JPH09309640A - Medium conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve conveying performance without changing an applying condition or the like by changing the mutual spaces of strip electrodes according to arranged areas. SOLUTION: When an uncharged conveyed medium 3 reaches a conveyance start position, voltage is applied to strip electrodes 12, for instance, positive voltage to an A-phase, negative voltage to a B-phase and 0 [V] to a C-phase. The medium 3 is pushed up, and starts its movement receiving force in a conveying direction. After moving by one pitch of the strip electrode, suction force of charge in the medium and charge in the strip electrode becomes maximum, and the medium 3 stops. When [negative, negative, positive] voltage is applied to each strip electrode 12, the conveyed medium 3 is moved by one pitch by the same action, and so forth. The pitch of the strip electrodes at the time of starting the conveyance of the medium 3 is narrowed, and the pitch after the conveyed medium starts moving is widened so as to realize stable conveyance start action without increasing applied voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium carrying device, for example, a copying machine, a printer, a facsimile, a cash automatic depositing / dispensing device, paper sheets such as paper and bills, cash cards and prepaid cards. The present invention relates to a medium carrying device that carries or processes media such as cards.

[0002]

2. Description of the Related Art Conventionally, copiers, printers, facsimile machines, automatic cash dispensers and the like have been disclosed in Japanese Unexamined Patent Publication No. Hei.
81, a transfer mechanism for pressing a rubber roller driven by a rotary electromagnetic motor against a medium such as paper has been used. However, according to such a technique, heat generation and large power consumption of the motor itself become a problem, and there is a limit to downsizing due to the configuration using the electromagnetic motor and the rubber roller. In addition, since the frictional force between the rubber roller and the transport medium is used as the force used for transporting the medium, the rubber roller itself or the rubber roller and the medium are used to obtain a stable transport force due to wear of rubber, adhesion of paper powder, and the like. It was necessary to periodically inspect and repair the pressure contact force.

As a technique for improving these problems, a transport technique utilizing electrostatic force is disclosed in "Japanese Patent Laid-Open No. 5-319602" and "Japanese Patent Laid-Open No. 6-56290". These techniques use a stator having a strip electrode and a mover having a resistance layer. "Japanese Patent Laid-Open No. 5-319602"
In the case of (1), the paper to be conveyed is directly used as the moving element, and in the case of "JP-A-6-56290", the conveyed object such as paper is placed on the moving element having a high resistance value. .
In both cases, the electrodes of the stator are divided into three systems (three phases), which are arranged in order at equal intervals.

The details of the operation principle are described in JP-A-2-2859.
78, "JP-A-5-319602" and "JP-A-6-5
6290 ”, the outline of the operating principle will be described here. Immediately before transporting, a special voltage combination is applied to each phase of the stator electrode to electrostatically polarize the positive and negative charges existing in the resistance layer of the mover (hereinafter, referred to as initial polarization). When electrostatic polarization is sufficiently advanced in the mover, voltage is applied to each phase of the stator electrode while switching the voltage pattern (combination) for transfer, and the mover is transferred by repulsion and attraction of electric charges.

[0005]

However, when attempting to convey a stopped medium, there are cases where the medium cannot be conveyed unless an external force is applied to the medium such as giving an initial velocity to the medium. In the case of the transport method using the electrostatic force as in the conventional example, the main forces applied to the medium in the transport direction are the transport force received from the stator and the frictional force due to the friction between the medium and the stator.

Generally, the friction between solids has a static friction coefficient and a dynamic friction coefficient, the static friction coefficient acts on the friction that works until the medium starts moving, and the dynamic friction coefficient acts after the medium starts moving. Since the static friction coefficient is generally larger than the dynamic friction coefficient,
Greater transport force is required. In the transport method using electrostatic force, the transport force depends on the applied voltage value, and the transport force increases by increasing the applied voltage. Therefore, in a region where static friction is dominant such as the start of conveyance, the problem can be solved by applying a high voltage at which conveyance can be started. However, high voltage is preferable because the higher the applied voltage, such as the discharge to the air or peripheral parts, the generation of ozone due to it, the more important the insulation measure for the peripheral equipment is, the lower the safety and the higher the cost. Absent.

