Patent Publication Number: US-2016236345-A1

Title: Transfer device and vacuum apparatus

Description:
TECHNICAL FIELD 
     The present invention generally relates to a transfer device that transfers a transfer object (such as, a substrate), and more particularly relates to a technique concerning a transfer device suitable for a vacuum apparatus (for example, in a semiconductor manufacturing device). 
     BACKGROUND ART 
       FIGS. 17 and 18  are diagrams for explaining problems in the conventional techniques. 
     Conventionally, as illustrated in  FIG. 17( a ) , there have been known a vacuum apparatus that has a transfer chamber having a quadrilateral shape, each side of which has two processing chambers. 
     For example, as illustrated in  FIG. 17( a ) , this vacuum processing device  101  includes pairs of processing chambers  102  and  103 ,  104  and  105 , and  108  and  109  (reference numerals  106  and  107  represent a loading and unloading chamber, respectively) provided at each side around the transfer chamber  100 . 
     Meanwhile, with this kind of transfer apparatus, a transfer device  120  that has a pair of substrate mounting units  121  and  122  to improve throughput in transferring substrates is known. 
     However, in such a conventional system, in many instances, the distance, for example, between the processing chambers  102  and  103  (in other words, the distance between substrates  110  and  111 ) may not be equal to the distance between the substrate mounting units  121  and  122  of the transfer device  120 , and there is a problem that positioning operations are difficult. 
     Furthermore, in the case where the distance between the substrate  110 ,  111  and the substrate mounting unit  121 ,  122  of the transfer device  120  is large, two substrates  110  and  111  cannot be placed on the substrate mounting units  121  and  122  of the transfer device  120  simultaneously as illustrated in, for example,  FIG. 17( b ) . 
     In such a case, it has also been done that the transfer device  120  is turned to angle the substrate mounting units  121  and  122  as illustrated in, for example,  FIGS. 18 ( a ) and 18( b ) , so that two substrates  110  and  111  are placed on the substrate mounting units  121  and  122  one by one, respectively. 
     However, there is a problem with such a conventional system because such an operation degrades throughput. 
     RELATED ART DOCUMENTS 
     Patent Document 
     
         
         Patent Literature 1: Japanese Patent Application Laid-Open Publication No. 2013-084823 
       
    
     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     The present invention has been made to solve the problems in the conventional system as described above; and an object of the present invention is to provide a system that facilitates positioning operations and also improves throughput in transferring substrates in a transfer device that can transfer a pair of transfer objects simultaneously. 
     Means for Solving the Problems 
     The present invention that has been made to achieve the object described above is a transfer device including first and second extension/contraction drive shafts for driving extension and contraction of first and second transfer mechanisms, the first and second extension/contraction drive shafts being disposed concentrically about a predetermined rotating axis as a center and each provided in an independently rotatable manner in a horizontal plane; and first and second turning drive shafts for turning the first and second transfer mechanisms, the first and second turning drive shafts being disposed concentrically about the first and second extension/contraction drive shafts, wherein the first transfer mechanism is configured to be driven to extend and contract by the first extension/contraction drive shaft so as to transfer a first transfer unit along a transfer object transfer direction, and the second transfer mechanism is configured to be driven to extend and contract by the second extension/contraction drive shaft so as to transfer a second transfer unit along the transfer object transfer direction, the first and second transfer mechanisms have first and second turning drive members that are driven by the first and second turning drive shafts, respectively, and turn the first and second transfer mechanisms, respectively, about the rotating axis as a center, and the first transfer mechanism and the second transfer mechanism are disposed opposite to each other in the transfer object transfer direction with the rotating axis in between. 
     Furthermore, the present invention is the transfer device in which the first and second transfer mechanisms are disposed at a same height position. 
     Furthermore, the present invention is a transfer device including a first transfer device and a second transfer device, the first transfer device comprises first and second extension/contraction drive shafts for driving extension and contraction of first and second transfer mechanisms, the first and second extension/contraction drive shafts being disposed concentrically about a predetermined rotating axis as a center, and each provided in an independently rotatable manner in a horizontal plane; and first and second turning drive shafts for turning the first and second transfer mechanisms, the first and second turning drive shafts being disposed concentrically about the first and second extension/contraction drive shafts, wherein the first transfer mechanism is configured to be driven to extend and contract by the first extension/contraction drive shaft so as to transfer a first transfer unit along a transfer object transfer direction, and the second transfer mechanism is configured to be driven to extend and contract by the second extension/contraction drive shaft so as to transfer a second transfer unit along the transfer object transfer direction, the first and second transfer mechanisms have first and second turning drive members that are driven by the first and second turning drive shafts, respectively, and turn the first and second transfer mechanisms, respectively, about the rotating axis as a center, and the first transfer mechanism and the second transfer mechanism are disposed opposite to each other in the transfer object transfer direction with the rotating axis in between; and the second transfer device comprises third and fourth extension/contraction drive shafts for driving extension and contraction of third and fourth transfer mechanisms corresponding to the first and second transfer mechanisms, the third and forth transfer mechanisms being disposed concentrically about the rotating axis as a center and each provided in an independently rotatable manner in a horizontal plane, wherein the third and fourth transfer mechanisms are disposed at height positions different from the first and second transfer mechanisms and opposite to each other in the transfer object transfer direction with the rotating axis in between, and are configured to be driven to extend and contract by the third and fourth extension/contraction drive shafts, respectively, so as to transfer third and fourth transfer units, respectively, along the transfer object transfer direction, and have a linkage mechanism connected with each of the first and second turning drive members provided to the first and second transfer mechanisms, and are configured to turn the third and fourth transfer mechanisms by the linkage mechanism about the rotating axis as a center. 
     Furthermore, the present invention is the transfer device, wherein the first and second transfer mechanisms are disposed at a same height, and the third and fourth transfer mechanisms are disposed at a same height. 
     Furthermore, the present invention is a vacuum apparatus including a vacuum chamber; and a transfer device provided in the vacuum chamber, the transfer device comprises: first and second extension/contraction drive shafts for driving extension and contraction of first and second transfer mechanisms, the first and second extension/contraction drive shafts being disposed concentrically about a predetermined rotating axis as a center, each provided in an independently rotatable manner in a horizontal plane; and first and second turning drive shafts for turning the first and second transfer mechanisms, the first and second turning drive shafts being disposed concentrically about the first and second extension/contraction drive shafts, wherein the first transfer mechanism is configured to be driven to extend and contract by the first extension/contraction drive shaft so as to transfer a first transfer unit along a transfer object transfer direction, and the second transfer mechanism is configured to be driven to extend and contract by the second extension/contraction drive shaft so as to transfer a second transfer unit along the transfer object transfer direction, the first and second transfer mechanisms have first and second turning drive members that are driven by the first and second turning drive shafts, respectively, and turn the first and second transfer mechanisms, respectively, about the rotating axis as a center, and the first transfer mechanism and the second transfer mechanism are disposed opposite to each other in the transfer object transfer direction with the rotating axis in between. 
     Furthermore, the present invention provides the vacuum apparatus further including a pair of transfer object detection sensors for detecting a pair of transfer objects transferred by the first and second transfer mechanisms, respectively, the pair of transfer object detection sensors being made of a plurality of sensors provided in the vacuum chamber; and a controller that controls movement of each of the first and second turning drive shafts so that the pair of transfer objects are placed on a pair of transfer object placement units on the basis of a result of detection by the pair of transfer object detection sensors. 
     According to the present invention, the first and second turning drive shafts configured to turn the first and second transfer mechanisms, respectively, are disposed concentrically with the first and second extension/contraction drive shafts that drive extension and contraction of the first and second transfer mechanisms, respectively, and these first and second turning drive shafts drive the first and second turning drive members, respectively, to turn the first and second transfer mechanisms, respectively, with the rotating axis as a center. This configuration makes it possible to adjust the distance between the transfer object mounting units of the first and second transfer mechanisms disposed opposite to each other in the transfer object transfer direction with the rotating axis in between and, for example, at the same height position, by spacing them apart from each other and approaching them to each other. 
     Consequently, according to the present invention, in the case where two transfer objects are placed side by side, the substrate mounting units of the first and second transfer mechanisms can be correctly positioned with respect to these transfer objects as well as portions where these transfer objects are placed. This makes it possible to facilitate positioning operations, and also improve throughput in transferring substrates. 
     Furthermore, a first transfer device may be configured as the transfer device described above, and a second transfer device may be configured such that: the second transfer device includes the third and fourth extension/contraction drive shafts disposed concentrically with the rotating axis as a center, each provided in an independently rotatable manner in a horizontal plane, and configured to drive extension and contraction of the third and fourth transfer mechanisms corresponding to the first and second transfer mechanisms, respectively, wherein the third and fourth transfer mechanisms: are disposed at height positions different from those of the first and second transfer mechanisms and opposite to each other in the transfer object transfer direction with the rotating axis in between are configured to be driven by the third and fourth extension/contraction drive shafts, respectively, to extend and contract so as to transfer the third and fourth transfer units, respectively, along the transfer object transfer direction; include the linkage mechanism connected with the first and second turning drive members provided to the first and second transfer mechanisms, respectively; and are configured to turn the third and fourth transfer mechanisms by the linkage mechanism with the rotating axis as a center. In the case where this configuration is employed, it is possible to adjust the distance between the substrate mounting units of the third and fourth transfer mechanisms by causing the third and fourth transfer mechanisms to extend and contract by the third and fourth extension/contraction drive shafts, spacing the substrate mounting units apart from each other, and approaching them to each other. 
