JP2000162780A - Static eliminator and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a static eliminator which can speedily and surely eliminate static electricity from a work. SOLUTION: A static eliminator for eliminating static electricity from an electrified work P by using ion is provided with a control circuit 13 for varying a balance between positive and negative ions. Further, the device can also be arranged so as to speedily and surely eliminate static electricity from the work P by measuring electrified condition of the work P by an electrification state measuring apparatus 11 and also varying a balance between positive and negative ions based on the measurement result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static electricity removing device and a static electricity removing method for removing static electricity charged on a work by using ions, and more particularly to a static electricity removing device suitable for use in a work carrying device for carrying a work. The present invention relates to an apparatus and a method for removing static electricity.

[0002]

2. Description of the Related Art As a transfer device attached to a glass plate exposure device for a liquid crystal display device, for example, a transfer device shown in FIG. 5 is known. The transfer device 1 moves a handling arm 2 supporting the lower surface of the glass plate P in a horizontal direction (arrows Y1 and Y2 directions) along rails 3 and 4 by two fingers 2a and 2b. The glass plate P accommodated in the carrier 6 is carried into a stage (not shown) of the exposure apparatus 7 by horizontally rotating the rail 3 and the handling arm 2 around the rotation axis 5, or the glass plate P on the stage is rotated.
Is carried out to the carrier 6. Reference numeral 8 denotes an elevating mechanism for elevating and lowering the carrier 6 in the direction in which the glass plates P are arranged (in the illustrated example, the vertical direction: the direction of the arrow Y3) and selecting the glass plate P to be conveyed.

In the exposure device 7, the loaded glass plate P is vacuum-sucked on a stage to expose a desired pattern. After the exposure, the glass plate P is peeled off from the stage and carried out to the carrier 6. At this time, the glass plate P is charged with static electricity. This charging phenomenon remarkably occurs particularly in the case of non-alkali glass for TFT liquid crystal. If this static electricity is left undischarged, discharge occurs between the glass plate P and a grounded part of the apparatus near the plate during unloading, or the static electricity of the glass plate P returned to the carrier 6 is reduced by the glass. The carrier 6 is accumulated as the number of plates P accommodated increases.
Finger 2a, 2 which is grounded to plate P
Discharge occurs between b. When the fingers 2a and 2b and the handling arm 2 are made of a conductor, such a discharge phenomenon causes holes in a resist layer formed on the surface of the glass plate P or damages elements on the surface. . Further, when the glass plate P is charged, dust easily adheres.

Therefore, in the above-described transport device, the exposure device 7
An electrostatic eliminator 9 is provided adjacent to the exposure device 7 to remove static electricity from the glass plate P carried out from
The static electricity on the glass plate P carried out from the exposure device 7 is removed. The static eliminator 9 removes static electricity by blowing an ion wind onto the glass plate P, and the positive and negative balance of the ion wind is always kept in a balanced state. This is because the uncharged glass plate P passes before exposure, that is, at the time of carry-in.
This is because it is necessary to give priority to the prevention of charging of the glass plate P, and the charging state (polarity and charge amount) of the glass plate P after exposure is unknown.

[0005]

The above-described conventional static eliminator has a low static elimination efficiency because the balance of the ion wind from the static eliminator 9 is maintained, and the glass plate carried out of the exposure device 7 When removing static electricity of P, it is necessary to expose the glass plate P to ion wind for a long time. For this reason, it is necessary to slow down the unloading speed of the glass plate P or to temporarily stop the glass plate P under the static eliminator 9, and it is unavoidable to lengthen the transport time.

Here, if the carrying speed of the glass plate P is increased with priority given to shortening the transport time, the static electricity cannot be sufficiently removed, and the possibility of causing discharge increases. When the static eliminator 9 is continuously used in a state where the balance of the ion wind is lost in order to enhance the static electricity removing effect, the glass plate P before the exposure processing is charged by the ion wind, causing a problem in the exposure processing. Further, as long as the charged state of the glass plate P to be conveyed is unknown, it is impossible to judge how to break the balance of the ion wind, and the ion wind and the static electricity are biased to the same polarity side, and the charge amount is reduced. May increase.

