JP2002368059A - Work carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work carrier in which the static charged state of a larger number of works can be detected efficiently and accurately using a small number of measuring instruments without limiting the object of measurement directly to a work, e.g. a liquid crystal substrate. SOLUTION: The liquid crystal substrate carrier 2 for receiving a liquid crystal substrate 1 and transferring it to an other place comprises an arm 3 for mounting and holding the liquid crystal substrate, and means 4, 6, 11 and 13 for detecting charged state of the liquid crystal substrate by measuring at least either one of the quantity of charges or the potential being induced on the arm 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to (a) a work,
The present invention relates to a work transfer device having a means for measuring a charged state of (b) a device on which a work is placed or (c) a device for transferring a work, and more specifically, (a) a liquid crystal substrate,
(B) A device on which a liquid crystal substrate is placed or (c) A device for transporting a liquid crystal substrate.

[0002]

2. Description of the Related Art As a substrate transport device for a liquid crystal display device, an example as shown in FIG.
No. 222563). In order to measure the charge amount of the liquid crystal substrate 101, a surface potential sensor 111 is installed outside the transfer device, and when the transfer device holds the liquid crystal substrate on the transfer arm and passes under the surface potential sensor, Has a structure for measuring the surface potential. It is also known that a surface potential sensor is similarly installed in a cassette or the like for storing a liquid crystal substrate to measure the charged state of the substrate.

[0003]

In manufacturing a liquid crystal display device, the following can be exemplified as a portion where the liquid crystal substrate is mounted in a stationary state and a device for moving the liquid crystal substrate. (A) a cassette made of resin or metal for storing a plurality of liquid crystal substrates; (b) a positioning portion for positioning the liquid crystal substrate; (c) a table for fixing the liquid crystal substrate for processing by a processing device; Transfer robot (e) Roller In recent years, transfer robots have been particularly frequently used.
In the above-described transfer device for measuring the surface potential of the liquid crystal substrate, a surface potential sensor is disposed above the surface of the substrate to directly detect the surface potential of the substrate in order to detect the charged state of the substrate. In order to directly measure the potential of the substrate, it is necessary to bring the surface potential sensor close to the substrate surface. However, since there is a possibility that the surface potential sensor at a position close to the substrate surface at the transfer position of the substrate may interfere with the transfer device, another measurement method is required.

Further, in order to measure the charged state of a portion where the liquid crystal substrate is being transported or a portion where the liquid crystal substrate is being transported, it is necessary to install a surface potential sensor for each measurement location. In addition, when measuring the charged state of a liquid crystal substrate housed like a cassette, a surface potential sensor cannot be mounted above the surface of the liquid crystal substrate.
Must be measured from the side of the cassette. Due to this aspect of the measurement, the accuracy of the measurement is reduced. Further, a cassette used for a liquid crystal substrate usually contains about 20 liquid crystal substrates, so that the height of the cassette is about 300 mm to 1000 mm depending on the size of the liquid crystal substrate. Therefore, in order to measure the potentials of all the liquid crystal substrates, a very large number, for example, ten or more surface potential sensors are required. In a liquid crystal display device manufacturing factory, there are numerous positions where cassettes are placed, and it is difficult to grasp the charged state of the substrate in all of them.

Accordingly, the present invention provides an apparatus capable of efficiently and accurately determining the charged state of a large number of works by installing a small number of measuring devices without directly measuring a work such as a liquid crystal substrate. The purpose is to do.

[0006]

SUMMARY OF THE INVENTION A work transfer device according to the present invention is a work transfer device for receiving a work and moving it to another location, comprising an arm for placing and holding the work, and an electric charge induced in the arm. And a charged state detecting means for detecting a charged state of the work by measuring at least one of the charged state and the potential (claim 1).

With this configuration, the charged state of the work can be known based on a phenomenon such as electrostatic induction generated in the arm without directly measuring the potential of the work. For this reason, it is not necessary to bring the measuring means close to the work, and there is no interference between the work conveying means and the measuring means. Further, it is sufficient to provide the arm measuring means only in the work transfer device at a special point where many flows of the works are joined, without providing the measuring means for all the flows of the works in the factory. As a result, it is possible to efficiently grasp the charged state of many works by disposing a small number of measuring means. Furthermore, for example, it is not necessary to forcefully measure the potential of a work placed on a cassette in a narrow place, and it is not necessary to perform measurement with low accuracy.

