Carrying device

Abstract

The invention provides a conveying device capable of detecting the presence or absence of a workpiece on a robot without arranging a sensor or a signal line in a vacuum environment. A conveyance device (A1, A2, A3) that conveys plate-shaped workpieces (W1, W2) disposed in a vacuum environment is provided with a support base (1), a robot (2) that is guided and supported on the support base (1) so as to move forward and backward in a horizontal linear direction and on which the plate-shaped workpieces (W1, W2) can be placed, and a drive mechanism (4) that drives the robot (2) to move forward and backward, the conveyance device (A1, A2, A3) being provided with: a sealed container (5) that is provided on the support base (1); the inner space is communicated with the atmosphere, and a light inlet window (51) is arranged at the upper part; and optical sensors (6A, 6B) housed in the sealed container (5), capable of selecting detectable distances (H1, H2) passing above the light-transmitting window (51), and capable of detecting the presence or absence of an object within the detectable distances (H1, H2).

Description

Technical Field

[0001] The present invention relates to a transfer device, and more particularly to a transfer device capable of linearly transferring a plate-shaped workpiece such as a glass substrate for an FPD (Flat Panel Display). Background Art

[0002] As an example of such a transfer device, there is a transfer device described in Patent Document 1. The transfer device described in this document is configured to support a robot arm by a linear guide mechanism provided on a support table so as to be movable in a horizontal linear direction, and to drive the robot arm to move forward and backward by a belt drive mechanism. The support table can generally be lifted and rotated.

[0003] Such a transfer device is used for transferring a plate-shaped workpiece received from a processing chamber of a previous process to a processing chamber of a next process in a vacuum and high-temperature environment. In this case, it is important to confirm whether the plate-shaped workpiece is correctly placed on the robot arm at the time when the plate-shaped workpiece should be placed on the robot arm for smoothly performing a series of processes for the plate-shaped workpiece.

[0004] The transfer device described in Patent Document 1 employs a structure in which sensors such as proximity sensors are arranged on the robot arm. In this case, in order to obtain a structure in which a sensor is arranged on the robot arm exposed to a vacuum environment and a signal is guided to a control unit in an atmospheric environment via a signal line while ensuring stable operation, various difficulties are involved. Incidentally, recently, an attempt has been made to further improve the efficiency by placing a plurality of plate-shaped workpieces on one robot arm to perform a series of transfer processes. In this case, it becomes more important to confirm whether a plurality of plate-shaped workpieces are correctly placed on one robot arm.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-65092 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The present invention has been conceived based on the above circumstances, and its problem is to be able to detect the presence or absence of a workpiece on a robot arm without arranging a sensor and a signal line in a vacuum environment in a transfer device that transfers a plate-shaped workpiece while moving forward and backward in a linear direction.

[0010] Means for Solving the Problems

[0011] In order to solve the above problems, in the present invention, the following technical means are adopted.

[0012] The transfer device provided by the present invention includes: a support table; at least one manipulator that is guided and supported on the support table so as to be able to move forward and backward in a horizontal straight line direction and can place a plate-shaped workpiece; and a drive mechanism that drives the at least one manipulator to move forward and backward. The transfer device transfers the plate-shaped workpiece arranged in a vacuum environment. The transfer device is characterized in that the support table is provided with: a sealed container whose internal space communicates with the atmosphere and has a light-transmitting window on the upper part; and at least one optical sensor that is housed in the sealed container, can select a detectable distance passing above the light-transmitting window, and can detect the presence or absence of an object within the detectable distance.

[0013] In a preferred embodiment, the at least one manipulator can place a plurality of plate-shaped workpieces arranged along the moving direction of the at least one manipulator, and multiple groups including the sealed container and the at least one optical sensor are provided corresponding to the plurality of plate-shaped workpieces.

[0014] In a preferred embodiment, the at least one manipulator includes an upper manipulator and a lower manipulator that can move forward and backward independently of each other and are arranged vertically. The at least one optical sensor includes a first optical sensor for detecting the presence or absence of an object placed on the upper manipulator and a second optical sensor for detecting the presence or absence of an object placed on the lower manipulator.

[0015] In a preferred embodiment, the at least one manipulator has a plurality of claws that extend along the moving direction of the at least one manipulator and place the plate-shaped workpiece, and the group including the sealed container and the at least one optical sensor is arranged at a position that does not overlap with the plurality of claws in a top view.

[0016] In a preferred embodiment, the drive mechanism is a belt drive mechanism.

[0017] Advantages of the Invention

[0018] The detectable distance of the optical sensor is set, for example, as the distance from the optical sensor to the plate-shaped workpiece placed on the manipulator. In this case, the reflected light from an object at a distance outside the detectable distance is not detected. For example, when the manipulator is in the original position, the presence or absence of the plate-shaped workpiece on the manipulator is detected as follows.

