JP2632452B2 - Paper transport mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper transport mechanism having a novel structure using an electrostatic actuator.

[0002]

2. Description of the Related Art For example, in OA equipment such as a facsimile, a paper transport mechanism requiring a motor-driven platen roller has been conventionally used. Fig. 4 shows the contact type image.
Of Document Reading Unit of Facsimile Using Image Sensor
Here is an example. Here, the paper (14) as the read original is transported.
Transported by the feed roller (15),
(16) pressed by the image sensor (17)
It is conveyed while. At this time, the transport roller (15)
A driving force transmitting means (18) is provided on the Latin roller (16).
(The drive belt in the figure), the motor (19)
The driving force is transmitted from. In addition, using the suction conveyance belt
FIG. 5 shows the transport system. This is disclosed in
No. 227657, and a conveying belt
(20) is a driving roller (21) and a driven roller (2).
2) It is stretched between. Also, a driving roller (21)
Is driven by the driving force transmitting means (23).
The driving force of 4) is transmitted to rotate, and this rotation causes transport.
The feed belt (20) is rotating in the direction of the arrow. here
When the paper (25) as the read original is inserted,
Paper (25) is electrostatically attracted to belt (20) and transported
As the belt (20) rotates, the paper (25) turns into an arrow.
In the direction of.

[0003]

However, in the above-described paper transport mechanism, in any case,
A motor for driving a ten roller or a sheet,
A transmission means for transmitting the driving force of the motor to the rollers is required.
An essential, therefore, there is disadvantage that heat and power consumption by the motor itself is generated is large, also, miniaturization of the apparatus
There are limits to the realization of. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a paper transport mechanism which can solve the above-mentioned disadvantages and can be miniaturized.

[0004]

That is, the gist of the present invention is to provide a stator in which strip electrodes are arranged on an insulating support at predetermined intervals and a movable member having a resistor layer provided on an insulating thin leaf. The paper transport mechanism using an electrostatic actuator arranged in the paper, the paper to be transported is placed on the mover via the insulating film spacer, and then from the surface of the stator strip electrode When the distance from the lower surface of the resistor layer of the mover to the lower surface of the paper is represented by G (μm), and the distance from the surface of the belt-like electrode of the stator to the lower surface of the paper is represented by D (μm), the thickness of the insulating film spacer is as described above. Is in a range satisfying a condition represented by 1.5 <D / G.

Hereinafter, the present invention will be described in detail. First, the outline of the electrostatic actuator will be described. The electrostatic actuator includes a stator in which strip electrodes are arranged at predetermined intervals on an insulating support, and a mover in which a resistor layer is provided on an insulating thin sheet such as an insulating film. It is arranged so as to be in contact with the child. Then, the movable element is instantaneously levitated and moved while preventing friction by the action of static electricity (Preliminary Proceedings of the 6th Annual Meeting of the Institute of Electrical Engineers of Japan 1991, Nikkei Mechanical 198).
9.5.29, pages 112 to 113).

FIGS. 2 (a) to 2 (d) are explanatory diagrams of the driving principle of an electrostatic actuator (electrostatic film actuator) in which a moving element is formed of an insulating film.
(1) is an insulating support, (2) is a strip electrode, (3) is a stator, (4) is an insulating film, (5) is a resistor layer,
(6) indicates a moving element, and (7) to (9) indicate electric wires.

First, as shown in FIG. 2A, a positive voltage is applied to the electric wire (7) and a negative voltage is applied to the electric wire (8). Thereby, by the potential difference between the electric charge existing in the electrode connected to the electric wire (7) and the electric charge existing in the electrode connected to the electric wire (8),
An electric current flows through the resistor layer (5), and electric charges are induced at a boundary between the insulating film (4) of the moving element (6) and the resistor layer (5), so that an equilibrium state is established. This charge is shown in FIG.
It can be replaced by the mirror image charge shown by the dotted line in (b). Since the polarity of the electric charge is different from the polarity of the electric charge, the moving element (6) is attracted to the stator (3) in the state of FIG.

Next, as shown in FIG. 2C, a negative voltage is applied to the electric wire (7), a positive voltage is applied to the electric wire (8), and a negative voltage is applied to the electric wire (9). Thereby, the charges in the electrodes can move instantaneously, but the induced charges of the mover (6) cannot move immediately due to the high resistance value of the resistor layer (5). as a result,
A repulsive force is generated between the moving element (6) and the stator (3). The repulsion reduces the friction between the stator (3) and the mover (6), resulting in a negative charge and a positive induced charge (mirror image charge) resulting from applying a voltage to the wire (9). As a result, a rightward driving force is generated.