     Consequently, according to the present invention, substrates can be transferred by the first and second transfer mechanisms and the third and fourth transfer mechanisms, which further improves throughput in transferring substrates. 
     Effect of the Invention 
     According to the present invention, it is possible to provide a system that facilitates positioning operation, and also improves throughput in transferring substrates in a transfer device that can transfer a pair of transfer objects simultaneously. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1( a ) and 1( b )  are plan views each illustrating a lower transfer device according to an embodiment of a transfer device relating to the present invention. 
         FIGS. 2( a ) and 2( b )  are plan views each illustrating an upper transfer device according to the same embodiment. 
         FIG. 3( a )  is a diagram illustrating a configuration of the transfer device when viewed from the downstream side in a transfer direction;  FIG. 3( b )  is a plan view illustrating the configuration of the transfer device; and  FIG. 3( c )  is a diagram illustrating the configuration of the transfer device when viewed from the upstream side in the transfer direction.  FIG. 4  is a plan view illustrating extension movement of the lower transfer mechanism. 
         FIG. 5  is a plan view illustrating extension movement of the upper transfer mechanism. 
         FIGS. 6( a ) and 6( b )  are explanatory views illustrating small turning movement of the upper transfer device and the lower transfer device according to the present embodiment (first). 
         FIGS. 7( a ) and 7( b )  are explanatory views illustrating small turning movement of the upper transfer device and the lower transfer device according to the present embodiment (second). 
         FIGS. 8( a ) and 8( b )  are explanatory views illustrating small turning movement of the upper transfer device and the lower transfer device according to the present embodiment (third). 
         FIGS. 9( a ) and 9( b )  are explanatory views illustrating small turning movement of the upper transfer device and the lower transfer device according to the present embodiment (fourth). 
         FIG. 10  is a plan view illustrating an embodiment of a vacuum apparatus according to the present invention (first). 
         FIG. 11  is a plan view illustrating an embodiment of the vacuum apparatus according to the present invention (second). 
         FIG. 12  is a plan view illustrating an embodiment of the vacuum apparatus according to the present invention (third). 
         FIG. 13  is a plan view illustrating a configuration of another embodiment of the vacuum apparatus according to the present invention. 
         FIG. 14  is an explanatory view illustrating a configuration of main portions of another embodiment of the vacuum apparatus according to the present invention. 
         FIG. 15  is a block diagram illustrating a configuration of circuit systems in another embodiment of the vacuum apparatus according to the present invention. 
         FIGS. 16( a ), 16( b ), 16( c ), 16( d )  and  16  ( e ) are explanatory views illustrating an operation of detecting positions of substrates according to the present embodiment. 
         FIGS. 17( a )  and  17  ( b ) are diagrams for explaining a problem in a conventional system (first). 
         FIGS. 18( a )  and  18  ( b ) are diagrams for explaining a problem in a conventional system (second). 
     
    
    
     BEST MODES FOR CARRYING OUT THE INVENTION 
     Hereinbelow, a preferred embodiment according to the present invention will be described in detail with reference to the drawings. 
       FIGS. 1( a ) and 1( b )  are plan views illustrating a lower transfer device according to an embodiment of a transfer device relating to the present invention.  FIGS. 2( a )  and  2  ( b ) are plan views illustrating an upper transfer device according to the same embodiment. 
       FIGS. 3( a ) to 3( c )  are diagrams illustrating the configuration of this transfer device.  FIG. 3( a )  is a diagram when viewed from the downstream side in a transfer direction;  FIG. 3 ( b )  is a plan view; and  FIG. 3( c )  is a diagram when viewed from the upstream side in the transfer direction. 
     A transfer device  1  according to the present invention transfers a transfer object such as a substrate, for example, in a vacuum chamber (not illustrated), and includes a lower transfer device  1 A serving as a first transfer device as illustrated in  FIGS. 1( a )  and  1  ( b ), and an upper transfer device  1 B serving as a second transfer device as illustrated in  FIGS. 2( a ) and 2( b ) . 
     As illustrated in  FIGS. 3 ( a ) to 3( c ) , the lower transfer device  1 A and the upper transfer device  1 B are arranged so as to be layered in a vertical direction. 
     As illustrated in  FIGS. 1( a ) and 1( b ) , this embodiment includes first, second, third, and fourth extension/contraction drive shafts  11 ,  12 ,  13 , and  14  and first and second turning drive shafts  15  and  16  which are concentric and to which rotational powers in a clockwise direction or a counterclockwise direction are transmitted respectively from an independent drive source (not illustrated). 
     Here, the first, second, third, and fourth extension/contraction drive shafts  11  to  14  and the first and second turning drive shafts  15  and  16  are provided, for example, so as to extend in the vertical direction. 
     As illustrated in  FIGS. 1 ( a )  and  1  ( b ), the lower transfer device  1 A comprises a left lower transfer mechanism  2 L and a right lower transfer mechanism  2 R that are provided on both sides (that is, on the left side and the right side respectively) of a straight line Y extending from the rotating axis O in a substrate transfer direction V (in a transfer object transfer direction). 
     The left lower transfer mechanism  2 L comprises a first left lower parallel crank mechanism  3   a  that is configured with a left lower driving arm  21 , a first turning drive member  31 , a first left lower driven arm  22 , and a second left lower driven arm  23 . 
     Here, the left lower driving arm  21  has one end portion (base end portion) connected with the first extension/contraction drive shaft  11  so as to rotate in the horizontal direction with the rotating axis O as a center. 
     Furthermore, the operational range of the left lower driving arm  21  is controlled such that it is located on the left side of the straight line Y passing through the rotating axis O and extending in parallel to the substrate transfer direction V. 
     On the other hand, the first turning drive member  31  is, for example, made up of a plate-like seating member, and is provided so as to extend toward the downstream side of the rotating axis O in the substrate transfer direction V. 
     This first turning drive member  31  is provided below the left lower driving arm  21 , and has one end portion (base end portion) connected with a first turning drive shaft  15  so as to rotate at predetermined angles in the horizontal direction with the rotating axis O as a center. 
     The left lower driving arm  21  has the other end portion (tip end portion) attached to one end portion (base end portion) of the first left lower driven arm  22  at the upper portion of the left lower driving arm  21  so as to freely rotate in the horizontal direction with a supporting shaft A as a center. 
     Furthermore, the first turning drive member  31  has the other end portion (tip end portion) attached to one end portion (base end portion) of the second left lower driven arm  23  at the upper portion of the first turning drive member  31  so as to freely rotate in the horizontal direction with a supporting shaft B as a center. 
     This supporting shaft B is provided so as to extend in the vertical direction through a connecting member  31   a , and is connected with a second right upper driven arm  63 , which will be described later, to forma linkage mechanism (see,  FIG. 3( a ) ). 
     In addition, the other end portion (tip end portion) of the second left lower driven arm  23  is attached freely rotatably in the horizontal direction at the lower portion of the first left lower driven arm  22  with the supporting shaft C as a center. 
     In this embodiment, the center distance between the supporting shafts A and C is set to be equal to the center distance between the rotating axis O and the supporting shaft B. In addition, the center distance between the supporting shafts B and C is set to be equal to the center distance between the rotating axis O and the supporting shaft A. 
     It should be noted that the center distance between the axes of the supporting shafts A and C and the center distance between the rotating axis O and the supporting shaft B are configured to be shorter than the center distance between the axes of the supporting shafts B and C and the center distance between the rotating axis O and the supporting shaft A. 
     The first left lower parallel crank mechanism  3   a  has a tip end portion, (i.e., an operation-side end portion connected with a second left lower parallel crank mechanism  3   b ). 
     This second left lower parallel crank mechanism  3   b  is configured with the first left lower driven arm  22  of the first left lower parallel crank mechanism  3   a , a third left lower driven arm  25 , a fourth left lower driven arm  26 , and a supporting portion  35 L of a left lower end effector  30 L. 
     Here, an end portion of the first left lower driven arm  22  on the left lower driving arm  21  side is attached to one end portion (base end portion) of the third left lower driven arm  25  at the upper portion of the first left lower driven arm  22  so as to freely rotate in the horizontal direction with the supporting shaft A described above as a center. 
     Furthermore, an end portion of the first left lower driven arm  22  on the second left lower driven arm  23  side is attached to one end portion (base end portion) of the fourth left lower driven arm  26  at the upper portion of the first left lower driven arm  22  so as to freely rotate in the horizontal direction with the supporting shaft C described above as a center. 
     In addition, the other end portions (tip end portions) of the third and fourth left lower driven arms  25  and  26  are attached freely rotatably in the horizontal direction at the lower portion of a supporting portion  35 L of the left lower end effector  30 L having a substrate mounting unit  36 L with the centers being a supporting shaft D and a supporting shaft E, respectively, which are provided at positions spaced apart from each other by the center distance equal to the center distance between the supporting shafts A and C. These third and fourth left lower driven arms  25  and  26  are configured such that the supporting shafts D and E for these arms are located on the side of the straight line Y passing through the rotating axis O and extending parallel to the substrate transfer direction V relative to the supporting shafts A and C, respectively. 
