Abstract:
A management apparatus is for managing a storage medium. The apparatus includes a rack including a cell which has a first opening and a second opening, a robot for inserting or ejecting the storage medium with respect to the cell through the first opening, and a controller for executing a process. The process includes driving the robot to start inserting or ejecting the storage medium with respect to the cell, detecting a failure in inserting or ejecting the storage medium, stopping the robot from inserting or ejecting the storage medium for a given time upon detecting the failure, and driving the robot to restart inserting or ejecting the storage medium with respect to the cell after the stopping the robot from inserting or ejecting the storage medium for the given time.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2010-087551, filed on Apr. 6, 2010, the entire contents of which are incorporated herein by reference. 
     FIELD 
     The embodiments discussed herein are related to a management apparatus and a management method. 
     BACKGROUND 
     A management system that manages cartridges as storage media is proposed. 
     As a management system, a system of the type including an access (take-in/take out) port through which an arbitrary cartridge is put into and ejected from a rack, the rack in which the cartridges are contained, an access (take-in/take-out) device that puts an arbitrary cartridge into the rack and ejects an arbitrary cartridge from the rack on the basis of an instruction, and a control device that controls the operation of the access device is proposed. In addition, a management device that retains information on a rack in which cartridges are contained is proposed. 
     In a management system as mentioned above, in taking a desired cartridge out of a rack, a user inputs the identification information of the desired cartridge into a management device, and a library management device refers to information on the storage position of the desired cartridge on the basis of the input identification information to acquire information on the storage position of the cartridge and sends the acquired information to an access device. 
     Then, the access device moves around in the rack, takes out the cartridge which is at the storage position concerned, and carries the cartridge to an access port. Then the user accepts the cartridge so carried through the access port. 
     Japanese Laid-open Patent Publication No. 2001-225917 is an example of the above mentioned system. 
     In addition to the above mentioned system configured to take in/out the desired cartridge using the access device, a mechanism that takes in and takes out an arbitrary cartridge by hand is also proposed. A mechanism as mentioned above may have such a drawback that management of cartridges is complicated. 
     SUMMARY 
     According to an aspect of the invention, a management apparatus for managing a storage medium, the apparatus includes a rack including a cell which has a first opening and a second opening, a robot for inserting or ejecting the storage medium with respect to the cell through the first opening, and a controller for executing a process including driving the robot to start inserting or ejecting the storage medium with respect to the cell, detecting a failure in inserting or ejecting the storage medium, stopping the robot from inserting or ejecting the storage medium for a given time upon detecting the failure, and driving the robot to restart inserting or ejecting the storage medium with respect to the cell after the stopping the robot from inserting or ejecting the storage medium for the given time. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a general configuration of a control device according to a first embodiment; 
         FIG. 2  is a diagram illustrating an example of a library system according to a second embodiment; 
         FIG. 3  is a side view of the library system according to the second embodiment taken along the III-III line in  FIG. 2 ; 
         FIG. 4  is a diagram illustrating an example of a hardware configuration of a library management device; 
         FIG. 5  is a block diagram illustrating an example of functions of a library management device; 
         FIG. 6A  is a diagram illustrating one example of the structure of a cell; 
         FIG. 6B  is a diagram illustrating another example of the structure of the cell; 
         FIG. 6C  is a diagram illustrating a further example of the structure of the cell; 
         FIG. 7A  is a diagram illustrating one example of a manner of reading data stored in a CM (Cartridge Memory); 
         FIG. 7B  is a diagram illustrating another example of the manner of reading data stored in the CM; 
         FIG. 8A  is a diagram illustrating one example of a manner of inserting an arbitrary cartridge into an arbitrary cell; 
         FIG. 8B  is a diagram illustrating another example of the manner of inserting an arbitrary cartridge into an arbitrary cell; 
         FIG. 8C  is a diagram illustrating a further example of the manner of inserting an arbitrary cartridge into an arbitrary cell; 
         FIG. 8D  is a diagram illustrating one example of a manner of taking an arbitrary cartridge out of an arbitrary cell; 
         FIG. 8E  is a diagram illustrating another example of the manner of taking an arbitrary cartridge out of an arbitrary cell; 
         FIG. 8F  is a diagram illustrating a further example of the manner of taking an arbitrary cartridge out of an arbitrary cell; 
         FIG. 9A  is a diagram illustrating one example of a method of drawing out an arbitrary cartridge using a robot; 
         FIG. 9B  is a diagram illustrating another example of the method of drawing out an arbitrary cartridge using the robot; 
