Conveying device

Abstract

To provide a conveying device that can sense whether a work-piece is put on a hand or not, without arranging a sensor and a signal wire under a vacuum environment.SOLUTION: Conveying devices A1, A2 and A3, which respectively comprise support tables 1, hands 2 which are guided and supported on the support tables 1, movably back and forth in a horizontal linear direction and on which plate-like work-pieces W1 and W2 can be placed, and driving mechanisms 4 that drive the hands 2, movably back and forth and which are arranged under a vacuum environment. The support table 1 is provided with a sealed container 5 whose inner space is conducted to the atmosphere and which has a translucent window 51 at an upper part thereof, and optical sensors 6A and 6B, stored in the sealed container 5, which can select detectable distances H1 and H2 at an upper side through the translucent window 51 and detect whether objects exist in the detectable distances H1 and H2 or not.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] As an example of this type of conveying device, there is one described in Patent Document 1. The conveying device described in the same document is configured to support a hand so as to be movable in a horizontal linear direction by a linear guide mechanism provided on a support table, and to drive the hand forward and backward by a belt drive mechanism. The support table is usually capable of ascending, descending, and turning.

[0003] This type of conveying device is used for performing conveyance such as receiving a plate-shaped workpiece from a processing chamber of a previous process and loading it into a processing chamber of a next process in a vacuum and high-temperature environment. In this case, it is important to confirm whether or not the plate-shaped workpiece is correctly placed on the hand at the time when the plate-shaped workpiece should be placed on the hand in order to smoothly perform a series of processes on the plate-shaped workpiece.

[0004] In the conveying device described in Patent Document 1, a configuration in which a sensor such as a proximity sensor is arranged near the hand is adopted. However, there are various difficulties in ensuring stable operation while adopting a configuration in which a sensor is arranged on the hand exposed to a vacuum environment and a signal is led to a control unit in an atmospheric environment via a signal line. Recently, there has been a movement to place a plurality of plate-shaped workpieces on one hand and convey them to further improve the efficiency of a series of processes for the plate-shaped workpieces. In this case, it is even more important to confirm whether or not a plurality of plate-shaped workpieces are correctly placed on one hand.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been conceived under the above circumstances, and in a conveying device that conveys a plate-shaped workpiece by placing it on a hand that can move forward and backward in a straight line direction, it is an object of the present invention to be configured to be able to detect the presence or absence of a workpiece on the hand without arranging sensors and signal lines in a vacuum environment.

Means for Solving the Problems

[0007] In order to solve the above problems, the present invention employs the following technical means.

[0008] The conveying device provided by the present invention includes a support table, a hand 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 on which a plate-shaped workpiece can be placed, and a drive mechanism that drives the hand forward and backward. It is a conveying device arranged in a vacuum environment. The support table is provided with a sealed container having an internal space communicating with the atmosphere and having a light-transmitting window at the upper part, and an optical sensor that is housed in the sealed container and has a selectable detectable distance above through the light-transmitting window and can detect the presence or absence of an object at the detectable distance.

[0009] In a preferred embodiment, the hand can place a plurality of plate-shaped workpieces arranged in the moving direction of the hand, and a plurality of sets of the sealed container and the optical sensor are provided corresponding to the plurality of plate-shaped workpieces.

[0010] In a preferred embodiment, the hand consists of an upper hand and a lower hand that can move forward and backward independently of each other and are arranged vertically. The optical sensor includes a first optical sensor for detecting the presence or absence of an object placed on the upper hand and a second optical sensor for detecting the presence or absence of an object placed on the lower hand.

[0011] In a preferred embodiment, the hand has a plurality of hook claws that extend in the moving direction of the hand and on which the plate-shaped workpiece is placed, and the combination of the sealed container and the optical sensor is provided at a position that does not overlap with the plurality of hook claws in a plan view.

[0012] In a preferred embodiment, the drive mechanism is a belt drive mechanism.

Advantages of the Invention

[0013] The detectable distance of the optical sensor is set, for example, to the distance from the optical sensor to the plate-shaped workpiece to be placed on the hand. In this case, the reflected light from an object located at a distance other than the detectable distance is canceled. For example, when the hand is in the home position, the presence or absence of the plate-shaped workpiece on the hand is detected as follows.