The material constituting the arm may be a conductor or a composite material of a conductor and an insulator. The work transfer device is a broad concept including a work transfer robot.

In the work transfer device of the present invention, the work transfer device determines the charged state of at least one of the work and the portion on which the work is mounted, based on the measurement data on the arm by the charged state detection means. Work charge state determination means can be provided (claim 2).

Since the potential of the work is not directly measured, a means for determining the potential of the work from the potential of the arm or the like is required. The means for determining the potential of the work includes, in advance, correspondence (calibration) data corresponding to the amount of charge such as electrostatic induction generated in the arm and the potential of the work. Further, the corresponding (calibration) data may be replaced with calculation data simulating the same contents instead of the actual measurement data. By comparing the measurement data of the arm with the above-mentioned charged state determining means of the work,
It is possible to know the work or a portion where the work is placed, for example, the charged state in the cassette.

The work transfer device of the present invention has an operation control means for controlling the operation of the arm, and the work charge state determining means determines the work and its work in accordance with the operation stage of the arm obtained from the operation control means. The charged state of at least one of the portion where the work is placed can be determined (claim 3).

In order to determine the charged state of the work from the measurement of the arm, it is important to know the environment around the arm. That is, whether the arm position is loading only the work, loading the work only in the cassette, and not loading the work, loading the work in the cassette, loading the work and loading the cassette It is necessary to know whether it was pulled out from. By the operation control means, the environment of the arm can be easily known, and the charged state of the cassette or the portion where the cassette is placed can be distinguished and accurately determined.

In the above-described work transfer apparatus of the present invention, the work charge state detecting means may include an electric quantity measuring means for measuring an electric quantity flowing between the arm and the ground.

Since the arm includes a conductor, electric charge is induced by electrostatic induction or the like. At the time of the electrostatic induction, a current (charge) flows with the ground. By measuring the current or the electric charge, it is possible to know the potential of the arm, and further to know the charged state of the work and the work placement site.

The work transfer apparatus of the present invention may include a potential measuring means for measuring the potential of the arm by the charged state detecting means. By knowing the potential of the arm, it is naturally possible to know the charged state of the work and the work placement site.

The work transfer device of the present invention may include a warning signal activating means for issuing a warning signal when the value of the work charged by the work charging state determining means exceeds an allowable value (claim 4). .

With this warning signal, it becomes possible to neutralize or detect and remove the cause of charging by an ionizer that scatters electric charge opposite to that of the work. Based on these warning signals, the activation of the ionizer and the like can be naturally automated.

The work transfer device of the present invention may include a ground connection means for connecting the work transfer means and a ground wire so that the potential of the arm becomes zero (claim 5).

In order to clarify the initial potential of the arm, the arm may be set to zero volt before measuring the potential of the arm. In such a case, the arm can be immediately brought to the ground potential by the ground connection means. As a result, it is possible to improve the measurement accuracy and accurately grasp the charged state of the work.

In the work transfer device of the present invention, the work may be a liquid crystal substrate, and the work transfer device may be a liquid crystal substrate transfer device.

With this configuration, it is possible to know the charged state of the liquid crystal substrate by measuring the potential or the like of the arm of the robot for transporting the liquid crystal substrate, and take necessary measures.

[0022]

Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a diagram showing a configuration of a liquid crystal substrate transport apparatus according to Embodiment 1 of the present invention. This liquid crystal substrate transfer device is a device that verifies whether or not the charged state of the liquid crystal substrate can be known by measuring the electric potential of the arm that forms the basis of the present invention and the amount of charge flowing between the arm and the ground. is there. In FIG. 1, cassette 2
The liquid crystal substrate 1 is placed on the reference numeral 0. This liquid crystal substrate has
The surface potential sensor 11 a is arranged near the surface of the liquid crystal substrate, and is connected to the surface potential meter 11. The surface potential sensor 11a is a measuring means for associating the data with the arm, and may be included in the original transport device of the present invention, but is not essential.

The arm 3 is connected to the ground 5,
A minute ammeter (charge meter) 4 is disposed between them to measure the charge flowing between the arm and the ground. This microammeter corresponds to a measuring means for the arm for measuring the amount of electric charge and potential induced in the arm. The surface potential and the electric charge (current) are recorded with time.