[0019] When a plate-shaped workpiece is placed on the manipulator, the optical sensor can detect the reflected light from the plate-shaped workpiece, and thus, it can be detected that there is a plate-shaped workpiece on the manipulator, that is, a plate-shaped workpiece is placed on the manipulator. On the other hand, when no plate-shaped workpiece is placed on the manipulator, the optical sensor does not detect any reflected light, so it can be detected that there is no plate-shaped workpiece on the manipulator, that is, no plate-shaped workpiece is placed on the manipulator.

[0020] Thus, with the transfer device according to the present invention, it is possible to detect the presence or absence of a plate-like workpiece on the robot arm without providing a sensor for the robot arm that moves in a vacuum environment.

[0021] Other features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 FIG. is a schematic side view showing the structure of a transfer device A1 according to an embodiment of the present invention in a manner omitting the belt drive mechanism.

[0023] Figure 2 FIG. is a schematic view showing the structure of the belt drive mechanism of the transfer device A1 according to an embodiment of the present invention.

[0024] Figure 3 FIG. shows in a manner omitting the upper robot arm Figure 1 a schematic top view of the transfer device shown.

[0025] Figure 4 FIG. is a schematic side view showing the structure of a transfer device A2 according to another embodiment of the present invention.

[0026] Figure 5 FIG. is a schematic side view showing the structure of a transfer device A3 according to still another embodiment of the present invention.

[0027] DESCRIPTION OF REFERENCE NUMERALS

[0028] A1, A2, A3: transfer devices, W1, W2: plate-like workpieces, H1, H2: detectable distances, 1: support table, 2: robot arm, 2a: upper robot arm, 2b: lower robot arm, 22a: fork claw, 4: belt drive mechanism, 5: sealed container, 51: light-transmitting window, 6A, 6B: optical sensors. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, based on preferred embodiments of the present invention, a detailed description will be given with reference to the accompanying drawings.

[0030] Figure 1 FIG. is a schematic side view showing the structure of a transfer device A1 according to an embodiment of the present invention in a manner omitting the belt drive mechanism 4, Figure 2 and FIG. is a schematic view showing the structure of the belt drive mechanism 4.

[0031] As shown in Figure 1 , Figure 2As shown, the transfer device A1 includes a support table 1, a robot 2 that is guided and supported on the support table 1 so as to be movable in a horizontal movement stroke in a linear direction, a belt drive mechanism 4 that drives the robot 2 to move forward and backward along the above-mentioned movement stroke, and optical sensors 6A and 6B for detecting the presence or absence of the plate-shaped workpieces W1 and W2 on the robot 2. The support table 1 can generally rotate and lift relative to the support base 3.

[0032] The robot 2 includes a robot holding member 21 and a robot body 22 for placing the plate-shaped workpiece W. The robot body 22 is held by the robot holding member 21. A guide block (not shown) provided on the support table 1 is fixed to the robot holding member 21. The guide block is slidably combined with a guide rail 46 extending in a horizontal straight line. The robot body 22 includes a plurality of (four in this embodiment) claws 22a extending along the moving direction of the robot 2. The robot holding member 21 is connected to an appropriate part of the endless belt 41 constituting the belt drive mechanism 4, whereby the robot 2 is driven to move forward and backward in a horizontal straight movement stroke. It should be noted that, as Figure 1 shown, in this embodiment, the upper robot 2a and the lower robot 2b are configured in two levels to form the robot 2 and are individually driven to move forward and backward. The following description of the belt drive mechanism 4 will be given by taking the structure of one of the lower robots 2b as a representative.

[0033] The belt drive mechanism 4, as Figure 2 shown, includes two driven pulleys 42a and 42b arranged corresponding to the vicinity of both ends of the movement stroke of the robot 2 in the support table 1, a drive pulley 43 arranged between the two driven pulleys 42a and 42b, two idler pulleys 44a and 44b that sandwich the drive pulley 43 front and back and are arranged close to the drive pulley 43, and an endless belt 41 wound around the pulleys 42a, 42b, 43, 44a, and 44b. The drive pulley 43 is rotationally driven by a motor 431 whose output shaft protrudes into the vacuum environment through a sealing mechanism (not shown) and is arranged in a drive box 45 communicating with the atmospheric environment.

[0034] As Figure 1 shown, the upper robot 2a and the lower robot 2b are each configured to be able to place two plate-shaped workpieces W1 and W2 arranged along the moving direction of the robots 2a and 2b at a predetermined interval. The plate-shaped workpieces W1 and W2 are, for example, glass plates having a rectangular shape in plan view with a thickness of 0.3 to 0.7 mm. In addition, Figure 1 the state shown shows the state where each of the robots 2a and 2b is in the original position where it has retreated to the maximum extent. It can be seen from this figure that the upper robot 2a is offset forward by some (for example, about 10 to 20 mm) relative to the lower robot 2b.