         FIG. 9C  is a diagram illustrating a further example of the method of drawing out an arbitrary cartridge using the robot; 
         FIG. 9D  is a diagram illustrating a still further example of the method of drawing out an arbitrary cartridge using the robot; 
         FIG. 10A  is a diagram illustrating one example of a manner of inserting an arbitrary cartridge into an arbitrary cell using a robot; 
         FIG. 10B  is a diagram illustrating another example of the manner of inserting an arbitrary cartridge into an arbitrary cell using the robot; 
         FIG. 10C  is a diagram illustrating a further example of the manner of inserting an arbitrary cartridge into an arbitrary cell using the robot; 
         FIG. 10D  is a diagram illustrating a still further example of the manner of inserting an arbitrary cartridge into an arbitrary cell using the robot; 
         FIG. 10E  is a diagram illustrating one example of a manner of taking an arbitrary cartridge out of an arbitrary cell by a user; 
         FIG. 11  is a diagram illustrating an example of a flowchart of a conflict avoiding process to be executed in taking cartridges out of an arbitrary cell; 
         FIG. 12  is a diagram illustrating an example of a flowchart of a management information changing process; 
         FIG. 13  is a diagram illustrating an example of a flowchart of a conflict avoiding process to be executed in inserting cartridges into an arbitrary cell; 
         FIG. 14A  is a diagram illustrating one example of a cell according to a third embodiment; 
         FIG. 14B  is a diagram illustrating another example of the cell according to the third embodiment; 
         FIG. 14C  is a diagram illustrating a further example of the cell according to the third embodiment; 
         FIG. 14D  is a diagram illustrating a still further example of the cell according to the third embodiment; 
         FIG. 14E  is a diagram illustrating a still further example of the cell according to the third embodiment; 
         FIG. 14F  is a diagram illustrating a still further example of the cell according to the third embodiment; 
         FIG. 15  is a diagram illustrating an example of a manner of controlling doors; 
         FIG. 16  is a diagram illustrating an example of a library system according to a fourth embodiment; 
         FIG. 17  is a diagram illustrating an example of a display image on a touch panel; 
         FIG. 18  is a diagram illustrating an example of a pop-up menu; 
         FIG. 19A  is a diagram illustrating an example of a library system according to one altered embodiment; 
         FIG. 19B  is a diagram illustrating an example of a library system according to another altered embodiment; and 
         FIG. 20  is a diagram illustrating an example of a configuration of a Z-axis motor illustrated in  FIG. 5 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Next, a plurality of embodiments will be described with reference to the accompanying drawings. 
     First, a control device according to an embodiment will be described and then the embodiment will be more specifically described. 
     &lt;First Embodiment&gt; 
       FIG. 1  is a diagram illustrating an example of a general configuration of a control device according to a first embodiment. 
     A control device (a computer)  1  according to the first embodiment controls the operation of a mount mechanism  2 . 
     The mount mechanism  2  takes an arbitrary storage medium  3  out of a containing unit  4  that includes a plurality of cells  4   a  in which the respective storage media  3  are contained and mounts the storage medium  3  so taken-out onto a drive device  5 . 
     In the example illustrated in  FIG. 1 , the control device  1 , the mount mechanism  2 , the containing unit  4  and the drive device  5  are housed in one case  6 . 
     As an example of the storage medium  3 , for example, a magnetic tape or the like may be given. 
     Each cell  4   a  has openings on the inner and outer sides of the case  6  and has different access surfaces. A user is allowed to take out an arbitrary storage medium  3  contained in an arbitrary cell  4   a  and to put an arbitrary storage medium  3  into an arbitrary cell  4   a  through the outer side opening. Likewise, the mount mechanism  2  is allowed to take out an arbitrary storage medium  3  contained in an arbitrary cell  4   a  and to put an arbitrary storage medium  3  into an arbitrary cell  4   a  through the inner side opening under the control of the control device  1 . 
     The control device  1  includes an execution unit  1   a  and a judgment unit  1   b.    
     The execution unit  1   a  makes the mount mechanism  2  execute a process of taking an arbitrary storage medium  3  out of an arbitrary cell  4   a  and a process of putting an arbitrary storage medium  3  into an arbitrary cell  4   a  in execution of a mounting process of mounting an arbitrary storage medium  3  onto the drive device  5 . 
     The judgment unit  1   b  judges whether conflict has occurred in access to storage media  3  contained in cells  4   a  while the mounting process is being executed. 
     As a first example of the conflict in access to storage media  3  contained in cells  4   a , for example, conflict which would occur in the case that when the mount mechanism  2  tries to take an arbitrary storage medium  3  out of an arbitrary cell  4   a , a user also tries to take that storage medium  3  out of that cell  4   a  simultaneously may be given. As a second example of the conflict in access to storage media  3  contained in cells  4   a , for example, conflict which would occur in the case that when the mount mechanism  2  tries to put one storage medium  3  into an arbitrary cell  4   a , the user also tries to put another storage medium  3  into that cell  4   a  simultaneously may be given. 