     In this embodiment, the first left lower driven arm  22  includes a power transmission mechanism  24  made up of a gear box that is configured so that the left lower driving arm  21  and the fourth left lower driven arm  26  rotate at the same angle in opposite rotation directions. In other words, power from the left lower driving arm  21  is transmitted through the power transmission mechanism  24  of the first left lower driven arm  22  to make the fourth left lower driven arm  26  rotate at the same angle in an opposite direction with respect to the left lower driving arm  21 . 
     In this embodiment, the center distance between the supporting shafts A and C is set to be equal to the center distance between the supporting shafts D and E. Furthermore, the center distance between the supporting shafts A and D is set to be equal to the center distance between the supporting shafts C and E. 
     It is noted that the center distance between the supporting shafts D and E and the center distance between the supporting shafts A and C are configured to be shorter than the center distance between the supporting shafts A and D and the center distance between the supporting shafts C and E. 
     On the other hand, in this embodiment, the center distance between the supporting shafts A and D and the center distance between the supporting shafts C and E are set to be shorter than the center distance between the rotating axis O and the supporting shaft A and the center distance between the supporting shafts B and C, respectively. 
     Furthermore, this configuration makes it possible to prevent the left lower end effector  30 L from being brought into contact with the first to fourth extension/contraction drive shafts  11  to  14  and the supporting shafts B and F in the case where the left lower transfer mechanism  2 L is moved in the substrate transfer direction V or in the opposite direction. 
     On the other hand, the right lower transfer mechanism  2 R according to this embodiment comprises a first right lower parallel crank mechanism  4   a  that is configured with a right lower driving arm  41 , a second turning drive member  32 , a first right lower driven arm  42 , and a second right lower driven arm  43 . 
     Here, one end portion (base end portion) of the right lower driving arm  41  is connected with the second extension/contraction drive shaft  12  so as to rotate in the horizontal direction with the rotating axis O as a center. 
     Furthermore, the operational range of the right lower driving arm  41  is configured to be controlled such that it is located on the right side of the straight line Y passing through the rotating axis O and extending in parallel to the substrate transfer direction V. 
     On the other hand, the second turning drive member  32  is, for example, configured with a plate-like seating member, and is provided so as to extend toward the upstream side of the rotating axis O in the substrate transfer direction V. 
     This second turning drive member  32  is provided below the first turning drive member  31  described above, and one end portion (base end portion) of the second turning drive member  32  is connected with a second turning drive shaft  16  so as to rotate at a predetermined angle in the horizontal direction with the rotating axis O being the center. 
     One end portion (base end portion) of the first right lower driven arm  42  is attached to the other end portion (tip end portion) of the right lower driving arm  41  at the upper portion of the right lower driving arm  41  so as to freely rotate in the horizontal direction with a supporting shaft Has a center. 
     Furthermore, one end portion (base end portion) of the second right lower driven arm  43  is attached to the other end portion (tip end portion) of the second turning drive member  32  at the upper portion of the second turning drive member  32  so as to freely rotate in the horizontal direction with a supporting shaft F as a center. 
     This supporting shaft F is provided so as to extend in the vertical direction through a connecting member  32   a , and is configured to be connected with a second left upper driven arm  53 , which will be described later (see  FIG. 3( c ) ). 
     In addition, the other end portion (tip end portion) of the second right lower driven arm  43  is attached freely rotatably in the horizontal direction at the lower portion of the first right lower driven arm  42  with a supporting shaft Gas a center. 
     In this embodiment, the center distance between the supporting shafts H and G is set to be equal to the center distance between the rotating axis O and the supporting shaft F. Furthermore, the center distance between the supporting shafts F and G is set to be equal to the center distance between the rotating axis O and the supporting shaft H. 
     It is noted that the center distance between the supporting shafts H and G and the center distance between the rotating axis O and the supporting shaft F are configured to be shorter than the center distance between the supporting shafts F and G and the center distance between the rotating axis O and the supporting shaft H. 
     A second right lower parallel crank mechanism  4   b  is connected with a tip end portion (i.e., an operation-side end portion of the first right lower parallel crank mechanism  4   a ). 
     This second right lower parallel crank mechanism  4   b  is configured with the first right lower driven arm  42  of the first right lower parallel crank mechanism  4   a , a third right lower driven arm  44 , a fourth right lower driven arm  45 , and a supporting portion  35 R of a right lower end effector  30 R. 
     Here, an end portion of the first right lower driven arm  42  on the right lower driving arm  41  side is attached to one end portion (base end portion) of the third right lower driven arm  44  at the upper portion of the first right lower driven arm  42  so as to freely rotate in the horizontal direction with the supporting shaft H described above as a center. 
     Furthermore, an end portion of the first right lower driven arm  42  on the second right lower driven arm  43  side is attached to one end portion (base end portion) of the fourth right lower driven arm  45  at the upper portion of the first right lower driven arm  42  so as to freely rotate in the horizontal direction with the supporting shaft G described above as a center. 
     In addition, the other end portions (tip end portions) of the third and fourth right lower driven arms  44  and  45  are attached freely rotatably in the horizontal direction at the lower portion of a supporting portion  35 R of the right lower end effector  30 R having a substrate mounting unit  36 R with a supporting shaft J and a supporting shaft I being centers, respectively, which are provided at positions spaced apart from each other by the center distance equal to the center distance between the supporting shafts H and G. 
     These third and fourth right lower driven arms  44  and  45  are configured such that the supporting shaft J and the supporting shaft I for these arms are located on the side of the straight line Y passing through the rotating axis O and extending parallel to the substrate transfer direction V relative to the supporting shaft H and the supporting shaft G. 
     In this embodiment, a power transmission mechanism  46  made up of a gear box, which is configured such that the right lower driving arm  41  and the fourth right lower driven arm  45  rotate at the same angle in opposite rotation directions, is provided in the first right lower driven arm  42 . 
     In other words, power from the right lower driving arm  41  is transmitted through the power transmission mechanism  46  of the first right lower driven arm  42  to make the fourth right lower driven arm  45  rotate at the same angle in an opposite direction with respect to the right lower driving arm  41 . In this embodiment, the center distance between the supporting shafts G and His configured to be equal to the center distance between the supporting shafts I and J. Furthermore, the center distance between the supporting shafts G and I is configured to be equal to the center distance between the supporting shafts H and J. 
     It is noted that, in this embodiment, the center distance between the supporting shafts I and J and the center distance between the supporting shafts G and H are configured to be shorter than the center distance between the supporting shafts G and I and the center distance between the supporting shafts H and J. 
     On the other hand, the center distance between the supporting shafts G and I and the center distance between the supporting shafts H and J are set to be shorter than the center distance between the rotating axis O and the supporting shaft H and the center distance between the supporting shafts F and G, respectively. 
     Furthermore, this structural arrangement makes it possible to prevent the right lower end effector  30 R from being brought into contact with the first to fourth extension/contraction drive shafts  11  to  14  and the supporting shafts B and F in the case where the right lower transfer mechanism  2 R is moved along the substrate transfer direction V. 
     It is noted that, in this embodiment, the first left lower parallel crank mechanism  3   a  of the left lower transfer mechanism  2 L and the first right lower parallel crank mechanism  4   a  of the right lower transfer mechanism  2 R are configured such that the center distances between the corresponding arms of these crank mechanisms are equal to each other. 
     Furthermore, the second left lower parallel crank mechanism  3   b  of the left lower transfer mechanism  2 L and the second right lower parallel crank mechanism  4   b  of the right lower transfer mechanism  2 R are configured such that the center distances between the corresponding arms of these crank mechanisms are equal to each other. 
     The right lower end effector  30 R according to this embodiment is configured such that the length of the supporting portion  35 R in the substrate transfer direction V is longer than the length of the supporting portion  35 L of the left lower end effector  30 L so that the center distance from the substrate mounting unit  36 R to the rotating axis O is equal to the distance from the substrate mounting unit  36 L to the rotating axis O in the left lower end effector  30 L. 
     Furthermore, in this embodiment, the shape and arrangement of each member of the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R are set in a manner such that the height position of the left lower end effector  30 L is equal to that of the right lower end effector  30 R. 
     As illustrated in  FIGS. 2 ( a )  and  2  ( b ), the upper transfer device  1 B comprises a left upper transfer mechanism  7 L and a right upper transfer mechanism  7 R that are provided on both sides (that is, on the left side and the right side respectively) of the straight line Y extending from the rotating axis O in the substrate transfer direction V. 
     The left upper transfer mechanism  7 L comprises a first left upper parallel crank mechanism  5   a  that is configured with a left upper driving arm  51 , the second turning drive member  32  described above, a first left upper driven arm  52 , and the second left upper driven arm  53 . 
     Here, the left upper driving arm  51  has one end portion (base end portion) connected with a fourth extension/contraction drive shaft  14  so as to rotate in the horizontal direction with the rotating axis O as a center. 
     Furthermore, the operational range of the left upper driving arm  51  is configured to be controlled such that it is located on the left side of the straight line Y passing through the rotating axis O and extending in parallel to the substrate transfer direction V. 