[0014] That is, if a plate-shaped workpiece is placed on the hand, the optical sensor can detect the reflected light from the plate-shaped workpiece, and thereby can detect the presence of the plate-shaped workpiece on the hand, that is, that the plate-shaped workpiece is placed on the hand. On the other hand, when no plate-shaped workpiece is placed on the hand, the optical sensor does not detect any reflected light, so it can detect the absence of the plate-shaped workpiece on the hand, that is, that the plate-shaped workpiece is not placed on the hand.

[0015] Thus, according to the transfer device of the present invention, it is possible to detect the presence or absence of the plate-shaped workpiece on the hand without providing a sensor on the hand that moves in a vacuum environment.

[0016] Other features and advantages of the present invention will become more apparent from the following detailed description with reference to the drawings.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0018] Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

[0019] FIG. 1 is a schematic side view showing the configuration of the transport device A1 according to an embodiment of the present invention, with the belt drive mechanism 4 omitted, and FIG. 2 is a schematic diagram showing the configuration of the belt drive mechanism 4.

[0020] As shown in FIGS. 1 and 2, the transport device A1 includes a support table 1, a hand 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 hand 2 to advance and retreat along the movement stroke, and optical sensors 6A and 6B for detecting the presence or absence of the plate-like workpieces W1 and W2 on the hand 2. The support table 1 is usually rotatable and vertically movable with respect to the support base 3.

[0021] The hand 2 is more specifically configured to hold a hand body 22 on which a plate-shaped workpiece W is placed by a hand holding member 21. A guide block (not shown) fixed to the hand holding member 21 is provided on the support table 1 and is slidably combined with a guide rail 46 that extends in a horizontal straight line. The hand body 22 includes a plurality (four in this embodiment) of hook claws 22a that extend in the moving direction of the hand 2. The hand holding member 21 is connected to an appropriate portion of an endless belt 41 that constitutes a belt drive mechanism 4. As a result, the hand 2 is driven to advance and retreat in a horizontal straight moving stroke. As shown in FIG. 1, in this embodiment, the hand 2 is composed of two upper hands 2a and lower hands 2b arranged in two upper and lower stages and are driven to advance and retreat separately. The following description of the belt drive mechanism 4 will be made on behalf of the configuration for one of the lower hands 2b.

[0022] As shown in FIG. 2, the belt drive mechanism 4 includes two driven pulleys 42a and 42b arranged corresponding to the vicinity of both ends of the moving stroke of the hand 2 on the support table 1, a drive pulley 43 arranged between these two driven pulleys 42a and 42b, two idler pulleys 44a and 44b arranged close to the drive pulley 43 while sandwiching the drive pulley 43 front and back, and an endless belt 41 wound around these pulleys 42a, 42b, 43, 44a, and 44b. The drive pulley 43 is rotationally driven by a motor 431 arranged in a drive box 45 that communicates with the atmospheric environment while protruding the output shaft into the vacuum environment through a seal mechanism (not shown).

[0023] As shown in FIG. 1, the upper hand 2a and the lower hand 2b are each configured to be able to place two plate-shaped workpieces W1 and W2 arranged in the moving direction of the hands 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. Also, the state shown in FIG. 1 shows the state where each hand 2a and 2b is located at the home position where it has retreated the most. As can be seen from the figure, the upper hand 2a is slightly (for example, about 10 to 20 mm) shifted forward with respect to the lower hand 2b.