Therefore, in order to realize a safer and lower cost transporting means, a medium transporting device that can reliably start transporting with a voltage value as low as the voltage required during medium transporting (when the dynamic friction coefficient is applied), A medium transportation method is required.

[0008]

According to the present invention, a plurality of strip electrodes are arranged on a resistor, and the strip electrodes are divided and connected in three or more phases to form a stator, which is applied to the strip electrodes of each phase. In the medium carrying device for carrying the medium along the stator by the electrostatic force generated by switching the voltage polarities, the interval between the strip electrodes is changed depending on the area in which they are arranged.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is an explanatory view showing an embodiment, and FIG. 2 is an explanatory view showing a connection example of a strip electrode of the first embodiment. The apparatus shown in the figure comprises a stator 1 and does not require a special mover, and carries the carrier medium 3 by directly applying a carrier force.

The stator 1 comprises a substrate 11 and a plurality of strip electrodes 1
2 are partially arranged at different pitches. Further, the coat layer 13 may be provided on the strip electrode 12 as necessary. (A surface of the base material 11 that is in contact with the transport medium 3 is called a transport surface, and the opposite surface is called a non-transport surface.) The base material 11 is a high resistance body, such as a substrate shape, a film shape, a shape and a thickness. Can be freely designed. In the present embodiment, as an example, an epoxy resin material is used after being processed into a plate shape.

The strip electrode 12 can be made of any conductive material such as copper or gold, and can be formed on the substrate 11 by a known technique such as printing or etching. After the strip electrode 12 is formed, an insulating coating may be applied on it if necessary. The width of the electrodes and the electrode pitch can be set freely. In the present embodiment, the pitch is made fine at a place where a high carrying force is required, such as the carrying start portion, and is made large in the usual carrying path. A coating layer may be provided on the strip-shaped electrode 12 for the purpose of reducing friction with the carrier medium 3.
In this embodiment, a solder resist is used by coating.

3 to 9 are explanatory diagrams (A) to (G) of the operation principle of the first embodiment, and the operation of the present embodiment will be described with reference to these drawings. The strip electrode 12 is divided into three phases, which are called A phase, B phase, and C phase, respectively.
The electrode connected to the phase is indicated as 12A, the electrode connected to the B phase is indicated as 12B, and the electrode connected to the C phase is indicated as 12C. Further, the right-hand direction in this figure is the conveyance direction of the medium 3.

When the transport medium 3 which is not charged reaches the transport start position, a voltage is applied to the belt-shaped electrode 12 by using a voltage applying means (not shown). For example, assuming that the A phase is a positive voltage, the B phase is a negative voltage, and the C phase is 0 [V] (hereinafter, this is expressed as [positive, negative, 0] in the order of A phase, B phase, and C phase). Electrostatic polarization occurs in the carrier medium 3 and negative charges are present inside the carrier medium 3 facing the strip electrode 12A to which a positive voltage is applied, and inside the carrier medium 3 opposite to the belt electrode 12B to which a negative voltage is applied. Are positively charged, respectively. As a result, the charges in the carrier medium 3 are polarized as shown in FIG. 3, and this is called initial polarization.

After the initial polarization is completed, a voltage of [negative, positive, negative] is applied to each phase of the strip electrode 12. The electric charge in the carrier medium 3 that has been initially polarized receives a repulsive force from the same polarity charge of the strip electrode 12 and an attractive force from the opposite polarity electrode. In the state of FIG. 4, the positive charges in the medium 3 receive a repulsive force in the direction of pushing up the medium 3 from the positive charges of the strip electrode 12B1. At the same time, the negative charges in the medium 3 receive a repulsive force in the direction of pushing up the medium 3 from the negative charges of the strip electrode 12A1, and a suction force in the transport direction from the positive charges of the strip electrode 12B1. The 0 [V] portion in the medium 3 is not particularly involved.