     In the case that the execution unit  1   a  has judged that the conflict in access to storage media  3  has occurred, the execution unit  1   a  keeps the mount mechanism  2  from executing the mounting process for a predetermined time period. For example, in the case that the conflict which has been described as the first example of the conflict has occurred in taking out an arbitrary storage medium  3 , the execution unit  1   a  keeps the mount mechanism  2  from executing the process of taking out an arbitrary storage medium  3 . In the case that the conflict which has been described as the second example of the conflict has occurred in putting an arbitrary storage medium  3  into an arbitrary cell  4   a , the execution unit  1   a  keeps the mount mechanism  2  from executing the process of putting an arbitrary storage medium  3  into that cell  4   a . By keeping the mount mechanism  2  from executing the process in the above mentioned manner, the execution unit  1   a  gives priority to the user in execution of the process. 
     Then, after the mount mechanism  2  has been kept from executing the process for the predetermined time period, the judgment unit  1   b  again judges whether the conflict in access to storage media  3  is occurring. In the case that the conflict in access to storage media  3  is occurring, the judgment unit  1   b  informs, for example, a host (a high-order) device that manages the control device  1  of occurrence of an error. 
     On the other hand, in the case that the conflict in access to storage media  3  does not occur, the mount mechanism  2  executes a desired operation in accordance with an instruction from the execution unit  1   a.    
     Owing to the above mentioned operations, the conflict which would occur between the user and the mount mechanism  2  may be avoided and hence the operability of the user may be increased. 
     Incidentally, the execution unit  1   a  and the control unit  1   b  may be implemented by functions that a CPU (Central Processing Unit) included in the control device  1  has. 
     Next, the control device according to the embodiment will be more specifically described by giving a library system including a library management device as an example. 
     &lt;Second Embodiment&gt; 
       FIG. 2  is a diagram illustrating an example of a library system according to a second embodiment.  FIG. 3  is a side view of the library system according to the second embodiment taken along the III-III line in  FIG. 2 . 
     A library system  100  includes a library management device (a control device)  10 , a rack  20 , a robot (a mount mechanism)  30  and a drive device  40 . 
     The library management device  10  is connected with a host device (not illustrated in the drawing) over a network. 
     The library management device  10  that receives a request to take out an arbitrary cartridge  50  that contains a storage medium from the host device controls the robot  30  to move to the drive device  40 . 
     The rack  20  includes a plurality of cells  21  which are arranged in a matrix so as to contain the cartridges  50  therein. 
     Each cell  21  is configured to be opened toward the front side (the front surface side of the rack  20 ) in the drawing from which the user may be accessible to it and toward the rear side (the rear surface side of the rack  20 ) in the drawing from which the robot  30  may be accessible to it. One cartridge  50  is contained in one cell  21 . That is to say, each cell  21  has openings on the front side and the rear side of the rack  20 . 
     In the example illustrated in  FIG. 2 , the robot  30  (not illustrated in the drawing) is disposed on the rear surface side of the rack  20 . 
     Incidentally, although in the example illustrated in  FIG. 2 , one rack  20  is illustrated, the library system  100  may be configured to include the plurality of racks  20 . 
     The user is allowed to insert an arbitrary cartridge  50  directly into an arbitrary cell  21  and to take out an arbitrary cartridge  50  contained in an arbitrary cell  21 . 
     Likewise, the robot  30  is allowed to insert an arbitrary cartridge  50  into an arbitrary cell  21  and to take out an arbitrary cartridge  50  contained in an arbitrary cell  21 . 
     As described above, the library system  100  according to the second embodiment is configured to allow the user to gain access directly to an arbitrary cell  21  in place of provision of a Cartridge Access Station (CAS) that puts an arbitrary cartridge  50  into an arbitrary cell  21  and ejects an arbitrary cartridge  50  from an arbitrary cell  21 . 
     Each cartridge  50  includes a storage medium. For example, still image data, moving image data, private information such as a housekeeping book, health maintenance data and the like, and other various kinds of information are stored in the storage medium. 
     In addition, a bar code used to identify the kind of each cartridge  50  using a computer is affixed to each cartridge  50 . Each cartridge  50  includes a CM (Cartridge Memory) in which information indicating a position at which each piece of data recorded in each cartridge  50  is recorded, the use history of each cartridge  50 , an error log and other user areas are recorded. Provision of the CM may make it possible to check up information such as the index, the use status and the like of each cartridge  50  in a short time period with no physical contact with an arbitrary cartridge  50  using an RF interface after an arbitrary cartridge  50  has been loaded onto the drive device  40 . 
     In addition, a ravel indicating information that the user uses in order to identify the kind or the like of each cartridge  50  is affixed to each cartridge  50 . 
     Further, each cartridge  50  includes an engaging part that the robot  30  uses in order to take out each cartridge  50 . 
       FIG. 3  illustrates an example of one column of cells  21  contained in the rack  20 . Each shaded block indicates each cartridge  50 . 
