JP2010008049A - Potential measurement apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a potential measurement apparatus for rapidly, safely and automatically calibrating a surface potential meter. <P>SOLUTION: The potential measurement apparatus includes a ring conductive member 6 for surrounding an area between a sensor section 2a of the surface potential meter 2 and a glass substrate 1, applies a reference potential to the conductive member 6 when there is no glass substrate 1 under the sensor section 2a, and calibrates the surface potential meter 2. The surface potential meter 2 is rapidly calibrated in comparison with a conventional apparatus manually calibrated by placing a metal plate 52 instead of the glass substrate 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a potential measuring device, and more particularly to a potential measuring device including a surface potentiometer that measures the potential of a charged object in a non-contact manner.

  A liquid crystal display panel is manufactured by repeating processing steps such as film formation and patterning on the surface of a glass substrate a plurality of times, and static electricity is generated on the surface of the glass substrate in each processing step. When this static electricity is discharged, electrode patterns and switching elements formed on the surface of the glass substrate are damaged, and the yield is lowered. Therefore, an ionizer and a surface potential meter are provided in each processing step to remove static electricity generated on the surface of the glass substrate by the ions generated by the ionizer, and the surface potential of the glass substrate is measured by the surface potential meter.

  In order to maintain the reliability of the measured value of the surface electrometer, it is necessary to periodically calibrate the surface electrometer (see, for example, Patent Document 1). FIG. 8 is a diagram showing a conventional method for calibrating a surface electrometer. In FIG. 8, the surface electrometer 50 includes a sensor unit 50a and a main body unit 50b. The sensor unit 50 a is fixed at a predetermined position in the processing device 51. The glass substrate is subjected to predetermined processing (for example, film formation) by the processing device 51, and then passes below the sensor unit 50a and is transported to the next processing device. At this time, the surface potential of the glass substrate is measured by the surface potentiometer 50, and the measured value is displayed on the main body 50b and recorded on a recorder (not shown).

When calibrating the surface electrometer 50, the worker places a metal plate 52 in place of the glass substrate below the sensor unit 50 a, applies a predetermined potential to the metal plate 52 by the DC power supply 53, and applies it. The difference between the measured potential and the measured value was recorded.
JP 2000-242136 A

  However, in the conventional method for calibrating the surface electrometer 50, since the operator manually calibrates, it is necessary to stop the processing device 51 during calibration. Further, since it is necessary to perform calibration in a large number of processing devices 51, there is a problem that it takes time for calibration. In addition, depending on the processing device 51, work at a high place is required, and there is a problem that it is dangerous.

  Therefore, a main object of the present invention is to provide an electric potential measuring device capable of quickly, safely and automatically calibrating a surface electrometer.

  A potential measuring device according to the present invention includes a surface potentiometer that measures the potential of a charged object disposed below the sensor unit in a non-contact manner, a conductive member fixed at a position different from the charged object below the sensor unit, A power supply that applies a reference potential to the conductive member when calibrating a surface potential meter that does not have a charged object under the sensor, and whether the measured value of the surface potential meter is within an acceptable range when the surface potential meter is calibrated Determination means.

  Preferably, the conductive member is formed in a ring shape and is disposed so as to surround a region between the sensor unit and the charged object.

  Preferably, the conductive member is formed in two flat plate shapes and is disposed so as to sandwich a region between the sensor unit and the charged object.

  Preferably, the conductive member is formed in a mesh shape and disposed in a region between the sensor unit and the charged object.

  In addition, another potential measuring device according to the present invention includes a surface potentiometer that measures the potential of a charged object disposed below the sensor unit in a non-contact manner, a conductive member, and the conductive member. When calibrating a surface electrometer that does not have a charged object on it, the conductive member is moved to a calibration position below the sensor unit, and during normal operation, the conductive member is moved to a standby position outside the sensor unit. A driving means, a power source that applies a reference potential to the conductive member during calibration of the surface electrometer, and a determination means that determines whether the measured value of the surface electrometer is within an allowable range during calibration of the surface electrometer It is.

Preferably, the driving means slides the conductive member between the calibration position and the standby position.
Further preferably, the driving means rotates the conductive member between the calibration position and the standby position.

  Preferably, the power supply sequentially applies a plurality of different reference potentials to the conductive member during calibration of the surface potentiometer, and the determination means indicates that each time the reference potential is applied, the measured value of the surface potentiometer It is determined whether or not the potential is within a predetermined allowable range.

  Preferably, the potential measuring device is used in a production process of a liquid crystal display panel, and the charged object includes a glass substrate of the liquid crystal display panel.

