the liquid movement hole 16 as shown in FIG. 1, the liquid is circulated by the subtraction force.

  As a result, a clockwise force is generated with respect to the liquid. The first liquid 23 in the back surface side space 22 and the second liquid moving hole 16 moves into the front surface side space 21 through the first liquid moving hole 15, and as shown in FIG. The first liquid 23 is filled in the surface-side space 21 and the first and second liquid moving holes 15 and 16, and accordingly, the second liquid 24 in the surface-side space 21 is filled with the second liquid 24. It moves into the back surface side space 22 through the liquid moving hole 16 and is stable in a state where the second liquid 24 is filled in the back surface side space 22.

This can be explained by considering the energy of the electric field of the system from the principle of virtual work as follows.
Virtual work ΔW + electric field energy change ΔU _E = Replenishment of energy from the power supply ...... (5)
The electric field energy U _E is obtained from the potential distribution obtained by electric field simulation.
U _E = ∫E · DdV / 2 = ∫εE ² dV / 2 = ∫D ² dV / 2ε (6)
It can be calculated with (Here, E is the electric field, D is the electric flux density, and ε is the dielectric constant.)
Note that if the electrode potential is constant due to the power supply, the replenishment of energy from the power supply will be twice the increase in electric field energy due to virtual work.
Virtual work ΔW = Electric field energy change ΔU _E (7)
Thus, the liquid tries to move so that the energy of the electric field increases.
When the energy of the electric field in the state of FIG. 1 and the energy of the electric field in the state of FIG. 2 are compared by electric field simulation under the voltage of the first condition, it can be seen that the state of FIG. That is, it becomes stable in a state where a material having a high dielectric constant, in this case, the first liquid 23 is buried in a portion where the electric field is strong.

  On the other hand, in the state shown in FIG. 2, a voltage of 0V is applied to the first electrode plate 4 and the third electrode plate 12, and a positive voltage of 10V and a voltage of 10V are applied to the second electrode plate 6, for example. (Second condition), a force due to an electric field is generated. In this case, this force is mainly applied to the first liquid 23 having the higher dielectric constant of the first and second liquids 23 and 24. It can be considered that a force as a difference is added. In addition, this force is applied as a strong downward force to the first liquid 23 in the first liquid moving hole 15 provided in the region facing the first and second electrode plates 4 and 6. In addition, a downward downward force is applied to the first liquid 23 in the second liquid moving hole 16 provided in a region not facing the second electrode plates 4 and 6.

  As a result, a counterclockwise force is generated on the liquid. The first liquid 23 in the front surface side space 21 and the second liquid moving hole 16 moves into the back surface side space 22 through the first liquid moving hole 15, and as shown in FIG. The first liquid 23 is filled in the back surface side space 22 and the first and second liquid moving holes 15 and 16, and accordingly, the second liquid 24 in the back surface side space 22 is filled with the second liquid 24. It moves into the surface side space 21 through the liquid moving hole 16, and the surface side space 21 is filled with the second liquid 24. (The phenomenon when the voltage of the first condition is applied to FIG.

  In the state shown in FIG. 1, since the colorless and transparent second liquid 24 is present in the surface side space 21, the white surface side insulating film 13 of the intermediate layer forming body 11 is viewed from the pixel surface side, and white display is performed. It becomes. In this case, the front side wall 17a may be formed of a white material. On the other hand, in the state shown in FIG. 2, since the first liquid 23 colored black is present in the surface-side space 21, the display is black.

  By the way, in this display device, in the state shown in FIG. 1, the back side space 22 and the first and second liquid moving holes 15 and 16 are filled with the first liquid 23, and the front side space 21 is filled. Since it is filled with the second liquid 24, all of the inner walls of both the spaces 21 and 23 and the both liquid moving holes 15 and 16 are wetted by the both liquids 23 and 24. In the state shown in FIG. 2 as well, all the inner surfaces of the spaces 21 and 23 and the liquid moving holes 15 and 16 are all wetted by the liquids 23 and 24.

  Therefore, when both the liquids 23 and 24 are moved clockwise from the state shown in FIG. 1 to the state shown in FIG. The liquids 23 and 24 move while maintaining the wetted state of all the inner surfaces of the spaces 21 and 23 and the liquid moving holes 15 and 16. As a result, the two liquids 23 and 24 cause the solid-gas-liquid contact angle history phenomenon to occur in the spaces 21 and 23 of the liquids 23 and 24 and the inner wall surfaces of the liquid moving holes 15 and 16. An adhesion force (frictional force) is not generated, and a force required to move both the liquids 23 and 24 may be relatively small, so that power consumption can be reduced.