     As illustrated in the example in  FIG. 3 , the robot  30  includes a support  31  that moves on a rail (not illustrated in the drawing) which is disposed in a column direction (an X-axis direction) of the rack  20  and extends in a row direction (a Y-axis direction) of the rack  20 , and a hand  33  which is attached to the support  31  to be movable in the Y-axis direction. 
     The robot  30  operates such that the hand  33  nips an arbitrary cartridge  50  on the basis of an instruction given from the library management device  10  to put the cartridge  50  out of an arbitrary cell  21  and/or to put the cartridge  50  into an arbitrary cell  21 . 
     Specifically, the robot  30  operates to move the support  31  to a row where the cell  21  that contains a cartridge  50  to be taken out is present in accordance with the instruction from the library management device  10 . 
     Then, the robot  30  operates such that the hand  33  moves upward and downward along the support  31  so as to reach the cell  21  so instructed and takes an arbitrary cartridge  50  into/out of one cell  21  using a picker (which will be described later) which is disposed on the leading end of the hand  33 . 
     The robot  30  operates to put an arbitrary cartridge  50  into the rack  20  such that the ravel (hereinafter, referred to as a “ravel surface”) affixed to the cartridge  50  is situated on its front surface side and the bar code affixed to the cartridge  50  is situated on the side of the robot  30  (the rear surface side of the cartridge  50 ). By putting each cartridge  50  into the rack  20  in the above mentioned manner, the user is allowed to readily grasp the contents of each cartridge  50  simply by looking at the ravel on it when the user tries to manually take out the cartridge  50 . 
     The drive device  40  records data in the storage medium included in an arbitrary cartridge  50  which has been carried using the robot  30  or reproduces the data stored in the storage medium. 
     In the library system  100  so configured as mentioned above, when an arbitrary cartridge  50  including the storage medium into which data is to be recorded or from which data is to be reproduced is designated by the host device, the library management device  10  specifies one cartridge  50  from within the cartridges  50  contained in the respective cells  21 . Then, the specified cartridge  50  is nip-held using the hand  33  of the robot  30 , is carried to the drive device  40  and is mounted onto the drive device  40 . 
     After data has been recorded into the storage medium in the specified cartridge  50  or reproduced from the storage medium using the drive device  40 , the cartridge  50  which is mounted onto the drive device  40  is nip-held using the hand  33  of the robot  30 , is taken out of the drive device  40  and is inserted into a designated place in an arbitrary cell  21 . 
     Next, a configuration of the library management device will be described. 
       FIG. 4  is a diagram illustrating an example of a hardware configuration of the library management device. 
     The library management  10  is generally controlled using a CPU (Central Processing Unit)  101 . A RAM (Random Access Memory)  102  and a plurality of pieces of peripheral equipment are connected with the CPU  101  via a bus  108 . 
     The RAM  102  is used as a main memory of the library management device  10 . At least part of OS (Operating System) programs and application programs that the CPU  101  executes is temporarily stored in the RAM  102 . In addition, various kinds of data desirable for execution of processes using the CPU  101  are stored in the RAM  102 . 
     As the plurality of pieces of peripheral equipment which are connected with the bus  108 , for example, an HDD (Hard Disk Drive)  103 , a graphic processor  104 , an input interface  105 , an optical driver  106 , and a communication interface  107  are included. 
     The HDD  103  magnetically writes data into a built-in disk and reads data out of the disk. The HDD  103  is used as a secondary memory of the library management device  10 . OS programs, application programs and various kinds of data are stored in the HDD  103 . Incidentally, a semiconductor memory such as a flash memory or the like may be used as the secondary memory. 
     A monitor  104   a  is connected with the graphic processor  104 . The graphic processor  104  makes the monitor  104   a  display an image on its screen in accordance with an instruction from the CPU  101 . As examples of the monitor  104   a , a display using a CRT (Cathode Ray Tube), a liquid crystal display and the like may be given. 
     A keyboard  105   a  and a mouse  105   b  are connected with the input interface  105 . The input interface  105  sends signals which are sent from the keyboard  105   a  and the mouse  105   b  to the CPU  101 . The mouse  105   b  is given as an example of a pointing device and other pointing devices may be used in place of the mouse  105   b . As examples of other pointing devices, a touch panel, a tablet, a touch pad, a track ball and the like may be given. 
     The optical driver  106  reads data which is recorded in an optical disc  200  utilizing laser light or the like. The optical disc  200  is a portable recording medium in which data is recorded to be readable by reflection of light. As examples of the optical disc  200 , a DVD (Digital Versatile Disc), a DVD-RAM, a CD-ROM (Compact Disc Read Only Memory), a CD-R (Recordable)/RW (Re Writable) and the like may be given. 
     The communication interface  107  is connected with a network  60 . The communication interface  107  sends data to another computer or another piece of communication equipment and receives data from the above mentioned computer or communication equipment over a network  60 . 
