Abstract:
The purpose of the present invention provides a disk transfer unit and inspection apparatus that can transfer a plurality of disks and increase throughput. 
     The present invention includes: a supply/discharge/transfer portion fetching disks from a disk supply portion and discharging inspected disks to a predetermined place; an inspection unit transfer portion transferring the disks within an inspection unit; and a delivery/transfer portion transferring the disks between the disk supply/discharge/transfer portion and the inspection unit transfer portion. The delivery/transfer portion comprises: a base having a rotational center and is formed in an arc-like shape with center at the rotational center and providing with even numbers of disk mounting portions for mounting the disks and a driving portion for moving the base up and down and rotating the base about the rotational center, and transfers the disks between the supply/discharge/transfer portion and the inspection unit transfer portion.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a disk transfer unit and inspection apparatus. Particularly, the invention relates to supply/discharge of disks to/from the disk transfer unit and the inspection apparatus. 
         [0002]    Plural pairs of arms for holding an outer circumference of a disk on the both sides are disposed in an upright position and arranged in a row with a predetermined spacing in an axial direction. A plurality of disks, each held by each pair of arms, are transferred in one axial direction while surfaces of the disks being transferred are scanned in a direction perpendicular to the one axial direction for detection of any defects (JP-A No. 2008-116340). 
       SUMMARY OF THE INVENTION 
       [0003]    A conventional disk inspection apparatus ((JP-A No. 2008-116340)) is a system which transfers the disks one by one in one direction. However, to inspect a plurality of disks, the conventional disk inspection apparatus is to be provided with a plurality of linear movement bases. Thus, the apparatus is increased in size. If the apparatus is to achieve increased throughput without being increased in size, any further throughput increase is impossible. 
         [0004]    An object of the invention is to provide a disk transfer unit or inspection apparatus that can transfer a plurality of disks and increase throughput. 
         [0005]    For solution to the above problem, the invention has at least the following features. 
         [0006]    A disk transfer unit according to an aspect of the invention includes: a supply/discharge/transfer portion fetching disks from a disk supply portion and discharging inspected disks to a predetermined place; an inspection unit transfer portion transferring the disks within an inspection unit; and a delivery/transfer portion transferring the disks between the disk supply/discharge/transfer portion and the inspection unit transfer portion, wherein the delivery/transfer portion comprises: a base having a rotational center and is formed in an arc-like shape with center at the rotational center and providing with even numbers of disk mounting portions for mounting the disks and a driving portion for moving the base up and down and rotating the base about the rotational center, and transfers the disks between the supply/discharge/transfer portion and the inspection unit transfer portion. 
         [0007]    The delivery/transfer portion transfers an uninspected disk having not been inspected and an inspected disk having not been inspected. 
         [0008]    In addition, the delivery/transfer portion transfers a plurality of the uninspected disks and a plurality of the inspected disks, and alternately places the uninspected disks and the inspected disks on the disk mounting portions. 
         [0009]    The base is shaped like a fan and the disk mounting portions are provided on a side of the fan shape. 
         [0010]    An inspection apparatus according to an aspect of the invention includes: the above-described disk transfer unit; and an inspection unit including an inspection optical system for inspecting the disks transferred by the inspection unit transfer portion. 