Here, an example of the size of a part of the display device will be described. The planar shape as a whole, that is, the planar shape of the portion constituting one pixel is square and the length of one side is about 500 μm, and the surface side transparent plate The distance between the insulating layer 5 of 2 and the surface side insulating film 13 of the intermediate layer forming body 11 and the distance between the insulating film 7 on the back side (transparent) plate 3 and the back side insulating film 14 of the intermediate layer forming body 11 are several. The thickness can be reduced to about 10 to several μm.
In the case of a system of the order of micrometer, the influence of gravity, which is a body force, is reduced, and the influence of the force relating to the surface energy, which is a surface force, is increased.

  By the way, in FIG. 1 and FIG. 2, a single pixel portion is described as a display device, and such a configuration may be used, but actually, a plurality of pixels are arranged in a matrix. In this case, the side wall 17 serves as a partition for dividing the space of the space forming body 1 into pixel units. In this example, the third electrode plate 12 may be a solid common electrode because a voltage of 0 V is applied to both the white display and the black display. In this case, the side wall 17 is separated into a front side wall 17a and a back side wall 17b.

  Since the first and second electrode plates 4 and 6 are selectively applied with a voltage of 0 V and a positive voltage of 10 V, for example, they correspond to each pixel like a pixel electrode of an active matrix liquid crystal display device. And separated into islands. Then, a switching element such as a thin film transistor may be used to selectively apply a voltage of 0 V and a positive voltage of 10 V to the first and second electrode plates 4 and 6. Further, since the force due to the electric field is proportional to the square of the electric field strength, a negative voltage of −10V may be applied instead of the positive voltage of 10V.

  The size of the first and second electrode plates 4 and 6 may be a slightly larger area than the display area surrounded by the side wall 17 and may be an area that bites into the side wall 17 and fits exactly into the display area. The area may be a full area, or may be slightly smaller than the display area. Further, the planar shape of the display area (pixel) is not limited to a square, and may be another shape such as a rectangle.

  For example, in the black display state shown in FIG. 2, when the application of voltage to the first to third electrode plates 4, 6, 12 is stopped, as shown in FIG. When the surface tension of the second liquid 24 is lower than that, the second liquid 24 having high wettability adheres extremely thinly to the surface side space 21 and the inner wall surfaces of the first and second liquid moving holes 15 and 16. . In the state shown in FIG. 3, when the voltage of the first condition as described above is applied to the first to third electrode plates 4, 6, 12, for example, to display a black color, When the wettability of the second liquid 24 is sufficiently overcome, a black display state as shown in FIG. 2 is obtained. Actually, the state between FIG. 2 and FIG.

  Here, in the black display state shown in FIG. 2, even if the colorless and transparent second liquid 24 remains extremely thinly deposited somewhere on the inner wall surface of the surface side space 21, there is no problem in black display. Absent. In the white display state shown in FIG. 1, even if the colorless and transparent second liquid 24 remains extremely thinly deposited somewhere on the inner wall surface of the back surface side space 22, there is no problem in white display. .

  In the first embodiment, the example using two types of liquids, the first liquid and the second liquid, has been described. However, three or more types of liquids may be used.

(Second Embodiment)
FIG. 4 is a sectional view showing a white display state of one pixel portion of a display device as a second embodiment of the present invention. This display device is different from the display device shown in FIG. 1 in that air 25 is included in the second liquid 24. In this case, in the white display state shown in FIG. 4 where a voltage is applied under the second condition, the relative dielectric constant (about 1.0) of the air 25 is lower than the dielectric constant of the first liquid 23. Existing in the lower surface side space 21.

In this case, as a liquid, the surface tension is low and the surface is completely wet. Γ _S > γ _LS + γ _L (8)
It is desirable to use one having characteristics that realize When the surface tension of the second liquid 24 is lower than that of the first liquid 23, the second liquid 24 adheres to the entire inner wall surface of the surface-side space 21 due to its wettability, and air 25 is enclosed therein. It becomes a state.