     Owing to provision of a hardware configuration as described above, processing functions of the second embodiment may be implemented. Functions which will be described hereinbelow are included in the library management device  10  having a hardware configuration as described above. 
       FIG. 5  is a block diagram illustrating an example of functions of the library management device. 
     The library management device  10  includes a main control unit  110 , a robot control unit  120 , a storage unit  130 , and a host interface (I/F)  140 . 
     The main control unit  110  generally controls the operation of the library management device  10 . The main control unit  110  controls, for example, so as to display information received from the robot control unit  120  on the monitor  104   a  and to instruct the robot control unit  120  to perform an operation on the basis of information received from the keyboard  105   a  or the mouse  105   b.    
     The robot control unit  120  controls the operations of an X-axis motor  32   a  that drives the robot  30  when the robot  30  is moved in the X-axis direction, a Y-axis motor  32   b  that drives the robot  30  when the robot  30  is moved in the Y-axis direction, and a Z-axis motor  32   c  that drives the robot  30  when the robot  30  is moved in a Z-axis direction. The Z-axis direction is a direction through both the openings of the cell. 
     Specifically, the robot control unit  120  receives an instruction to take out one cartridge  50  which is given from the main control unit  110  and controls movement of the robot  30  to one cell  21  concerned in response to the instruction. 
     In addition, the robot control unit  120  is connected with the hand control unit  121 . The robot control unit  120  sends various instructions to the hand control unit  121 . In addition, the robot control unit  120  receives various pieces of information from the hand control unit  121  and sends the received information to the main control unit  110 . 
     The Z-axis motor  32   c  may be, for example, a servo motor. The Z-axis motor  32   c  includes a motor main body  41  and an encoder  42  that detects the number of rotations of the motor main body  41 . The encoder  42  outputs an encoder signal to the main control unit  110  on the basis of the detected number of rotations the motor main body  41 . The encoder signal includes, for example, pulse signals of the number corresponding to the number of rotations of the motor main body  41 . The main control unit  110  calculates a distance over which the hand  33  has been moved in the Z-axis direction on the basis of the encoder signal sent from the encoder  42 . In the case that the distance over which the hand  33  has been moved in the Z-axis direction is shorter than a distance which is determined in advance, it is judged that the operation of one cartridge  50  by a user conflicts with the operation of another cartridge  50  using the robot  30 . Specifically, when a number of pulses in the encoder signal does not increase even though a current value of the motor main body  41  increases, it may be judged that the operation of one cartridge  50 . 
     That is, in the above mentioned situation, in the case that while the user is manually inserting one cartridge  50  into an arbitrary cell  21 , the hand  33  also tries to insert another cartridge  50  into that cell  21 , an inserting operation performed using the hand  33  is hindered by an inserting operation performed by the user and hence it may become difficult for the hand  33  to insert the cartridge  50  into that cell  21  over a distance which is determined in advance. Likewise, in the case that while the user is manually drawing one cartridge  50  out of an arbitrary cell  21 , the hand  33  also tries to draw that cartridge  50  out of that cell  21 , a drawing-out operation performed using the hand  33  is hindered by a drawing-out operation performed by the user and it may become difficult for the hand  33  to draw the cartridge  50  out of that cell  21  over a distance which is determined in advance. 
     Thus, conflict which would occur in the operations of cartridges  50  between the user and the hand  33  may be readily detected by comparing a distance over which the hand  33  has been moved with the distance which is determined in advance. Incidentally, a distance over which the hand  33  is moved in the Z-axis direction and which is desirable when the hand  33  takes an arbitrary cartridge  50  out of an arbitrary cell  21  and a distance over which the hand  33  is moved in the Z-axis direction and which is desirable when the hand  33  inserts an arbitrary cartridge  50  into an arbitrary cell  21  are stored in advance in the storage unit  130 . Thus, the main control unit  110  judges whether conflict occurs with reference to data stored in the storage unit  130 . 
     In this embodiment, conflict is detected by comparing the distance over which the hand  33  has been moved with the distance which is determined in advance. However, conflict may be detected by comparing the number of rotations the motor main body  41  with the number which is determined in advance. In this case, the number which is determined in advance is stored in the storage unit  130  in advance. Thus, the main control unit  110  also judges whether conflict occurs with reverence to data stored in the storage unit  130 . 
     The hand control unit  121  is connected with the hand  33 . 
     The hand  33  includes a P (picker) motor  33   a , a bar code reader  33   b , and a CM (cartridge memory) reader  33   c.    
     The hand control unit  121  drives the P motor  33   a  in accordance with a drive instruction given from the robot control unit  120 . Owing to the above mentioned operation, the hand  33  is allowed to nip an arbitrary cartridge  50  or to release the nipped cartridge  50 . 