         [0011]    The disk transfer unit and inspection apparatus according to the invention are adapted for efficient transfer of a plurality of disks without involving disk collision or disk stagnation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a diagram showing an overall layout of an inspection apparatus according to one embodiment of the invention; 
           [0013]      FIG. 2  is a block diagram showing a control system and operations of the system mainly composed of a disk transfer unit according to one embodiment of the invention; 
           [0014]      FIG. 3  is a group of diagrams illustrating operations of the disk transfer unit, focusing on a delivery holder constituting a delivery/transfer portion according to one embodiment of the invention; and 
           [0015]      FIG. 4  is a group of diagrams illustrating the operations of the disk transfer unit, focusing on the delivery holder constituting the delivery/transfer portion according to one embodiment of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]    A disk transfer unit and inspection apparatus according to the invention are described with reference to the accompanying drawings.  FIG. 1  is a diagram showing an overall layout of an inspection apparatus according to one embodiment of the invention. An inspection apparatus  100  of the invention includes a horizontal multijoint robot  1  having a hand capable of holding two disks; an inspection unit  2  for inspecting various characteristics of the disk, a delivery holder  3  as one example of a delivery/transfer portion having functions to move up and down and to rotate horizontally while holding four disks, a washing basket  4  accommodating, for example, 100 disks to be supplied, a disk cassette  5  storing good-quality disks therein after inspection and a sorting table  6  for ranking defective disks after inspection. 
         [0017]    The horizontal multijoint robot  1  has a robot hand  11  which holds the circumference of the disk with two claws and releases the disk. The horizontal multijoint robot  1  uses this robot hand  11  to fetch uninspected disks from the washing basket  4 , to deliver the disks to the delivery holder  3 , to receive inspected disks from the delivery holder  3 , and to set the disks on a sorting table  6 . At this time, good-quality disks are stored in the disk cassette  5 . Thus, the horizontal multijoint robot  1  constitutes an example of a disk supply/discharge/transfer portion that supplies the uninspected disks to the inspection unit  2  through the delivery holder  3  and discharges the inspected disks to predetermined place through the delivery holder  3 . 
         [0018]    The delivery holder  3  as a feature of the embodiment includes a base  31  having a plurality of disk mounting portions capable of retaining the disks and a driving mechanism  35  rotating the base  31  about a rotational center  32  and moving up and down the base  31 . The delivery holder  3  is capable of retaining four disks at a time such that at the time of delivery/reception of disks to/from the inspection unit  2 , the delivery holder  3  can receive two inspected disks while retaining two uninspected disks to be supplied to the inspection unit  2 . At the time of delivery/reception to/from the inspection unit  2 , the delivery holder  3  vertically moves so as to receive two disks from two spindles  21  provided at the inspection unit  2 . Subsequently, the delivery holder  3  horizontally rotates to bring the two uninspected disks into face-to-face relation to the two spindles  21  and mounts the two uninspected disks to the two spindles  21 . 
         [0019]    The four disk mounting portions of the delivery holder  3  are arranged in a manner such that a disk supplying holder and a disk receiving holder alternate with each other in order to allow the delivery holder  3  to deliver/receive disks by movement through the minimum horizontal rotational angle. As a result, disk transfer operation time can be reduced, increasing throughput. 
         [0020]    Of the four disk mounting portions of the delivery holder  3 , two disk mounting portions at one end side may be used as the disk supplying holders while the other two disk mounting portions at the other side end may be used as the disk receiving holders. In this case, the horizontal rotational angle of the delivery holder  3  is increased and hence, the throughput is decreased as compared with the above-described case. However, a stage  25  to be described hereinafter and the robot hand  11  can be reduced in size. 
         [0021]    The number of disk mounting portions is not limited to four but may be any multiples of 2 (any even number) because what is required is that the number of the disk supplying holders is equal to that of the disk receiving holders. 
         [0022]    As with the delivery/reception of disks to/from the inspection unit  2 , the delivery holder  3  delivers two inspected disks to the horizontal multijoint robot  1  and receives two uninspected disks from the horizontal robot  1 . 
         [0023]    The delivery holder  3  performs the disk delivery/reception alternately with the inspection unit  2  and the horizontal multijoint robot  1 . By doing so, the inspection unit  2  and the horizontal multijoint robot  1  are little affected by the operation timing of the counterpart. This eliminates wasted time such as that of stagnation from the disk transfer operation time, contributing to the increase in throughput. 