[0024] 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 such 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 in the direction of movement of the hands 2a and 2b are accommodated therein. A set consisting of the sealed container 5 and the two optical sensors 6A and 6B is provided at two locations with a space corresponding to the placement interval P of the two plate-shaped workpieces W1 and W2 to be placed on the hands 2a and 2b. In the present embodiment, it is provided at positions corresponding to the vicinity of each tip of the two plate-shaped workpieces W2 placed on the lower hand 2b. The communication of each sealed container 5 with 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 pipe 53. The bellows pipe 53 is provided for performing, for example, position adjustment in the front-rear direction of a rigid configuration in which the front and rear two sealed containers 5 are connected by the sealed pipe 52. The signal lines 61 connected to each of the optical sensors 6A and 6B are routed to the control unit 7 via the drive box 45 and the support base 3 through the sealed pipe 52 and the bellows pipe 53. Further, the configuration consisting of these two sealed containers 5 and the two optical sensors 6A and 6B accommodated in their internal spaces is arranged at the center in the width direction of the support table 1 so as not to overlap with the four hook claws 22a of the hand 2 in a plan view, as shown in FIG. 3.

[0025] The optical sensors 6A and 6B receive the reflected light of the emitted light (laser light) and detect the presence or absence of an object at a detectable distance. In the present embodiment, the light emitting and receiving parts are installed in the sealed container 5 with the upward direction. Further, an optical sensor 6A, 6B which can set a detectable distance is preferably used. By setting the optical sensors 6A and 6B to cancel the reflected light from a distance other than the detectable distance (having a certain distance range), the detectable distance can be selected. For example, a CMOS laser sensor (model number: LR-XH250) manufactured by Keyence Corporation can be used.

[0026] Of the two optical sensors 6A and 6B disposed in each sealed container 5, the detectable distance H1 of the optical sensor (first optical sensor) 6A on the front side in the moving direction of the hand 2 is set to the distance from the optical sensor 6A to the plate-shaped workpiece W1 to be placed on the upper hand 2a, and the detectable distance H2 of the optical sensor 6B (second optical sensor) on the rear side in the moving direction of the hand 2 is set to the distance from the optical sensor 6B to the plate-shaped workpiece W2 to be placed on the lower hand 2b.

[0027] When the plate-shaped workpiece W1 is placed on the upper hand 2a, the front-side optical sensor 6A detects the reflected light from the plate-shaped workpiece W1 at the detectable distance H1. On the other hand, if the plate-shaped workpiece W1 is not placed on the upper hand 2a, the optical sensor 6A does not detect the reflected light from the object at the detectable distance H1. In this way, the optical sensor 6A can detect the presence or absence of the plate-shaped workpiece W1 on the upper hand 2a by detecting or not detecting the reflected light. Similarly, when the plate-shaped workpiece W2 is placed on the lower hand 2b, the rear-side optical sensor 6B detects the reflected light from the plate-shaped workpiece W2 at the detectable distance H2. On the other hand, if the plate-shaped workpiece W2 is not placed on the lower hand 2b, the optical sensor 6B does not detect the reflected light from the object at the detectable distance H2. In this way, the optical sensor 6B can detect the presence or absence of the plate-shaped workpiece W2 on the lower hand 2b by detecting or not detecting the reflected light.

[0028] Note that most of the light from each of the optical sensors 6A and 6B passes through the light-transmitting window 51 of the sealed container 5, but a part of it is reflected by the light-transmitting window 51. Therefore, strictly speaking, the reflected light received by the optical sensors 6A and 6B includes the reflected light from the light-transmitting window 51. However, since the distance from the optical sensors 6A and 6B to the light-transmitting window 51 is a distance outside the detectable distances H1 and H2, the reflected light from the light-transmitting window 51 is canceled out, and the presence of the light-transmitting window 51 is not detected as noise. Similarly, when the plate-shaped workpieces W1 and W2 are made of transparent glass, strictly speaking, the reflected light received by the optical sensor 6B includes the reflected light from the plate-shaped workpiece W1 placed on the upper hand 2a. However, since the distance from the optical sensor 6B to the plate-shaped workpiece W1 placed on the upper hand 2a is a distance outside the detectable distance H2 of the optical sensor 6B, the reflected light from the plate-shaped workpiece W1 placed on the upper hand 2a is canceled out, and the presence of the plate-shaped workpiece W1 placed on the upper hand 2A is not detected as noise.