     In addition, the hand control unit  121  operates the bar code reader  33   b  and the CM reader  33   c  in accordance with a read instruction given from the robot control unit  120 . Then, the hand control unit  121  sends bar code information that the bar code reader  33   b  has read and CM information that the CM reader  33   c  has read to the robot control unit  120 . 
     For example, in the case that the robot  30  has received an instruction to read the bar code affixed to an arbitrary cartridge  50  from the hand control unit  121 , the bar code is read using the bar code reader  33   b . The robot  30  sends the read bar code information to the hand control unit  121 . As a result, the library management device  10  is allowed to identify that cartridge  50  on the basis of the information which has been read using the bar code reader  33   b.    
     Information indicating, for example, the kind of each cartridge  50  in correspondence with the position where each cartridge  50  is contained is stored in the storage unit  130 . The information is collected, for example, by a method of controlling the robot  30  using the main control unit  110  to scan all the cells  21  in the rack  20  thereby to make the CM reader  33   c  read the CM information of each cartridge  50  or the like. 
     The host interface  140  is connected with a host device  300  over a network. 
     Incidentally, the main control unit  110 , the robot control unit  120 , the hand control unit  121 , and the host interface  140  may be implemented using functions that the CPU  101  includes. In addition, the storage unit  130  may be implemented using one area in the RAM  102 . 
     Next, the structure of each cell  21  will be described. 
       FIG. 6A  to  FIG. 6C  are diagrams illustrating examples of the structure of each cell  21 . 
       FIG. 6A  is a diagram (a front view) of each cell  21  viewed from its front surface side toward its rear surface side. 
     A door  211  is attached to the cell  21 . 
     Intrusion of dust and dirt into the library system  100  may be reduced by attaching the door  211  to each cell  21 . Thus, failures of the robot  30  may be reduced. 
     In addition, through-holes  211   a  through which the picker of the hand  33  passes are formed at two positions in the door  211 . In the case that the hand  33  tries to take out an arbitrary cartridge  50  contained in an arbitrary cell  21 , the picker of the hand  33  passes through the through-holes  211   a . Incidentally, a method of taking out an arbitrary cartridge  50  will be described later. 
     In a state in which any cartridge  50  is not inserted into an arbitrary cell  21 , the user is allowed to visually confirm the front surface of the door  211  of the cell  21 . 
       FIG. 6B  is a diagram of each cell  21  viewed from its side surface. 
     The door  211  rotates about a fulcrum A. The rotation of the door  211  may be controlled using the main control unit  110 . In addition, a stopper (a lock mechanism)  212  for restricting the rotation of the door  211  toward the rear surface side of the cell  21  is disposed on the rear surface side of the door  211 . 
     The stopper  212  may be situated at a position (an engagement position) where the stopper  212  engages with the door  211  and at a position (a release position) where the stopper  212  does not engage with the door  211  under the control of the main control unit  110 . 
     In the case that the stopper  212  is situated at the engagement position, when the user inserts an arbitrary cartridge  50  into an arbitrary cell  21  from its front surface side, the cartridge  50  may be prevented from falling down to the rear surface side of the cell  21 . 
     In the case that the stopper  212  is situated at the release position as illustrated in the example in  FIG. 6C , the rotation of the door  211  toward the rear surface side of the cell  21  is allowed. 
     Owing to provision of the door  211  and the stopper  212 , contact of the user with the robot  30  may be reduced to prevent the user from being injured. 
     Next, reading of data stored in a CM (cartridge memory)  50   a  will be described. 
       FIG. 7A  and  FIG. 7B  are diagrams illustrating examples of reading of data stored in the CM  50   a.    
     The CM  50   a  is in the form of a plate and is disposed on an end surface (a ravel surface)  50   b  of each cartridge  50  to which the ravel is affixed at an inclination angle of 45° viewed from its side surface. As a result, data reading from both of the side of the end surface  50   b  and the lower surface side of the cartridge  50  is allowed. 
     For example, as an example in which the data stored in the CM  50   a  is read from the side of the end surface  50   b , a case in which the data is read using the CM reader  33   c  attached to the robot  30  as illustrated in the example in  FIG. 7A  may be given. 
     In addition, as an example in which the data stored in the CM  50   a  is read from the lower surface side of each cartridge  50 , a case in which the data is read using the CM reader  53  which is provided on each cell  21  corresponding to a position at which the CM  50   a  is situated when an arbitrary cartridge  50  has been put into an arbitrary cell  21  may be given. 
     Incidentally, as illustrated in the examples in  FIG. 7A  and  FIG. 7B , recessed parts  51  with which the picker of the hand  33  engages are formed in the both side parts of each cartridge  50 . 
     Next, insertion of an arbitrary cartridge  50  into an arbitrary cell  21  will be described. 
       FIG. 8A  to  FIG. 8C  are diagrams illustrating examples of a manner of inserting an arbitrary cartridge  50  into an arbitrary cell  21 . 