         [0024]    Further, the transfer time of the delivery holder  3  can be minimized by locating the horizontal multijoint robot  1  and the inspection unit  2  at 90°-angular positions relative to the delivery holder  3 . As a matter of course, the horizontal multijoint robot and the inspection unit may be located at another-angular positions. 
         [0025]    The inspection unit  2  includes the stage  25  equipped with the above-described two spindles  21 , an inspection optical system  22  for disk inspection, a turnover mechanism  24  for inspection of the top and bottom sides of the disk and a carriage  23  for moving the stage  25 . The carriage  23  constitutes an example of an inspection unit transfer portion jointly with the stage  25  and reciprocates the disks between a place to deliver/receive disks to/from the delivery holder  3  and the turnover mechanism  24 . The inspection optical system  22  spirally inspects surface defects on the disk while rotating the spindles  21  at high speed during the passage of the stage  25  through a lower part of the inspection optical system  22 . The top side of the disk is inspected during moving to the turnover mechanism  24 . The disk is inverted by the turnover mechanism  24  and the bottom side of the disk is inspected during moving to the place to deliver/receive disks to/from the delivery holder  3 . 
         [0026]    The horizontal multijoint robot  1 , the washing basket  4  accommodating the disks to be supplied and the disk cassette  5  storing the good-quality disks after inspection, and the like are disposed on the right side of the delivery holder  3  as seen in  FIG. 1 . However, if these components are disposed on the left side of the delivery holder as seen in the figure, the arrangement is likely to produce the same effects. 
         [0027]    Next, a control system and operations of the system mainly composed of the disk transfer unit according to one embodiment of the invention are described with reference to a block diagram shown in  FIG. 2 . The disk transfer unit of the embodiment includes the supply/discharge/transfer portion, the delivery/transfer portion and the inspection unit transfer portion which are illustrated in  FIG. 1 . 
         [0028]    A sequencer  8  controls the delivery holder  3 . The sequencer  8  operates the horizontal multijoint robot  1  by issuing a command to a robot controller  9 . In response to the command from the robot controller  9 , the horizontal multijoint robot  1  fetches the uninspected disks from the washing basket  4 , delivers the disks to the delivery holder  3 , and delivers the inspected disks to the disk cassette  5  or the sorting table  6 . 
         [0029]    The sequencer  8  also controls cassette transfer from the washing basket  4  and to the disk cassette  5 . The washing basket  4  contains therein the uninspected disks, which are sequentially extracted by the horizontal multijoint robot  1 . When the washing basket  4  becomes empty, the horizontal multijoint robot  1  displaces the empty washing basket  4  and transfers another washing basket  4  accommodating the uninspected disks to a predetermined position from which the robot hand  11  can carry away the uninspected disks. The inspected disks determined to be of good quality are stored in the disk cassette  5  when the inspection is completed. When the disk cassette  5  is filled with the inspected disks, the disk cassette  5  thus filled is displaced and replaced by an empty disk cassette  5  which allows the robot hand  11  to store the inspected disks therein. 
         [0030]    The sequencer  8  further controls the rotation angle and stoppage of the delivery holder  3 . A detailed description on the operations of the delivery holder  3  is made hereinafter. The sequencer  8  determines whether the sorting table  6  is full of defective disks or not. When the sorting table is filled up, the sequencer puts the defective disks in an empty sorting table  6 . 
         [0031]    The sequencer  8  also outputs to a personal computer (PC)  28  a signal for controlling the inspection unit  2 . The operations of the inspection unit  2  are controlled by one personal computer  28 . This is to provide control in which wasteful stagnation time is eliminated by omitting signal communication with any other control unit. The personal computer  28  controls the operations of the spindles  21 , inspection optical system  22 , carriage  23  and turnover mechanism  24 . The inspection optical system  22  spirally inspects surface defects on the disks by bringing the disks received on the spindles  21  while rotating the spindles  21  at high speed and during moving the disks through the lower part of the inspection optical system. 
