JP2008293792A - Static eliminator - Google Patents

Abstract

The present invention relates to a static eliminator that neutralizes paper sheets, and realizes a static eliminator that does not deteriorate the characteristics of resin parts of a transport mechanism and does not require an AC high-voltage power supply.
An outer peripheral surface is formed of a chargeable insulator, and the main roller is driven by rotation, and the main roller is charged by rotating in contact with the outer peripheral surface of the main roller and rotating with the main roller. A sub-roller 3 to be grounded, the tip of which is disposed in the vicinity of the outer peripheral surface 11 of the main roller 1, and a conductive discharge needle 4 that causes self-discharge with the main roller 1. As a result of the discharge, the paper sheet 5 that is the object of charge removal is discharged with air ions generated around the tip of the discharge needle 4.
[Selection] Figure 1

Description

  The present invention relates to a static eliminator that neutralizes paper sheets in, for example, an automatic teller machine, a printer, a copier, and the like.

  In devices that transport and process paper sheets, static electricity builds up on the paper sheets due to friction and peeling between rollers and belts, especially in low humidity environments, which can cause problems with transport operations and electrical problems in the transport mechanism. May cause. In order to solve this problem, countermeasures are taken such that an antistatic material is used for the parts so that static electricity does not collect easily, or static electricity is removed by disposing a static elimination brush on the conveyance path.

  The static elimination brush is made of conductive fibers or the like. When a paper sheet, which is a charged material, approaches the static elimination brush, electrostatic charge induces a charge having a polarity opposite to that of the paper sheet at the tip of the conductive fiber of the static elimination brush, and self-discharge (corona discharge) occurs. The emitted electrons then violently collide with air molecules, generating air ions. In the self-discharge type static eliminator, the paper sheet is neutralized with these air ions. For this reason, if the electric potential of the paper sheet is not very high (absolute value of about 3 kV), self-discharge does not occur, and the charge eliminating effect cannot be obtained.

  In order to improve this point, when an electric field forming electrode is provided in the surroundings and an AC high voltage is applied to the electrode to generate an electric field, and this electric field is added to the electric field from the charged object, the potential of the charged object is low. In addition, a voltage application type static eliminator has been proposed in which corona discharge occurs in the static eliminator brush (see, for example, Patent Document 1).

As another static elimination apparatus, there is an apparatus called an ionizer that applies a high voltage of direct current or alternating current to an electrode, generates ions by discharge caused thereby, and sends the ions toward a static elimination region. According to this, it is possible to stably remove static electricity to around 0V.
JP-A-6-63788 (FIGS. 1 and 2)

  In the ionizer, a large amount of ozone is generated with the generation of a large amount of ions, which deteriorates the characteristics of the resin parts of the transport mechanism. On the other hand, the voltage application type static eliminator described in Patent Document 1 has a problem that an AC high voltage power supply is required.

  The present invention has been made to solve the above problem, and aims to realize a static eliminator that does not deteriorate the characteristics of the resin parts of the transport mechanism and does not require an AC high-voltage power supply.

  In the invention according to claim 1 for solving the above-mentioned problem, the outer peripheral surface is formed of a chargeable insulator, and is rotated with the main roller in contact with the outer peripheral surface of the main roller that is rotationally driven. And a sub-roller for charging the main roller, and a grounding, the tip of which is disposed close to the outer peripheral surface of the main roller, and a conductive discharge needle for causing self-discharge with the main roller. A static eliminator that neutralizes a paper sheet to be neutralized with air ions generated around the tip of the discharge needle as a result of the self-discharge.

Here, the discharge needle refers to a linear conductive member formed so that corona discharge is performed from the tip, such as a metal needle with a sharp tip or a static elimination brush made of conductive fiber. .
In this invention, when the main roller is driven to rotate, the sub-roller in contact with the outer peripheral surface of the main roller also rotates, and the contact portion between the outer peripheral surface of the main roller and the outer peripheral surface of the sub-roller is in the circumferential direction. Then, contact and peeling are repeated continuously, and the outer peripheral surface of the main roller is charged stably and continuously. The charged portion of the main roller moves toward the vicinity of the discharge needle by the rotation of the main roller.

  When the charged spot of the main roller approaches the discharge needle, electrostatic charge induces a charge opposite in polarity to the paper sheet at the tip of the discharge needle, and self-discharge (corona discharge) occurs between the discharge needle and the main roller. The emitted electrons collide violently with air molecules, resulting in the production of air ions.