An object of the present invention is to provide a static electricity removing device and a static electricity removing method capable of quickly and surely removing static electricity regardless of a charged state of a work.

[0008]

An embodiment of the present invention will be described with reference to FIG. (1) The first aspect of the present invention is applied to a static electricity removing device that removes static electricity charged on a workpiece P using ions, and the above object is achieved by providing a changing means 13 for changing the positive / negative balance of ions. To achieve. (2) The invention according to claim 2 is applied to the static eliminator according to claim 1, and further includes a charged state measuring means 11 for measuring a charged state of the work P, and a changing means 13 is provided for the charged state measuring means 11. The positive / negative balance of ions is changed based on the measurement result. (3) A third aspect of the present invention is a static electricity removing method for removing static electricity charged on a workpiece P by using ions, wherein the static electricity on the workpiece P is removed by changing the positive / negative balance of ions. To achieve. (4) According to a fourth aspect of the present invention, in the method for removing static electricity according to the third aspect, the charged state of the work P is measured, and the positive / negative balance of ions is changed based on the charged state.

According to the first aspect of the present invention, the changing means changes the positive / negative balance of ions.
In the static eliminator according to claim 2, the charged state measuring means 11 measures the charged state of the work P, and the changing means 13 changes the positive / negative balance of the ions based on the measurement result of the charged state measuring means 11. . In the static electricity removing method according to the third aspect, the positive / negative balance of ions is changed when static electricity on the work P is removed. In the static electricity removing method according to the fourth aspect, the change of the positive / negative balance of the ions is performed based on the measurement result of the charged state of the work P.

In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments of the present invention are used to facilitate understanding of the present invention. However, the present invention is not limited to the embodiment.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Parts common to the above-described conventional example shown in FIG. 5 are denoted by the same reference numerals, and description thereof is omitted. In a transport device 10 shown in FIG. 1, a charge state measuring device 11 and a static electricity eliminator 12 are arranged in order from an exposure device 7 to a carrier 6 on a transport path in which a glass plate P for a liquid crystal display device reciprocates. I have. The charged state measuring device 11 measures a potential difference between the glass plate P and a conductor facing the glass plate P at a predetermined measurement distance,
This is a known method for determining the polarity and the charge amount of the glass plate P from the result and the above-described measured distance. The polarity and charge amount measured by the charge state measuring device 11 are supplied to the control circuit 13 as charge information.

As shown in FIGS. 1 and 2, the static eliminator 12 has a columnar main body 120 arranged so as to cross the conveying path of the glass plate P, and has a predetermined interval in the longitudinal direction on the lower surface side of the main body 120. And four (in the figure, four) nozzles 121 attached thereto, and a needle-like positive electrode 122 and a negative electrode 123 alternately inserted one by one at the center of each nozzle 121. With a voltage applied to the negative electrode 123 to generate positive ions and negative ions, air or nitrogen gas is pressure-fed from the nitrogen supply source NS to the upper portion of the nozzle 121 to eject ion wind from the lower opening of the nozzle 121. When this ion wind is blown onto the glass plate P, the surface of the glass plate P is electrically neutralized and static electricity is removed. The static eliminator 12 has a static elimination performance of the positive electrode 122 and the negative electrode 12.
The voltage changes in accordance with the voltage applied to 3, and when a voltage equal to both is applied, the positive / negative balance of the generated ionic wind is balanced and the static electricity removing performance for an object having a high charged potential is reduced. When the voltage of either the positive electrode 122 or the negative electrode 123 increases, the balance of the ion wind is biased to the positive or negative side accordingly, and the static electricity removing performance increases.

The control circuit 13 controls the operation of the handling arm 2 and the elevating mechanism 8 according to an operation program stored therein, and also controls the operation of the glass plate P based on the charging information sent from the charging state measuring device 11 and the conveying direction of the glass plate P. Thus, the voltage applied to the positive electrode 122 and the negative electrode 123 of the static eliminator 12 is controlled. The control circuit 13 itself determines the transport direction of the glass plate P. Specifically, it is determined whether the currently executed operation program of the handling arm 2 corresponds to the carry-in instruction or the carry-out instruction of the glass plate P, or the operation direction of the actuator that drives the handling arm 2 is detected. Then, it is determined which of the loading operation and the unloading operation of the glass plate P is activated. Note that a sensor may be arranged on the transport path of the glass plate P to detect the actual transport direction of the glass plate P.