FIG. 2D shows the result of the movement of the moving element (6) to the right by one pitch of the electrode due to the above driving force. When moving the slider (6) to the left,
What is necessary is just to apply a positive voltage to the electric wire (9). The applied voltage pattern (pattern shown in FIG. 2 (c)) in the above-described moving operation for each electrode pitch is the same as the state shown in FIG. 2 (c), the induced charge (in terms of mirror image charge) is attenuated.

Therefore, in order to continuously move the moving element (6) to the right at every pitch of the electrode, it is necessary to repeatedly apply a voltage having the following pattern in which the charge charging operation and the moving operation are repeated. . In addition, the voltage pattern illustrated in the following [Table 1] is a voltage pattern of one cycle,
(G) shows a state where no voltage is applied, (C) and (A) show a charge charging operation and a movement operation, respectively.
The first (C) is the state shown in FIG. 2 (a), and the first (A) is the state shown in FIG. 2 (c).

[0011]

[Table 1]

In order to stably and continuously move the electrostatic actuator at every electrode pitch, the surface specific resistivity of the moving element (6) (resistor layer (5)) should be 10 ¹² to 10 ¹⁵ Ω /.
It must be within the range of □. The reason is as follows. That is, when the surface resistivity of the moving element (6) is large, a relatively long time is required for charge charging, and when it is small, the induced charge is instantaneously attenuated.
However, in the case of the electrostatic actuator shown in FIG. 2, since the resistance value of the insulating film constituting the moving element is too large, the above-described resistor layer is provided on the insulating film to provide a small conductive property. It is necessary to give the property. In addition,
As a matter of course, in the known electrostatic actuator shown in FIG. 2, instead of the insulating film (4), another insulating thin body having a similar resistance value may be used.

Next, the paper transport mechanism of the present invention will be described. The paper transport mechanism of the present invention utilizes the above-described electrostatic actuator, and is mainly composed of a stator, a moving element, and an insulating film spacer that constitute the electrostatic actuator. FIG. 1 is a conceptual diagram of a paper transport mechanism of the present invention. In FIG. 1, the same reference numerals as those in FIG. 2 have the same meaning, (10) is an insulating spacer film,
1) represents paper, and (12) represents an insulating cover film. This
Here, the paper transport mechanism of the present invention is used for an OA machine such as a facsimile machine.
FIG. 3 shows a configuration example when used in a vessel. In the figure,
(3) is the stator, and (13) is the absolute as shown in FIG.
Movable element provided with edge thin body (4) and resistor layer (5)
(6) Insulating spacer film (10), read original
Paper (11) and insulating cover film (12)
It is a conveyed document composed of: As shown in this figure,
When the paper transport mechanism of the present invention is used, the driving motor and the driving force
No need for transmission means, platen roller, etc.
Heat and power consumption
It is.

In the paper transport mechanism according to the present invention, the electrostatic actuator is, like the known one, a stator (3) in which strip electrodes (2) are arranged at predetermined intervals on an insulating support (1). Movable element (6) provided with a resistor layer (5) on a thin leaf (4)
Are arranged so as to be in contact with each other.

First, the stator (3) will be described. The stator (3) is configured by arranging strip electrodes (2) on an insulating support (1) at predetermined intervals, similarly to a known electrostatic actuator. The insulating support (1) is composed of a film or sheet made of an insulating material. The insulating material is not particularly limited, and various synthetic resins, ceramics, glass, and the like having good insulating properties can be used.
Specific examples of the insulating resin include an epoxy resin, a polyimide resin, a polyester resin, a polypropylene resin, a polyvinylidene chloride resin, a polystyrene resin, a polyamide resin, a polyvinyl chloride resin, a polyethylene resin, and a polyvinyl alcohol-based resin. Preferred insulating resins are epoxy resins and polyester resins.

The strip electrodes (2) provided on the insulating support (1) may be provided side by side on the surface of the insulating support (1), or may be embedded in the insulating support (1). It may be provided. The interval between the strip electrodes (2) is not particularly limited, but is usually 0.1 to 2 mm. In order to improve the driving force of the electrostatic actuator, such as the generation force and the driving voltage, the strip electrodes (2) are used. Finer spacing is desirable.

Next, the moving element (6) will be described. In the paper transport mechanism of the present invention, the paper (11) to be transported is
It is placed on the moving element (6) via the insulating film spacer (10). Paper (cellulose paper) is obtained by making pulp, and the pulp is a hydrophilic material, and absorbs or desorbs moisture depending on the temperature and humidity of the atmosphere. Performs the so-called respiratory action of water. That is, the resistance value of paper is greatly affected by temperature and humidity, for example,
So-called PPC widely used in OA equipment such as facsimile
The surface resistivity of the paper is fairly small even at low humidity, and is about 5 × 10 ¹¹ Ω in an atmosphere of 26 ° C. and 30% humidity.
/ □. Therefore, the movable element (6) of the electrostatic actuator is omitted, and the paper (11) to be conveyed is replaced with the stator (3).
When placed directly on the paper (11), the charge induced in the paper (11) is instantaneously attenuated, and no static action occurs between the stator (3) and the paper (11). I can't let it. Therefore, in the paper transport mechanism of the present invention, the moving element (6) of the electrostatic actuator is used as it is, and the paper (11) to be transported is moved together with the moving element (6).

