JP2002261152A - Method and device for detecting position of cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect a cassette position. SOLUTION: In a cassette 14 vertically storing a plurality of substrates 12 at intervals in the thickness direction thereof, technology for detecting the position of the cassette 14 having on a bottom a hole 24 corresponding to the arrangement part of at least one substrate mutually moves the cassette 14 and one or more sensors 32 arranged downward thereof in the direction of the arrangement of the substrates and detects the hole 24 from downward of the cassette by the sensor 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and an apparatus for detecting the position of a substrate cassette used in an apparatus for inspecting a substrate such as a liquid crystal display substrate.

[0002]

2. Description of the Related Art A substrate such as a liquid crystal display substrate is housed in a cassette for the purpose of facilitating storage, transportation, processing, and the like in the course of manufacturing and inspection. For this reason, in the inspection of the quality of the substrate, unexamined substrates are taken out of the cassette one by one and inspected, and the delivery of storing the inspected substrate in the original cassette or another cassette is performed by a delivery device such as a robot. Is being done.

[0003] As one of such cassettes, there is a vertical cassette in which a plurality of substrates having a strip shape are vertically stored at intervals in a thickness direction thereof. This type of vertical cassette generally has a pair of substrate receivers each having a plurality of slots for receiving the ends of a strip-shaped substrate facing each other in a box-shaped frame that opens upward. The slots are spaced in the longitudinal direction of the substrate receiver and open to the side and above the opposing substrate receiver.

[0004] Each substrate is positioned perpendicular to the cassette, with each longitudinal end being received in a slot.
For this reason, a plurality of substrates are maintained vertically in the cassette at intervals in the thickness direction thereof. After detecting the position of the cassette with respect to the transfer device, the transfer device transfers the substrate to and from the cassette. Such detection of the cassette position needs to be performed with high accuracy because the interval between adjacent substrates in the cassette is narrow.

[0005] As this kind of cassette position detecting device, there are a technology for detecting the position outside the cassette (outside the frame) and a technology for detecting the upper edge of the substrate in the cassette. The detected value is used for transferring a plurality of substrates to the same cassette.

[0006]

However, in the case of a cassette having a substrate receiver arranged in a frame, the size of the cassette varies from cassette to cassette depending on the size of the substrate receiver. Because the deformation differs for each cassette, even if the outer position of the cassette is detected, the correct cassette position with respect to the transfer device is not detected, and as a result, a transfer error occurs.

In addition, the upper edge of the substrate is detected because the substrate is tilted in one of the substrate arrangement directions in the cassette, or the substrate is not correctly accommodated in the cassette due to distortion or deformation of the cassette. However, the exact cassette position with respect to the transfer device is not detected, resulting in a transfer error.

An object of the present invention is to make it possible to more accurately detect the position of a cassette.

[0009]

SUMMARY OF THE INVENTION The present invention is a method for detecting the position of a cassette capable of vertically storing a plurality of substrates at intervals in a thickness direction thereof and having at least one mark at the bottom. And the device.

A cassette position detecting method according to the present invention comprises:
The method further includes relatively moving the cassette and one or more sensors disposed below the cassette in a direction in which the substrates are arranged, and sensing the mark from below the cassette by the sensor.

A cassette position detecting device according to the present invention comprises:
One or more sensors arranged below the cassette to sense the mark from below the cassette, and a moving mechanism for relatively moving the cassette and the sensors in the arrangement direction of the substrates.

When the cassette and the sensor are relatively moved in the direction in which the substrates are arranged, the sensor and the mark face each other. At this time, the mark of the cassette is sensed by the sensor, and the position of the cassette with respect to the transfer device is detected from the relative positional relationship between the sensor and the cassette at that time.

When the sensor uses a light beam such as a laser beam, the mark indicates a sudden change in reflected light input to the sensor,
For example, it can be sensed by detecting a change in reflected light when a light beam is applied to the mark. Further, for example, when the mark is a hole corresponding to the location of the substrate on the cassette, the mark can be sensed by detecting a change in reflected light when the edge of the hole is irradiated.

Since the bottom of the cassette is the place where the distortion and deformation of the cassette itself are least, when the mark formed in such a place is sensed from below the cassette as described above, the positional relationship between the sensor and the cassette is determined. It is easy and accurate to know, so that the cassette position can be accurately detected.