[0035] The optical sensors 6A and 6B (the first optical sensor 6A and the second optical sensor 6B) are arranged in a sealed container 5 provided on the support table 1 in such a way that the internal space communicates with the atmospheric environment. The sealed container 5 has a light-transmitting window 51 at the upper part, and two optical sensors arranged along the moving direction of the robot arms 2a and 2b are accommodated therein. The assembly including the sealed container 5 and the two optical sensors 6A and 6B is provided at two locations with a spacing approximately corresponding to the placement interval P of the two plate-like workpieces W1 and W2 placed on the robot arms 2a and 2b. In the present embodiment, it is provided at positions corresponding to the vicinity of the front ends of the two plate-like workpieces W2 placed on the lower robot arm 2b. The communication between each sealed container 5 and the atmospheric environment is achieved by connecting the front and rear sealed containers 5 with a sealed pipe 52 and communicating the rear sealed container 5 with the atmospheric environment in the drive box 45 via a bellows 53. The bellows 53 is provided for position adjustment in the front-rear direction of a rigid structure formed by connecting the front and rear two sealed containers 5 with the sealed pipe 52. The signal lines 61 connected to the optical sensors 6A and 6B are laid in the control unit 7 via the sealed pipe 52, the bellows 53, the drive box 45, and the support base 3. In addition, the structure including the above two sealed containers 5 and the two optical sensors 6A and 6B accommodated in their internal spaces is as Figure 3 shown, and is arranged at the center in the width direction of the support table 1 so as not to overlap with the four claws 22a of the robot arm 2 in a top view.

[0036] The optical sensors 6A and 6B receive the reflected light of the emitted light (laser) and detect the presence or absence of an object within the detectable distance. In the present embodiment, the light emitting and receiving parts are arranged upward in the sealed container 5. In addition, it is preferable to use an optical sensor capable of setting the detectable distance for the optical sensors 6A and 6B. The optical sensors 6A and 6B can select the detectable distance by setting not to detect the reflected light from distances outside the detectable distance (having a certain distance width). For example, a CMOS laser sensor (model: LR-XH250) manufactured by Keyence Corporation can be used.

[0037] The two optical sensors 6A and 6B arranged in each sealed container 5 include a first optical sensor 6A on the front side in the moving direction of the robot arm 2 and a second optical sensor 6B on the rear side in the moving direction of the robot arm 2. The detectable distance H1 of the first optical sensor 6A is set to the distance from the optical sensor 6A to the plate-like workpiece W1 placed on the upper robot arm 2a. The detectable distance H2 of the second optical sensor 6B is set to the distance from the optical sensor 6B to the plate-like workpiece W2 placed on the lower robot arm 2b.

[0038] When the plate-shaped workpiece W1 is placed on the upper manipulator 2a, the first optical sensor 6A detects the reflected light from the plate-shaped workpiece W1 at the detectable distance H1. On the other hand, when the plate-shaped workpiece W1 is not placed on the upper manipulator 2a, the first optical sensor 6A does not detect the reflected light from an object at the detectable distance H1. In this way, the first optical sensor 6A can detect the presence or absence of the plate-shaped workpiece W1 on the upper manipulator 2a by detecting whether the reflected light is detected or not. Similarly, when the plate-shaped workpiece W2 is placed on the lower manipulator 2b, the second optical sensor 6B detects the reflected light from the plate-shaped workpiece W2 at the detectable distance H2. On the other hand, when the plate-shaped workpiece W2 is not placed on the lower manipulator 2b, the second optical sensor 6B does not detect the reflected light from an object at the detectable distance H2. In this way, the second optical sensor 6B can detect the presence or absence of the plate-shaped workpiece W2 on the lower manipulator 2b by detecting whether the reflected light is detected or not.

[0039] Most of the light from the respective optical sensors 6A, 6B passes through the light-transmitting window 51 of the hermetic container 5, but a part is reflected by the light-transmitting window 51. Therefore, strictly speaking, the reflected light received by the optical sensors 6A, 6B also includes the reflected light from the light-transmitting window 51, but the distance from the optical sensors 6A, 6B to the light-transmitting window 51 is beyond the detectable distances H1, H2, so the reflected light from the light-transmitting window 51 is not detected, and the presence of the light-transmitting window 51 does not become noise. Similarly, when the plate-shaped workpieces W1, W2 are transparent glass, strictly speaking, the reflected light received by the optical sensor 6B also includes the reflected light from the plate-shaped workpiece W1 placed on the upper manipulator 2a, but the distance from the optical sensor 6B to the plate-shaped workpiece W1 placed on the upper manipulator 2a is beyond the detectable distance H2 of this optical sensor 6B, so the reflected light from the plate-shaped workpiece W1 placed on the upper manipulator 2a is not detected, and the presence of the plate-shaped workpiece W1 placed on the upper manipulator 2a does not become noise.