The moving element (6) is constituted by providing a resistor layer (5) on an insulating thin sheet (4), similarly to a known electrostatic actuator. The insulating thin body (4) is preferably made of the same synthetic resin as the above-mentioned insulating resin constituting the stator (3), but has a resistance value similar to that of the synthetic resin. Alternatively, it can be made of ceramics. When the insulating thin body (4) is made of an insulating film, a particularly preferred film is a polyethylene terephthalate film in terms of density, flexural modulus, wrinkle resistance and the like. The thickness of the insulating thin body (4) is usually from 10 to 20.
0 μm, and preferably, the interval between the strip electrodes (5) arranged on the insulating thin sheet (4) is P, and the surface of the strip electrode (5), the insulating thin sheet (4) and the resistor layer (5) Assuming that the distance from the boundary surface to G is G, the thickness of the insulating thin leaf (4) is
This is a range that satisfies the relationship of 0.10 <G / P <0.4.

The resistance layer (5) provided on the insulating thin sheet (4) must have a surface specific resistivity in the range of 10 ¹² Ω / □ to 10 ¹⁵ Ω / □, similarly to a known electrostatic actuator. . Such a resistor layer (5) can be easily provided, for example, by applying a weakly effective antistatic agent by a method such as spraying.

Next, an insulating film spacer (10)
Will be described. First, the significance of using the insulating film spacer (10) will be described. As described above, the paper (11) is made of the moving element (6) (the surface specific resistivity 10).
¹² to 10 ¹⁵ Ω / □), it acts as a conductor. Therefore, when the paper (11) to be conveyed is placed directly on the movable element (6), the electrostatic field formed on the movable element (6) is disturbed, and the movable element (6) based on the action of static electricity is disturbed. ) Driving force is reduced. Therefore, in the paper transport mechanism of the present invention,
In order to prevent disturbance of the electrostatic field formed on the moving element (6), an insulating film spacer (10) having a predetermined thickness is interposed between the paper (11) to be conveyed and the moving element (6). .

The thickness of the insulating film spacer (10) is G (μm) from the surface of the stator strip electrode to the lower surface of the resistor layer of the moving element, and the thickness of the paper from the stator strip electrode is When the distance to the lower surface is represented by D (μm), the thickness of the insulating film spacer must be in a range satisfying the condition represented by 1.5 <D / G. The greater the thickness of the insulating film spacer (10), that is, the greater the ratio D / G, the greater the effect of preventing the disturbance of the electrostatic field, but the greater the thickness of the insulating film spacer (10). Is too large and too heavy, the driving force of the moving element (6) is reduced. Therefore, the thickness of the insulating film spacer (10) is 2.
A range that satisfies the condition represented by 0 <D / G <4.0 is preferable. Also, the insulating film spacer (10)
The stator (3) is made of the same synthetic resin as the insulating resin described above, but is preferably made of a polyethylene terephthalate film in terms of density, flexural modulus, wrinkle resistance and the like. It is preferable that the optimum range of the thickness of the insulating film spacer (10) is determined in consideration of the relative dielectric constant in addition to the weight. For example, when a film having a relative permittivity smaller than that of a polyethylene terephthalate film (relative permittivity: 3 to 4), for example, a polytetrachloroethylene film is used, its thickness is 1.5.
A range that satisfies the condition represented by <D / G <3.0 is preferable.

Next, the insulating cover film (12) will be described. The insulating cover film (12) is used as a preferred embodiment. That is, the insulating cover film (12) is placed on the paper (11) to be conveyed, prevents the movable member (6) from being displaced from the paper (11) during conveyance, and secures the paper (11). Achieving an optimal transport. Therefore, it is used as needed according to the mode of use of the transport mechanism of the present invention. The insulating cover film (12) is preferably made of a polyethylene terephthalate film as in the case of the insulating film spacer (10).

In the paper transport mechanism of the present invention, the moving element (6) and the insulating film spacer (10) can be laminated and integrated. When the insulating cover film (12) is used, one end of the insulating film spacer (10) and the insulating cover film (12) are attached to each other by, for example, a fusion sealing method, and the paper (11) is used. ) Can also be formed.

The type of paper to which the paper transport mechanism of the present invention can be applied is not particularly limited, and typically includes various types of information paper such as PPC paper, but is not limited thereto. Not something. Generally speaking, the paper transport mechanism of the present invention is effective for paper having a surface resistivity of less than 10 ¹² Ω / □.