[0015] The position detecting device may further include detecting means for detecting the position of the cassette from the position of the sensor when the mark is detected. The detection means may include a target assembled to the moving mechanism or the sensor and moved by the moving mechanism together with the sensor, and a target detector for sensing the target from above. The position detection device may further include a transfer unit that transfers the substrate to the cassette, and the target sensor may be disposed in the transfer unit.

[0016] The position detecting device may further include a cassette stage for moving the cassette in one direction with the cassette mounted thereon. The cassette stage includes two or more guide rails extending in the direction in which the substrates are arranged, and a first and second movable tables mounted on the guide rails so as to be movable in the longitudinal direction thereof and located above the sensor. , A free stage selectively movable at the position, a free stage mounted on the movable table so as to be able to move the two-dimensionally in a plane parallel to a moving surface of the movable table for mounting the cassette, A plurality of guides arranged to guide the position of the cassette with respect to the free stage, a first pusher for pushing the cassette in a first direction in a plane parallel to the moving table, and a moving surface of the moving table. A second pusher for pushing said cassette in a second direction intersecting said first direction in a parallel plane. The carriage and the free stage allow the sensor to sense the mark when the carriage is moved to the first position. According to such a position detecting device, since the positioning of the cassette with respect to the cassette stage is performed, the position of the cassette can be detected more accurately.

[0017] The cassette stage may further include one or more stoppers for preventing the movable table from moving from the first position to a side opposite to the second position. By doing so, the relative position between the cassette and the sensor in the arrangement direction of the substrates at the first position can be regulated by the stopper.

[0018]

1 to 8, a position detecting device 10 is a cassette 14 for accommodating a plurality of substrates 12 in a display panel inspection device in a vertical state at intervals in their thickness direction. Used for position detection. Substrate 1
2 has a rectangular or strip shape.

The substrate 12 includes a liquid crystal display panel or an organic EL (e
(Electroluminescense), and a rectangular plate-like test object such as a glass substrate used for manufacturing a display panel. As such a substrate 12, a so-called multi-unit substrate integrally provided with a plurality of small cells, such as a display panel for a mobile phone, can be given. However, the present invention can be applied to a case where the substrate is formed of a single cell.

In the cassette 14, a pair of substrate receivers 18 extending in the direction in which the substrates 12 are arranged are arranged in parallel in a rectangular frame 16 opened vertically. Each substrate receiver 18 has a plurality of slots 20 formed at predetermined intervals in the longitudinal direction so as to receive the longitudinal ends of the substrate 12, and a long plate-shaped bottom closing the lower end of the slot 20. 2
2 is provided.

Each slot 20 is open to the other side of the substrate receiver 18 and open upward. Both substrate receivers 18 are assembled to the frame 16 with the slots 20 facing each other. Each substrate receiver 18 has a hole 24 in the bottom 22 communicating with each slot 20. Each hole 24 corresponds to the location of the substrate 12 on the cassette 14 since it communicates with the slot 20. In this embodiment, as described later, one hole 24 is used as a mark for cassette position detection.

The position detecting device 10 includes a cassette stage 30 for moving the cassette 14 to the first and second positions with the cassette 14 mounted thereon, a pair of sensors 32 disposed below the cassette 14 at the first position, It includes a moving mechanism 34 for moving both sensors 32 synchronously with respect to the cassette 14 at the first position, and a transfer device 36 for transferring the substrate 12 to the cassette 14 at the first position.

The first position is a so-called substrate transfer position for transferring the substrate 12 to and from the cassette 14, and is the position of the cassette 14 shown in FIGS. 2 and 7C. On the other hand, the second position is the cassette stage 30
This is a so-called cassette transfer position for transferring the cassette 14 to the cassette 14, and is the position of the cassette 14 shown in FIGS. 7A and 7B.

In the cassette stage 30, a pair of guide rails 38 extending in parallel from the first position to the second position are assembled to a frame 40 of the inspection apparatus.
A stopper 42 is assembled at each end of the first and second positions, and a plate-shaped movable base 44 is disposed on both guide rails 38 so as to be movable in their longitudinal direction, and a plate-shaped free table on which the cassette 14 is placed is mounted. The stage 46 is mounted on the movable base 44 so as to be two-dimensionally movable in a plane parallel to the stage.

The moving table 44 is connected to both guide rails 38 by a plurality of linear guides 48 slidably fitted on the guide rails 38. Free Stage 46
Has a rectangular shape that is long in the moving direction of the moving table 44, a width smaller than the length of the substrate 12, and a plurality of balls 50 mounted on the moving table 44 at intervals. And is arranged at the center of the moving table 44 via the.