Combining these forces, the medium 3 starts to move because it is pushed up and receives a force in the transport direction.
When it moves by one pitch of the strip electrodes, the attraction force between the charges in the medium and the charges in the strip electrodes facing each other becomes maximum and stops. This is the state of FIG. Next, when a [negative, negative, positive] voltage is applied to each strip electrode 12 (state in FIG. 6), the medium 3 moves one pitch in the transport direction by the same action (state in FIG. 7). When [positive, negative, negative] is further applied (state in FIG. 8), the medium similarly moves by one pitch in the transport direction (state in FIG. 9).

Here, [positive, negative, 0] is used as the applied voltage polarity pattern for initial polarization, and [negative, positive, negative], [negative, negative, as the applied voltage pattern for medium conveyance.
Positive] and [positive, negative, negative] were sequentially repeated to convey the medium 3 in a desired direction. However, the force for transporting the medium 3 depends on the balance between the attraction force and the repulsive force due to the polarity of the initial polarization charge in the medium and the voltage polarity applied to the strip electrode 12 of the stator 1, as described above. There are many possible combinations of patterns capable of transporting the medium other than the initial polarization pattern described above and the pattern applied to the strip electrode 12 of the stator 1.

FIG. 10 is an explanatory view showing a simple dynamic model.
Shows a simple mechanical model when the medium 3 starts to move.
You. Thus, in order to convey the medium 3, the conveyance force F
Is the coefficient of static friction μ_SAnd medium mass M, gravitational acceleration g, repulsion
Force F_C(-F for suction force _C) Static friction force F_uYo
Must be bigger than that. The medium 3 is on the strip electrode 12.
The repulsive force and attractive force received from the charged electric charges of each polarity are
The force charged in the strip electrode 12 is generated by a force called ron force.
It is proportional to the product of the load and the amount of charge polarized in the medium,
It is inversely proportional to the square of the will distance. Therefore, the conveyance force F is increased.
The following three types of methods can be considered to achieve this.

(1) The voltage value applied to the strip electrode is increased to increase the charge amount of the electrode. (2) The initial polarization time is lengthened to sufficiently perform polarization in the medium and increase the polarization charge amount in the medium. (3) The distance between the strip-shaped electrode and the polarization charge in the medium related to the transportation is shortened. In the case of the stator 1 where the pitch of the strip electrodes 12 is constant from the transfer start position to the transfer end position, it is difficult to carry out (3) as a method of increasing the transfer force F. ) Need to do. As described above, (1) has disadvantages such as discharge and generation of ozone, and (2) is not very practical because it takes time to start conveyance.

FIG. 11 is an explanatory diagram showing changes in the strip electrode pitch and the distance between charges. In the present embodiment, the band-shaped electrode pitch in the region where the static frictional force works is made finer than that in the normal transport path, so that the charge charged in the band-shaped electrode 12 and the charge polarized in the medium are changed. Even if it does not exist, the carrying force F can be improved without increasing the applied voltage or the initial polarization time by the effect of (3) as shown in FIG.

The pitch of the strip electrodes 12 is enlarged so that the desired transport speed is reached when the medium starts moving and enters the area of the dynamic friction force where the dynamic friction coefficient acts. Since the carrying force F decreases when the strip electrode pitch is expanded, it is necessary to determine the voltage value applied to the strip electrode 12 within a range in which the medium carrying operation can be performed in the region where the dynamic friction force acts. As described above, according to the present embodiment, by narrowing the strip electrode pitch at the start of medium transport and widening the pitch after the medium starts moving, a stable transport start operation can be performed without an increase in applied voltage. Can be realized.

[Second Embodiment] FIG. 1 is an explanatory view showing an embodiment, and FIG. 12 is an explanatory view showing a connection example of a strip electrode according to the second embodiment. The apparatus shown in these figures is composed of a stator 1 and basically does not require a special moving element and directly conveys a conveying medium 3 by conveying force.

The stator 1 comprises a base material 11 and a plurality of strip electrodes 1
2 are partially arranged at different pitches.
(A surface of the base material 11 that is in contact with the transport medium 3 is called a transport surface, and the opposite surface is called a non-transport surface.) The base material 11 is a high resistance body, such as a substrate shape, a film shape, a shape and a thickness. Can be freely designed. In this embodiment, an epoxy resin material is used.