[0025]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In the following examples, the following materials and driving conditions were employed.

(1) Stator A stator having a width of 0.2 mm and a pitch of 0.4 mm was formed on the surface of a polyethylene terephthalate film having a thickness of 125 μm. Then, an insulating material was applied to the surface of the strip-shaped electrode, and G / P was adjusted to 0.13 before use. (2) Moving element A moving element was formed by spraying a weakly effective antistatic agent spray on one surface of a 25 μm-thick polyethylene terephthalate film (A4 size). The surface resistivity is 5 × 10
It was ¹⁴ Ω / □.

(3) Insulating spacer film Polyethylene terephthalate film (A4 size)
(A different thickness was used according to each example below). (4) Transport paper A4 size PPC paper The above PPC paper has a surface specific resistivity of 24 ° C.
In an atmosphere of 65% humidity, 3.5 × 10 ¹⁰ Ω / □,
The thickness is 90 μm and the weight is about 4 g. (5) Insulating film cover A polyethylene terephthalate film (A4 size) having a thickness of 25 μm was used.

(6) Driving Conditions Driving was performed under the following conditions in accordance with the procedures shown in FIGS. 2 (a) to 2 (d).

[Table 2] <Driving conditions> Initial charging time: 2 s Charging time: 9 ms Moving time: 1 ms Driving frequency: 100 Hz (paper transport speed 4 cm / s) Driving voltage: ± 600 v Atmosphere: 24 ° C., 65% RH

Example 1 A transport mechanism was constructed using an insulating spacer film having a thickness of 50 μm, and a transport test of PPC paper was performed. The distance (D) from the surface of the stator strip electrode to the lower surface of the paper was 102 μm, and D / G was about 2. The PPC paper moved with the mover and the insulating spacer film, and the insulating film cover moved with it.

Example 2 In Example 1, the thickness of the insulating spacer film was changed to 100 μm. (D) is 152 μm, and D
/ G was about 2.9. As a result of the transport test, the movable member, the insulating spacer film, the PPC paper, and the insulating film cover moved more smoothly as a unit than in Example 1 despite the increase in the overall weight.

Comparative Example 1 In Example 1, the thickness of the insulating spacer film was changed to 25 μm. (D) is 77 μm, and D / G
Was about 1.5. As a result of the transport test, the moving element, the insulating spacer film, the PPC paper, and the insulating film cover could not move, although they seemed to move integrally.

Comparative Example 2 A PPC sheet was placed directly on the stator, and a transport test was performed. The PPC paper was attracted to the stator and did not move at all.

[0033]

According to the present invention described above, the problem of heat generation and power consumption of the motor itself in the conventional paper transport mechanism can be solved and the miniaturization can be realized by skillfully utilizing the electrostatic actuator. Is provided.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a paper transport mechanism of the present invention.

FIG. 2 is an explanatory diagram of a driving principle of an electrostatic actuator.

FIG. 3 shows a facsimile document reading using the paper transport mechanism of the present invention .
FIG. 4 is a diagram schematically illustrating a configuration example when used in a fixing unit.

FIG. 4 is a facsimile using a conventional contact image sensor.
FIG. 3 is a diagram schematically illustrating a configuration example of a millimeter document reading unit.

FIG. 5 is an outline of a configuration example of a transport system using a suction transport belt .
FIG.

[Explanation of symbols]

 (1): Insulating support (2): Strip electrode (3): Stator (4): Insulating film or insulating thin plate (5): Resistor layer (6): Moving element (7) to ( 9): Electric wire (10): Insulating spacer film (11): Paper (12): Insulating cover film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Etsushi Hatabe 2-14-40 Ofuna, Kamakura City, Kanagawa Prefecture Inside the Living Systems Research Laboratory, Mitsubishi Electric Corporation (72) Inventor Yoshihiro Nagata 2-14, Ofuna, Kamakura City, Kanagawa Prefecture No. 40 Mitsubishi Electric Corporation Living System Laboratory (56) References JP-A-1-186178 (JP, A) JP-A-4-351478 (JP, A)

Claims (2)

(57) [Claims] 1. A paper using an electrostatic actuator in which a stator having strip electrodes arranged on an insulating support at predetermined intervals and a mover having a resistor layer provided on an insulating thin leaf are arranged so as to be in contact with each other. In the transport mechanism, the paper to be transported is placed on the mover via the insulating film spacer, and the distance from the surface of the strip electrode of the stator to the lower surface of the resistor layer of the mover is determined. G (μm), and when the distance from the surface of the strip electrode of the stator to the lower surface of the paper is represented by D (μm), the thickness of the insulating film spacer is represented by 1.5 <D / G. A paper transport mechanism characterized by satisfying the conditions. 2. The paper transport mechanism according to claim 1, wherein an insulating film cover is placed on the paper to be transported.