  In this display device, for example, in the white display state shown in FIG. 4, when the voltage of the first condition as described above for applying the black display state to the first to third electrode plates 4, 6, 12 is applied. The first liquid 23 in the back surface side space 22 and the second liquid moving hole 16 moves into the front surface side space 21 through the first liquid moving hole 15, and as shown in FIG. The first liquid 23 is filled in the surface-side space 21 and the first and second liquid moving holes 15 and 16, and accordingly, the second liquid containing the air 25 in the surface-side space 21. 24 moves into the back surface side space 22 through the second liquid moving hole 16, and the second liquid 24 adheres to the entire inner wall surface of the back surface side space 22 due to its wettability, and air 25 is contained therein. It will be in a sealed state.

For example, in the black display state shown in FIG. 5, when the application of voltage to the first to third electrode plates 4, 6, 12 is stopped, as shown in FIG. 6, the first liquid 23 The second liquid 24 having higher wettability adheres extremely thinly to the surface side space 21 and the inner wall surfaces of the first and second liquid moving holes 15 and 16. In the state shown in FIG. 6, when the voltage of the first condition as described above for making the black display state, for example, is applied to the first to third electrode plates 4, 6, 12, the force due to the electric field When the wettability of the second liquid 24 is sufficiently overcome, the black display state shown in FIG. 5 is obtained. Actually, the state between FIG. 5 and FIG.
In the second embodiment, the air 25 is included in addition to the first liquid 23 and the second liquid 24. However, it is not necessary to be air, and may be an inert gas such as nitrogen.

(Third embodiment)
FIG. 7 is a cross-sectional view showing a white display state of one pixel portion of a display device as a third embodiment of the present invention. This display device is different from the display device shown in FIG. 1 in that the first electrode plate is divided into two first electrode plates 4a and 4b, and the second electrode plate is also two second electrodes. This is a point divided into plates 6a and 6b.

  In this display device, in the white display state shown in FIG. 7, a positive voltage of 10 V, for example, is applied to the two first electrode plates 4 a and 4 b in a state where a voltage of 0 V is applied to the third electrode plate 12. When a voltage of 0 V is applied to the two second electrode plates 6a and 6b, as shown in FIG. 8, the first liquid 23 having a high dielectric constant moves to the surface side space 21, and the first As in the case of the first embodiment, a black display state is obtained.

  On the other hand, in the black display state shown in FIG. 8, a voltage of 0 V is applied to the two first electrode plates 4a and 4b in a state where a voltage of 0 V is applied to the third electrode plate 12, and two When a positive voltage of 10 V, for example, is applied to the second electrode plates 6a and 6b, the first liquid 23 having a high dielectric constant moves to the back surface side space 22 as shown in FIG. 7, and the first embodiment described above. As in the case of, the white display state is obtained.

  By the way, this display device can perform halftone gray display. For example, in the case of changing from the white display state shown in FIG. 7 to the halftone gray display state, the first electrode plate 4a on the left side and the left side electrode plate 4a in the state where the voltage of 0V is applied to the third electrode plate 12 are shown. For example, a positive voltage of 10V is applied to the second electrode plate 6a, and the right first electrode plate 4b and the right second electrode plate 6b are in an open state in which no voltage is applied (third condition). .

  Then, since the electric field strength of the left half portion becomes larger than that of the right half portion, as shown in FIG. 9, the first liquid 23 in the back surface side space 22 and the second liquid moving hole 16 About half moves to the left half in the surface-side space 21 (the portion corresponding to the lower part of the left first electrode plate 4a) through the first liquid moving hole 15, and the left in both spaces 21, 22 Half and the first liquid transfer hole 15 are filled with the first liquid 23, and accordingly, about half of the second liquid 24 in the surface-side space 21 passes through the second liquid transfer hole 16. To the right half in the back surface side space 22 (the portion corresponding to the upper part of the second electrode plate 6b on the right side) and into the right half in both the spaces 21 and 22 and the second liquid moving hole 16. Filled with the second liquid 24, the left side is black and the right side is white, which is recognized as a halftone gray display. .

  On the other hand, in the case of changing from the black display state shown in FIG. 8 to the halftone gray display state, the voltage may be applied under the third condition.