  The air ions are classified into positive ions and negative ions. Air ions having a polarity opposite to that of the main roller are attracted to the main roller. Conversely, air ions having the same polarity as the main roller are charged from the main roller. Move away.

  Now, if the charge polarity of the paper sheet is opposite to the charge polarity of the main roller, the air ions with the polarity moving away from the main roller are attracted to the paper sheet, combined with the charge of the paper sheet, and electrically neutralized. It will be neutralized. If the charged polarity of the paper sheet is the same as the charged polarity of the main roller, air ions of opposite polarity to these are attracted to the paper sheet and the main roller, and some of the air ions are combined with the charge of the paper sheet. Neutralized and the paper sheet is neutralized.

As described above, in the present invention, some of the air ions generated by the corona discharge reach the paper sheet being transported, and the paper sheet is neutralized.
According to a second aspect of the present invention, in the static eliminator according to the first aspect, the material of the outer peripheral surface of the sub-roller is selected so that the charging polarity of the main roller is opposite to the charging polarity of the paper sheet. The air ions having a polarity that contributes to static elimination are prevented from being attracted to the main roller.

  According to a third aspect of the present invention, in the static eliminator according to the first aspect, as the sub roller, the first and second sub rollers capable of switching the contact position / non-contact position with respect to the main roller are used. The material of the outer peripheral surface of each of the first and second sub-rollers is that of the main roller when the first sub-roller is brought into contact with the main roller and when the second sub-roller is brought into contact with the main roller. The one having the opposite charging polarity is used.

In the present invention, the charging polarity of the main roller can be freely selected by switching the sub roller that contacts the main roller.
According to a fourth aspect of the present invention, in the static eliminator according to the first aspect, polarity detection means for detecting the charging polarity of the paper sheet is provided, and the contact position / retraction position with the main roller can be switched as a sub-roller. The first and second sub-rollers, and the materials of the outer peripheral surfaces of the first and second sub-rollers are the same when the first sub-roller is brought into contact with the main roller and when the second sub-roller is the main When the roller is brought into contact with the roller, there is provided a roller in which the charging polarity of the main roller is reversed, and the charging polarity of the main roller is opposite to the charging polarity of the paper sheet based on the detection result of the polarity detection means. As described above, automatic switching means for selecting either the first or second sub-roller and bringing it into contact with the main roller is provided. Thereby, the charging polarity of the paper sheet and the charging polarity of the main roller can be automatically reversed.

According to the first aspect of the present invention, it is possible to realize a static eliminator that does not deteriorate the characteristics of the resin parts of the transport mechanism and does not require an AC high-voltage power supply.
According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the air ions having a polarity that contributes to the neutralization of the paper sheet are avoided from being attracted to the main roller, and the air is efficiently supplied to the paper sheet. There is an effect that it is possible to realize a static eliminator capable of attracting ions and neutralizing a paper sheet.

According to the invention of claim 3, in addition to the effect of the invention of claim 1, there is an effect that it is possible to realize a static eliminator that can freely select the charging polarity of the main roller.
According to the invention of claim 4, in addition to the effect of the invention of claim 1, the charge polarity of the paper sheet and the charge polarity of the main roller are always reversed, and a static elimination device that can efficiently remove the paper sheet is realized. There is an effect that can be done.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. In FIG. 1, the main roller 1 has an outer peripheral surface 11 formed of a chargeable insulator and is driven to rotate by a motor 2. The sub-roller 3 is for rotating the main roller 1 with the outer peripheral surface 31 coming into contact with the outer peripheral surface 11 of the main roller 1 and for charging the main roller 1. The conductive core member 32 of the sub roller 3 is grounded.

  An insulating material is charged by generating static electricity due to contact with or peeling from another material. In this case, the charge polarity and the charge amount differ depending not only on the material but also on the other material such as contact and peeling. The materials of the main roller 1 and the sub-roller 3 in this embodiment are selected so that the charge amount of the main roller 1 is increased to some extent. For example, the material located at the plus side end of the charge train table is the material of the main roller 1, and the material located at the minus side end is the material of the sub roller 3. In this way, the electrostatic voltage is considerably increased.