         [0032]    Now referring to  FIG. 3  and  FIG. 4 , description is made on the operations of the disk transfer unit, focusing on the delivery holder  3  constituting the delivery/transfer portion. Of the symbols such as “1T” and “2B” shown in  FIG. 3  and  FIG. 4 , the numerals denote the order of disks delivered to the disk transfer unit . The character “T” denotes the top side of the disk delivered to the disk transfer unit, while the character “B” indicates that the disk was inverted to turn the bottom side up. 
         [0033]    The horizontal multijoint robot  1  rotates and the robot hand  11  stretches its arms and fetch two uninspected disks  51 ,  52  of the first cycle from the washing basket  4  ( FIG. 3A ). 
         [0034]    The robot hand  11  mounts the inspection disks  51 ,  52  on uninspected-disk mounting portions  33   a,    33   b  that carries the inspection disks  51 ,  52 . At this time, the disk  51  of the first cycle is mounted to the uninspected-disk mounting portion  33   a  and the disk  52  of the first cycle is mounted to the uninspected-disk mounting portion  33   b.  In this embodiment, the disks  51 ,  52  of the first cycle are not mounted in an adjoining relation but in a manner to allow the insertion of another disk between the disks  51 ,  52  of the first cycle. As a result, transfer time for disk change can be reduced because the robot needs to rotate through only a small angle for disk change ( FIG. 3B ). 
         [0035]    The delivery holder  3  rotates 90° clockwise about the rotational center  32 . The stage  25  of the inspection unit  2  moves to receive the disks  51 ,  52  of the first cycle ( FIG. 3C ). 
         [0036]    The disks  51 ,  52  of the first cycle are mounted on the spindles  21  that rotate the disks as holding the disks at inner circumferences of disk holes. When the disks  51 ,  52  of the first cycle are mounted on the spindles  21 , the disks  51 ,  52  of the first cycle, with the inner circumferences of the respective holes thereof fitted with the spindles  21 , are retained by the spindles  21 , respectively. On the other hand, the horizontal multijoint robot  1  fetches disks  53 ,  54  of the second cycle from the washing basket  4 , getting ready for disk supply to the delivery holder  3 . Subsequently, the stage  25  moves to the inspection optical system  22 , although omitted the figure. The disks  51 ,  52  of the first cycle have the respective top sides thereof inspected by being rotated on the respective spindles  21  ( FIG. 3D ). 
         [0037]    The delivery holder  3  rotates 90° counter-clockwise about the rotational center  32 . The robot hand  11  of the horizontal multijoint robot  1  mounts the disks  53 ,  54  of the second cycle on the uninspected-disk mounting portions  33   a,    33   b  provided at the base  31  of the delivery holder  3 . When the inspection on the respective top sides of the disks  51 ,  52  of the first cycle is completed, the stage  25  with the two disks mounted moves to the turnover mechanism  24 . The turnover mechanism  24  starts an operation of inverting the disks  51 ,  52  of the first cycle as holding outer circumferences of the disks  51 ,  52  of the first cycle. When the operation of inverting the disks  51 ,  52  of the first cycle is completed, the disks  51 ,  52  of the first cycle are retained on the spindles  21  by bringing the inner circumferences of the holes of the disks  51 ,  52  of the first cycle into fitting engagement with the spindles  21 . The disks  51 ,  52  of the first cycle are placed with the uninspected bottom sides up, respectively. When the disks  51 ,  52  of the first cycle are retained by the spindles  21 , the turnover mechanism  24  disengages from the retained outer circumferences of the disks  51 ,  52  of the first cycle ( FIG. 4E ). 
         [0038]    The bottom sides of the disks  51 ,  52  of the first cycle are inspected by the inspection optical system  22 . When the inspection of the disks  51 ,  52  of the first cycle is completed, the stage  25  moves to the delivery position to deliver the inspected disks  51 ,  52  of the first cycle to the delivery holder  3 . 