Then, as shown in FIG. 9 also, the electric field strength of the left half portion is larger than that of the right half portion, so that the first liquid 23 in the surface-side space 21 and the second liquid moving hole 16 is present. About half of the distance moves to the left half (the portion corresponding to the upper portion of the second electrode plate 6a on the left side) in the back surface side space 22 through the first liquid moving hole 15, The left half and the first liquid moving hole 15 are filled with the first liquid 23, and accordingly, about half of the second liquid 24 in the back surface side space 22 is the second liquid moving hole 16. To the right half in the surface-side space 21 (the part corresponding to the lower part of the first electrode plate 4b on the right side), and in the right half in both the spaces 21 and 22 and in the second liquid movement hole 16 Is filled with the second liquid 24, black on the left side and white on the right side. It is. (This is the same as the phenomenon when the voltage of the third condition is applied to FIG. 7 and upside down.)
Here, the voltage was applied so that the electric field strength of the left half portion was larger than that of the right half portion, but conversely, the voltage was applied so that the electric field strength of the right half portion was larger than that of the left half portion. The right half may be black and the left half white.

  For example, in the display device shown in FIG. 1, the color of the first liquid 23 may be blue, red, or the like other than black. For example, in the display device shown in FIG. 1, the first and second liquids 23 and 24 may have different colors. For example, the first liquid 23 may be blue and the second liquid 24 may be blue. The color may be red. In this case, the coloring material for coloring the second liquid 24 does not dissolve in the first liquid 23 made of water or the like but dissolves only in the second liquid 24 made of silicone oil or the like. Or oil-based dye ink.

  Further, for example, in the display device shown in FIG. 1, the first and second liquids 23 and 24 are different from each other, and the surface side insulating film 12 of the intermediate layer forming body is further different from the front side. The thickness of the liquid layer in the space 21 is thinned so that the color of the surface-side insulating film 12 can be seen to some extent, and 2 by mixing the colors of the first and second liquids 23 and 24 and the color of the surface-side insulating film 12. Color display may be used.

  Further, for example, in the display device shown in FIG. 1, the first and second liquid moving holes 15 and 16 may be provided not on the left and right sides of the intermediate layer forming body 11 but on the inner side. There may be a plurality of liquid movement holes 15, and there may be a plurality of second liquid movement holes 16. When a plurality of the first and second liquid moving holes 15 and 16 are provided, the size and shape may be the same or different. Further, the liquid moving hole 15 and the liquid moving hole 16 may be the same.

  Moreover, although the said embodiment demonstrated the case where a DC voltage was applied to each electrode plate 4,6,12, you may make it apply an AC voltage. For example, when the first liquid 23 is moved to the surface-side space 21, the first electrode plate 4 has a phase opposite to that of the third electrode plate 12, and the second electrode plate 6 has the third electrode plate 12. In the same phase, 10V and 0V may be switched and applied to the three electrode plates 4, 6, and 12 at a constant period. The number of electrode plates is not limited to three. If the first and second liquids 23 and 24 are moved by the difference in the strength of the electric field, the number of electrode plates or more The following number of electrode plates may be used. (An electric field simulation including the shape and arrangement of the liquid transfer hole and electrode may be performed to perform an optimum design.)

(Fourth embodiment)
FIG. 10 is a schematic cross-sectional view of a main part of a liquid moving device as a fourth embodiment of the present invention. This liquid transfer device is, for example, part of a microchemical analysis system (μTAS) and includes a microchannel structure 31 having a microchannel 32. One predetermined portion of the microchannel structure 31 is provided so that one end of the supply channel structure 33 protrudes into the microchannel 32 to some extent. One end portion of the discharge flow path structure 34 is provided in the other predetermined portion of the micro flow path structure 31 so as to protrude into the micro flow path 32 to some extent.

  A pair of electrode plates 35, 36 that are opposed to each other are provided at equal intervals along the plurality of sets of microchannels 32 outside the microchannel configuration 31. In this case, in the portion corresponding to the supply flow path structure 33 and the discharge flow path structure 34, only one of the electrode plates 35 is shown. The electrode plates 35 and 36 are disposed on both sides of each end of the supply flow path structure 33 and the discharge flow path structure 34. A pair of electrode plates 37 and 38 facing each other are provided outside the discharge flow path structure 34.