  The discharge needle 4 has conductivity, its base is grounded, and its tip is disposed close to the outer peripheral surface of the main roller 1. The discharge needle 4 causes self-discharge with the main roller 1, and as a result of this self-discharge, air ions are generated around the tip of the discharge needle 4, and the paper sheet 5 to be neutralized with these air ions. Is neutralized.

  In the present embodiment, a metal needle having a sharp tip is used as the discharge needle 4. However, a static elimination brush made of conductive fibers may be used. In short, it may be a linear conductive member formed so as to cause corona discharge from the tip, such as a metal needle or a static elimination brush. A conveyance path 6 for conveying the paper sheet 5 is formed so that the paper sheet 5 passes in the vicinity of the discharge needle 4.

  In this embodiment, when the main roller 1 is rotationally driven by the motor 2, the sub roller 3 in contact with the outer peripheral surface 11 of the main roller 1 also rotates, and the outer peripheral surface 11 of the main roller 1 is the outer peripheral surface 31 of the sub roller 3. And the contact and peeling are continuously repeated while moving the contact portion in the circumferential direction. As a result, the outer peripheral surface 11 of the main roller 1 is stably and continuously charged. At the same time, as the main roller 1 rotates, the charged portion of the main roller 1 moves toward the vicinity of the discharge needle 4.

  When the charged portion of the main roller 1 approaches the discharge needle 4, electric charges having a polarity opposite to that of the paper sheet 5 are collected at the tip of the discharge needle 4 due to electrostatic induction, and self-discharge between the discharge needle 4 and the main roller 1 ( Corona discharge) occurs, and the emitted electrons collide violently with air molecules. As a result, air ions are generated.

  The air ions include positive ions and negative ions. Air ions having a polarity opposite to the charging polarity of the main roller 1 are attracted to the main roller 1, and conversely, air ions having the same polarity as the charging polarity of the main roller 1 are Move away from the main roller 1. Some of these air ions go to the discharge needle 4.

  In this embodiment, the material of the outer peripheral surface 31 of the sub-roller 3 is selected so that the charging polarity of the main roller 1 is opposite to the charging polarity of the paper sheet 5, and the air has a polarity that contributes to charge removal of the paper sheet 5. The ions are prevented from being attracted to the main roller 1. For this reason, most of the polar air ions moving away from the main roller 1 are attracted to the paper sheet 5, and the air ions that have reached the paper sheet 5 are electrically neutralized by being combined with the charge of the paper sheet 5. Will be neutralized.

  Unlike the above-described embodiment, when the charging polarity of the main roller 1 is the same as the charging polarity of the paper sheet 5, air ions having a polarity opposite to that of the paper sheet 5 or the main roller 1 However, eventually, a part of them is combined with the electric charge of the paper sheet 5 to neutralize it electrically, and the paper sheet 5 is neutralized. Therefore, in this case as well, although efficiency is low, some of the air ions generated by corona discharge reach the paper sheet 5 and the paper sheet 5 is neutralized.

  Thus, in this embodiment, ozone is not generated in a large amount unlike the ionizer, and the characteristics of the resin parts of the transport mechanism are not deteriorated. Also, no AC high voltage power supply is required. In addition, the polar air ions that contribute to the neutralization of the paper sheet are avoided from being attracted to the main roller 1, and the air ions are efficiently attracted to the paper sheet 5 to neutralize the paper sheet 5. In addition, self-discharge can be stably caused in the main roller 1, and air ions are generated even when the charge potential of the paper sheet 5 is low, so there is an effect of static elimination. Compared with normal self-discharge type static elimination, It is possible to remove static electricity to a potential closer to 0V.

FIG. 2 is a block diagram showing a second embodiment of the present invention. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.
The second embodiment is the same as the first embodiment in that the polarity detection means 7 for detecting the charging polarity of the paper sheet is provided, and the contact position / retraction position with the main roller 1 can be switched as the sub roller 3. The second sub-rollers 3A and 3B are provided, and the automatic switching means 8 selects either the first or second sub-rollers 3A or 3B to contact the main roller 1.

  As materials of the outer peripheral surfaces of the first and second sub rollers 3A and 3B, the first sub roller 3A is brought into contact with the main roller 1 and the second sub roller 3B is brought into contact with the main roller 1. The case where the charging polarity of the main roller 1 is reversed is selected. Based on the detection result of the polarity detection means 7, the automatic switching means 8 is one of the first and second sub-rollers 3 </ b> A, 3 </ b> B so that the charging polarity of the main roller 1 is opposite to the charging polarity of the paper sheet 5. Is selected and brought into contact with the main roller 1.