     In the other end portion (tip end portion) of the left upper driving arm  51 , one end portion (base end portion) of the first left upper driven arm  52  is rotatably attached in the horizontal direction with a supporting shaft K as a center at the lower portion of the left upper driving arm  51   a.    
     Furthermore, in the other end portion (tip end portion) of the second turning drive member  32 , the one end portion (base end portion) of the second left upper driven arm  53  is rotatably attached in the horizontal direction with the supporting shaft F as a center above the second turning drive member  32 . 
     Here, the supporting shaft F is provided through a connecting member  32   a  extending in the vertical direction as described above, and the second left upper driven arm  53  is attached to the supporting shaft F so as to have the same height as the left upper driving arm  51 . 
     In addition, the other end portion (tip end portion) of the second left upper driven arm  53  is attached freely rotatably in the horizontal direction at the upper portion of the first left upper driven arm  52  with a supporting shaft Las a center. 
     In this embodiment, the center distance between the supporting shafts K and L is set to be equal to the center distance between the rotating axis O and the supporting shaft F. 
     Furthermore, the center distance between the supporting shafts F and L is set to be equal to the center distance between the rotating axis O and the supporting shaft K. 
     It is noted that the center distance between the supporting shafts K and L and the center distance between the rotating axis O and the supporting shaft F are configured to be shorter than the center distance between the supporting shafts F and L and the center distance between the rotating axis O and the supporting shaft K. 
     The first left upper parallel crank mechanism  5   a  has a tip end portion (i.e., an operation-side end portion connected with a second left upper parallel crank mechanism  5   b ). 
     This second left upper parallel crank mechanism  5   b  is configured with the first left upper driven arm.  52  of the first left upper parallel crank mechanism  5   a , a third left upper driven arm  55 , a fourth left upper driven arm  56 , and a supporting portion  75 L of a left upper end effector  70 L. 
     Here, an end portion of the first left upper driven arm  52  on the left upper driving arm  51  side is attached to one end portion (base end portion) of the fourth left upper driven arm  56  at the lower portion of the first left upper driven arm  52  so as to freely rotate in the horizontal direction with the supporting shaft K described above as a center. 
     Furthermore, an end portion of the first left upper driven arm  52  on the second left upper driven arm  53  side is attached to one end portion (base end portion) of the third left upper driven arm  55  at the lower portion of the first left upper driven arm  52  so as to freely rotate in the horizontal direction with the supporting shaft L described above as a center. 
     In addition, the other end portions (tip end portions) of the third and fourth left upper driven arms  55  and  56  are attached freely rotatably in the horizontal direction at the lower portion of a supporting portion  75 L of the left upper end effector  70 L having a substrate mounting unit  76 L with a supporting shaft M and a supporting shaft P being centers, respectively, which are provided at positions spaced apart from each other by the distance equal to the center distance between the supporting shafts L and K. These third and fourth left upper driven arms  55  and  56  are configured such that the supporting shaft M and the supporting shaft P for these arms are located on the side of the straight line Y passing through the rotating axis O and extending parallel to the substrate transfer direction V relative to the supporting shaft L and the supporting shaft K. 
     In this embodiment, a power transmission mechanism  54  made up of a gear box that is configured so that the left upper driving arm  51  and the third left upper driven arm  55  rotate at the same angle in opposite rotation directions is provided in the first left upper driven arm  52 . In other words, power from the left upper driving arm  51  is transmitted through the power transmission mechanism  54  of the first left upper driven arm  52  to make the third left upper driven arm  55  rotate at the same angle in an opposite direction with respect to the left upper driving arm  51 . 
     In this embodiment, the center distance between the supporting shafts K and L is set to be equal to the center distance between the supporting shafts P and M. Furthermore, the center distance between the supporting shafts K and P is set to be equal to the center distance between the supporting shafts L and M. 
     It is noted that the center distance between the supporting shafts P and M and the distance between the axes of the supporting shafts K and L are configured to be shorter than the center distance between the supporting shafts L and M and the center distance between the supporting shafts K and P, respectively. 
     On the other hand, in this embodiment, the center distance between the supporting shafts L and M and the center distance between the supporting shafts K and P are set to be shorter than the center distance between the rotating axis O and the supporting shaft K and the center distance between the supporting shafts F and L. 
     Furthermore, the left upper end effector  70 L according to this embodiment is configured such that the height position of the upper surface thereof is located lower than the height position of the lower portion of each of the left upper driving arm  51  and the second left upper driven arm  53  of the first left upper parallel crank mechanism  5   a.    
     Furthermore, this structural arrangement makes it possible to allow the left upper end effector  70 L to pass through below the left upper driving arm  51  and the second left upper driven arm  53  and to prevent the left upper end effector  70 L from being brought into contact with the first to fourth extension/contraction drive shafts  11  to  14  and the supporting shafts B and F in a case where the left upper transfer mechanism  7 L is moved in the substrate transfer direction V or in the opposite direction. 
     On the other hand, the right upper transfer mechanism  7 R according to this embodiment comprises a first right upper parallel crank mechanism  6   a  that is configured with a right upper driving arm  61 , the first turning drive member  31 , a first right upper driven arm  62 , and a second right upper driven arm  63 . 
     Here, one end portion (base end portion) of the right upper driving arm  61  is connected with the third extension/contraction drive shaft  13  so as to rotate in the horizontal direction with the rotating axis O as a center. 
     Furthermore, the operational range of the right upper driving arm  61  is configured to be controlled such that it is located on the right side of the straight line Y passing through the rotating axis O and extending in parallel to the substrate transfer direction V. 
     The other end portion (tip end portion) of the right upper driving arm  61  is attached to one end portion (base end portion) of the first right upper driven arm  62  at the lower portion of the right upper driving arm  61  so as to freely rotate in the horizontal direction with a supporting shaft Q as a center. 
     Furthermore, the other end portion (tip end portion) of the first turning drive member  31  is attached to one end portion (base end portion) of the second right upper driven arm  63  above the first turning drive member  31  so as to freely rotate in the horizontal direction with the supporting shaft B as a center. 
     Here, the supporting shaft B is provided through the connecting member  31   a  extending in the vertical direction as described above, and the second right upper driven arm  63  is attached to the supporting shaft B so as to have the same height as the right upper driving arm  61 . 
     In addition, the other end portion (tip end portion) of the second right upper driven arm  63  is attached freely rotatably in the horizontal direction at the upper portion of the first right upper driven arm  62  with a supporting shaft R as a center. 
     In this embodiment, the center distance between the supporting shafts R and Q is set to be equal to the center distance between the rotating axis O and the supporting shaft B. Furthermore, the center distance between the supporting shafts B and R is set to be equal to the center distance between the rotating axis O and the supporting shaft Q. 
     It is noted that the center distance between the supporting shafts Q and R and the center distance between the rotating axis O and the supporting shaft B are configured to be shorter than the center distance between the supporting shafts B and R and the center distance between the rotating axis O and the supporting shaft Q. 
     A second right upper parallel crank mechanism  6   b  is connected with a tip end portion (i.e., an operation-side end portion of the first right upper parallel crank mechanism  6   a ). 
     This second right upper parallel crank mechanism  6   b  is configured with the first right upper driven arm  62  of the first right upper parallel crank mechanism  6   a , a third right upper driven arm  64 , a fourth right upper driven arm  65 , and a supporting portion  75 R of a right upper end effector  70 R. 
     Here, an end portion of the first right upper driven arm  62  on the right upper driving arm  61  side is attached to one end portion (base end portion) of the fourth right upper driven arm  65  at the lower portion of the first right upper driven arm  62  so as to freely rotate in the horizontal direction with the supporting shaft Q described above as a center. 
     Furthermore, an end portion of the first right upper driven arm  62  on the second right upper driven arm  63  side is attached to one end portion (base end portion) of the third right upper driven arm  64  at the lower portion of the first right upper driven arm.  62  so as to freely rotate in the horizontal direction with the supporting shaft R described above as a center. 
     In addition, the other end portions (tip end portions) of the third and fourth right upper driven arms  64  and  65  are attached freely rotatably in the horizontal direction at the lower portion of the supporting portion  75 R of the right upper end effector  70 R with a supporting shaft T and a supporting shaft S being centers, respectively, which are provided at positions spaced apart from each other by the center distance equal to the center distance between the supporting shafts Q and R. 
     These third and fourth right upper driven arms  64  and  65  are configured such that the supporting shaft S and the supporting shaft T for these arms are located on the side of the straight line Y passing through the rotating axis O and extending parallel to the substrate transfer direction V relative to the supporting shaft R and the supporting shaft Q. 
     In this embodiment, in the first right upper driven arm  62 , a power transmission mechanism  66  made up of a gear box that is configured such that the right upper driving arm  61  and the third right upper driven arm  64  rotate at the same angle in opposite rotation directions is provided in the first right upper driven arm  62 . In other words, power from the right upper driving arm  61  is transmitted through the power transmission mechanism  66  of the first right upper driven arm  62  to make the third right upper driven arm  64  rotate at the same angle in an opposite direction with respect to the right upper driving arm  61 . 
     In this embodiment, the center distance between the supporting shafts R and Q is configured to be equal to the center distance between the supporting shafts S and T. Furthermore, the center distance between the supporting shafts Q and T is configured to be equal to the center distance between the supporting shafts R and S. 