The strip electrode 12 can be made of any conductive material such as copper or gold, and can be formed on the substrate 11 by a known technique such as printing or etching. After forming the strip-shaped electrode 12, a coating layer 13 having a coating may be provided thereon, if necessary. In the present embodiment, the insulating coating is performed for the purpose of improving the dielectric strength, smoothing the conveying surface, reducing friction, and preventing triboelectricity.

The electrode width and electrode pitch can be set freely,
In the present embodiment, the pitch is made fine in a place where a high conveyance force is required such as a conveyance start portion or a portion where conveyance accuracy is required,
The pitch is set to be large in the normal conveyance path. Further, the strip electrodes 12 are separately connected in three phases, which are A phase,
The electrodes connected to the A phase are 12A and B, which are called B phase and C phase.
The electrode connected to the phase is indicated as 12B, and the electrode connected to the C phase is indicated as 12C. This connection path is called a drive connection system.

Among the strip-shaped electrodes 12, in a portion having a fine pitch such as a transport start position, when the pitch is P, P (1 + 3m) [m = 1,2,3, ...] It is connected to each phase and is connected to a normal drive connection system via a relay 4 or the like which is a connection system switching means. This path is called a connection system for initial polarization. In the figure, 12A1, 12B1, 12C1 to 12A3, 12
B3 and 12C3 are the fine pitch portions, and of these, every 4P (when m = 1), 12A1 and 12B
Two electrodes of 2, 12C3 are connected to another system.

The relay 4 is used for switching between the drive connection system and the initial polarization connection system described above. Therefore, a structure that can withstand the magnitude of the voltage applied to each connection system is required. The switching method is mechanical using an electromagnet,
Known techniques such as a photo-moss method in which the resistance value is changed by light irradiation can be used. This switching is performed by a control signal from the control circuit 7.

The power supply 5 is a voltage source of a voltage applied to the strip electrode 12, and supplies a positive voltage and a negative voltage to the drive circuit 6. The drive circuit 6 has a positive voltage for each of the A phase, B phase, and C phase,
A negative voltage, 0 [V] (ground potential) can be freely switched and applied, and the voltage polarity applied to each phase is changed by a control signal from the control circuit 7.

13 to 23 are explanatory views (A) to (K) of the operation principle of the second embodiment, and the operation of the present embodiment will be described with reference to these drawings. First, the operation at the transport start position will be described. When the transport medium 3 reaches the transport start position, the voltage application path is switched to the initial polarization connection system by a signal from the control circuit 7. A voltage is applied to the strip electrode 12 from the drive circuit 6 through this path.

For example, 0 [V] is applied to the A phase, a negative voltage is applied to the B phase, and a positive voltage is applied to the C phase (hereinafter, this will be referred to as A phase, B phase, and C phase in this order.
Expressed as [0, negative, positive]. ) Is applied, the strip electrode 12A1 is applied with the ground potential, the strip electrode 12B2 is applied with a negative voltage, and the strip electrode 12C3 is applied with a positive voltage. Strip electrode 1 not connected to the initial polarization connection system
No voltage is applied to 2B1 and 12A2.

Each strip electrode 1 belonging to the connection system for initial polarization
Due to the voltage applied to 2, the charge in the carrier medium 3 facing the strip electrode 12 causes electrostatic polarization. Specifically, negative charges are present inside the carrier medium 3 facing the strip electrode 12C3 to which a positive voltage is applied, and positive charges inside the carrier medium 3 facing the strip electrode 12B2 to which a negative voltage is applied. , Are each guided. As a result, the charges in the carrier medium are polarized as shown in FIG. 13, which is called initial polarization.

After the initial polarization is completed, the voltage application path is switched to the drive connection system by a signal from the control circuit 7, and each phase of the belt circuit 12 from the drive circuit 6 [positive, positive,
Negative] voltage is applied. The charge in the carrier medium 3 which is initially polarized has a repulsive force from the charge of the same polarity in the strip electrode 12,
Further, each attracts an attractive force from the opposite polarity charges. Specifically, in the state of FIG. 14, the positive charges in the medium 3 are pushed in the direction in which the medium 3 is pushed up from the positive charges in the strip electrode 12B2, and in the transport direction (right direction in the figure) from the positive charges in the strip electrode 12A2. Repulsive force is applied to each, and a negative charge of the strip electrode 12C2 is attracted in the transport direction.

