Transport device

Abstract

To provide a transport device that transports a workpiece on a hand that moves back and forth in a linear direction on a support table in a vacuum environment, and constantly supplies electricity to sensors placed on the hand without laying a signal line between the hand and the support table.SOLUTION: A transport device A1 is provided in a vacuum environment and includes a support table 1, a guide rail 46 provided on the support table 1, a hand 2 that is guided by the guide rail 46 so as to be able to move back and forth in a horizontal linear direction and on which a workpiece can be placed, and a belt drive mechanism 4 provided on the support table for driving the hand back and forth, and the hand includes a hand support 21 guided by the guide rail and a hand body 22 supported by the hand support, a sensor 6 is provided on the hand, and at least a portion 41b of a belt 41 that constitutes the belt drive mechanism 4 is electrically conductive and is connected to the sensor via a signal line 61 arranged inside the hand support, allowing power to be supplied and signals to be transmitted.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a conveying device, and more particularly to a conveying device capable of linearly conveying a workpiece such as a glass substrate for an FPD (flat panel display). [Background technology]

[0002] An example of this type of conveying device is described in Patent Document 1. The conveying device described in this document is configured so that a hand is supported by a linear guide mechanism provided on a support table so that it can move horizontally in a straight line, and the hand is driven forward and backward by a belt drive mechanism. The support table is usually capable of moving up and down and rotating.

[0003] This type of transfer device is used to transfer workpieces in a vacuum and high-temperature environment, such as receiving them from a processing chamber for a previous process and carrying them into a processing chamber for a next process. In this case, it is important to check whether the workpiece is correctly placed on the hand at the time when it should be placed on the hand in order to smoothly carry out a series of processes for the workpiece.

[0004] The conveying device described in Patent Document 1 employs a configuration in which a sensor, such as a proximity sensor, is mounted on the hand. However, if the sensor is mounted on the hand, which is exposed to a vacuum environment, and the signal is transmitted to a control unit, which is placed in an atmospheric environment, via a signal line, a long signal line must be routed between the hand and the support table, whose bending state changes with hand movement. This poses various challenges to ensuring stable operation. The conveying device described in Patent Document 1 is configured so that the contacts on the hand and the support table are connected and power is applied to the sensor only when the hand is at its most retracted home position and its most advanced position. This eliminates the need for a signal line between the reciprocating hand and the support table, but it can only confirm the presence or absence of a plate-shaped workpiece on the hand when the hand is at its home position and its advanced position. Furthermore, repeated contact separation in a vacuum environment inevitably generates particles, potentially hindering stable operation of the system in which the conveying device is installed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-65092 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention was devised in light of the above circumstances, and its object is to provide a transport device that transports a workpiece on a hand that can be moved back and forth in a linear direction on a support table in a vacuum environment, in such a way that a stable operating state can be maintained while allowing constant current to be applied to a sensor placed on the hand without installing a signal line between the hand and the support table. [Means for solving the problem]

[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 is a conveying device that is installed in a vacuum environment and includes a support table, a guide rail provided on the support table, a hand that is guided by the guide rail so as to be able to move back and forth in a horizontal linear direction and on which a workpiece can be placed, and a belt drive mechanism that is provided on the support table and drives the hand back and forth, wherein the hand includes a hand support guided by the guide rail and a hand body supported by the hand support, a sensor is provided on the hand, and at least a portion of the belt that constitutes the belt drive mechanism is composed of an electrically conductive belt that is conductive to the sensor and is capable of supplying power and transmitting signals.

[0009] In a preferred embodiment, the belt drive mechanism includes a drive pulley, a first driven pulley and a second driven pulley provided at one end and the other end of the movement path of the hand, a pulley support arranged along the movement path, supporting a first pulley located on the side of the first driven pulley and a second pulley located on the side of the second driven pulley, and movable along the movement path, and a pulley support having one end connected to the hand support and being wound around the second driven pulley, the drive pulley, the first driven pulley, and the first pulley in this order, and having the other end connected to the support table. and a second belt having one end connected to the hand body and looped around the second pulley and the other end fixed to the support table or a member integral therewith, at least one of the first belt and the second belt being formed by the conductive belt, and the first belt or the second belt formed by the conductive belt having one end connected to the hand support that is electrically connected to the sensor and the other end that is electrically connected to an external control unit.