     It is noted that, in this embodiment, the center distance between the supporting shafts S and T and the center distance between the supporting shafts R and Q are configured to be shorter than the center distance between the supporting shafts Q and T and the center distance between the supporting shafts R and S. 
     On the other hand, in this embodiment, the center distance between the supporting shafts Q and T and the center distance between the supporting shafts R and S are set to be shorter than the center distance between the rotating axis O and the supporting shaft Q and the center distance between the supporting shafts B and R, respectively. 
     Furthermore, the right upper end effector  70 R according to this embodiment is configured such that the height position of the upper surface thereof is located lower than the height position of the lower portion of each of the right upper driving arm  61  and the second right upper driven arm  63  of the first right upper parallel crank mechanism  6   a.    
     Furthermore, this configuration makes it possible to allow the right upper end effector  70 R to pass through below the right upper driving arm  61  and the second right upper driven arm  63  and to prevent the right upper end effector  70 R from being brought into contact with the first to fourth extension/contraction drive shafts  11  to  14  and the supporting shafts B and F in the case where the right upper transfer mechanism  7 R is moved in the substrate transfer direction V or in the opposite direction. 
     It is noted that, in this embodiment, the first left upper parallel crank mechanism  5   a  of the left upper transfer mechanism  7 L and the first right upper parallel crank mechanism  6   a  of the right upper transfer mechanism  7 R are configured such that the center distances between the corresponding arms of these crank mechanisms are equal to each other. 
     Furthermore, the second left upper parallel crank mechanism  5   b  of the left upper transfer mechanism  7 L and the second right upper parallel crank mechanism  6   b  of the right upper transfer mechanism  7 R are configured such that the center distances between the corresponding arms of these crank mechanisms are equal to each other. 
     The right upper end effector  70 R according to this embodiment is configured such that the length of the supporting portion  75 R in the substrate transfer direction V is shorter than the length of the supporting portion  75 L of the left upper end effector  70 L so that the distance from the substrate mounting unit  76 R to the rotating axis O is equal to the distance from the substrate mounting unit  76 L to the rotating axis O in the left upper end effector  70 L. 
     Next, the operation of this embodiment of the invention hereinafter will be described. 
     First, a description will be made of a case where the lower transfer device  1 A is caused to extend. 
     In this case, the first extension/contraction drive shaft  11  is caused to rotate at a predetermined angle in a clockwise direction from a home position as illustrated in  FIGS. 1( b ) and 3( b ) , and the second extension/contraction drive shaft  12  is caused to rotate at a predetermined angle (for example, the same degree of angle) in a counterclockwise direction. 
     With these operations, the rotational power from the left lower driving arm  21  of the lower transfer device  1 A connected with the first extension/contraction drive shaft  11  energizes, in the substrate transfer direction V, the first left lower parallel crank mechanism  3   a  and the second left lower parallel crank mechanism  3   b  to move these mechanisms in this direction, at the same time, the rotational power from the right lower driving arm  41  of the lower transfer device  1 A connected with the second extension/contraction drive shaft  12  energizes, in the substrate transfer direction V, the first right lower parallel crank mechanism  4   a  and the second right lower parallel crank mechanism  4   b  to move these mechanisms in this direction. 
     With these operations, both the left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A are disposed on the downstream side relative to the rotating axis O in the substrate transfer direction V as illustrated in  FIGS. 1( a )  and  4 . 
     On the other hand, as for the upper transfer device  1 B, the third and fourth extension/contraction drive shafts  13  and  14  are not operated; and thus, the rotational power is not provided, so that the upper transfer device  1 B is at rest. These operations can bring the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer device  1 A into an extended state as illustrated in  FIG. 4 . 
     On the other hand, the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer device  1 A can be brought back to the home position by performing reversed operations with respect to those described above; in other words, the first extension/contraction drive shaft  11  is rotated in a counterclockwise direction, and the second extension/contraction drive shaft  12  is rotated in a clockwise direction. 
     Furthermore, the upper transfer device  1 B can be caused to extend by rotating the fourth extension/contraction drive shaft  14  at a predetermined angle in a clockwise direction from a home position as illustrated in  FIGS. 2 ( b ) and 3( b ) , and by rotating the third extension/contraction drive shaft  13  at a predetermined angle (for example, the same degree of angle) in a counterclockwise direction. 
     With these operations, the rotational power from the left upper driving arm  51  of the upper transfer device  1 B connected with the fourth extension/contraction drive shaft  14  energizes, in the substrate transfer direction V, the first left upper parallel crank mechanism  5   a  and the second left upper parallel crank mechanism  5   b  to move these mechanisms in this direction, at the same time, the rotational power from the right upper driving arm  61  of the upper transfer device  1 B connected with the third extension/contraction drive shaft  13  energizes, in the substrate transfer direction V, the first right upper parallel crank mechanism  6   a  and the second right upper parallel crank mechanism  6   b  to move these mechanisms in this direction. 
     With these operations, both the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B are disposed on the downstream side relative to the rotating axis O in the substrate transfer direction V as illustrated in  FIGS. 2( a )  and  5 . 
     On the other hand, as for the lower transfer device  1 A, the first and second extension/contraction drive shafts  11  and  12  are not operated, and thus the rotational power is not provided, so that the lower transfer device  1 A is at rest. 
     These operations bring the left upper transfer mechanism  7 L and the right upper transfer mechanism  7 R of the upper transfer device  1 B into an extended state as illustrated in  FIG. 5 . 
     On the other hand, the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer device  1 A can be brought back to the home position by performing reversed operations with respect to those described above; in other words, the first extension/contraction drive shaft  11  is rotated in a counterclockwise direction, and the second extension/contraction drive shaft  12  is rotated in a clockwise direction. 
       FIGS. 6 ( a )  and  6  ( b ) to  FIGS. 9 ( a )  and  9  ( b ) are explanatory views illustrating small turning movements of the upper transfer device and the lower transfer device according to this embodiment. 
     It is noted that, in the following description, for the purpose of facilitating understanding operations, description will be made of an example in which a small turning movement is performed in a state where the lower transfer device  1 A and the upper transfer device  1 B are in an extended state. However, the present invention is not limited to this. It may be possible to perform the small turning movement at the time when the lower transfer device  1 A or the upper transfer device  1 B described above is caused to extend. 
       FIG. 6 ( a )  is an explanatory view illustrating the lower transfer device  1 A being in a separating operation; and  FIG. 6 ( b )  is an explanatory view illustrating operations performed by the upper transfer device  1 B related to the separating operation. 
     In this case, in a state where the lower transfer device  1 A is extended (see,  FIG. 4 ), the first turning drive member  31  is caused to rotate at a predetermined small angle (for example, approximately 5 degrees) in a counterclockwise direction with the rotating axis O as a center using the rotational power from the first turning drive shaft  15 , and the second turning drive member  32  is caused to rotate at a predetermined small angle (for example, approximately 5 degrees) in a clockwise direction with the rotating axis O as a center using the rotational power from the second turning drive shaft  16 . 
     With these operations, the first left lower parallel crank mechanism  3   a  rotates and moves in a counterclockwise direction with the rotating axis O as a center using the rotational power from the first turning drive member  31 , and the second left lower parallel crank mechanism  3   b  rotates and moves in a counterclockwise direction with the supporting shaft A as a center. 
     Consequently, the left lower transfer mechanism  2 L turns at a small angle in a direction in which the left lower end effector  30 L is spaced away from the straight line Y extending from the rotating axis O in the substrate transfer direction V as illustrated in  FIG. 6( a ) . 
     On the other hand, the first right lower parallel crank mechanism  4   a  rotates and moves in a clockwise direction with the rotating axis O as a center using the rotational power from the second turning drive member  32 , and the second right lower parallel crank mechanism  4   b  rotates and moves in a clockwise direction with the supporting shaft H as a center. 
     Consequently, the right lower transfer mechanism  2 R turns in a direction in which the right lower end effector  30 R is spaced away from the straight line Y extending from the rotating axis O in the substrate transfer direction V as illustrated in  FIG. 6( a ) . 
     With these operations, it is possible to perform operation (open) of spacing the left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A apart from each other. 
     On the other hand, in this embodiment, the second left lower driven arm  23  of the lower transfer device  1 A is connected with the second right upper driven arm  63  of the upper transfer device  1 B through the connecting member  31   a  extending in the vertical direction, and the second left lower driven arm  23  and the second right upper driven arm  63  are attached to each other rotatably in a horizontal direction with the supporting shaft B as a center as illustrated  FIGS. 3 ( a ) and 3( b ) . Thus, in association with rotation of the first turning drive member  31 , the first right upper parallel crank mechanism  6   a  of the upper transfer device  1 B rotates and moves in a counterclockwise direction with the rotating axis O as a center, and the second right upper parallel crank mechanism  6   b  rotates and moves in a counterclockwise direction with the supporting shaft Q as a center. 
     Consequently, the right upper transfer mechanism  7 R turns in a direction in which the right upper end effector  70 R of the upper transfer device  1 B approaches the straight line Y extending from the rotating axis O in the substrate transfer direction V as illustrated in  FIG. 6( b ) . 