  The supply flow path structure 33 is filled with a first liquid 39 of interest made of a liquid dielectric. An auxiliary second liquid 40 made of a liquid dielectric adheres to the entire inner wall surface of the micro-channel 32 of the micro-channel constituting body 31 due to its wettability, and air 41 is enclosed therein. In this case, the first and second liquids 39 and 40 are basically the same as those in the second embodiment, but need not be colored.

  Next, the operation of the liquid moving device will be described. First, when, for example, a voltage of 0 V and a positive voltage of 10 V are applied to the first pair of electrode plates 35 and 36 disposed on both sides of one end of the supply flow path structure 33, a supply flow path structure is provided. A first liquid 39 having a high dielectric constant in one end of 33 is a fixed amount of the first pair of electrode plates 35, 36 in the second liquid 40 in the microchannel 32 of the supply channel structure 33. Moves to the position corresponding to.

  Next, when a voltage of 0 V and a positive voltage of 10 V, for example, are applied to the second pair of electrode plates 35 and 36 adjacent to the first pair of electrode plates 35 and 36 for a certain period of time, the second liquid 40, the first liquid 39 located at a position corresponding to the first pair of electrode plates 35, 36 corresponds to the second pair of electrode plates 35, 36, as indicated by a dotted line in FIG. It is attracted to the position to move.

  In this way, the first liquid 39 moves intermittently in the second liquid 40, and the n-th pair of electrode plates 35 disposed on both sides of one end portion of the discharge channel constituting body 34. , 36 to a position corresponding to. Next, when, for example, a voltage of 0 V and a positive voltage of 10 V are applied to the pair of electrode plates 37 and 38 provided outside the discharge flow path structure 34 for a certain period of time, the n-th in the second liquid 40 The first liquid 39 located at a position corresponding to the pair of electrode plates 35 and 36 is located at a position corresponding to the pair of electrode plates 37 and 38 in the discharge channel constituting body 34 as shown by a one-dot chain line in FIG. Attracted to move.

Thus, in this liquid moving device, the first liquid 39 moves in the second liquid 40 attached to the entire inner wall surface of the microchannel 32 of the microchannel structure 31 due to its wettability, so that the first Adhesive force (frictional force) due to the solid-gas-liquid contact angle history phenomenon with respect to the inner wall surface of the minute flow path 32 of the liquid 39 is not generated, and is necessary for moving the first liquid 39. The force may be relatively small, and thus power consumption can be reduced.
Here, an example is shown in which the second liquid 40 is not filled in the microchannel 32 of the microchannel structure 31, but the second liquid 40 is filled as in the first embodiment, You may make it move the 1st liquid 39 to which attention is paid in it.

Instead of the pair of electrode plates 35 and 36 (including the pair of electrode plates 37 and 38), an electromagnet or a coil may be used and the first liquid 39 may be moved by the force of a magnetic field. In this case, the second liquid 40 has a lower magnetic permeability than the first liquid 39. When a magnetic field is used, the energy of the electric field corresponds to the energy of the magnetic field, and the first liquid 39 having a high magnetic permeability moves to a portion where the magnetic field strength is strong and becomes stable. Therefore, as in FIG. 10, the first liquid 39 can be moved by the force of the magnetic field.
Further, the second liquid 40 may be filled in the minute flow path 32 of the minute flow path structure 31, and the first liquid 39 may be moved therein.

  Furthermore, although the example using the force by an electric field or a magnetic field was shown here as a liquid moving means, you may make it move using other forces, such as an air pressure.

