Patent Document

TECHNICAL FIELD 
       [0001]    The present invention relates to a substrate floating apparatus, substrate transfer apparatus, and substrate transport apparatus for floating and transporting an object to be transported, such as a substrate, by blowing air. 
       BACKGROUND ART 
       [0002]    A conventional transport apparatus is known that floats an object to be transported by generating high-pressure air using a compressor, storing the high-pressure air in a tank, and blowing the high-pressure air stored in the tank from a plurality of nozzles toward the bottom surface of the object to be transported (see for example Patent Literature (PTL) 1). 
       CITATION LIST 
     Patent Literature 
       [0003]    [PTL 1] Japanese Unexamined Patent Application Publication No. 2005-75497. 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0004]    With the above-described conventional technique, however, when an apparatus that generates high-pressure air such as a compressor, small fan, or blower (hereinafter such an apparatus is referred to as a high-pressure air generator) is used, a large amount of power is required to generate the high-pressure air. 
         [0005]    Moreover, in this case, since the high-pressure air generator includes a rotating mechanism or sliding mechanism, there is a problem that the friction from the mechanism generates dust. For this reason, with this conventional technique, a filter is provided to remove dust. However, since the filter clogs after removing a predetermined amount of dust, regular maintenance is required in order to maintain the amount of high-pressure air pumped in. In other words, with this conventional technique, if maintenance is not regularly performed, performance cannot be maintained. 
         [0006]    Moreover, since high-pressure air is blown from the transportation path along which the object to be transported travels, plumbing equipment is required to feed the high-pressure air to the transportation path. This increases the cubic volume of the transport apparatus, which in turn makes it necessary to secure a space of sufficient size to install the transport device. Installation of the plumbing equipment is also costly. 
         [0007]    Moreover, when the transport apparatus is applied in a clean room, installation of equipment for rectifying the high-pressure air such as a chamber in the plumbing equipment is further required, which further increases the cubic volume of the transport apparatus. 
         [0008]    Furthermore, when the plumbing is equipped with a filter or chamber, for example, control of the flow of the high-pressure air (the responsiveness of the flow) worsens and efficient operation cannot be carried out. 
         [0009]    Thus, the present invention has been made in view of the above problems, and has an object to provide a substrate floating apparatus, substrate transfer apparatus, and substrate transport apparatus that achieve energy savings, the saving of space, maintenance-free operation, low costs, and an increase in controllability of airflow. 
       Solution to Problem 
       [0010]    In order to achieve the above object, a substrate floating apparatus according to one aspect of the present invention floats a substrate above a placing surface by jetting air from a plurality of jetting ports, and includes: a plate having a surface that is the placing surface and including the plurality of jetting ports, the plurality of jetting ports penetrating the plate in a thickness direction of the plate and spaced apart from one another at a given interval, a plurality of air blowers that blow air toward the plurality of jetting ports from a rear side of the plate by vibrating a diaphragm; and a controller that controls driving of the plurality of air blowers. 
         [0011]    According to this configuration, the plurality of air blowers can blow air by vibrating the diaphragm. In other words, since the air blower, which is the source of generation of the flow of air blown from the plurality of jetting ports, does not include a rotating mechanism or a sliding mechanism, generation of dust can be suppressed. Therefore, a filter for removing dust resulting from friction generated by such a mechanism need not be provided. This eliminates the need for regular maintenance and increases user convenience. 
         [0012]    Moreover, since the plurality of air blowers are disposed directly on the rear sides of the plurality of jetting ports, installation of plumbing is not required. For this reason, a space for installing plumbing equipment need not be secured and the substrate floating apparatus itself can be compact in cubic volume. Moreover, costs incurred from installing plumbing equipment (including a chamber) can be cut. Furthermore, since the plurality of air blowers can directly send air to the plurality of jetting ports, air jetted from the plurality of jetting ports can be controlled by controlling the plurality of air blowers, and controllability of the flow of air can be increased. 
         [0013]    For example, the plurality of air blowers may be provided in one-to-one correspondence with the plurality of jetting ports. 
         [0014]    According to this configuration, controllability of the air jetted from each of the plurality of jetting ports can be increased. 
         [0015]    For example, the controller may control driving of the plurality of air blowers individually. 
         [0016]    According to this configuration, since each of the plurality of air blowers is individually controlled, it is possible, for example, to control only the plurality of air blowers directly under the substrate among the plurality of air blowers. In this way, since the number of air blowers used to float the substrate can be controlled, the amount of power consumed by the plurality of air blowers can be kept to the minimum amount required. 