[0010] In a preferred embodiment, the pulley support is movable along the travel path while being guided by the guide rail.

[0011] In a preferred embodiment, the hand comprises an upper hand and a lower hand that are arranged vertically and can move forward and backward independently of each other.

[0012] In a preferred embodiment, the sensor is a sensor for detecting the presence or absence of an object on the hand. [Effects of the Invention]

[0013] The conductive belt, which constitutes at least a part of the belts constituting the belt drive mechanism, is electrically connected to the sensor provided in the hand to supply power and transmit signals, and one end of the conductive belt is connected to the hand support. Power is supplied to the sensor and detection signals are transmitted via the conductive belt. In other words, the conductive belt has both the function of transmitting the driving force for moving the hand back and forth and the function of supplying power to the sensor and transmitting detection signals.

[0014] Therefore, the sensor can function regardless of the position of the hand in its movement process, and if a sensor that detects the presence or absence of an object on the hand is used, it can always detect whether a workpiece is placed on the hand regardless of the position of the hand in its movement process. This makes it possible to more accurately detect abnormalities in workpiece transportation in a system in which the transportation device of the present invention is installed. It can be done.

[0015] Furthermore, as described above, the sensor can be made to function at all times regardless of the position of the hand, so any type of sensor can be used, including sensors that detect the presence or absence of an object on the hand, vibration sensors, acceleration sensors, or cameras as image sensors.

[0016] Other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the drawings. [Brief explanation of the drawings]

[0017] [Figure 1]1 is a side view showing an outline of the overall configuration of a conveying device A1 according to an embodiment of the present invention, with a belt driving mechanism omitted. [Figure 2] FIG. 2 is a schematic side view for explaining the operating principle of the transport device A1, showing a state in which the hand is at the home position. [Figure 3] FIG. 10 is a schematic side view for explaining the operating principle of the transport device A1, showing a state in which the hand is at the advanced position. [Figure 4] FIG. 10 is a schematic side view for explaining the operation principle of a transport device A2 according to another embodiment of the present invention, showing a state in which the hand is at the home position. [Figure 5] FIG. 10 is a schematic side view for explaining the operating principle of a transport device A2 according to another embodiment of the present invention, showing a state in which the hand is at an advanced position. DETAILED DESCRIPTION OF THE INVENTION

[0018] Preferred embodiments of the present invention will now be described in detail with reference to the drawings.

[0019] Fig. 1 is a side view showing the overall appearance of a conveying device A1 according to one embodiment of the present invention. Fig. 2 and Fig. 3 are schematic side views for explaining the operating principle of the conveying device A1, showing a representative configuration for driving one hand 2 forward and backward. Fig. 2 shows the hand 2 in its most retracted position (home position), and Fig. 3 shows the hand 2 in its most advanced position.

[0020] As shown in Figures 1, 2, and 3, the transfer device A1 is installed in a vacuum environment and includes a support table 1, a hand 2 that is guided and supported on the support table 1 so that it can move linearly along a horizontal movement path, and a belt drive mechanism 4 that drives the hand 2 forward and backward along the movement path. The hand 2 is guided by a guide rail 46 provided on the support table 1. Typically, a pair of guide rails 46, one on the left and one on the right, are provided parallel to each other. The support table 1 is typically rotatable and movable up and down relative to a support base 3.

[0021] More specifically, the hand 2 is configured by a hand support 21 holding a hand body 22 on which a workpiece W, such as a thin glass substrate, is placed. A guide block 51 fixed to the hand support 21 is slidably combined with a guide rail 46. The hand body 22 includes a fork 22a extending in the direction of movement of the hand 2. A belt 41 constituting a belt drive mechanism 4 is connected to the hand support 21, thereby driving the hand 2 forward and backward along a horizontal linear movement path. The hand 2 also has a sensor 6, such as an optical proximity sensor, that can detect the presence or absence of an object on the hand body 22. As shown in FIG. 1, the hand 2 of this transport device A1 is configured as two hands, an upper hand 2a and a lower hand 2b, arranged vertically in two stages and driven forward and backward independently. However, the following description, including the belt drive mechanism 4, with reference to FIGS. 2 and 3 will be based on the configuration of one of the upper hands, 2a.