     First, operations of respective parts performed when an arbitrary cartridge  50  is inserted into an arbitrary cell  21  from the front surface side of the cell  21  will be described. 
     As the user inserts an arbitrary cartridge  50  into an arbitrary cell  21  from the front surface side (see the examples in  FIG. 8A  and  FIG. 8B ), the end surface  50   b  of the cartridge  50  comes into abutment against the door  211  at a position where the entire of the cartridge  50  has been inserted into the cell  21 . When the cartridge  50  is pushed into the cell  21  toward its rear surface side in the above mentioned state, the stopper  212  comes into abutment against the door  211 . As a result, further movement of the cartridge  50  toward the rear surface side of the cell  21  is restricted (see the example in  FIG. 8C ). 
     Next, a manner of taking out an arbitrary cartridge  50  from the rear surface side of an arbitrary cell  21  using the robot  30  will be described with reference to  FIG. 8D  to  FIG. 8F . 
     The main control unit  110  refers to the information stored in the storage unit  130  and specifies one cell  21  in which a cartridge  50  to be taken out using the robot  30  is disposed on the basis of the information indicating the kinds of the respective cartridges  50  in correspondence with the positions where the respective cartridges  50  are contained. 
     Then, the main control unit  110  controls to move the stopper  212  of the specified cell  21  to the release position (see the example in  FIG. 8D ). Then, the robot  30  opens the door  211 , draws the cartridge  50  out of the cell  21  and takes the cartridge  50  out of the cell  21  (see the example in  FIG. 8E ) under the control of the main control unit  110 . Incidentally, a method of drawing out an arbitrary cartridge will be described later. 
     Then, after the cartridge  50  has been entirely drawn out of the cell  21 , the door  211  goes back to its original position. The main control unit  110  confirms that the cartridge has been drawn out of the cell  21  using the robot  30  with reference to position sensor information that the robot  30  retains and then returns the stopper  212  to the engagement position (see the example in  FIG. 8F ). 
     Next, a direction in which the robot  30  draws an arbitrary cartridge  50  out of an arbitrary cell  21  will be described. 
       FIG. 9A  to  FIG. 9D  are diagrams illustrating examples of the method of drawing an arbitrary cartridge  50  out of an arbitrary cell  21  using the robot  30 . 
     As illustrated in the example in  FIG. 9A , protruded pickers  33   d  that engage with the recessed parts  51  in each cartridge  50  are disposed on the both end parts of the hand  33 . 
     The hand  33  is configured to change its width (the length in a transversal direction in  FIG. 9 ). 
       FIG. 9A  illustrates a state in which the hand  33  is widened to have a width W 1 . 
     In the case that the robot  30  draws an arbitrary cartridge  50  out of an arbitrary cell  21 , first, the robot  30  makes the hand  33  draw near the cartridge  50  and inserts the hand  33  into the cell  21  through the through-holes  211   a.    
     Then, as illustrated in the example in  FIG. 9B , the robot  30  makes the pickers  33   d  position in the recessed parts  51  in the cartridge  50 . 
     Then, as illustrated in the example in  FIG. 9C , the pickers  33   d  are inserted into the recessed parts  51  while changing the width W of the hand  33  so as to nip-hold the cartridge  50  using the hand  33 .  FIG. 9C  illustrates a state in which the hand is narrowed to have a width W 2  which is narrower than the width W 1 . 
     Then, as illustrated in the example in  FIG. 9D , the hand  33  is moved in a direction going away from the cell  21  in a state in which the hand  33  keeps nip-holding the cartridge  50 . As a result, the door  211  is pushed by the cartridge  50  and is opened toward the rear surface side of the cell  21  and the cartridge  50  is drawn out of the cell  21 . 
     In addition, as another method of drawing an arbitrary cartridge  50  out of an arbitrary cell  21  using the robot  30 , a method in which a second hand mechanism for opening the door  211  is provided in addition to the hand  33  and an arbitrary cartridge  50  is drawn out of an arbitrary cell  21  using the hand  33  simultaneously with opening of the door  211  using the second hand mechanism may be given by way of example. 
     Next, a manner of inserting an arbitrary cartridge  50  into an arbitrary cell  21  using the robot  30  will be described. 
       FIG. 10A  to  FIG. 10D  are diagrams illustrating examples of a manner of inserting an arbitrary cartridge  50  into an arbitrary cell  21  using the robot  30 . 
     The main control unit  110  specifies an arbitrary cell  21  into which an arbitrary cartridge  50  is to be inserted using the robot  30 . 
     Then, the main control unit  110  controls to move the stopper  212  of the specified cell  21  from the engagement position to the release position (see the examples in  FIG. 10A  and  FIG. 10B ). Then, the main control unit  110  controls to move the hand  33  which is in a state in which it nip-holds the cartridge  50  to the specified cell  21  and to make the hand  33  insert the cartridge  50  into the cell  21 . When the cartridge  50  comes into abutment against the door  211 , the door  211  rotates toward the front surface side of the cell  21 . As a result, the cartridge  50  is allowed to move toward the front surface side of the cell  21  (see the example in  FIG. 10C ). 