  For example, the material of the outer peripheral surface of the main roller 1 is polyurethane, the material of the outer peripheral surface of the sub roller 3A is polyvinyl chloride, and the material of the outer peripheral surface of the sub roller 3B is polymethyl methacrylate, so that the sub roller 3A is the main roller. When the main roller 1 is in contact with the main roller 1, the main roller 1 is positively charged. When the sub roller 3B is in contact with the main roller 1, the main roller 1 is negatively charged. Based on the detection result of the polarity detection means 7, the automatic switching means 8 brings the sub roller 3B into contact with the main roller 1 when the paper sheet 5 is positively charged and the paper sheet 5 is negatively charged. Controls the sub roller 3A to come into contact with the main roller 1.

  Thereby, the charging polarity of the paper sheet 5 and the charging polarity of the main roller 1 can be automatically reversed. Therefore, most of the polar air ions moving away from the main roller 1 are attracted to the paper sheet 5, and the air ions that have reached the paper sheet 5 are combined with the electric charge of the paper sheet 5 to be electrically neutralized. It will be neutralized.

  Even in the second embodiment, ozone is not generated in a large amount unlike the ionizer, and the characteristics of the resin parts of the transport mechanism are not deteriorated. Also, no AC high voltage power supply is required. Moreover, it is possible to avoid attracting air ions having a polarity that contributes to the charge removal of the paper sheet to the main roller 1, efficiently attracting the air ions to the paper sheet 5, and neutralize the paper sheet 5. In addition, self-discharge can be stably caused in the main roller 1, and air ions are generated even when the charge potential of the paper sheet 5 is low, so there is an effect of static elimination. Compared with normal self-discharge type static elimination, It is possible to remove static electricity to a potential closer to 0V.

  The present invention is not limited to the above embodiment. For example, in the second embodiment, the polarity detecting means 7 for detecting the charging polarity of the paper sheet, and the automatic switching means for selecting any one of the first and second sub-rollers 3A and 3B and bringing them into contact with the main roller 1 8 is provided, but these may not be provided, and any one of the first and second sub-rollers 3A and 3B may be manually selected and brought into contact with the main roller 1.

It is a block diagram which shows the 1st Example of this invention. It is a block diagram which shows the 2nd Example of this invention.

Explanation of symbols

1: Main roller 2: Motor 3, 3A, 3B: Sub roller 4: Discharge needle 5: Paper sheet 6: Transport path 7: Polarity detection means 8: Automatic switching means 11, 31: Outer surface

Claims (4)

A main roller whose outer peripheral surface is formed of a chargeable insulator and is driven to rotate;
A sub-roller that charges the main roller by rotating together with the main roller in contact with the outer peripheral surface of the main roller;
Grounded, the tip thereof is disposed in the vicinity of the outer peripheral surface of the main roller, and comprises a conductive discharge needle that causes self-discharge with the main roller,
A static eliminator that neutralizes a paper sheet to be neutralized with air ions generated around the tip of the discharge needle as a result of the self-discharge.   2. The static eliminator according to claim 1, wherein a material of an outer peripheral surface of the sub roller is selected so that a charging polarity of the main roller is opposite to a charging polarity of the paper sheet.   As the sub-roller, a first sub-roller and a second sub-roller that can be switched between a contact position and a non-contact position with respect to the main roller. The material of the outer peripheral surfaces of the first and second sub-rollers is There is provided that the charging polarity of the main roller is reversed between when the first sub roller is brought into contact with the main roller and when the second sub roller is brought into contact with the main roller. The static eliminator according to claim 1.   Polarity detection means for detecting the charging polarity of the paper sheet is provided, and the first and second sub-rollers that can switch the contact position / retraction position with the main roller as the sub-roller. And the material of each outer peripheral surface of the second sub-roller is the main material when the first sub-roller is brought into contact with the main roller and when the second sub-roller is brought into contact with the main roller. The first and second rollers are provided such that the charging polarity of the roller is reversed, and further, based on the detection result of the polarity detection means, the charging polarity of the main roller is opposite to the charging polarity of the paper sheet. 2. The static eliminator according to claim 1, further comprising automatic switching means for selecting any of the second sub-rollers and bringing it into contact with the main roller.

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