  In the potential measuring device according to the present invention, a surface potentiometer that measures the potential of a charged object disposed below the sensor unit in a non-contact manner, a conductive member fixed at a position different from the charged object below the sensor unit, A power supply that applies a reference potential to the conductive member when calibrating a surface potential meter that does not have a charged object under the sensor, and whether the measured value of the surface potential meter is within an acceptable range when the surface potential meter is calibrated Determining means is provided. Therefore, the surface electrometer can be calibrated quickly, safely and automatically regardless of the manual work of the worker.

  In another potential measuring device according to the present invention, a surface potentiometer that measures the potential of a charged object arranged below the sensor unit in a non-contact manner, a conductive member, and the conductive member are held, and the lower part of the sensor unit When calibrating a surface electrometer that does not have a charged object on it, the conductive member is moved to a calibration position below the sensor unit, and during normal operation, the conductive member is moved to a standby position outside the sensor unit. Driving means, a power source for applying a reference potential to the conductive member during calibration of the surface electrometer, and determination means for determining whether or not the measured value of the surface electrometer is within an allowable range during calibration of the surface electrometer. Therefore, the surface electrometer can be calibrated quickly, safely and automatically regardless of the manual work of the worker.

[Embodiment 1]
FIG. 1 is a diagram showing a configuration of a potential measuring apparatus according to Embodiment 1 of the present invention. In FIG. 1, this potential measuring device measures the surface potential of a charged glass substrate 1 in the manufacturing process of a liquid crystal display panel.

  The potential measuring device includes a surface potential meter 2 that measures the surface potential of the glass substrate 1 and a recorder 3 that records the measured value of the surface potential meter 2. The surface electrometer 2 includes a sensor part 2a and a main body part 2b. The sensor unit 2 a is fixed at a predetermined position in the processing apparatus 4 that performs film formation, patterning, and the like on the glass substrate 1. A small window is opened at the lower part of the tip of the sensor unit 2a, and the average value of the potential in the region facing the small window can be measured.

  The glass substrate 1 is subjected to predetermined processing (for example, film formation) by the processing device 4, then passes below the sensor unit 2 a and is conveyed to the processing device at the next stage (for example, the back side in FIG. 1). When the glass substrate 1 passes below the sensor unit 2a, the surface potential of the glass substrate 1 is measured by the surface potentiometer 2, and the measured value is displayed on the main body unit 2b and recorded on the recorder 3.

  In addition, this potential measuring device includes a sensor 5 that detects whether or not the glass substrate 1 is present below the sensor portion 2a of the surface potential meter 2, a conductive member 6 for calibrating the surface potential meter 2, and a conductive material. A DC power source 7 for applying a potential to the member 6, a control device 8 for controlling the entire device, and a buzzer 9 for notifying an operator of an abnormality of the device are provided.

  The glass substrate 1 is conveyed with a predetermined interval. The sensor 5 is disposed to face the conveyance path of the glass substrate 1. The output signal of the sensor 5 is given to the control device 8. As shown in FIG. 2, the conductive member 6 is formed in a circular ring shape, and is disposed in parallel to the glass substrate 1 so as to surround a region between the small window at the bottom of the sensor portion 2 a and the glass substrate 1. . The sensor part 2a is fixed to the lower part of the base end part of the sensor part 2a via the conductive holder 10 and the insulating member 11. An output terminal of the power source 7 is connected to the holder 10.

  The power source 7 applies a potential set by the control device 8 to the conductive member 6. The power source 7 applies a ground potential (0 V) to the conductive member 6 during normal operation for measuring the surface potential of the glass substrate 1, and a plurality of different conductive members 6 are used for calibration when the surface potential meter 2 is calibrated. Are sequentially applied (for example, −1 kV, 0 V, and +1 kV).

  Based on the output signal of the sensor 5, the control device 8 detects the timing at which the glass substrate 1 passes under the sensor unit 2 a of the surface electrometer 2 and the interval between the two glass substrates 1 that are continuously conveyed. To do. During normal operation, the control device 8 controls the power source 7 to apply a ground potential to the conductive member 6 and controls the surface potential meter 2 to measure the surface potential at the center of each glass substrate 1. Control and record the measurement. The control device 8 determines whether or not the measured value is within the allowable range. If the measured value is higher than the allowable range, the control device 8 sounds the buzzer 9 to notify the operator of the abnormality. When the buzzer 9 sounds, the worker stops the processing device 4 as necessary, investigates the cause, and performs appropriate measures (for example, repair of the ionizer).

  In addition, the controller 8 controls the power source 7 and sequentially applies a plurality of different reference potentials to the conductive member 6 at the timing when the glass substrate 1 is not present below the surface electrometer 2 when the surface electrometer 2 is calibrated. Then, the surface potential meter 2 is controlled to measure the surface potential of the conductive member 6 corresponding to each reference potential, and the recorder 3 is controlled to record the measured value. For each reference potential, the control device 8 determines whether or not the measured value is within the allowable range. If the measured value exceeds the allowable range, the control device 8 sounds the buzzer 9 to notify the operator of the abnormality. When the buzzer 9 sounds, the worker stops the processing device 4 as necessary, investigates the cause, and performs an appropriate treatment (for example, adjustment of the surface electrometer 2).