FIG. 3 shows a control procedure of the static eliminator 12 in the control circuit 13. When the transfer device 10 is started to transfer the glass plate P, the control circuit 13 first determines whether or not the operation of unloading the glass plate P is performed in step S1. When it is determined that the carry-out operation is performed, the process proceeds to step S2, and the charge polarity and the charge amount of the glass plate P carried out from the exposure device 7 are read from the charge state measuring device 11.
In step S3, the voltage applied to the positive electrode 122 and the negative electrode 123 of the static eliminator 12 is changed according to the obtained charging information, and the static elimination performance is set to an optimal state. That is, by increasing the voltage of the electrode having the polarity opposite to the charge polarity of the glass plate P measured in step S2 according to the charge amount of the glass plate P, ions having the polarity opposite to the glass plate P can be charged. Is increased by an appropriate amount.

After the static elimination performance is set to a desired state, a static elimination time measuring timer is started in step S4 to keep the ion unbalance state for a predetermined time, and until the time is up in step S5. Repeat the decision. When it is determined that the time is up, the process proceeds to step S6, where the voltages applied to the positive electrode 122 and the negative electrode 123 of the static electricity eliminator 12 are made equal to zero the positive / negative imbalance amount of the ion wind, that is, a state where the ion balance is balanced. And the process ends. If it is determined in step S1 that the glass plate P is not unloaded, the process proceeds to step S6, and the ion balance is maintained in a balanced state.

As is apparent from the above description, in the present embodiment, the charged state of the glass plate P is measured when the glass plate P is carried out of the exposure device 7, and the ionic wind of the static eliminator 12 is measured in accordance with the measurement result. Since the positive / negative balance is broken according to the amount of charge to the opposite side to the charge polarity of the glass plate P, a high static electricity removing effect is obtained, and the time required for removing the static electricity of the glass plate P carried out from the exposure apparatus 7 is reduced. Is significantly shortened as compared with. Therefore, static electricity can be reliably removed even if the speed of carrying out the glass plate P is increased, and the transport time can be reduced. When the glass plate P is carried in, the ion balance of the static eliminator 12 is maintained in a balanced state, so that there is no possibility that the uncharged glass plate P may be erroneously charged.

In the present embodiment, the charge state of each glass plate P is measured by the charge state measuring device 11 to set the static electricity removal performance individually. When the charge amount is almost constant, the charge state measuring device 11 is omitted and the glass plate P
While maintaining the ion balance when carrying in the glass plate P, the ion balance may be uniformly disrupted when carrying out the glass plate P. Since the charged state of the glass plate P depends on the process before processing in the exposure device 7, the ion balance at the time of carrying out the glass plate P may be changed according to the process before exposure. At this time, if there is a host computer that manages the entire process, the host computer can also give an instruction for ion balance to the control circuit 13.

In the embodiment, the polarity and the unbalance amount of the ion wind are controlled to change the static electricity removing performance of the static electricity removing device 12. However, when the charging polarity of the glass plate P is determined and only the charging amount is unknown, It is only necessary to control the amount of imbalance of the static electricity removing unit 12. Incidentally, the charging polarity of the glass plate P is substantially determined by the material of the surface. For example, when the glass itself is exposed, it is charged to the positive side, and when the metal is laminated on the surface, it is charged to the negative side. When changing the static electricity removal performance, the amount of ion wind may be added to the control target. When the glass plate P is carried in, the power of the static eliminator 12 may be turned off to prevent charging, instead of setting the ion balance in a balanced state.

When a single static eliminator 12 cannot sufficiently remove static electricity due to a high carrying-out speed of the glass plate P, for example, a plurality of static eliminators 12A, 12B, 12B as shown in a transporting apparatus 10A shown in FIG. 12C may be arranged side by side on the transport path. In this case, the amount of imbalance of the ion wind of each static electricity removing device 12 may be reduced as the distance from the exposure device 7 increases, and the static electricity may be removed stepwise. When a plurality of sets of static eliminators 12 are required, each static eliminator 1
2, the required number of static eliminators 12 is smaller than before. When a plurality of static eliminators are provided, the glass plate P
Static eliminator 12 to a position where ion wind blows
When D is installed, it is necessary to always keep the ion balance of the static eliminator 12D balanced. In this case, the static eliminator 12D is not limited to the DC power supply type that can change the ion balance, and may be an AC power supply type that always balances the ion balance, and its operation needs to be synchronized with the transfer operation of the transfer device 10A. There is no.