FIGS. 2A, 2B, and 2C show the arm 3 facing the liquid crystal substrate 1 placed on the cassette 20. FIG.
, The operation until the liquid crystal substrate 1 is lifted up is divided into three stages. FIG. 2A is a stage S1 in which a voltage of 1 kV is applied to the liquid crystal substrate 1 in the cassette, FIG. 2B is a stage S2 in which the arm 3 is inserted in the cassette, and FIG. Shows a step S3 in which the arm is lifted up and the liquid crystal substrate is loaded.

FIG. 3 is a diagram showing the time transition of the surface potential of the liquid crystal substrate from S1 to S3 and the amount of charge flowing between the arm and the ground. According to this figure, it is found that there is a very good correlation between the substrate surface potential and the charge amount at each stage. Therefore, by measuring the amount of charge flowing between the arm and the ground, the surface potential of the liquid crystal substrate can be determined with high accuracy based on this figure. For this reason, the charged state of the liquid crystal substrate can be measured without causing interference between the transport device and the measuring device. A charge meter (ammeter) that measures the flow of charge between the arm and the ground can be installed with a small number of measuring devices if it is placed on a transfer robot where the flow of the liquid crystal substrate merges, such as in a liquid crystal display device manufacturing factory. The charged state of many liquid crystal substrates can be grasped efficiently.

(Embodiment 2) FIG. 4 is a view showing a liquid crystal substrate transport apparatus according to Embodiment 2 of the present invention. According to this figure, a measurement sensor 11a of a surface voltmeter (I) is disposed on the liquid crystal substrate 1, and a surface voltmeter (I) is mounted on the arm 3.
The measurement sensor 11a of I) is arranged. This device is provided to verify whether the surface potential of the liquid crystal substrate can be accurately determined from the surface potential of the arm.

FIG. 5 is a diagram showing the time transition between the surface potential of the liquid crystal substrate and the surface potential of the arm, including the three steps S1, S2 and S3 of the arm and the cassette shown in FIG.
According to this figure, there is a very good correlation between the substrate surface potential and the arm surface potential for each state. Therefore, by measuring the surface potential of the arm, the surface potential of the liquid crystal substrate can be determined with high accuracy based on this figure. For this reason, the charged state of the liquid crystal substrate can be determined without causing interference between the transport device and the measuring device. In addition, if the surface electrometer of the arm is placed on the transfer robot where the flow of the liquid crystal substrate merges in the manufacturing factory of the liquid crystal display device, etc., the charged state of many liquid crystal substrates can be grasped efficiently with a small number of measuring devices. it can.

(Embodiment 3) FIG. 6 is a view showing a liquid crystal substrate transport apparatus according to Embodiment 3 of the present invention. The liquid crystal substrate 1 is transported by attracting or mechanically holding the liquid crystal substrate 1 on the arm 3 of the transport device 2.
In addition, the ammeter 4 and the controller 7,
In addition, connection wiring for connecting the arm 3, the ammeter 4, the controller 7, and the ground 5 is provided.

Next, the operation when the liquid crystal substrate 1 fixed to the stage 8 is stored in the cassette 10 will be described with reference to FIG. (A) First, the liquid crystal substrate 1 is lifted from the stage 8 with the lift-up pins 9 and the arm 3 of the transfer device 2 is moved to the liquid crystal substrate 1.
And the stage 8. (B) Next, the liquid crystal substrate is attracted to the arm 3, and the arm is pulled back by the operation of the arm driving unit 23. (C) After rotating and moving the transfer device, the arm driving unit 2
3 inserts the arm into the cassette and releases the suction of the liquid crystal substrate. Further, the liquid crystal substrate is stored in the cassette 10, and the arm is pulled back.

It is also possible that the arm driving section 23 causes the arm 3 to perform the reverse operation, and similarly, the liquid crystal substrate 1 stored in the cassette 10 is taken out and transferred to the stage 8. Note that the arm 3 and the arm driving unit 23 constitute a main part of the work transfer means or the liquid crystal substrate transfer means.

The arm 3 is electrically insulated from the outside,
It is made of (a) a conductive material or (b) a composite of a conductive material and an insulating material. (A) Examples of the conductive material include aluminum, stainless steel, a metal material, a conductive resin such as a carbon reinforced material, a conductive ceramic, a composite conductive material of a metal and a ceramic, and the like. Examples of the insulating material include an insulating ceramic material such as alumina, an insulating resin material such as an epoxy resin, and glass fiber.