Sectional drawing which shows the white display state of the 1 pixel part of the display apparatus as 1st Embodiment of this invention. Sectional drawing which shows the black display state of the display apparatus shown in FIG. Sectional drawing shown in order to demonstrate the case where it is set as the state which does not apply an electric field from the black display state shown in FIG. Sectional drawing which shows the white display state of 1 pixel part of the display apparatus as 2nd Embodiment of this invention. Sectional drawing which shows the black display state of the display apparatus shown in FIG. Sectional drawing shown in order to demonstrate the case where it is set as the state which does not apply an electric field from the black display state shown in FIG. Sectional drawing which shows the white display state of 1 pixel part of the display apparatus as 3rd Embodiment of this invention. Sectional drawing which shows the black display state of the display apparatus shown in FIG. Sectional drawing which shows the gray display state of the halftone of the display apparatus shown in FIG. The schematic sectional drawing of the principal part of the liquid moving apparatus as 4th Embodiment of this invention. Sectional drawing for demonstrating the contact angle of the droplet on a solid surface. Sectional drawing for demonstrating the phenomenon of the droplet on the inclined solid surface. Sectional drawing for demonstrating the phenomenon of the liquid column which stays in a perpendicular capillary.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Space formation body 2 Front surface side transparent plate 3 Back surface side (transparent) plate 4 1st electrode plate 4a Left side 1st electrode plate 4b Right side 1st electrode plate 5 Insulating film 6 2nd electrode plate 6a Left side Second electrode plate 6b Second electrode plate on the right side 7 Insulating film 11 Intermediate layer forming body 12 Third electrode plate 13 Front surface side insulating film 14 Back surface side insulating film 15 First liquid moving hole 16 Second liquid Movement hole 17 Side wall 17a Front side wall 17b Back side wall 21 Front side space 22 Back side space 23 First liquid 24 Second liquid 25 Air 31 Micro flow path structure 32 Micro flow path 33 Supply flow path structure 34 Discharge flow path structure 35 to 38 A pair of electrode plates 39 First liquid 40 Second liquid 41 Air

Claims (12)

  The liquid movement path is filled with the first liquid and at least one second liquid that does not mix with the first liquid, and the inner wall surface of the liquid movement path is the first liquid or the second liquid. In the state where the adhesion force due to the contact angle history phenomenon of the first liquid with respect to the inner wall surface of the liquid movement path is not generated by being wetted by the liquid, the liquid movement means causes the first liquid to move within the liquid movement path. A liquid moving device that moves at least the first liquid.   The liquid moving apparatus according to claim 1, wherein the liquid moving path is formed of a space forming body that forms a space divided in units of pixels, and the liquid moving means selectively applies an electric field in the space forming body. And the second liquid has a dielectric constant different from that of the first liquid, and at least the first liquid according to the action of a force generated by the electric field formed by the electric field forming means. A liquid moving apparatus for moving a liquid.   3. The liquid moving apparatus according to claim 2, wherein the first and second liquids are moved according to an action of a force by an electric field formed by the electric field forming means.   4. The liquid moving apparatus according to claim 3, wherein the space forming body includes a front surface side substrate and a back surface side substrate, and a space corresponding to one pixel in the space forming body is provided between the substrates. A liquid moving device comprising a front side space and a back side space divided into two by an intermediate layer forming body having a moving hole.   5. The liquid movement apparatus according to claim 4, wherein the first liquid is supplied to the front surface side space and the rear surface side space through the liquid movement hole in accordance with an action of a force generated by the electric field formed by the electric field forming unit. And the second liquid is moved from the other space to the one space or the other through the liquid moving hole. A liquid moving device, wherein the liquid moving device is moved from one space to the other.   6. The liquid transfer device according to claim 5, wherein the liquid moving device is insoluble or hardly soluble in at least one of the first and second liquids and in the other of the first and second liquids. A liquid moving device characterized in that a coloring material having a melting point is dissolved.   6. The liquid moving device according to claim 5, wherein a gas is partly contained in the first liquid or the second liquid without touching an inner wall surface of the liquid moving path. Mobile equipment.   2. The liquid movement apparatus according to claim 1, wherein the liquid movement path includes a micro flow channel, and the liquid movement unit includes an electric field forming unit that selectively forms an electric field in the micro flow channel. The liquid has a dielectric constant different from that of the first liquid, and moves the first liquid according to the action of a force generated by the electric field formed by the electric field forming means.   2. The liquid movement apparatus according to claim 1, wherein the liquid movement path includes a micro flow path, and the liquid movement means includes a magnetic field forming means that selectively forms a magnetic field in the micro flow path, and The liquid has a magnetic permeability different from that of the first liquid, and moves the first liquid in accordance with the action of a force generated by the magnetic field formed by the magnetic field forming means.   10. The liquid moving apparatus according to claim 8, wherein the second liquid is attached to an inner wall surface of the microchannel by wettability, and the first liquid moves therein. Mobile equipment.   10. The liquid moving apparatus according to claim 8, wherein the second liquid is filled in the minute flow path, and the first liquid moves through the second liquid.   2. The liquid transfer device according to claim 1, wherein the first liquid and the second liquid are different from each other and include a liquid selected from water, alcohol, silicone oil, and a fluorine-based inert liquid. A liquid transfer device characterized by that.

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