         [0017]    For example, each of the plurality of air blowers may include: the diaphragm; a housing that includes an inlet for drawing air into an interior space, and an outlet that communicates at least one of the plurality of jetting ports with the interior space, the diaphragm being disposed in the interior space of the housing; and a drive source that vibrates the diaphragm. The drive source may draw air into the interior space of the housing through the inlet and expel air from the interior space through the outlet by vibrating the diaphragm. 
         [0018]    According to this configuration, since each of the plurality of air blowers has a configuration that draws air into the interior space of the housing through the inlet and expels air from the interior space through the outlet as a result of the drive source vibrating the diaphragm, generation of mechanical friction is unlikely when driven. Consequently, even when the air blower is driven, dust can be kept from being generated. 
         [0019]    For example, the drive source may be a piezoelectric element that vibrates when applied with voltage. 
         [0020]    According to this configuration, vibration can be efficiently transmitted to the diaphragm by applying voltage to the drive source. Moreover, since diaphragm can be instantly vibrated when voltage is applied, the responsiveness of vibration of the diaphragm can be increased. 
         [0021]    For example, each of the plurality of air blowers may be a blower without a check valve between the inlet and the outlet of the housing. Moreover, for example, each of the plurality of air blowers may be a piezoelectric pump that includes a check valve between the inlet and the outlet of the housing. 
         [0022]    Moreover, for example, each of the plurality of air blowers may further include, at the inlet of the housing, a filter for removing dust. 
         [0023]    According to this configuration, dust in the air outside the air blower can be prevented from being drawn in. This keeps the blowing efficiency of the air blower from decreasing due to dust. 
         [0024]    A substrate transfer apparatus according to another aspect of the present invention is for placing and removing a substrate in and from a predetermined placement position, and includes: a plurality of arms that are elongated and plate-shaped and include a plurality of jetting ports penetrating the plurality of arms in a plate thickness direction and spaced apart from one another at a given interval; a plurality of air blowers that blow air toward the plurality of jetting ports from rear sides of the plurality of arms; and a controller that controls driving of the plurality of air blowers. 
         [0025]    Moreover, a substrate transport apparatus according to another aspect of the present invention transports a substrate by floating the substrate from a surface of a transporting path by jetting air from a plurality of jetting ports formed in the transporting path, and includes: a plate having a surface that is the surface of the transporting path and including the plurality of jetting ports, the plurality of jetting ports penetrating the plate in a thickness direction of the plate and spaced apart from one another at a given interval; a plurality of air blowers that blow air toward the plurality of jetting ports from a rear side of the plate; and a controller that causes, among the plurality of air blowers, an air blower corresponding to a jetting port positioned below the substrate to blow air. 
       Advantageous Effects of Invention 
       [0026]    The substrate floating apparatus, substrate transfer apparatus, and substrate transport apparatus according to the present invention can achieve energy savings, the saving of space, maintenance-free operation, low costs, and an increase in controllability of airflow. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0027]      FIG. 1  illustrates a substrate transport apparatus which uses a substrate floating apparatus according to Embodiment 1. 
           [0028]      FIG. 2  is an enlarged view of region P 1  in (b) in  FIG. 1 . 
           [0029]      FIG. 3  is an enlarged view of a region of a substrate floating apparatus according to Variation (1) corresponding to region P 1  in (b) in  FIG. 1 . 
           [0030]      FIG. 4  is an enlarged view of a region of a substrate floating apparatus according to Variation (3) corresponding to region P 1  in (b) in  FIG. 1 . 
           [0031]      FIG. 5  is a perspective external view of a substrate transfer apparatus according to Embodiment 2. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0032]    Hereinafter, the substrate floating apparatus, substrate transfer apparatus, and substrate transport apparatus according to one aspect of the present invention will be described in detail with reference to the drawings. 
         [0033]    It is to be noted that each of the embodiments described below shows a specific example of the present invention. The numerical values, shapes, materials, elements, the arrangement and connection of the elements, steps, the processing order of the steps etc. shown in the following embodiments are mere examples, and therefore do not limit the present invention. Moreover, among the elements in the following embodiments, those elements not recited in any one of the independent claims defining the most generic part of the inventive concept are described as arbitrary elements. 