At the same time, the negative charges in the medium 3 are transferred to the strip electrode 12
Repulsive force is applied upward from the negative charge of C3. The 0 [V] portion in the medium 3 is not particularly involved. Combining these forces, the medium 3 is pushed up and moves from the left to the right in the figure, and when it moves one pitch portion of the strip electrode 12, the charge of the medium 3 moves downward from the strip electrode 12. , The frictional force on the surface of the stator 1 increases and stops. FIG. 15 shows this state.

Next, a [negative, positive, positive] voltage is applied to each strip electrode 1.
When applied to the medium 2 (FIG. 16), the medium 3 has the same effect.
Moves 1 pitch in the transport direction (FIG. 17). further,
When [positive, negative, positive] is applied (FIG. 18), similarly, the medium 3 moves one pitch in the transport direction (FIG. 19). Here, as an applied voltage polarity pattern for initial polarization, [0,
Negative, positive] as an applied voltage pattern for medium conveyance, [positive, positive, negative], [negative, positive, positive], [positive, negative, positive]
The above procedure was repeated in order to convey the medium 3 in a desired direction. However, since the force for transporting the medium 3 depends on the balance between the attraction force and the repulsive force due to the polarity of the initial polarization charge in the medium 3 and the voltage polarity applied to the stator electrode, as described above, it has been described here. Besides the initial polarization pattern and the voltage pattern applied to each strip electrode 12, there are many possible combinations of patterns that can transport the medium 3.

When the conveyance of the medium is started and the leading portion of the medium reaches the portion where the strip electrode pitch is wide, the moving speed is improved because the pitch is wide (FIGS. 20 to 23). For example, a portion where the strip electrode pitch is 0.1 [mm] and a portion where the strip electrode pitch is 0.4 [mm] are compared. When the switching frequency of the applied voltage pattern for medium conveyance is 1 [kHz], the medium moves at 0.001 [s] in one pitch of the strip electrodes. Therefore, 100 [mm / s] (0.1 [mm] /
The transport speed is 0.001 [s], but the pitch is 0.4 [mm].
In the portion of, the conveyance speed is 400 [mm / s]. Thus, when the switching frequency of the applied voltage pattern is constant,
The transport speed is directly proportional to the strip electrode pitch.

Similarly, when the medium reaches from the wide pitch portion to the narrow pitch portion, the transport speed of the medium decreases and the medium starts to move with high transport accuracy. Further, here, the transfer state from the left to the right in the drawing has been described, but the transfer from the right to the left in the drawing is also possible by changing the applied voltage pattern of the strip electrode. Since the medium always moves by one pitch, the accuracy of transporting the medium is determined by the pitch of the strip electrodes 12. Therefore, the finer the pitch, the higher the conveyance accuracy. On the contrary, the transfer speed is improved by widening the pitch.Therefore, it is possible to automatically change the transfer speed without a sensor or a special drive frequency control circuit by changing the pitch of the strip electrode of the stator not partially but partially. The transfer accuracy can be changed.

FIG. 10 is an explanatory diagram showing a simple dynamic model.
Shows a simple mechanical model when the medium 3 starts to move.
You. Thus, in order to convey the medium 3, the conveyance force F
Is the coefficient of static friction μ_SAnd medium mass M, gravitational acceleration g, repulsion
Force F_C(-F for suction force _C) Static friction force F
_u(= Μ_S(Mg-F_C)) Must be greater than
No. The medium 3 is charged in the strip electrode 12 and the electric charge of each polarity is obtained.
The repulsive force and suction force received from the load are called Coulomb force
And polarized in the medium with the amount of charge charged on the stator electrode
Proportional to the product of the amount of charge and inversely proportional to the square of the distance between charges
I do. Therefore, in order to increase the carrying force F, the following three types
The method is conceivable.

(1) The voltage value applied to the strip electrode is increased to increase the amount of charge charged in the electrode. (2) The initial polarization time is lengthened to sufficiently perform polarization in the medium and increase the polarization charge amount in the medium. (3) The distance between the strip-shaped electrode and the polarization charge in the medium related to the transportation is shortened.