The cassette 14 is mounted on the free stage 46 at the second position so that the arrangement direction of the accommodated substrates 12 is the moving direction of the cassette stage 30 (FIGS. 7A and 7B). )reference). At this time, cassette 1
4 is guided to a predetermined mounting position on the cassette stage 30 by one or more guides 52 assembled at locations corresponding to each rectangular side of the moving table 44.

The cassette 14 placed on the free stage 46 is moved by one or more pushers 54 attached to portions corresponding to two adjacent sides of the rectangular shape of the movable base 44.
It is pushed toward the guide 52 arranged on the opposite side (see FIGS. 5 and 6). Thereby, the cassette 14
With the free stage 46, the movable table 44
Are moved two-dimensionally in a plane parallel to the moving surface of the cassette stage 30 and come into contact with a predetermined guide 52 to be positioned with respect to the cassette stage 30. The pusher 54 is moved by a driving source 56 such as an air cylinder.

Cassette 1 for cassette stage 30
The movement of No. 4 is achieved by the movement of the free stage 46 with respect to the moving table 44. Therefore, the movement of the cassette 14 with respect to the cassette stage 30 becomes smooth.
When the cassette 14 is placed on the cassette stage 30,
The moving table 44 is manually or automatically moved to the first position as shown in FIG.

The movable table 44 is provided with a stopper 4 on the first position side.
2 is stopped at the first position in a state in which it comes into contact with the second position, and stopped at the second position in a state in which it comes into contact with the stopper 42 on the second position side. Thus, the moving table 44 is positioned with respect to the inspection device at any of the first and second positions. For this reason, the stopper 42 has a function of positioning the movable table 44 with respect to the inspection device.

Each of the sensors 32 is an optical sensor using a light beam such as a laser beam.
It is arranged below the longitudinal end of the substrate 12 in the cassette 14 at the first position so that the bottom of the cassette 14 on the top 0 is irradiated almost vertically to receive the reflected light from the cassette 14.

The sensor 32 detects a mark, that is, the hole 24 of the cassette 14 by detecting a sudden change in the received reflected light. The moving base 44 has a pair of long holes 58 that allow the passage of the light beam from the sensor 32 and the reflected light toward the sensor 32. Each long hole 58 is long in the moving direction of the moving table 44.

The moving mechanism 34 includes a reversible motor 60 mounted on the frame 40 so as to be located at the center in the longitudinal direction of the substrate in the cassette 14 at the first position.
A lead screw 62 coupled to the rotating shaft of the motor 60; a lead nut 64 screwed to the lead screw 62; and a pair of attachments extending from the lead nut 64 in the longitudinal direction of the substrate 12 and in directions opposite to each other. Bar 6
6 and a guide 68 for guiding the movement of each mounting bar 66 in the moving direction of the moving table 44.

The lead screw 62 extends in the moving direction of the movable base 44, and each sensor 32 is attached to the tip of a mounting bar 66. For this reason, when the motor 60 is rotated, the sensor 32 is moved below the movable table 44 in the moving direction of the movable table 44.

A target 70 is attached to one of the attachment bars 66 in a cantilever manner. Target 7
0 protrudes forward (to the left in FIG. 7) from the cassette stage 30 so as to be sensed by the transfer device 36.

In the transfer device 36, a gate-shaped slider 72 that opens downward is mounted on a support 74 mounted on the frame of the inspection device so as to be movable in the direction of movement of the movable base 44 by a pair of guides 76, and a lead screw 78 is provided. This is rotatably supported by a support 74 in a state where it extends in the moving direction of the moving table 44, and a lead nut 80 screwed to a lead screw 78 is connected to the slider 72.

The lead screw 78 is rotated by a reversible motor 81. Thereby, the lead nut 8
0 is moved in the moving direction of the moving base 44 and the slider 72 is moved.
Are moved in the same direction.

The slider 72 has a target sensor 82
Are mounted so as to detect the tip of the target 70 from above the cassette stage 30. The target sensor 82 detects a reflected light from the target 70 by directing a light beam such as a laser beam toward the target 70, and detects a sharp change in the received reflected light, thereby setting the tip of the target 70 to a target. Sense.