     In addition, as illustrated in  FIGS. 3( b ) and 3( c ) , the second right lower driven arm  43  of the lower transfer device  1 A is connected with the second left upper driven arm  53  of the upper transfer device  1 B through the connecting member  32   a  extending in the vertical direction, and the second right lower driven arm  43  and the second left upper driven arm  53  are attached to each other rotatably in a horizontal direction with the supporting shaft F as a center. Thus, in association with rotation of the second turning drive member  32 , the first left upper parallel crank mechanism  5   a  of the upper transfer device  1 B rotates and moves in a clockwise direction with the rotating axis O as a center, and the second left upper parallel crank mechanism  5   b  rotates and moves in a clockwise direction with the supporting shaft K as a center. 
     Consequently, the left upper transfer mechanism  7 L turns in a direction in which the left upper end effector  70 L of the upper transfer device  1 B approaches the straight line Y extending from the rotating axis O in the substrate transfer direction V as illustrated in  FIG. 6( b ) . 
     The operations described above also make the left upper transfer mechanism  7 L and the right upper transfer mechanism  7 R of the upper transfer device  1 B operate so as to approach each other at the same time in association with the operation of the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer device  1 A; however, the upper transfer device  1 B is in a contracted state and is located at the home position. Hence, this approach does not pose any particular problem. 
       FIG. 7( a )  is an explanatory view illustrating an approaching operation of the lower transfer device  1 A; and  FIG. 7( b )  is an explanatory view illustrating an associating operation of the upper transfer device  1 B. 
     In this case, in a state where the lower transfer device  1 A is extended, the first turning drive member  31  is caused to rotate at a small angle (for example, approximately 5 degrees) in a clockwise direction with the rotating axis O as a center using the rotational power from the first turning drive shaft  15 , and the second turning drive member  32  is caused to rotate at a small angle (for example, approximately 5 degrees) in a counterclockwise direction with the rotating axis O as a center using the rotational power from the second turning drive shaft  16 . 
     With these operations, power acting in a direction opposite to the separating operation of the lower transfer device  1 A as described above is transmitted (details thereof are omitted), and the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R are caused to turn in a direction in which the left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A each approach the straight line Y extending from the rotating axis O in the substrate transfer direction V. 
     Consequently, it is possible to perform a close operation where the left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A approach each other. 
     It is noted that the separating operations of the left upper transfer mechanism  7 L and the right upper transfer mechanism  7 R of the upper transfer device  1 B associated with these approaching operations as described above, are performed in a state where the upper transfer device  1 B is in a contracted state, and is located at the home position, as described above. Hence, these operations do not pose any particular problem (see,  FIG. 7 ( b ) ). 
       FIG. 8 ( a )  is a diagram illustrating a separating operation of the upper transfer device  1 B. 
     In this case, in a state where the upper transfer device  1 B is extended (see,  FIG. 5 ), the first turning drive member  31  is caused to rotate at a predetermined small angle (for example, approximately 5 degrees) in a clockwise direction with the rotating axis O as a center using the rotational power from the first turning drive shaft  15 , and the second turning drive member  32  is caused to rotate at a predetermined small angle (for example, approximately 5 degrees) in a counterclockwise direction with the rotating axis O as a center using the rotational power from the second turning drive shaft  16 . 
     With these operations, the first right upper parallel crank mechanism  6   a  rotates and moves in a clockwise direction with the rotating axis O as a center using the rotational power from the first turning drive member  31 , and the second right upper parallel crank mechanism  6   b  rotates and moves in a clockwise direction with the supporting shaft Q as a center. 
     Consequently, the right upper transfer mechanism  7 R turns in a direction in which the right upper end effector  70 R is spaced away from the straight line Y extending from the rotating axis O in the substrate transfer direction V as illustrated in  FIG. 8( a ) . 
     On the other hand, the first left upper parallel crank mechanism  5   a  rotates and moves in a counterclockwise direction with the rotating axis O as a center using the rotational power from the second turning drive member  32 , and the second left upper parallel crank mechanism  5   b  rotates and moves in a counterclockwise direction with the supporting shaft K as a center. 
     Consequently, the left upper transfer mechanism  7 L turns in a direction in which the left upper end effector  70 L is spaced away from the straight line Y extending from the rotating axis O in the substrate transfer direction V as illustrated in FIG.  8 ( a ). 
     With these operations, it is possible to perform operation of spacing the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B apart from each other. 
     Furthermore, in this embodiment, as illustrated in  FIGS. 3 ( a )  and  3  ( b ), the second right upper driven arm  63  of the upper transfer device  1 B is connected with the second left lower driven arm  23  of the lower transfer device  1 A through the connecting member  31   a  extending in the vertical direction, and the second right upper driven arm  63  and the second left lower driven arm  23  are attached to each other rotatably in a horizontal direction with the supporting shaft B as a center. Thus, in association with the rotation of the first turning drive member  31 , the first left lower parallel crank mechanism  3   a  of the lower transfer device  1 A rotates and moves in a clockwise direction with the rotating axis O as a center, and the second left lower parallel crank mechanism  3   b  rotates and moves in a clockwise direction with the supporting shaft A as a center. 
     Consequently, the left lower transfer mechanism  2 L turns in a direction in which the left lower end effector  30 L of the lower transfer device  1 A approaches the straight line Y extending from the rotating axis O in the substrate transfer direction V as illustrated in  FIG. 8( b ) . 
     In addition, as illustrated in  FIGS. 3( b ) and 3( c ) , the second left upper driven arm  53  of the upper transfer device  1 B is connected with the second right lower driven arm  43  of the lower transfer device  1 A through the connecting member  32   a  extending in the vertical direction, and the second left upper driven arm  53  and the second right lower driven arm  43  are attached to each other rotatably in a horizontal direction with the supporting shaft F as a center. Thus, in association with rotation of the second turning drive member  32 , the first right lower parallel crank mechanism  4   a  of the lower transfer device  1 A rotates and moves in a counterclockwise direction with the rotating axis O as a center, and the second right lower parallel crank mechanism  4   b  rotates and moves in a counterclockwise direction with the supporting shaft H as a center. 
     Consequently, the right lower transfer mechanism  2 R turns in a direction in which the right lower end effector  30 R of the lower transfer device  1 A approaches the straight line Y extending from the rotating axis O in the substrate transfer direction V as illustrated in  FIG. 8( b ) . 
     It is noted that the approaching operations of the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer device  1 A associated with these approaching operations described above are performed in a state where the lower transfer device  1 A is in a contracted state as described above and is located at the home position, so that these operations do not pose any particular problem. 
       FIG. 9( a )  is a diagram illustrating an approaching operation of the upper transfer device. 
     In this case, in a state where the upper transfer device  1 B is extended, the first turning drive member  31  is caused to rotate at a predetermined small angle (for example, approximately 5 degrees) in a counterclockwise direction with the rotating axis O as a center using the rotational power from the first turning drive shaft  15 , and the second turning drive member  32  is caused to rotate at a predetermined small angle (for example, approximately 5 degrees) in a clockwise direction with the rotating axis O as a center using the rotational power from the second turning drive shaft  16 . 
     With these operations, power acting in a direction opposite to the separating operation of the upper transfer device  1 B as described above is transmitted (details thereof are omitted), and the right upper transfer mechanism  7 R and the left upper transfer mechanism  7 L are caused to turn in a direction in which each the right upper end effector  70 R and the left upper end effector  70 L of the upper transfer device  1 B approaches the straight line Y extending from the rotating axis O in the substrate transfer direction V. 
     Consequently, it is possible to perform an approaching operation where the right upper end effector  70 R and the left upper end effector  70 L of the upper transfer device  1 B approach each other. 
     It is noted that the separating operations of the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer device  1 A associated with these approaching operations as described above are performed in a state where the lower transfer device  1 A is in a contracted state, and is located at the home position as described above, so that these operations do not pose any particular problem (see  FIG. 9( b ) ). 
     This embodiment as described above is configured such that: the first and second turning drive shafts  15  and  16  used to cause the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer mechanism  1 A, respectively, to turn are disposed concentrically with the first and second extension/contraction drive shafts  11  and  12 ; and these first and second turning drive shafts  15  and  16  drive the first and second turning drive members  31  and  32 , respectively, to cause the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R to turn with the rotating axis O as a center. Thus, it is possible to adjust the distance between the left lower end effector  30 L and the right lower end effector  30 R of the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R, which are disposed on both sides of the substrate transfer direction V with the rotating axis O being disposed therebetween and at the same height position, by spacing these effectors apart from each other and approaching these effectors to each other. 
     Consequently, according to this embodiment, the left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A can be correctly positioned with respect to two substrates in the case where these two substrates are arranged side by side. This makes it possible to facilitate positioning operation, and also improve throughput in transferring substrates. 
     Furthermore, in this embodiment, the transfer device  1  as described below is configured with the lower transfer device  1 A and the upper transfer device  1 B provided above the lower transfer device  1 A. 