       Embodiment 1 
       [0034]    The substrate transport apparatus according to Embodiment 1 transports substrates along a transporting path using a substrate floating apparatus that jets air from a plurality of jetting ports formed in the transporting path to float the substrate from a placing surface. 
         [0035]      FIG. 1  illustrates the substrate transport apparatus which uses the substrate floating apparatus according to Embodiment 1. In  FIG. 1 , (a) is a plan view of the substrate transport apparatus  1  from above, and (b) is a cross sectional view taken along line a-a in (a). 
         [0036]    The substrate transport apparatus  1  includes a substrate floating apparatus  100  as a frame, a transport roller  140 , and a guide roller  150 . 
         [0037]    The substrate floating apparatus  100  includes a plate  110 , a plurality of air blowers  120 , and a controller  130 . 
         [0038]    The plate  110  has a surface A 1  that is the placing surface for a substrate  160  and includes a plurality of jetting ports  111  penetrating the plate  110  in a thickness direction and spaced apart from one another at a given interval. 
         [0039]    The plurality of air blowers  120  blow air toward the plurality of jetting ports  111  from a rear side of the plate  110  by vibrating a diaphragm. Moreover, the plurality of air blowers  120  are provided in one-to-one correspondence with the plurality of jetting ports  111  included in the plate  110 . 
         [0040]    The controller  130  controls driving of the plurality of air blowers  120 . The controller  130 , for example, controls driving of the plurality of air blowers  120  individually. In other words, the controller  130  may control each of the plurality of air blowers  120  individually. 
         [0041]      FIG. 2  is an enlarged view of region P 1  in (b) in  FIG. 1 . In other words,  FIG. 2  is for illustrating the configuration of the air blower  120 . 
         [0042]    Each of the plurality of air blowers  120  includes a diaphragm  124 , a housing  121 , and a piezoelectric element  125  as a drive source. 
         [0043]    The housing  121  includes an inlet  122  and an outlet  123 . Moreover, the housing  121  defines an interior space S 1  in which the diaphragm  124  and the piezoelectric element  125  are disposed. In other words, housing  121  contains therein the diaphragm  124 . The inlet  122  is formed in the bottom of housing  121 . The inlet  122  is an opening for drawing air into the interior space S 1  from outside. The outlet  123  is formed on the top of housing  121 . The outlet  123  is cylindrical in shape and blows the flow of air generated in the interior space S 1  of housing  121  into one of the plurality of jetting ports  111  formed in the plate  110 . In other words, the outlet  123  communicatively connects one of the plurality of jetting ports  111  with the interior space S 1 . Moreover, the outer circumferential surface of the cylindrical shape of the outlet  123  is in contact with the inner circumferential surface of the jetting port  111 . Therefore, airflow generated from each of the plurality of air blowers  120  is efficiently jetted out from a corresponding one of the plurality of jetting ports  111 . 
         [0044]    When voltage is applied, the piezoelectric element  125  vibrates and causes the diaphragm  124  to vibrate. The piezoelectric element  125  vibrates the diaphragm  124  to draw air into the interior space S 1  of the housing  121  through the inlet  122  and expel air from the interior space S 1  through the outlet  123 . The piezoelectric element  125  transmits vibrations to the diaphragm  124  by coming into surface contact with the diaphragm  124 . Note that the diaphragm  124  is simply a film-like member, but the piezoelectric element  125  may include the functions of diaphragm  124 . In other words, the diaphragm may be structured to be a piezoelectric element itself. 
         [0045]    For example, a microblower manufactured by Murata Manufacturing Company, Ltd. may be used as the above-described air blower  120 . 
         [0046]    With the substrate floating apparatus  100  according to Embodiment 1, each of the plurality of air blowers  120  blow air by vibrating the diaphragm  124 . In other words, since the air blower  120 , which is the source of generation of the flow of air blown from each of the plurality of jetting ports  111 , does not include a rotating mechanism or a sliding mechanism, generation of dust can be suppressed. Therefore, a filter for removing dust resulting from friction generated by such a mechanism need not be provided. This eliminates the need for regular maintenance and increases user convenience. 
         [0047]    Moreover, since the plurality of air blowers  120  are disposed directly on the rear sides of the plurality of jetting ports  111 , installation of plumbing is not required. For this reason, a space for installing plumbing equipment need not be secured and the substrate floating apparatus  100  itself can be compact in cubic volume. Moreover, costs incurred from installing plumbing equipment (including a chamber) can be cut. Furthermore, since the plurality of air blowers  120  can directly send air to the plurality of jetting ports  111 , air jetted from the plurality of jetting ports  111  can be controlled by controlling the plurality of air blowers  120 . In other words, controllability of the air jetted from the plurality of jetting ports  111  can be increased. 