A gate-shaped elevating body 84 is mounted on the slider 72 so as to be vertically movable by a pair of guides 86. The elevating body 84 includes a motor 88 mounted on the slider 72, a lead screw 90 connected to a rotating shaft of the motor 88, and a lead nut 92 screwed to the lead screw 90 and assembled to the elevating body 84. It is raised and lowered by a lifting mechanism.

The elevating body 84 includes a gate-shaped rotating arm 9.
4 are assembled. The substrate 1 is attached to the rotating arm 94.
A pair of transfer arms 96 extending in the vertical direction at intervals in the longitudinal direction 2 and a pair of air cylinders 98 extending in the vertical direction at intervals in the longitudinal direction of the substrate 12 are assembled. The air cylinder 98 is located ahead of the transfer arm 96 in the moving direction of the moving table 44 (leftward in FIG. 2).

Each transfer arm 96 is bent in an L-shape at the lower end so as to receive the lower edge of the substrate 12.
Further, a suction pad 1 for suctioning an end face of the substrate 12 in the longitudinal direction.
00 at the lower end. Each air cylinder 98 has a drop prevention pad 102 at a lower end thereof for preventing the substrate 12 received by the transfer arm 96 from falling down and falling.

The fall prevention pad 102 is usually the pad 1
The distance between the lower end of the transfer arm 96 and the lower end of the transfer arm 96 is raised to a height position larger than the width of the substrate 12, and is lowered when the fall prevention function is to be exerted, and is maintained at a predetermined height position. Is done. As each of the guides 68, each of the guides 76, and each of the guides 86, a commercially available guide mechanism including a linear guide and a guide rail can be used.

When the substrate 12 is transferred to the cassette 14, as shown in FIG. 1 and FIG. Is moved in the moving direction of the moving body 44 by the moving mechanism 34, and the predetermined hole 24, for example, the front end (the left end in FIGS. 2 and 6)
Is stopped at a position where the hole 24 located at the position is detected. Thus, the tip of the target 70 indicates the position of the cassette 14 with respect to the transfer device 36. At this time, since the two sensors 32 detect the holes 28 separated in the longitudinal direction of the substrate 12, the tip of the target 70 is
The position of the cassette 14 relative to 8 is accurately represented.

Next, in the above state, the slider 72 is moved in the moving direction of the moving body 44 by the motor 81 and stopped at the position where the tip of the target 70 is sensed. This is the cassette origin position. Thereby, the delivery device 3
The position of the cassette 14 relative to 6 is detected.

Next, the transfer device 36 takes out the substrate 12 from the cassette 14. This operation is performed as follows.

First, the transfer arm 96 moves the predetermined substrate 12
For example, the slider 72 is moved by a predetermined amount by the motor 81 so as to be positioned above the rearmost substrate 12, and in this state, the transfer arm 96 and the air cylinder 98 are
Is lowered by Thereby, the lower end of the transfer arm 96 is inserted behind the substrate 12 in the cassette 14 until the bent lower end is below the substrate 12.

When the transfer arm 96 is lowered to a position where it can receive the lower edge of the substrate 12 at its lower end, the suction pad 100 is connected to a vacuum device (not shown), and the lower front surface of the substrate 12 is evacuated. Adsorb. At this time, the transfer arm 96 may be brought close to the substrate 12 to be sucked by an appropriate means such as a motor 81 or another mechanism (not shown).
The lower edge of the substrate 12 is placed at a location bent forward of the lower end of the transfer arm 96.

As described above, the substrate 12 is
The transfer arm 96 and the air cylinder 98 are lifted by the motor 88 in a state of being sucked by the motor. As a result, the substrate 12 gripped by the transfer arm 96 is raised inside the cassette 14.

The upper portion of the sucked substrate 12 is the cassette 14
When the transfer arm 96 and the air cylinder 98 are raised in a state where the transfer arm 96 projects upward, the fall prevention pad 102 is lowered by the air cylinder 98 so as to be able to contact the substrate 12 received by the transfer arm 96, and Located in front of. This prevents the substrate 12 from falling down and falling. In this state, the transfer arm 96 and the air cylinder 98 are further raised to a predetermined height position by the motor 88.

Thereafter, the slider 72 is moved leftward in FIG. Thus, the substrate 12 received by the transfer arm 96 is transferred to a predetermined location. During this time, by maintaining the rotating arm 94 rotated clockwise by 90 degrees in FIG.
2 may be transported in a horizontal state.

The above-described operation, particularly the operation related to taking out the substrate 12, is performed for each substrate 12. When the substrate 12 is transferred to the empty cassette 14 by the transfer device 36, the reverse operation is performed.