     More specifically, this embodiment has a configuration in which: there are provided the third and fourth extension/contraction drive shafts  13  and  14  disposed concentrically with the rotating axis O as a center and provided in an independently rotatable manner in the horizontal plane; the upper transfer device  1 B has the right upper transfer mechanism  7 R and the left upper transfer mechanism  7 L disposed above the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer device  1 A and on both sides of the substrate transfer direction V with the rotating axis O being disposed therebetween; and these right upper transfer mechanism  7 R and left upper transfer mechanism  7 L are caused to move in an extending and contracting manner by the third and fourth extension/contraction drive shafts  13  and  14 , respectively. 
     Furthermore, this embodiment is configured to cause each of the right upper transfer mechanism  7 R and the left upper transfer mechanism  7 L of the upper transfer device  1 B to turn with the rotating axis O as a center by the linkage mechanisms connected with the first and second turning drive members  31  and  32 , respectively. 
     According to this embodiment having the configuration described above, it is possible to extend and contract the right upper transfer mechanism  7 R and the left upper transfer mechanism  7 L of the upper transfer device  1 B by the third and fourth extension/contraction drive shafts  13  and  14 , and it is also possible to adjust the distance between the left upper end effector  70 L and the right upper end effector  70 R by spacing these effectors apart from each other and having them approach each other. As a result, it is possible to transfer substrates with the lower transfer device  1 A and the upper transfer device  1 B, which makes it possible to further improve throughput in transferring substrates. 
     It should be noted that the transfer device according to the present invention is not limited to the embodiment described above, and various modifications can be made. 
     For example, in the embodiment described above, the separating operation and the approaching operation are performed on the left lower transfer mechanism  2 L (the left upper transfer mechanism  7 L) and the right lower transfer mechanism  2 R (the right upper transfer mechanism  7 R) in the lower transfer device  1 A and the upper transfer device  1 B. However, since the left lower transfer mechanism  2 L and the right lower transfer mechanism  2 R of the lower transfer device  1 A and each of the left upper transfer mechanism  7 L and the right upper transfer mechanism  7 R of the upper transfer device  1 B can be caused to extend and contract as well as turn in an independent manner, it may be possible to employ a configuration in which various operations are performed according to arrangement of a pair of substrates. 
       FIGS. 10 to 12  are plan views each illustrating an embodiment of a vacuum apparatus according to the present invention. 
     As illustrated in  FIG. 10 , a vacuum apparatus  10  according to this embodiment includes a rectangular transfer chamber  80  serving as a vacuum chamber connected with a vacuum exhaust system (not illustrated). 
     Furthermore, pairs of processing chambers  81  and  82 ,  83  and  84 , and  87  and  88 , each serving as a vacuum chamber connected with a vacuum exhaust system (not illustrated), are provided on three sides surrounding this transfer chamber  80 , respectively. Furthermore, a pair of preparation chamber  85  and delivery chamber  86  are provided on the remaining side. 
     In these processing chambers  81  and  82 ,  83  and  84 ,  87  and  88 , as well as the preparation chamber  85  and delivery chamber  86  respectively, substrate placement units  20 L and  20 R each serving as a transfer object placement unit are provided. 
     In the transfer chamber  80 , the transfer device  1  as described above is provided. 
     Here, the transfer device  1  is provided so as to be able to turn within the transfer chamber  80 , and is configured such that the lower transfer device  1 A and the upper transfer device  1 B can extend and contract within the transfer chamber  80 . 
     More specifically, as illustrated in  FIGS. 10 to 12 , configuration is made such that, for example, substrates  20  that are yet to be processed are placed on the substrate mounting units  76 L and  76 R of the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B, respectively, the upper transfer device  1 B is caused to extend to place the pair of substrates  20  on the substrate placement units  20 L and  20 R within the pair of processing chambers  81  and  82  (see  FIG. 11 ), and then, the upper transfer device  1 B is caused to contract to make the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B return to the original positions. (The lower transfer device  1 A is configured so as to operate in the same manner. Also, as for the other pairs of processing chambers  83  and  84 ,  87  and  88 , and the pair of preparation chamber  85  and delivery chamber  86 , transfer is performed in the same manner). 
     With the vacuum apparatus  10  according to this embodiment having the configuration as described above, when the transfer device  1  performs an extending operation, it is possible to correctly position the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B and the left lower end effector  30 L and the right lower end effector  30 R of the lower transfer mechanism  1 A relative to substrate placement units in a pair of processing chambers (for example, the substrate placement units  20 L and  20 R of the processing chambers  81  and  82 ) by spacing the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B apart from each other and having them approach each other to adjust the distance between these effectors, and spacing the left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A apart from each other and having them approach each other to adjust the distance between these effectors. Thus, it is possible to easily perform positioning operation for the substrate  20 , and also improve throughput in carrying in or out the substrate  20  into or from each chamber. 
       FIGS. 13 to 15  are diagrams each illustrating a configuration of another embodiment of the vacuum apparatus according to the present invention.  FIG. 13  is a plan view.  FIG. 14  is an explanatory view illustrating arrangement configuration of main portions.  FIG. 15  is a block diagram illustrating a configuration of circuit systems. Below, the same reference numerals are attached to portions corresponding to those in the embodiment described above, and explanation thereof will not be repeated. 
     As illustrated in  FIG. 13 , in a vacuum apparatus  10 A according to this embodiment, a plurality of (three in this embodiment) position sensors  91  to  93  (transfer object detection sensors) is provided in each of the above described processing chambers  81  and  82 ,  83  and  84 ,  87  and  88  and the preparation chamber  85  and the delivery chamber  86 . 
     These position sensors  91  to  93 , each made of, for example, an optical detector, are disposed between the transfer chamber  80  and the substrate placement unit  20 L or substrate placement unit  20 R in each of the chambers. 
     Here, the position sensors  91  to  93  are disposed at predetermined intervals spaced apart in a direction crossing the substrate transfer direction V as illustrated in  FIG. 14 . 
     The position sensors  91  and  93  on both sides among these position sensors  91  to  93  are disposed at a distance smaller than the width of the substrate  20  and larger than the widths of the substrate mounting unit  76 L of the left upper end effector  70 L and the substrate mounting unit  76 R of the right upper end effector  70 R of the upper transfer device  1 B, as illustrated in  FIG. 14 . 
     Furthermore, this configuration makes it possible to allow the position sensors  91  and  93  to detect end edge portions at both side portions of the substrate  20  in the case where the left upper end effector  70 L and the right upper end effector  70 R are transferred in the substrate transfer direction V. (The left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A are configured in the same manner.) 
     On the other hand, the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B each has a detection opening  70   a  provided for the position sensor  92  to detect the position of a substrate  20  and the positions of the left upper end effector  70 L and the right upper end effector  70 R. (The left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A each also has the same detection opening (not illustrated).) 
     This detection opening  70   a  is formed, for example, into a shape elongated in the substrate transfer direction V, and is provided so as to stride over the edge of the substrate mounting unit  76 L,  76 R of each of the left upper end effector  70 L and the right upper end effector  70 R. (The detection opening of each of the left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A also has the same configuration.) 
     On the other hand, the position sensor  92  disposed at the center among the position sensors  91  to  93  is provided on the straight line extending parallel to the substrate transfer direction V and passing through the detection opening  70   a  of each of the left upper end effector  70 L and the right upper end effector  70 R. This configuration makes it possible to allow the position sensor  92  to detect the end edge portion of the central portion of the substrate  20  and an end portion of the detection opening  70   a  of each of the left upper end effector  70 L and the right upper end effector  70 R on the upstream side in the substrate transfer direction in the case where the left upper end effector  70 L and the right upper end effector  70 R are transferred in the substrate transfer direction V. (The left lower end effector  30 L and the right lower end effector  30 R of the lower transfer device  1 A each also has the same configuration.) 
     As illustrated in  FIG. 15 , the position sensors  91  to  93  according to this embodiment are connected with a controller  94  having a computer, and are each configured to send results of detection of the position sensors  91  to  93  to the controller  94 . 
     This controller  94  stores data on a path that a predetermined specific substrate  20  takes when this substrate  20  is transferred to the substrate placement unit  20 L,  20 R in each of the chambers. 
     Furthermore, the controller  94  is connected with drive sources  95  and  96  for driving the first and second turning drive shafts  15  and  16  as described above, respectively, and is configured such that operations of the drive sources  95  and  96  are controlled in accordance with instructions that the controller  94  gives on the basis of information sent from the position sensors  91  to  93 . 
       FIGS. 16( a ), 16( b ), 16( c ), 16( d )  and  16  ( e ) are explanatory views illustrating operations of detecting a position of a substrate in this embodiment. 
     In the following, with reference to  FIGS. 16( a ), 16( b ), 16( c ), 16( d ) and 16( e ) , a description will be made of an example in which the substrate  20  is placed on the substrate mounting unit  76 L of the left upper end effector  70 L of the upper transfer device  1 B, and is transferred. 
     After the substrate  20  is placed on the substrate mounting unit  76 L of the left upper end effector  70 L of the upper transfer device  1 B, and the left upper transfer mechanism  7 L is caused to operate to transfer the left upper end effector  70 L in the substrate transfer direction V, the position sensor  92 , located at the center, first detects the end edge portion of the central portion of the substrate  20  on the downstream side in the substrate transfer direction as illustrated in  FIG. 16( a ) . Then, the results obtained with the position sensor  92  are sent to the controller  94 , and are converted into a position coordinate in the controller  94 , and then, the position coordinate is stored in the controller  94  (coordinate  1  of the detected position). 