         [0048]    Moreover, with the substrate floating apparatus  100  according to Embodiment 1, since each of the plurality of air blowers  120  has a configuration that draws air into the interior space S 1  of the housing  121  through the inlet  122  and expels air from the interior space S 1  through the outlet  123  as a result of the piezoelectric element  125  vibrating the diaphragm  124 , generation of mechanical friction is unlikely when driven. Consequently, even when the air blower  120  is driven, dust can be kept from being generated. 
         [0049]    Moreover, with the substrate floating apparatus  100  according to Embodiment 1, since the plurality of air blowers  120  are provided in one-to-one correspondence with the plurality of jetting ports  111 , controllability of the air jetted from each of the plurality of jetting ports  111  can be increased. 
         [0050]    Moreover, with the substrate floating apparatus  100  according to Embodiment 1, since each of the plurality of air blowers  120  is individually controlled, it is possible, for example, to control only the plurality of air blowers  120  directly under the substrate among the plurality of air blowers  120 . In this way, since the number of air blowers  120  used to float the substrate  160  can be controlled, the amount of power consumed by the plurality of air blowers  120  can be kept to the minimum amount required. 
         [0051]    Moreover, with the substrate floating apparatus  100  according to Embodiment 1, since the piezoelectric element  125 , which vibrates when applied with voltage, is used as the drive source, vibration can be efficiently transmitted to the diaphragm  124  by applying voltage to the piezoelectric element  125 . Moreover, since the diaphragm  124  can be instantly vibrated when voltage is applied to the piezoelectric element  125 , the responsiveness of vibration of the diaphragm  124  can be increased. 
         [0052]    (Variations) 
         [0053]    (1) 
         [0054]    With the substrate floating apparatus  100  according to Embodiment 1, the inlet  122  of the housing  121  of the plurality of air blowers  120  is merely an opening, but this is only one example. For example, as illustrated in  FIG. 3 , a substrate floating apparatus  100   a  which employs an air blower  120   a  including a filter  126  disposed at the inlet  122  for removing dust is acceptable. 
         [0055]    According to this configuration, even when dust is in the air outside each of the plurality of air blowers  120   a,  the dust can be kept from being drawn into the interior space S 1  of the housing  121 . Therefore, the blowing efficiency of the air blower  120   a  can be kept from decreasing due to dust. 
         [0056]    (2) 
         [0057]    With the substrate floating apparatus  100  according to Embodiment 1, the diaphragm  124  of each of the plurality of air blowers  120  is vibrated by the piezoelectric element  125 , but this is only one example. For example, the diaphragm  124  may be vibrated by rotating a cam. Note that in this case, the plurality of air blowers generate dust from friction, but this configuration is still advantageous since plumbing equipment is not required for the substrate floating apparatus. 
         [0058]    (3) 
         [0059]    With the substrate floating apparatus  100  according to the above embodiment, each of the plurality of air blowers  120  is a microblower that does not include a check valve between the inlet  122  and the outlet  123  of the housing  121 , but this is just one example. For example, as illustrated in  FIG. 4 , a substrate floating apparatus  100   b  that employs piezoelectric pumps as the plurality of air blowers  120  is acceptable. 
         [0060]    The air blower  120   b  according to Variation (3) includes check valves  127  and  128  in addition to a diaphragm  124   b,  a housing  121   b , and a piezoelectric element  125   b  as the drive source. 
         [0061]    The housing  121   b  includes a cylindrical inlet  122   b  and outlet  123   b.  Moreover, the housing  121  defines an interior space S 2  in which the diaphragm  124   b  and the piezoelectric element  125   b  are disposed. The inlet  122   b  and the outlet  123   b  are in communication with the interior space S 2 . The check valve  127  is disposed between the inlet  122   b  and the interior space S 2  and is for preventing reverse flow of air drawn into interior space S 2  toward inlet  122 . Moreover, the check valve  128  is disposed between the outlet  123   b  and the interior space S 2  and is for preventing reverse flow of air expelled from interior space S 2  toward interior space S 2 . The outlet  123   b  of air blower  120   b  and the jetting port  111  formed in the plate  110  are connected together in a state in which they are in communication with one another via communicating members  129   a  and  129   b.    