In the case of the stator 1 in which the pitch of the belt-shaped electrodes 12 is constant from the carrying start position to the carrying end position, it is difficult to carry out (3) as a method of increasing the carrying force F. It is necessary to do step (2). As described above, (1) has many disadvantages in safety and cost, such as discharge and ozone generation, a new high-voltage power supply, and a high-voltage drive circuit. Further, in (2), since it takes a long time to start conveyance, both (1) and (2) are not very practical.

FIG. 11 is an explanatory diagram showing changes in the strip electrode pitch and the distance between charges. In the present embodiment, the strip electrode pitch in the region where the static frictional force such as the transport start position is dominant,
Since the pitch is made finer than the strip electrode pitch in a region where the dynamic frictional force is dominant, such as a portion where the medium is moving, the voltage applied to the strip electrode 12 and the amount of charge polarized in the medium are changed. Even if there is no, (3) as shown in FIG.
By the effect of, the transport force F can be improved without increasing the applied voltage or the initial polarization time.

The pitch of the strip electrodes 12 is enlarged so that the desired transport speed is reached when the medium starts moving and enters the area of the dynamic friction force where the dynamic friction coefficient acts. Strip electrode 12
When the pitch is expanded, the distance between the charges is increased and the carrying force F is reduced. Therefore, it is necessary to determine the voltage value applied to the strip electrode 12 within a range where the medium carrying operation can be performed in the region where the dynamic frictional force acts. .

When it is only intended to make the medium carrying speed variable, the distance between the strip electrodes 12 does not need to satisfy the conditions in the wide part and the narrow part, but high medium carrying accuracy is maintained. When the medium transport speed is variable, the stop error of the medium is reduced by matching the polarization charge in the medium with the position of the strip electrodes. Therefore, more preferable concrete condition is that the electrode pitch of the fine portion is P. In that case:

(1) When the finest strip electrode pitch is P, the other strip electrode pitches a satisfy the following equation. a = P (1 + 3m) [m = 0,1,2,3, ...] Example: In FIG. 12, 12A1 to 12C3 is the finest pitch portion, and the pitch of this portion is P. Therefore, between the strip-shaped electrodes after 12C3, for example, between 12C3 and 12A4, between 12B4 and 12C4, 12A1 and 12
It is necessary to make the distance between B1 times (1 + 3 m) times. In the figure, it is four times (m = 1).

(2) Interval between electrodes connected to connection system for initial polarization (polarization charge pitch in medium) bb = a _max (a _max : maximum value of strip electrode pitch a) Example: In FIG. 12, strip electrodes of 12C3 or later Pitch is a _max
It is. Therefore, it is necessary to connect to the initial polarization connection system at an interval corresponding to the distance between 12C3 and 12A4 in the fine pitch portion from 12A1 to 12C3. In the figure, since the distance between 12C3 and 12A4 is 4P, 12A1, 12B2, and 12C3 are connected to the connection system for initial polarization.

(3) Length L L ≧ 2b + P of Transport Medium in Transport Direction Example: In FIG. 12, b is the distance between 12A1 and 12B2. Therefore, 2b is the distance from 12A1 to 12C3, which is 12C from the center of the 12A1 electrode.
Up to the center of the three electrodes. By adding a half pitch before and after this, the area from the left end of the 12A1 electrode to the right end of the 12C3 electrode is obtained.

24 and 25 are explanatory views (A) of the relationship between the initial polarization charge position, the strip electrode pitch, and the medium transport accuracy.
It is (B), and the above conditions will be briefly described with reference to these drawings. The condition (1) is for causing the polarization charge position and the strip electrode position in the medium to face each other when the medium stops. When the stator is manufactured according to this condition, the error at the medium stop position becomes extremely small, as shown in FIG. On the other hand, when the stator is manufactured without satisfying this condition, as shown in FIG. 25, the medium stop error becomes large and the transport accuracy is significantly reduced.