     Then, as the transfer of the left upper end effector  70 L continues, the position sensors  91  and  93 , located on both sides, detect the end edge portions of both side portions of the substrate  20  on the downstream side in the substrate transfer direction as illustrated in  FIG. 16 ( b ) . The results of detection are sent to the controller  94 , and are converted into position coordinates in the controller  94 , and then, these position coordinates are stored in the controller  94  (coordinates  2  and  3  of the detected positions). 
     Furthermore, as the transfer of the left upper end effector  70 L continues, the position sensors  91  and  93 , located on both sides, detect the end edge portions of both side portions of the substrate  20  on the upstream side in the substrate transfer direction as illustrated in  FIG. 16( c ) . The results of the detection are sent to the controller  94 , and are converted into position coordinates in the controller  94 , and then, these position coordinates are stored in the controller  94  (coordinates  4  and  5  of the detected positions). 
     In addition, as the transfer of the left upper end effector  70 L continues, the position sensor  92 , located at the center, detects the end edge portion of the central portion of the substrate  20  on the upstream side in the substrate transfer direction through the detection opening  70   a  as illustrated in  FIG. 16( d ) . The results of detection are sent to the controller  94 , and are converted into a position coordinate in the controller  94 , and then, the position coordinate is stored in the controller  94  (coordinate  6  of the detected position). 
     Then, as the transfer of the left upper end effector  70 L continues, the position sensor  92 , located at the center, detects the end portion of the detection opening  70   a  of the left upper end effector  70 L on the upstream side in the substrate transfer direction as illustrated in  FIG. 16( e ) . The results of detection are sent to the controller  94 , and are converted into a position coordinate in the controller  94 , and then, the position coordinate is stored in the controller  94  (coordinate  7  of the detected position). 
     This coordinate  7  of the detected position is data for identifying the original coordinate for the coordinates  1  to  6  of the detected positions. 
     With these operations, the position coordinate of the substrate  20  at the time of passing through, for example, the position sensors  91  to  93  is calculated on the basis of the coordinates  1  to  7  of the detected positions stored in the controller  94 . Data on the position coordinate of this substrate  20  is compared with data on the position coordinates stored in the controller  94  in advance, whereby calculation is made to obtain data concerning a difference (deviation of position coordinates) of the position coordinate of the substrate  20  being transferred, from an original path that this substrate  20  should take when being transferred to the substrate placement unit  20 L. 
     Then, the drive source  95  is caused to operate on the basis of the calculated data on the deviation of the position coordinates, and the first turning drive shaft  15  is caused to drive to rotate the first turning drive member  31  at a predetermined small angle in a clockwise direction or counterclockwise direction with the rotating axis O as a center as illustrated in  FIGS. 8 and 9 , as described above, so that the substrate  20  placed on the substrate mounting unit  76 L of the left upper end effector  70 L of the upper transfer device  1 B is positioned on the original path that the substrate  20  should take when being transferred. 
     Subsequently, by operating the left upper transfer mechanism.  7 L of the upper transfer device  1 B in accordance with a predetermined sequence, this substrate  20  is transferred and is placed on the substrate placement unit  20 L within the processing chamber  81 . 
     On the other hand, the right upper end effector  70 R of the upper transfer device  1 B also operates in substantially the same way as the left upper end effector  70 L. 
     More specifically, in a similar way to the left upper end effector  70 L, with the right upper end effector  70 R, the substrate  20  is placed on the substrate mounting unit  76 R and is transferred. The position sensors  91  to  93  detect each end edge portion of the substrate  20  and an end portion of the detection opening  70   a  on the upstream side in the substrate transfer direction; and the results of detection are sent to the controller  94 . On the basis of data on each position coordinate converted by the controller  94 , data on a position coordinate of this substrate  20  is calculated. The data thus obtained is compared with position coordinates stored in advance to calculate data on a deviation of the position coordinate of the substrate  20  being transferred, from an original path that this substrate  20  should take when being transferred to the substrate placement unit  20 R. 
     Consequently, the drive source  96  is caused to operate on the basis of the calculated data on the deviation of the position coordinate. The second turning drive shaft  16  is caused to drive and rotate the second turning drive member  32  at a predetermined small angle in a clockwise direction or counterclockwise direction with the rotating axis O as a center as illustrated in  FIGS. 8 and 9  for which description have been made above, so that the substrate  20  placed on the substrate mounting unit  76 R of the right upper end effector  70 R of the upper transfer device  1 B is positioned on an original path that this substrate  20  should take when being transferred. 
     Subsequently, by operating the right upper transfer mechanism  7 R of the upper transfer device  1 B in accordance with a predetermined sequence, this substrate  20  is transferred and is placed on the substrate placement unit  20 R within the processing chamber  82 . 
     Description has been made by giving an example in which substrates  20  are placed on the substrate mounting units  76 L and  76 R of the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B, and are transferred. However, in the case where substrates  20  are placed on the substrate mounting units  36 L and  36 R of the left upper end effector  30 L and the right upper end effector  30 R of the lower transfer device  1 A and are transferred, substantially the same operations are performed to place a pair of substrates  20  on the substrate placement units  20 L and  20 R within the pair of processing chambers  81  and  82 . 
     In the vacuum apparatus  10 A according to this embodiment as described above, when substrates  20  are transferred and placed on the substrate placement units  20 L and  20 R, for example, within a pair of processing chambers  81  and  82 , position coordinates of the substrates  20  calculated on the basis of the result of detection with the positioning sensors  91  to  93  are compared with position coordinates stored in the controller  94  in advance, and calculation is made to obtain a deviation of each position coordinate from the original path that the substrate  20  should take. Based on the calculated deviation of the position coordinate, substrates  20  on the substrate mounting units  76 L and  76 R of the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B are positioned on the original path that these substrates  20  should take when being transferred. This makes it possible to correctly position the pair of substrates  20  transferred by the upper transfer device  1 B on the substrate placement units  20 L and  20 R within the respective processing chambers  81  and  82 . Thus, it is possible to improve throughput in carrying in or out the substrates  20  into or from each chamber. 
     Furthermore, according to this embodiment, it is possible to move a pair of substrates  20  placed on the substrate mounting units  76 L and  76 R of the left upper end effector  70 L and the right upper end effector  70 R of the upper transfer device  1 B to position the substrates  20  on an original path that these substrates  20  should take, which makes it possible to rapidly place the pair of substrates  20  at correct positions as compared with a conventional system, which cannot correct the positional deviations for a pair of substrates simultaneously. 
     On the other hand, as understood from the above descriptions, the effects described above can be obtained in the case where substrates  20  are placed on the substrate mounting units  36 L and  36 R of the left upper end effector  30 L and the right upper end effector  30 R of the lower transfer device  1 A having substantially the same configuration as the upper transfer device  1 B; and the substrates  20  are transferred and placed. 
     It is noted that the vacuum apparatus according to the present invention is not limited to the embodiment described above, and various modifications are possible. 
     For example, the number of or the arrangement of the transfer object detection sensors that detect the position of a transfer object is not limited to three position sensors  91  to  93  as described above, and it may be possible to employ various number of sensors with various arrangements. Furthermore, as for the method of calculating position coordinates of a transfer object, it may be possible to employ various methods. 
     In addition, in the embodiment described above, position coordinates are calculated for each of the substrates  20 , and then, these substrates  20  are positioned on an original path that each of these substrates  20  should take when being transferred. However, the present invention is not limited to such a structural arrangement, and it may be possible to employ a structural arrangement in which each substrate  20  is transferred to the vicinity of the substrate placement unit  20 L,  20 R, and then, the substrate  20  is moved to place it on the substrate placement unit  20 L,  20 R. 
     EXPLANATION OF REFERENCE NUMERALS 
     
         
           1  transfer device 
           1 A lower transfer device (first transfer device) 
           1 B upper transfer device (second transfer device) 
           2 L left lower transfer mechanism (first transfer mechanism) 
           2 R right lower transfer mechanism (second transfer mechanism) 
           3   a  first left lower parallel crank mechanism 
           3   b  second left lower parallel crank mechanism 
           4   a  first right lower parallel crank mechanism 
           4   b  second right lower parallel crank mechanism 
           5   a  first left upper parallel crank mechanism 
           5   b  second left upper parallel crank mechanism 
           6   a  first right upper parallel crank mechanism 
           6   b  second right upper parallel crank mechanism 
           7 L left upper transfer mechanism (third transfer mechanism) 
           7 R right upper transfer mechanism (fourth transfer mechanism) 
           10  vacuum apparatus 
           11  first extension/contraction drive shaft 
           12  second extension/contraction drive shaft 
           13  third extension/contraction drive shaft 
           14  fourth extension/contraction drive shaft 
           15  first turning drive shaft 
           16  second turning drive shaft 
           20  substrate (transfer object) 
           20 L,  20 R substrate placement unit (transfer object placement unit) 
           31  first turning drive member 
           31   a  connecting member 
           32  second turning drive member 
           32   a  connecting member 
           80  transfer chamber (vacuum chamber) 
           81 ,  82 ,  83 ,  84 ,  87 ,  88  processing chamber 
         O rotating axis 
         V substrate transfer direction (transfer object transfer direction)