  The calibration of the surface electrometer 2 may be performed at a predetermined time, every time a predetermined time elapses, or every time the number of treatments of the glass substrate 1 reaches a predetermined number. May be. Moreover, you may provide a lamp | ramp instead of the buzzer 9 as an alerting | reporting means, or in addition to the buzzer 9. FIG. Further, an automatic calibration mode for automatically performing calibration and a manual calibration mode for manually performing calibration may be provided.

  FIG. 3 is a flowchart showing the operation of the potential measuring device when the surface electrometer 2 is calibrated. When the calibration mode is set, the control device 8 resets n to 1 in step S1. In step S2, a reference potential V1 (for example, −1 kV) is applied to the conductive member 6, and in step S3, the surface potential VD1 of the conductive member 6 is measured.

  Next, in step S4, the control device 8 compares the potential VD1 measured in step S3 with a lower limit value VL1 and an upper limit value VH1 that are set in advance with respect to the reference potential V1, and whether or not VL1 <VD1 <VH1. Determine. If VL1 <VD1 <VH1, it is determined in step S5 whether n = N (here, N = 3). Since n = N, n is incremented (+1) in step S6. Return to step S2.

  In the second step S2, a reference potential V2 (for example, 0 V) is applied to the conductive member 6, and in step S3, the surface potential VD2 of the conductive member 6 is measured. Next, in step S4, the control device 8 compares the potential VD2 measured in step S3 with the lower limit value VL2 and the upper limit value VH2 that are set in advance with respect to the reference potential V2, and determines whether VL2 <VD2 <VH2. Determine. If VL2 <VD2 <VH2, it is determined in step S5 whether n = N. Since n = N (N = 3) is not satisfied, n is incremented (+1) in step S6 and the process returns to step S2.

  In step S2 for the third time, a reference potential V3 (for example, −1 kV) is applied to the conductive member 6, and in step S3, the surface potential VD3 of the conductive member 6 is measured. Next, in step S4, the control device 8 compares the potential VD3 measured in step S3 with a lower limit value VL3 and an upper limit value VH3 that are set in advance with respect to the reference potential V3, and whether or not VL3 <VD3 <VH3. Determine. If VL3 <VD3 <VH3, it is determined in step S5 whether or not n = N. Since n = N (N = 3), calibration is terminated.

  In step S4, if VLn <VDn <VHn is not satisfied, the buzzer 9 is sounded in step S7, and the calibration is completed. Note that after sounding the buzzer 9, the process may proceed to step S5 to continue calibration.

  In the first embodiment, a ring-shaped conductive member 6 is provided so as to surround a region between the sensor unit 2a of the surface electrometer 2 and the glass substrate 1, and the conductive member is provided when the glass substrate 1 is not present below the sensor unit 2a. A reference potential is applied to 6 to calibrate the surface potentiometer 2. Therefore, the surface potential meter 2 can be calibrated quickly compared to the conventional case where the metal plate 52 is placed in place of the glass substrate 1 and the calibration is performed manually. Even when the glass substrate 1 is transported at a high place, the calibration can be performed safely. Moreover, since it can calibrate, conveying the glass substrate 1 with a predetermined space | interval, it is not necessary to stop the processing apparatus 4 at the time of calibration.

  FIG. 4 is a diagram showing a modification of the first embodiment, and is a diagram contrasted with FIG. In FIG. 4, in this modification, the conductive member 6 is replaced with the conductive member 12. The conductive member 12 is formed in a U shape. The two parallel flat plate portions 12 a and 12 b are arranged in parallel to the glass substrate 1 so as to sandwich the region between the sensor portion 2 a and the glass substrate 1. Even in this modified example, the same effect as in the first embodiment can be obtained.

  5, the conductive member 6 is replaced with the conductive member 13. The conductive member 13 is formed in a mesh shape and is disposed in a region between the sensor unit 2 a and the glass substrate 1. Even in this modified example, the same effect as in the first embodiment can be obtained.

[Embodiment 2]
6 (a) and 6 (b) are diagrams showing the configuration and operation of the main part of the potential measuring device according to the second embodiment of the present invention, and are compared with FIG. 6A and 6B, a linear actuator 21 is fixed via an insulating member 20 below the sensor portion 2a of the surface electrometer 3, and a flat conductive member 22 is fixed to a movable portion of the linear actuator 21. ing. The conductive member 22 is translated in the length direction of the sensor unit 2 a by the linear actuator 21. The linear actuator 21 is composed of, for example, an air cylinder or an electromagnetic solenoid.