(2) is related to (1). As described above, the force for transporting the medium is due to the Coulomb force with the polarized charge in the medium. Therefore, as the polarization charge in the medium increases, the generated transporting force increases. However, in the medium transport of this method, the carrier is transported by being influenced by the finer of the polarization charge in the medium and the stator electrode pitch. Therefore, if the polarization charge pitch in the medium is made fine, how Even if the electrode pitch is widened, since the conveyance proceeds depending on the polarization pitch in the medium, the conveyance speed cannot be made variable only by changing the stator strip electrode pitch. Therefore, in order to obtain the strong carrier force, the polarization charge pitch b in the medium should be made as small as possible, and the carrier speed depending on the belt electrode pitch should be obtained, the widest portion (a _max ) of the belt electrode pitch a.
The optimum condition is to form the polarization charge in the medium at the same pitch as.

(3) In the medium conveyance of this embodiment, at least one charge corresponding to the A phase, B phase, and C phase must exist in the medium. Therefore, at the pitch a of the connection system for initial polarization, at least the medium length from the left end of the A-phase electrode to the right end of the C-phase electrode is required. However, in reality, from the length L of the medium to be conveyed, the parameters (P,
It is better to decide a, b).

As described above, according to the present embodiment, when the stator having the non-uniform electrode pitch is used, the initial polarization of the carrier medium is performed in accordance with the portion having the widest pitch on the stator. Under a constant applied voltage, stable operation is possible in a portion where static friction is dominant, such as a conveyance start portion. Also, without a sensor or special drive frequency control circuit,
It is possible to change the transfer speed and transfer accuracy.

In both of the above embodiments, the rectangular conveying device has been described as an example, but the present invention is not limited to this, and since the stator can be formed into a film-like thin plate, the conveying path is formed by a curved surface. You can also Further, in both of the above-described embodiments, the case where the transport medium is directly transported by generating the transport force has been described, but a special mover is prepared and the medium is placed on the mover, and the transport force is generated in the mover. For example, the carrying force may not be directly applied to the carrying medium.

[0050]

As described above in detail, by changing the pitch of the strip-shaped electrode array of the stator according to the region, the transport performance is improved and the reliable and high-speed transport is always possible. In addition to the above, there is an effect that the carrying speed, the carrying accuracy, the carrying force, etc. can be freely set without adding any special means.

Further, by narrowing the strip electrode pitch at the start of medium transport and widening the pitch after the medium starts moving, it is possible to realize a stable transport start operation without increasing the applied voltage. Have. Furthermore, by performing the initial polarization of the carrier medium in conformity with the part having the widest pitch on the stator, it is possible to perform a stable operation in a part where static friction is dominant such as a carrier start part under a constant applied voltage. Have an effect.

At the same time, without controlling the switching frequency of the applied voltage pattern, depending on the electrode pitch of the stator,
This has the effect of automatically changing the medium transportation speed and the transportation accuracy.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment.

FIG. 2 is an explanatory diagram showing a connection example of the strip electrodes according to the first embodiment.

FIG. 3 is an explanatory diagram of an operation principle of the first embodiment (A).

FIG. 4 is an explanatory diagram (B) of the operation principle of the first embodiment.

FIG. 5 is an explanatory diagram (C) of the operation principle of the first embodiment.

FIG. 6 is an explanatory diagram (D) of the operation principle of the first embodiment.

FIG. 7 is an explanatory diagram (E) of the operating principle of the first embodiment.

FIG. 8 is an explanatory diagram (F) of the operating principle of the first embodiment.

FIG. 9 is an explanatory diagram (G) of the operation principle of the first embodiment.

FIG. 10 is an explanatory diagram showing a simplified dynamic model.

FIG. 11 is an explanatory diagram showing changes in the strip electrode pitch and the distance between charges.

FIG. 12 is an explanatory diagram showing a connection example of the strip electrodes according to the second embodiment.

FIG. 13 is an explanatory diagram (A) of the operation principle of the second embodiment.

FIG. 14 is an explanatory diagram (B) of the operation principle of the second embodiment.

FIG. 15 is an explanatory diagram (C) of the operating principle of the second embodiment.

FIG. 16 is an explanatory diagram (D) of the operation principle of the second embodiment.