The arm 3 is connected to GND through an ammeter 6 for measuring the value of a current flowing between the arm 3 and a ground (hereinafter referred to as GND) 5.

The ammeter 6 may be a coulomb meter, a wattmeter, or a measuring device capable of cumulatively detecting electricity flowing through a combination of a resistance and a voltmeter. As shown in FIG. 7, when the arm 3 is inserted between the stage 8 and the liquid crystal substrate in order to transport the liquid crystal substrate 1 lifted up on the stage 8, the arm 3 is connected to the arm 3 according to the charge amount of the liquid crystal substrate. A current flows between this terminal and the GND 11. For this reason, the amount of electricity flowing can be detected by the detecting means, and the charged state of the substrate to be transported can be determined based on the value. Here, inserting the arm between the stage and the liquid crystal substrate means electrically bringing the arm closer to the liquid crystal substrate, and the arm may contact the liquid crystal substrate.

When taking out the substrate stored in the cassette, similarly to the above, the amount of electricity flowing when the handling arm is inserted into the cassette, the amount of electricity flowing when transferring the substrate, and the amount of electricity flowing when the arm is pulled out of the cassette. The charged state in the substrate and the cassette can be determined based on the quantity of electricity.

(Embodiment 4) FIG. 8 is a configuration diagram of a liquid crystal substrate transport apparatus according to Embodiment 2 of the present invention. The difference from the liquid crystal substrate transport device of FIG. 6 in the third embodiment is that the surface potential meter 11 is used to measure the potential of the arm 3.
Is installed. FIG.
As shown in (1), the arm 3 is inserted between the stage 8 and the liquid crystal substrate 1 to transport the lifted-up liquid crystal substrate, and the liquid crystal substrate 1 is received. When receiving the liquid crystal substrate 1, if the received liquid crystal substrate is charged,
The surface potential of the arm 3 itself increases, and the charge amount of the liquid crystal substrate can be detected based on the value.

When the liquid crystal substrate is pulled out by inserting the arm into the cassette 3 in order to take out the substrate stored in the cassette, if the substrate in the cassette is charged,
The following phenomenon occurs: That is, when the arm is inserted into the cassette, the surface potential of the arm increases. Based on the rise in the surface potential, the charged state in the cassette can be determined.

Further, by measuring the surface potential of the arm 3 after the liquid crystal substrate has been pulled out of the cassette, the charge state of the received liquid crystal substrate can be determined. In order to clarify the initial potential of the arm 3, it may be necessary to attach a switch 12 as shown in FIG. 10 to bring the arm to ground potential (zero volts) before measuring the potential.
In order to make the potential zero, a resistor having a high resistance of 1 MΩ to 1000 GΩ may be connected. By using a high resistance, the voltage can be slowly reduced to zero V according to a time constant CR determined by the resistance R and the capacitance C.

In the liquid crystal substrate transfer device (FIG. 8) according to the fourth embodiment, the surface voltmeter 11 is used to measure the potential of the arm 3. However, as shown in FIG. A total of 13 can also be used.

FIG. 12 is a view showing another liquid crystal substrate transfer device according to the second embodiment of the present invention. In this liquid crystal substrate transfer device, the potential of the arm 3 is measured, so that the potential of the arm 3 is not directly measured but dropped from the arm 3 to the ground 5 via the capacitor 15. This capacity 15
It is characterized in that the potential at a position extended from the cable by an extension cable is measured by a high input impedance electrometer or a surface electrometer.

The data detected in the above-described embodiment or an alarm or the like issued based on the data may be a control device for controlling an external device, a computer for managing the processing steps, or a CIM for managing the entire factory. It can be output to a computer for use. Further, when the detected value exceeds the allowable value, it is possible to prevent electrostatic destruction and the adhesion phenomenon of dust due to high voltage in conjunction with the ionizer.

Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is limited to these embodiments of the present invention. Not done. (A) The shape of the arm is not limited to two plate-shaped protrusions, and if it extends so as to protrude so that the work can be placed and stably held, regardless of the number of arms, one or three. Applicable. (B) The material constituting the arm may be a conductor, a composite of a conductor and an insulator, or any material. It is better to have a little conductivity than an insulator, but it is not necessary to be a good conductor. (C) The electric charge and potential induced in the arm are mainly induced by an electrostatic induction phenomenon. However, if the phenomenon is such that the charged state of the arm or the part where the arm is placed can be known, It is not limited to the measurement target. (D) The transfer device may be a transfer robot.