  At the time of normal operation, as shown in FIG. 6A, the conductive member 22 is disposed at a standby position deviated from the lower end of the sensor portion 2a, and a ground potential is applied to the conductive member 22. At the time of calibration, as shown in FIG. 6B, the conductive member 22 is disposed in a region between the sensor unit 2a and the glass substrate 1, and a plurality of different reference potentials are sequentially applied to the conductive member 22. Since other configurations and operations are the same as those in the first embodiment, description thereof will not be repeated. Also in this second embodiment, the same effect as in the first embodiment can be obtained.

  FIGS. 7A and 7B are diagrams showing a modification of the second embodiment. 7 (a) and 7 (b), in this modification, a semi-cylindrical conductive member 23 is fixed to a rotating shaft of a motor (not shown), and the conductive member 23 rotates around the front end portion of the sensor portion 2a. It is provided as possible.

  During normal operation, as shown in FIG. 7A, the conductive member 23 is disposed at a standby position above the tip of the sensor unit 2a, and a ground potential is applied to the conductive member 23. At the time of calibration, as shown in FIG. 7B, the conductive member 23 is disposed in a region between the sensor unit 2a and the glass substrate 1, and a plurality of different reference potentials are sequentially applied to the conductive member 23. Even in this modified example, the same effect as in the second embodiment can be obtained.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a block diagram which shows the structure of the electric potential measurement apparatus by Embodiment 1 of this invention. It is a figure which shows the structure of the electrically-conductive member shown in FIG. It is a flowchart which shows the operation | movement at the time of calibration of the electric potential measuring apparatus shown in FIG. 5 is a diagram illustrating a modification example of the first embodiment. FIG. It is a figure which shows the other example of a change of Embodiment 1. FIG. It is a figure which shows the principal part of the electric potential measurement apparatus by Embodiment 2 of this invention. It is a figure which shows the example of a change of Embodiment 2. FIG. It is a figure which shows the calibration method of the conventional surface electrometer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Glass substrate, 2,50 Surface potential meter, 2a, 50a Sensor part, 2b, 50b Main body part, 3 Recorder, 4,51 Processing apparatus, 5 Sensor, 6, 12, 13, 22, 23 Conductive member, 7,53 DC power supply, 8 control device, 9 buzzer, 10 holder, 11, 20 insulating member, 12a, 12b flat plate portion, 21 linear actuator, 52 metal plate.

Claims (9)

A surface potentiometer that measures the potential of a charged object arranged below the sensor unit in a non-contact manner;
A conductive member fixed at a position different from the charged object below the sensor unit;
A power source for applying a reference potential to the conductive member during calibration of the surface potentiometer in which the charged object is not disposed below the sensor unit;
A potential measuring apparatus comprising: a determination unit that determines whether or not a measured value of the surface electrometer is within an allowable range when the surface electrometer is calibrated.   The potential measuring device according to claim 1, wherein the conductive member is formed in a ring shape and is disposed so as to surround a region between the sensor unit and the charged object.   The potential measuring device according to claim 1, wherein the conductive member is formed in two flat plate shapes and is disposed so as to sandwich a region between the sensor unit and the charged object.   The potential measuring device according to claim 1, wherein the conductive member is formed in a mesh shape and disposed in a region between the sensor unit and the charged object. A surface potentiometer that measures the potential of a charged object arranged below the sensor unit in a non-contact manner;
A conductive member;
When calibrating the surface potentiometer that holds the conductive member and the charged object is not disposed below the sensor unit, the conductive member is moved to a calibration position below the sensor unit, and during normal operation. Driving means for moving the conductive member to a standby position removed from below the sensor unit;
A power source for applying a reference potential to the conductive member during calibration of the surface potential meter;
A potential measuring apparatus comprising: a determination unit that determines whether or not a measured value of the surface electrometer is within an allowable range when the surface electrometer is calibrated.   The potential measuring apparatus according to claim 5, wherein the driving unit slides the conductive member between the calibration position and the standby position.   The potential measuring apparatus according to claim 5, wherein the driving unit rotates the conductive member between the calibration position and the standby position. The power source sequentially applies a plurality of different reference potentials to the conductive member during calibration of the surface potentiometer,
2. The determination unit according to claim 1, wherein each time the reference potential is applied, the determination unit determines whether the measured value of the surface electrometer is within a predetermined allowable range with respect to each reference potential. 8. The potential measuring device according to any one of 7 to 7. The potential measuring device is used in the production process of a liquid crystal display panel,
The potential measuring device according to claim 1, wherein the charged object includes a glass substrate of the liquid crystal display panel.

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