[0040] In the transfer device A1 having the above structure, when each of the mechanical hands 2a and 2b is in the original position where it is retracted to the maximum extent, the presence or absence of the plate-shaped workpieces W1 and W2 on each of the mechanical hands 2a and 2b is detected as described above. In the present embodiment, in the original position, the upper mechanical hand 2a is offset forward by a predetermined distance with respect to the lower mechanical hand 2b, and the first optical sensor 6A for detecting the presence or absence of the plate-shaped workpiece W1 placed on the upper mechanical hand 2a and the second optical sensor 6B for detecting the presence or absence of the plate-shaped workpiece W2 arranged on the lower mechanical hand 2b are arranged in the moving direction of the mechanical hands 2a and 2b. Therefore, the detection light emitted from each of the front optical sensors 6A passes through the gap S between the two plate-shaped workpieces W2 and W2 placed on the lower mechanical hand 2b without being interfered by the plate-shaped workpiece W2 placed on the lower mechanical hand 2b. Thus, the presence or absence of the plate-shaped workpiece W1 placed on the upper mechanical hand 2a can be appropriately detected.

[0041] The transfer device A1 having the above structure is configured to be able to detect the presence or absence of the plate-shaped workpieces W1 and W2 on the mechanical hands 2a and 2b in a vacuum environment while placing the optical sensors 6A and 6B, which are precision electronic devices, and the signal lines 61 connected thereto in the atmospheric environment. Therefore, the high performance of the optical sensors 6A and 6B can be utilized to more accurately detect the presence or absence of the plate-shaped workpieces W1 and W2.

[0042] As described above, according to the transfer device A1 having the above structure, it is possible to detect the presence or absence of the plate-shaped workpieces W1 and W2 on the mechanical hands 2a and 2b without arranging sensors and signal lines on the mechanical hands 2a and 2b in a vacuum environment.

[0043] Of course, the scope of the present invention is not limited to the above-described embodiments, and all design changes within the scope of the matters described in each technical solution are included in the scope of the present invention.

[0044] For example, as Figure 4 shown, the present invention can also be applied to a transfer device A2 in which one plate-shaped workpiece W1 and W2 are placed on each of the upper mechanical hand 2a and the lower mechanical hand 2b. As Figure 5 shown, the present invention can also be applied to a transfer device A3 in which the lower mechanical hand 2b is located at a predetermined distance in front of the upper mechanical hand 2a in the original position. In this case, the optical sensors 6B and 6A are arranged in a manner corresponding to the vicinity of the rear ends of the plate-shaped workpieces W1 and W2 placed on each of the mechanical hands 2a and 2b. The front optical sensor 6B is used to detect the presence or absence of the plate-shaped workpiece W2 placed on the lower mechanical hand 2b, and the rear optical sensor 6A is used to detect the presence or absence of the plate-shaped workpiece W1 placed on the upper mechanical hand 2a. The above Figure 4 and Figure 5Descriptions of other structures of the transfer devices A2 and A3 shown are omitted by assigning the same reference numerals to components or parts that are the same as or equivalent to those of the transfer device A1 shown in Figures 1 to 3 the drawings.

Claims

1. A conveying device for conveying a plate-shaped workpiece arranged in a vacuum environment, The transport device is characterized in that The transport device comprises: a support platform; at least one robot, which is guided and supported on the support platform so as to be able to move forward and backward in a horizontal straight line direction and can carry the plate-like workpiece; and a driving mechanism, which drives the at least one robot to move forward and backward, The support platform is provided with: a sealed container, whose internal space is connected to the atmosphere and has a light-transmitting window at the top; and at least one optical sensor, which is housed in the sealed container and can select a detectable distance passing above the light-transmitting window and can detect the presence or absence of an object within the detectable distance.

2. The transport device according to claim 1, wherein: The at least one robot can carry a plurality of plate-like workpieces arranged along a moving direction of the at least one robot, and a plurality of groups including the sealed container and the at least one optical sensor are provided corresponding to the plurality of plate-like workpieces.

3. The transport device according to claim 2, wherein: The at least one robot comprises an upper robot and a lower robot which can move forward and backward independently of each other and are arranged up and down, The at least one optical sensor includes a first optical sensor for detecting the presence or absence of an object placed on the upper robot and a second optical sensor for detecting the presence or absence of an object placed on the lower robot.

4. The transport device according to any one of claims 1 to 3, wherein: The at least one robot arm has a plurality of forks extending along a moving direction of the robot arm and carrying the plate-like workpiece. The group including the sealed container and the at least one optical sensor is arranged at a position that does not overlap with the plurality of forks in a plan view.

5. The transport device according to claim 1, wherein: The drive mechanism is a belt drive mechanism.

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