[0022] As shown in FIGS. 2 and 3, the belt drive mechanism 4 supports a first driven pulley 42a and a second driven pulley 42b disposed corresponding to both ends of the movement path of the hand 2 on the support table 1, a drive pulley 43 disposed between the two driven pulleys 42a and 42b, two idler pulleys 44a and 44b disposed adjacent to the drive pulley 43 so as to sandwich the drive pulley 43 from the front and rear, a first pulley 47a located on the first driven pulley 42a side, and a second pulley 47b located on the second driven pulley 42b side, and drives the hand 2 along the movement path. The system includes a movable pulley support 47, a first belt 41a having one end connected to the hand support 21 and passed around the second driven pulley 42b, the idler pulley 44a, the drive pulley 43, the idler pulley 44b, the first driven pulley 42a, and the first pulley 47a in that order and the other end connected to a support frame 47c of the pulley support 47, which is an integral member with the support table 1, and a second belt 41b having one end connected to the hand support 21 and passed around the second pulley 47b and the other end fixed to a drive box 45, which is an integral member with the support table 1. In this embodiment, the second driven pulley 42b is constantly biased in the advancing direction of the hand 2 by an elastic member 49, applying a predetermined tension to the first belt 41a and the second belt 41b. The drive pulley 43 is rotated by a motor 431 disposed in a drive box 45 that communicates with the atmospheric environment, with the output shaft projecting into a vacuum environment via a sealing mechanism (not shown).

[0023] In this embodiment, the pulley support 47 is supported by a moving body 52 having a guide block 52 a slidably combined with the guide rail 46 , and is movable horizontally and linearly along the guide rail 46 .

[0024] The first belt 41a and the second belt 41b are so-called toothed belts, and at least one of them is an electrically conductive belt 48. In this embodiment, the second belt 41b is the electrically conductive belt 48, and the first belt 41a is a normal toothed belt. In the drawings, the second belt 41b, which is the electrically conductive belt 48, is shown by a solid line, and the first belt 41a, which is a normal belt, is shown by a dashed line.

[0025] The conductive belt 48 is a belt containing a multi-core conductor (not shown) over its entire length, which is capable of supplying power and transmitting signals, and is commercially available. One end of the second belt 41b, which is the conductive belt 48, is connected to the sensor 6 via a signal line 61 arranged inside the hand support 21, and the other end is connected to a signal line 63 arranged inside the drive box 45 via an airtight connector 62, for example, called a feedthrough, and this signal line 63 is connected to the external control unit 7. Note that the airtight connector 62 is fixedly provided at an appropriate part of the drive box 45, and is therefore an integral member of the support base 1.

[0026] Next, the operation of the transport device A1 having the above configuration will be described.

[0027] FIG. 2 shows the state where the hand 2 is at the origin position (home position), and FIG. 3 shows the state where the hand 2 is at its most advanced position.

[0028] When the drive pulley 43 is rotated and driven to pull and move the hand support 21 by the first belt 41a in the direction of advancement of the hand 2, i.e., to the right in FIG. 2, the second pulley 47b, around which the second belt 41b, one end of which is connected to the hand support 21, is wound, operates as a movable pulley, and the pulley support 47 moves to the right at half the speed of the hand support 21. As a result, as shown in FIG. 3, the movement distance of the pulley support 47 when the hand 2 is fully advanced is half the movement distance of the hand support 21. On the other hand, when the drive pulley 43 is rotated in the reverse direction from the state shown in FIG. 3 to pull the portion around which the first belt 41a is wound to the right in FIG. 3, the first pulley 47a around which the first belt 41a is wound functions as a movable pulley, and the pulley support 47 moves to the left in FIG. 3. The movement distance of the pulley support 47 at this time is half the pulling distance of the first belt 41a. The hand support 21 moves to the left, i.e., toward the home position of the hand 2, reflecting the pulling distance of the first belt 41a at this time, and the hand 2 eventually returns to the home position shown in Fig. 2. The moving distance of the hand 2 to the left in Fig. 3 at this time is twice that of the pulley support 47.

[0029] In this way, according to the transport device A1 configured as described above, power can be supplied to and signals can be transmitted to the sensor 6 provided on the hand 2 via the second belt 41b, which is an electrically conductive belt, regardless of the position of the hand 2 in its movement process. As a result, if a sensor that detects the presence or absence of an object on the hand 2 is used as the sensor 6, it is possible to constantly monitor the presence or absence of a workpiece W on the hand 2 regardless of the position of the hand 2, and in a system in which the transport device A1 is installed, abnormalities in workpiece transport can be more accurately detected.