FIG. 17 is an explanatory diagram (E) of the operation principle of the second embodiment.

FIG. 18 is an explanatory diagram (F) of the operating principle of the second embodiment.

FIG. 19 is an explanatory diagram (G) of the operating principle of the second embodiment.

FIG. 20 is an explanatory diagram (H) of the operation principle of the second embodiment.

FIG. 21 is an explanatory diagram (I) of the operating principle of the second embodiment.

FIG. 22 is an explanatory diagram (J) of the operation principle of the second embodiment.

FIG. 23 is an explanatory diagram (K) of the operation principle of the second embodiment.

FIG. 24 is an explanatory diagram of the relationship between the initial polarization charge position and the strip electrode pitch and the medium transport accuracy (A).

FIG. 25 is an explanatory diagram of the relationship between the initial polarization charge position and the strip electrode pitch and the medium transport accuracy (B).

[Explanation of symbols]

 1 Stator 4 Connection System Switching Means 5 Power Supply 6 Drive Circuit 7 Control Circuit 11 Base Material 12 Strip Electrode 13 Coat Layer

Claims (10)

[Claims] 1. A plurality of strip-shaped electrodes are arranged on a resistor, the strip-shaped electrodes are divided and connected in three or more phases to form a stator, and the polarity of a voltage applied to the strip-shaped electrodes of each phase is switched. In the medium transporting device that transports the medium along the stator by the electrostatic force, the distance between the strip-shaped electrodes is changed depending on the area in which they are arranged. 2. The medium transport according to claim 1, wherein the medium is directly placed on the transport surface of the stator, and the medium is transported by an electrostatic force generated between the stator and the medium. apparatus. 3. The static electricity generated between the stator and the mover according to claim 1, wherein the mover is placed on the transport surface of the stator, the medium is placed on the mover. A medium carrying device, which carries a medium by force. 4. The distance between the strip electrodes in the area where the medium starts to move from the distance between the strip electrodes in the area where the medium passes during operation according to any one of claims 1, 2 and 3. A medium transport device characterized by narrowing. 5. The belt-shaped electrodes according to claim 1, claim 2, claim 3 and claim 4, wherein the distance between the belt-shaped electrodes at the medium transport start position is made narrowest and the distance between the belt-shaped electrodes is gradually widened. A medium carrying device characterized in that a stator is formed so as to widen to an interval at which a desired carrying speed is obtained. 6. The medium carrying device according to claim 1, claim 2, claim 3, claim 4 or claim 5, wherein the interval between the strip electrodes in a region where a strong carrying force is required is narrowed. . 7. The method according to claim 1, claim 2, claim 3, claim 4, claim 5, and claim 6, characterized in that the interval between the strip-shaped electrodes in a region where high transport accuracy is required is narrowed. Media transport device. 8. In claim 1, claim 2, claim 3, claim 4, claim 5, claim 6 and claim 7, the interval between the strip electrodes is increased in a region where a high transport speed is required. A medium transport device characterized by the above. 9. In claim 1, claim 2, claim 3, claim 4, claim 5, claim 6, claim 7, and claim 8, application for medium transport is performed to the strip electrode. In addition to the drive connection system, a connection system for initial polarization for initial polarization of the medium, and a connection system switching means for switching the drive connection system and the connection system for initial polarization are provided. Only the initial polarization connection system is used to apply a voltage pattern for initial polarization, and when carrying is performed, the connection system switching means is switched to the drive connection system to apply the voltage pattern for carrying. A medium carrying device comprising a control circuit for controlling. 10. The length of a medium to be transported in the transport direction according to claim 1, claim 2, claim 3, claim 4, claim 5, claim 6, claim 7, claim 8 and claim 9. Is L, the minimum value of the interval between the strip electrodes existing in the stator is P, the interval between the strip electrodes is a, and the interval between the strip electrodes in the stator portion other than P is a, and the maximum value of this a is a
_{When max} is set and b is an in-medium polarization charge pitch, which is an interval between the strip electrodes connected to the initial polarization connection system at the transport start position, the following equation is given: a = P (1 + 3m) [m = 0, 1, 2, 3, ...] b = a _max L ≧ 2b + P