         [0062]    Note that, for example, a piezo-micro pump manufactured by Takasago Electric, Inc. may be used as the above-described air blower  120   b.    
       Embodiment 2 
       [0063]    The substrate transfer apparatus according to Embodiment 2 includes a plurality of jetting ports formed in an arm on which a substrate is placed, and the substrate is floated from the surface of the arm by jetting air from the plurality of jetting ports to transfer the substrate from the arm to a predetermined placement position. 
         [0064]      FIG. 5  is a perspective external view of the substrate transfer apparatus according to Embodiment 2. 
         [0065]    The substrate transfer apparatus  2  includes at least a plurality of arms  210  and the plurality of air blowers  120 . As illustrated in  FIG. 5 , the substrate transfer apparatus  2  according to Embodiment 2 further includes a support  310  that supports the plurality of arms  210  (four arms  210  in this embodiment), a first guide  320 , a second guide  330 , and a third guide  340 . 
         [0066]    Each of the plurality of arms  210  is an elongated and plate-shaped member that extends in the depthwise direction (Y axis direction) and includes a plurality of the jetting ports  211  penetrating the arm  210  in the plate thickness direction and spaced apart from one another at a given interval. The plurality of air blowers  120  blow air toward the plurality of jetting ports  211  from the rear sides of the plurality of arms  210 . In Embodiment 2, the plurality of air blowers  120  are provided in one-to-one correspondence with the plurality of jetting ports  211  provided in each of the plurality of arms  210 . Note that details regarding the structure of the plurality of air blowers  120  are the same as the air blower  120  according to Embodiment 1, and as such, description thereof is omitted. 
         [0067]    The first guide  320  is a guide for sliding the support  310  in a vertical (Z axis) direction. More specifically, the first guide  320  includes a pair of columnar members that sandwich the support  310  in the widthwise (X axis) direction. The outer side of the support  310  in the X axis direction and the inner sides of the pair of first guides  320  are connected so as to be slidable in the Z axis direction. 
         [0068]    The second guide  330  is a guide that slides the first guide  320  to which the support  310  is connected in the depthwise (Y axis) direction. More specifically, the second guide  330  is a plate, and is sandwiched in the X axis direction by lower portions of the pair of first guides  320 . The outer side of the first guide  320  in the X axis direction and the outer side of the second guide  330  are connected so as to be slidable the Y axis direction. 
         [0069]    The third guide  340  is a guide for sliding the second guide  330  to which the support  310  and the first guide  320  is connected in the 
         [0070]    X axis direction. More specifically, the third guide  340  is an elongated member that extends in the X axis direction, and is connected to the bottom surface of second guide  330  such that the second guide  330  is slidable in the X axis direction. 
         [0071]    The first guide  320 , the second guide  330 , and the third guide  340  may each include a power source, and may be configured to be able to slide in a direction in which a member connected thereto is slidable. 
         [0072]    With the substrate transfer apparatus  2  according to Embodiment 2, the substrate floating apparatus  100  described in Embodiment 1 is applied as the plurality of arms  210  for transferring the substrate  160 . As such, while the substrate  160  is floated from the plurality of arms  210 , the substrate  160  can be transferred to a predetermined placement position. Therefore, since the substrate  160  and the plurality of arms  210  are not in contact when placing and removing the substrate  160  in and from a predetermined placement position, the substrate  160  can be transferred without being damaged. 
         [0073]    Although only some exemplary embodiments of the substrate floating apparatus according to the present invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of the present invention. Accordingly, all such modifications are intended to be included within the scope of the present invention. 
       INDUSTRIAL APPLICABILITY 
       [0074]    The present invention is applicable as, for example, a substrate floating apparatus capable of being used to transport or transfer an object to be transported such as a liquid crystal substrate by floating the object to be transported with air. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  substrate transport apparatus 
           100 ,  100   a,    100   b  substrate floating apparatus 
           110  plate 
           111 ,  211  jetting port 
           120 ,  120   a,    120   b  air blower 
           121 ,  121   b  housing 
           122 ,  122   b  inlet 
           123 ,  123   b  outlet 
           124 ,  124   b  diaphragm 
           125 ,  125   b  piezoelectric element 
           126  filter 
           127 ,  128  check valve 
           129   a,    129   b  communicating member 
           130  controller 
           140  transport roller 
           150  guide roller 
           160  substrate 
           210  arm 
           310  support 
           320  first guide 
           330  second guide 
           340  third guide

Technology Category: 7