         [0039]    On the other hand, the delivery holder  3  rotates clockwise about the rotational center  32 . At this time, the two uninspected disks are already mounted on the delivery holder  3 . However, the delivery holder  3  needs to receive the inspected disks  51 ,  52  in first. Hence, the delivery holder  3  rotates by a rotational angle corrected from 90° of the correct position of the uninspected-disk mounting portions  33   a,    33   b  so as to bring inspected-disk mounting portions  34   a,    34   b  in front of the stage  25 . 
         [0040]    The inspected disks  51 ,  52  of the first cycle are released from the fitting engagement with the spindles  21 . The inspected disks  51 ,  52  of the first cycle with the bottom sides up are mounted on the inspected-disk mounting portions  34   a,    34   b.  When mounting of the inspected disks  51 ,  52  of the first cycle is completed, the delivery holder  3  rotates about the rotational center  32  so as to bring the uninspected-disk mounting portions  34   a,    34   b  in front of the stage  25 . The disks  53 ,  54  of the second cycle are delivered to the stage  25 . At this time, the disks  53 ,  54  of the second cycle are retained on the spindles  21  by bringing the inner circumferences of the holes of the disks  53 ,  54  of the first cycle into fitting engagement with the spindles  21  ( FIG. 4F ). 
         [0041]    The delivery holder  3  rotates counter-clockwise about the rotational center  32 . At this time, the delivery holder  3  stops at position to set the uninspected-disk mounting portions  33   a,    33   b  in front of the robot hand  11 . 
         [0042]    On the other hand, the stage  25  moves to the inspection optical system  22 , which inspects the top sides of the disks  53 ,  54  of the second cycle. When the inspection of the top sides of the disks  53 ,  54  of the second cycle is completed, the stage  25  moves to the turnover mechanism  24  for inspection of the bottom sides of the disks  53 ,  54  of the second cycle. The turnover mechanism  24  removes the disks  53 ,  54  of the second cycle from the spindles  21  by holding the disks  53 ,  54  on the outer circumferences. Subsequently, the turnover mechanism  24  starts the operation of inverting the disks  53 ,  54  of the second cycle. When the operation of inverting the disks  53 ,  54  of the second cycle is completed, the disks  53 ,  54  of the second cycle are retained on the spindles  21  by bringing the inner circumferences of the holes of the disks  53 ,  54  of the second cycle into fitting engagement with the spindles  21 . The disks  53 ,  54  of the second cycle are placed with the uninspected bottom sides up, respectively. When the disks  53 ,  54  of the second cycle are retained on the spindles  21 , the turnover mechanism  24  disengages from the retained outer circumferences of the disks  53 ,  54  of the second cycle ( FIG. 4G ). 
         [0043]    On the other hand, the robot hand  11  holds disks  55 ,  56  of the third cycle to deliver the disks so as to the delivery holder  3  ( FIG. 4G ). 
         [0044]    When the disks  55 ,  56  of the third cycle are mounted on the uninspected-disk mounting portions  33   a,    33   b,  respectively, the robot hand  11  is free of disks. The delivery holder  3  rotates about the rotational center  32  so as to bring the inspected-disk mounting portions  34   a,    34   b  in front of the robot hand  11 . The robot hand  11  receives the two inspected disks  51 ,  52  of the first cycle from the inspected-disk mounting portions  34   a,    34   b,  respectively. When the inspection unit  2  completes the inspection on the respective bottom sides of the disks  53 ,  54  of the second cycle, the stage  25  moves to the place to deliver/receive disks to/from the delivery holder  3  ( FIG. 4H ). 
         [0045]    The delivery holder  3  repeats the operations in the order of that shown in  FIG. 4H  and those shown in  FIG. 4E  to  FIG. 4G . 
         [0046]    According to the embodiment of the invention as described above, the disk transfer unit or the inspection apparatus that can increase throughput is provided because the embodiment is capable of efficient transfer of plural disks without disk collision or stagnation.