In the above-described embodiment, it is assumed that the glass plate P before the exposure processing is uncharged, and when the glass plate P is carried in, the balance of the ion wind from the static eliminator 12 is balanced to prevent charging. When the glass plate P is charged in the process before exposure, the static eliminator 1 is set in accordance with the charged state.
The static electricity removal performance of No. 2 may be changed. For example, in the case where resist formation and baking processing are provided prior to the exposure processing, the glass plate P is attracted and peeled at that stage, so that charging may occur. In addition,
If the charged state at the time of loading is unknown, the charged state measuring device 11
Is added to the carrier 6 side of the static eliminator 12 to measure the charged state.

In the above-described embodiment, an example is described in which the glass plate P for a liquid crystal display device reciprocates in a conveying path, and a case where the charged state is different between the time of carrying in and the time of carrying out is assumed. Any type of work transfer device that needs to remove static electricity by the method may be used. Further, the present invention is not limited to a device in which a work reciprocates on the same path, and may be a transfer device in which a work whose charging state is unknown passes through the transfer path one way. In this case, the charged state measuring device 11 is provided on the transport path.
And the static eliminator 12 are arranged side by side in the transport direction, the charged state of the work to be conveyed is measured, and the static elimination performance of the static eliminator 12 is set in accordance with the result. Can be removed.

In the correspondence between the embodiment described above and the elements of the claims, the glass plate P constitutes a work, the charged state measuring device 11 constitutes a charged state measuring means, and the control circuit 13 constitutes a changing means. The charge state measuring device 11, the static electricity eliminators 12, 12A, 12B, 12C and the control circuit 13 constitute an electrostatic elimination device.

[0023]

As described above, according to the first aspect of the present invention, since the positive / negative balance of ions generated by the static electricity removing means is changed by the changing means, it is necessary to remove the static electricity charged on the work. The time can be reduced as compared with the conventional case. According to the second and fourth aspects of the present invention, the charged state of the work is measured, and the positive / negative balance of the ions is changed based on the measurement result. The static electricity can be removed, and the time required for removing the static electricity can be reduced as compared with the related art. According to the third aspect of the present invention, the positive / negative balance of the ions is changed when removing the static electricity from the work, so that the time required for removing the static electricity from the work can be shortened as compared with the related art.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams showing a transfer device provided with a static electricity removing device according to the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a side view from the direction of arrow Ib in FIG.

FIG. 2 is a diagram showing a schematic configuration of a static eliminator of the apparatus of FIG. 1;

FIG. 3 is a flowchart showing a control procedure in the control circuit of FIG. 1;

FIG. 4 is a diagram showing a modification in which a plurality of static eliminators are provided;
(A) is a plan view, (b) is a side view from the direction of the arrow IVb in (a) of FIG.

5A and 5B are diagrams illustrating an example of a conventional transport device, wherein FIG. 5A is a plan view, and FIG. 5B is a side view of the same in FIG.

[Explanation of symbols]

 10, 10A Conveying device 11 Charge state measuring device 12, 12A, 12B, 12C Static eliminator 13 Control circuit P Glass plate

Claims (4)

[Claims] 1. An electrostatic eliminator for removing static electricity charged on a workpiece by using ions, the static eliminator comprising changing means for changing the positive / negative balance of the ions. 2. The static eliminator according to claim 1, further comprising a charged state measuring means for measuring a charged state of the workpiece, wherein the changing means determines whether the ion is positive or negative based on a measurement result of the charged state measuring means. A static eliminator characterized by changing the balance. 3. A static electricity removing method for removing static electricity charged on a work by using ions, wherein the static electricity on the work is removed by changing a positive / negative balance of the ions. 4. The method for removing static electricity according to claim 3, wherein the charged state of the work is measured, and the positive / negative balance of the ions is changed based on the charged state.