The scope of the present invention is shown by the description of the claims, and further includes all modifications within the meaning and scope equivalent to the description of the claims.

[0044]

According to the liquid crystal substrate transfer device of the present invention, in the liquid crystal substrate transfer device, the amount of charge flowing between the arm for transferring the liquid crystal substrate and the ground is detected, or the potential of the arm is detected. By doing so, it is possible to determine the charged state of the liquid crystal substrate, its mounting site or the mounting site of the transport device.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a liquid crystal substrate transport device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a positional relationship between a liquid crystal substrate and an arm of a liquid crystal substrate transfer device. (A) is a step in which a voltage of 1 kV is applied to the liquid crystal substrate and the arm is positioned outside the cassette;
(B) shows a stage where the arm is inserted into the cassette, and (c) shows a stage where the arm is lifted up and the liquid crystal substrate is loaded.

FIG. 3 is a diagram showing a measurement result in the apparatus of FIG. 1;

FIG. 4 is a diagram illustrating a liquid crystal substrate transport device according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a measurement result in the apparatus of FIG.

FIG. 6 is a diagram showing a liquid crystal substrate transfer device according to a third embodiment of the present invention.

FIG. 7 is a diagram showing another liquid crystal substrate transport device according to the third embodiment of the present invention.

FIG. 8 is a diagram illustrating a liquid crystal substrate transfer device according to a fourth embodiment of the present invention.

FIG. 9 is a view showing the use of the liquid crystal substrate transfer device of FIG. 8;

FIG. 10 is a diagram in which a ground wire with a switch is provided in the liquid crystal substrate transfer device according to the fourth embodiment of the present invention.

FIG. 11 is a diagram showing a liquid crystal substrate transfer device provided with a voltmeter having a high input impedance for measuring a surface potential of an arm in the fourth embodiment of the present invention.

FIG. 12 is a diagram showing a liquid crystal substrate transport device in which an extension cable is provided for measuring an arm potential and a voltmeter having a high input impedance is provided at an extension point in the fourth embodiment of the present invention.

FIG. 13 is a view showing a conventional apparatus for directly measuring the surface potential of a substrate in order to measure the charged state of the substrate.

[Explanation of symbols]

1 liquid crystal substrate, 2 transfer device (robot), 3 arm, 4,6 ammeter, 5 ground, 7 controller,
8 stage (one mounting part), 9 lift-up pin, 10 cassette, 11 surface voltmeter, 11a surface potential sensor, 12 switch, 13 voltmeter (high input impedance), 14 extension cable, 15 capacity, 2
0 cassette, 22 recorder, 23 arm drive unit.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 FA17 FA25 FA30 HA01 MA20 2H090 JC18 3C007 AS24 BS15 KS00 KS27 KS37 KX07 MS30 NS12 5F031 CA05 FA02 FA11 GA08 GA35 GA36 GA43 HA33 JA45 JA51 PA21

Claims (6)

[Claims] 1. A work transfer device for receiving a work and moving it to another place, comprising: an arm for mounting and holding the work; and measuring at least one of a charge amount and a potential induced on the arm. And a work charging state detecting means for detecting a charging state of the work. 2. The work transfer device according to claim 2, wherein the work transfer device determines a charge state of at least one of the work and a portion on which the work is mounted based on measurement data on the arm by the charge state detection unit. The work transfer device according to claim 1, further comprising an indexing unit. 3. The work transfer device includes an operation control unit that controls an operation of the arm, wherein the work charging state determining unit determines an operation state of the arm obtained from the operation control unit. 3. The work transfer device according to claim 1, wherein the charged state of at least one of the work and a portion on which the work is placed is determined. 4. 4. The work transfer device according to claim 1, wherein said work transfer device includes a warning signal activating means for generating a warning signal when a charge value of said work by said work charge state determining means exceeds an allowable value. The work transfer device according to any one of the above. 5. The work transfer device according to claim 1, wherein the transfer device includes a ground connection unit that connects the arm and a ground wire such that a potential of the arm becomes zero. . 6. The work transfer device according to claim 1, wherein the work is a liquid crystal substrate, and the work transfer device is a liquid crystal substrate transfer device.