[0030] Furthermore, in the conveying device A1 configured as described above, the belt 41 of the belt drive mechanism 4 has the function of supplying power and transmitting signals to the hand 2, so there is no need to provide a long signal line between the hand 2 and the support table 1 whose bending state changes as the hand 2 moves, or a contact point that repeatedly comes into contact and separates as in the configuration of Patent Document 1, thereby improving the reliability of operation in a vacuum environment.

[0031] Of course, the scope of the present invention is not limited to the above-described embodiment, and all design modifications within the scope of the claims are included in the scope of the present invention.

[0032] For example, in the conveying device A1, the second belt 41b is an electrically conductive belt, but the first belt 41a may also be an electrically conductive belt. In this case, the other end of the first belt 41a needs to be connected to a signal line that is connected to the control unit 7 via an airtight connector.

[0033] 4 and 5, the configuration of the belt drive mechanism 4 may be reversed from the configuration shown in FIGS. 2 and 3, so that the hand 2 is in the origin position (home position) when the belt drive mechanism 4 is in the state shown in FIG. 3, and the hand 2 is in the advanced position when the belt drive mechanism 4 is in the state shown in FIG. 2. For example, in a configuration having two hands, an upper hand 2a and a lower hand 2b, positioned so as to overlap one another, as shown in FIG. 1, the configuration shown in FIGS. 2 and 3 can be used for the belt drive mechanism 4 for the upper hand 2a, and the configuration shown in FIGS. 4 and 5 can be used for the belt drive mechanism 4 for the lower hand 2a, as described above. The remaining configuration of the transport device A2 will not be described here, with the same reference numerals used to designate members or parts that are the same or equivalent to those of the transport device A1 shown in FIGS. 2 and 3.

[0034] Furthermore, the sensor 6 may be any type of sensor, such as a sensor that detects the presence or absence of an object on the hand 2, a vibration sensor, an acceleration sensor, or a camera as an image sensor. [Explanation of symbols]

[0035] A1, A2: conveying device, W: workpiece, 1: support table, 2: hand, 2a: upper hand, 2b: lower hand, 21: hand support, 22: hand body, 4: belt drive mechanism, 41: belt, 41a: first belt, 41b: second belt, 42a: first driven pulley, 42b: second driven pulley, 43: drive pulley, 46: guide rail, 47: pulley support, 47a: first pulley, 47b: second pulley, 48: conductive belt, 6: sensor, 7: control unit

Claims

1. A conveying device that is disposed in a vacuum environment and includes: a support table; a guide rail provided on the support table; a hand that is guided by the guide rail so as to be movable forward and backward in a horizontal linear direction and on which a workpiece can be placed; and a belt drive mechanism that is provided on the support table and drives the hand forward and backward, the hand includes a hand support guided by the guide rail and a hand body supported by the hand support, The hand is provided with a sensor, A conveying device characterized in that at least a part of the belt constituting the belt driving mechanism is made of an electrically conductive belt that is electrically connected to the sensor and is capable of supplying power and transmitting signals.

2. The belt drive mechanism is A drive pulley; a first driven pulley and a second driven pulley provided at one end and the other end of a movement stroke of the hand; a pulley support member arranged along the travel path, supporting a first pulley located on the first driven pulley side and a second pulley located on the second driven pulley side, and movable along the travel path; a first belt having one end connected to the hand support and wound around the second driven pulley, the driving pulley, the first driven pulley, and the first pulley in this order, and the other end connected to the support table or a member integral therewith; a second belt having one end connected to the hand body and looped around the second pulley, and the other end fixed to the support table or a member integral therewith; Including, At least one of the first belt and the second belt is formed of the conductive belt, 2. The conveying device according to claim 1, wherein the first belt or the second belt formed of the conductive belt has one end connected to the hand support that is electrically connected to the sensor and the other end that is electrically connected to an external control unit.

3. The transport device according to claim 2 , wherein the pulley support is guided by the guide rail and is movable along the travel path.

4. 4. The transfer device according to claim 1, wherein the hand comprises an upper hand and a lower hand that are arranged vertically and can move forward and backward independently of each other.

5. 2. The conveying device according to claim 1, wherein the sensor is a sensor for detecting the presence or absence of an object on the hand.

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