[0029] In the transfer device A1 having the above configuration, when each of the hands 2a and 2b is in the home position where it has retracted the most, the presence or absence of the plate-shaped workpieces W1 and W2 on each of the hands 2a and 2b is detected as described above. In the present embodiment, in the home position, the upper hand 2a is shifted forward by a predetermined distance with respect to the lower hand 2b, and the front optical sensor 6A for detecting the presence or absence of the plate-shaped workpiece W1 placed on the upper hand 2a and the rear optical sensor 6B for detecting the presence or absence of the plate-shaped workpiece placed on the lower hand 2b are arranged side by side in the moving direction of the 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 hand 2b, and the presence or absence of the plate-shaped workpiece W1 placed on the upper hand 2a can be appropriately detected without being affected by the interference of the plate-shaped workpiece W2 placed on the lower hand 2b.

[0030] In addition, the transfer device A1 with the above configuration is configured to be able to detect the presence or absence of the plate-shaped workpieces W1 and W2 on the hands 2a and 2b in the vacuum environment by placing the optical sensors 6A and 6B, which are precision electronic devices, and the signal lines 61 connected thereto in the atmospheric environment. Therefore, due to the high performance of the optical sensors 6A and 6B, it is possible to more accurately detect the presence or absence of the plate-shaped workpieces W1 and W2.

[0031] As described above, according to the transfer device A1 with the above configuration, it is possible to detect the presence or absence of the plate-shaped workpieces W1 and W2 on the hands 2a and 2b without arranging sensors and signal lines on the hands 2a and 2b in the vacuum environment.

[0032] 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 claim are included in the scope of the present invention.

[0033] For example, as shown in FIG. 4, the present invention can also be applied to a transfer device A2 that places one plate-shaped workpiece W1 and W2 on the upper hand 2a and the lower hand 2b, respectively. As shown in FIG. 5, in the home position, the present invention can also be applied to a transfer device A3 in which the lower hand 2b is positioned a predetermined distance forward with respect to the upper hand 2a. In this case, the optical sensors 6B and 6A are positioned so as to correspond to the vicinity of the rear end of the plate-shaped workpieces W1 and W2 placed on the hands 2a and 2b, respectively. The front optical sensor 6B is used to detect the presence or absence of the plate-shaped workpiece W2 placed on the lower 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 hand 2a. The description of the other configurations of the transfer devices A2 and A3 shown in FIGS. 4 and 5 is omitted by assigning the same reference numerals to the same or equivalent members or parts as those of the transfer device A1 shown in FIGS. 1 to 3.

Description of Reference Numerals

[0034] A1, A2, A3: Conveyor device, W1, W2: Plate-shaped workpieces, H1, H2: Detectable distances, 1: Support table, 2: Hand, 2a: Upper hand, 2b: Lower hand, 22a: Hook claw, 4: Belt drive mechanism, 5: Sealed container, 51: Translucent window, 6A, 6B: Optical sensors

Claims

1. A conveying device disposed in a vacuum environment, comprising: a support table; a hand 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 on which a plate-shaped workpiece can be placed; and a drive mechanism that drives the hand to move forward and backward. The support table is provided with: a sealed container having an internal space communicating with the atmosphere and having a light-transmitting window at the upper part; and an optical sensor housed in the sealed container, the detectable distance above the light-transmitting window being selectable, and the presence or absence of an object at the detectable distance being detectable. The conveying device is characterized in that.

2. The hand can place a plurality of plate-shaped workpieces arranged in the moving direction of the hand, and a plurality of sets of the sealed container and the optical sensor are provided corresponding to the plurality of plate-shaped workpieces. The conveying device according to Claim 1.

3. The hand consists of an upper hand and a lower hand that can move forward and backward independently of each other and are arranged vertically. The optical sensor includes a first optical sensor for detecting the presence or absence of an object placed on the upper hand and a second optical sensor for detecting the presence or absence of an object placed on the lower hand. The conveying device according to Claim 2.

4. The hand has a plurality of hook claws that extend in the moving direction of the hand and on which the plate-shaped workpieces are placed. The set of the sealed container and the optical sensor is provided at a position that does not overlap with the plurality of hook claws in a plan view. The conveying device according to any one of Claims 1 to 3.

5. The drive mechanism is a belt drive mechanism. The conveying device according to Claim 1.

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