The bottom 22 is a place where the distortion or deformation of the cassette 14 itself is least. When the hole 24 formed in such a place is sensed from below the cassette 14, the positional relationship between the sensor 32 and the cassette 14 can be easily changed. As a result, the position of the cassette 12 relative to the transfer device can be accurately detected.

The present invention can be applied not only to the position detection technology in the display substrate inspection apparatus but also to the position detection technology of another flat substrate. The sensor 32 and the target sensor 82 may use not only a device using a light beam but also other devices such as a device including a video camera and an image processing circuit for processing an output signal of the video camera.

The present invention is not limited to the above embodiment. For example, instead of moving the sensor relative to the cassette when detecting the position, the cassette may be moved relative to the sensor. The present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a position detection device according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 in FIG.

FIG. 3 is a plan view of a cassette stage in the position detection device shown in FIG. 1 and shows a state where a cassette is mounted.

FIG. 4 is a plan view of a cassette stage in the position detection device shown in FIG. 1, showing a state where the cassette is removed.

FIG. 5 is a sectional view taken along line 5-5 in FIGS. 3 and 4;

FIG. 6 is a sectional view taken along line 6-6 in FIGS. 3 and 4;

FIG. 7 is a view showing a state where the cassette stage is moved in the position detection device shown in FIG. 1;

FIG. 8 is a perspective view showing an embodiment of the cassette.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Position detection apparatus 12 Substrate 14 Cassette 16 Cassette frame 18 Cassette substrate receiving 20 Cassette slot 22 Cassette bottom 24 Cassette hole 30 Cassette stage 32 Sensor 34 Sensor moving mechanism 36 Transfer device 38 Guide rail 40 Bracket (stopper) Reference Signs List 42 Frame of inspection apparatus 44 Moving table 46 Free stage 48 Linear guide 50 Ball 52 Cassette guide 54 Pusher 56 Pusher driving mechanism 58 Long hole of moving table 70 Target 82 Target sensor 96 Transfer arm

Claims (8)

[Claims] 1. A cassette capable of vertically storing a plurality of substrates at an interval in a thickness direction of the substrates.
In a method for detecting the position of a cassette having one mark at the bottom, the cassette and one or more sensors disposed below the cassette are relatively moved in the arrangement direction of the substrate, and the mark is moved by the sensor. A method for detecting the position of a cassette, comprising sensing from below the cassette. 2. The position detecting method according to claim 1, further comprising detecting a position of the cassette from a position of the sensor when the mark is detected. 3. A cassette capable of vertically storing a plurality of substrates at an interval in a thickness direction of the plurality of substrates.
An apparatus for detecting the position of a cassette having two marks at the bottom, comprising: one or more sensors disposed below the cassette to sense the marks from below the cassette; and an arrangement of the cassette and the sensors on the substrate. And a moving mechanism for relatively moving the cassette in a direction. 4. The position detecting device according to claim 3, further comprising a detecting means for detecting a position of said cassette from a position of said sensor when said mark is sensed. 5. The detection means includes a target assembled to the moving mechanism or the sensor and moved by the moving mechanism together with the sensor, and a target sensor for sensing the target from above. 3. The position detecting device according to claim 1. 6. The position detecting device according to claim 5, further comprising a transfer unit that transfers the substrate to the cassette, wherein the target sensor is disposed in the transfer unit. 7. A cassette stage for moving the cassette in at least one direction with the cassette mounted thereon,
The cassette stage includes two or more guide rails extending in the direction in which the substrates are arranged, and first and second movable tables mounted on the guide rails so as to be movable in the longitudinal direction thereof and located above the sensor. A movable stage selectively movable to the position of, a free stage mounted on the movable platform in a plane parallel to the movable platform for loading the cassette, and a free stage mounted on the movable platform. A plurality of guides for guiding the position of the cassette with respect to the free stage; a first pusher for pushing the cassette in a first direction in a plane parallel to the moving table; A second pusher for pushing the cassette in a second direction intersecting the first direction, wherein the movable table and the free stage are configured such that the movable table is moved to the first position. The position detecting device according to any one of claims 3 to 6, wherein the sensor allows the sensor to detect the mark. 8. The cassette stage according to claim 7, wherein the cassette stage further comprises one or more stoppers that prevent the movable table from moving from the first position to the opposite side to the second position. Position detection device.