     Then, the end surface  50   c  of the cartridge  50  is inserted to the depth of the leading end of the cell  21  and when the hand  33  is drawn out of the cell  21 , the door  211  goes back to its original position. The main control unit  110  confirms that the hand  33  has been drawn out of the cell  21  and returns the stopper  212  to the engagement position (see the example in  FIG. 10D ). 
     In the case that the user intends to take out an arbitrary cartridge  50  which is disposed in an arbitrary cell  21 , the user is allowed to take out the cartridge  50  as it is (see an example in  FIG. 10E ). 
     Incidentally, such a situation (conflict in access to the cartridges  50 ) may sometimes occur that the user and the robot  30  try to take out the cartridges  50  which are disposed in one cell  21  simultaneously. 
     In the above mentioned case, conflict is avoided by performing processes as follows. 
       FIG. 11  is a diagram illustrating an example of a flowchart of a conflict avoiding process executed in taking out the cartridges  50 . 
     [Step S 1 ] 
     The robot control unit  120  controls the robot  30  such that its hand  33  is situated at the position of an instructed cell  21  (which has been instructed to draw a cartridge  50  out of it) in accordance with an instruction from the main control unit  110 . Then, the process proceeds to step S 2 . 
     [Step S 2 ] 
     The robot control unit  120  sends an instruction to the hand control unit  121  to try to draw the cartridge  50  out of the instructed cell  21  using the hand  33 . Then, the process proceeds to step S 3 . 
     [Step S 3 ] 
     The robot control unit  120  judges whether the robot  30  has succeeded in drawing out the cartridge  50 . Judgment is made, for example, by detecting the value of a torque sensor of the hand  33 . In the case that the robot control unit  120  judges that drawing-out of the cartridge  50  has been successfully performed (Yes at step S 3 ), the robot control unit  120  decides that conflict does not occur and terminates execution of the process illustrated in  FIG. 11 . On the other hand, in the case that the robot control unit  120  judges that the robot  30  has failed at drawing out the cartridge  50  (No at step S 3 ), the process proceeds to step S 4 . 
     Incidentally, although in the second embodiment, it is judged that the cause for a failure in drawing out the cartridge  50  lies in occurrence of conflict and execution of the process has been terminated, judgment is not limited to the above. That is, another criterion may be prepared and whether the cause for a failure in drawing out the cartridge  50  lies in occurrence of conflict or another factor may be judged on the basis of the criterion. 
     [Step S 4 ] 
     The robot control unit  120  controls the hand  33  to stop in the front of the instructed cell  21  and keeps the hand  33  waiting for a fixed time period. Owing to the above mentioned operation, it may become possible to avoid conflict by giving priority to the user in drawing out an arbitrary cartridge  50 . After the fixed time period has elapsed, the process proceeds to step S 5 . 
     [Step S 5 ] 
     The robot control unit  120  judges whether a cartridge  50  is present in the instructed cell  21 . Judgment may be made, for example, on the basis of a result of detection performed using the CM reader  33   c . In the case that any cartridge  50  is not present in the instructed cell  21  (No at step S 5 ), the robot control unit  120  judges that the cartridge  50  has been drawn out of the cell  21  by the user when it has kept the hand  33  from drawing out the cartridge  50  at step S 4  and terminates execution of the process of avoiding conflict to be executed in taking out the cartridges  50 . On the other hand, in the case that it is judged that a cartridge  50  is present in the instructed cell  21  (Yes at step S 5 ), the process proceeds to step S 6 . 
     [Step S 6 ] 
     The hand  33  tries to draw the cartridge  50  out of the instructed cell  21  in accordance with an instruction given from the robot control unit  120  to the hand control unit  121 . Then, the process proceeds to step S 7 . 
     [Step S 7 ] 
     The robot control unit  120  judges whether the cartridge  50  has been successfully drawn out of the instructed cell  21 . In the case that it is judged that drawing-out of the cartridge  50  has been successfully performed (Yes at step S 7 ), the robot control unit  120  decides that conflict does not occur and terminates execution of the conflict avoiding process to be executed in taking out the cartridges  50 . On the other hand, in the case that the robot control unit  120  judges that the robot  30  has failed at drawing out the cartridge  50  (No at step S 7 ), the process proceeds to step S 8 . 
     [Step S 8 ] 
     The robot control unit  120  decides that abnormality has occurred in the instructed cell  21  and sends the main control unit  110  a notification that abnormality has occurred. Then, execution of the conflict avoiding process to be executed in taking out the cartridges  50  is terminated. The main control unit which has received the notification makes the monitor  104   a  display a screen indicating that abnormality has occurred. 
     Explanation of the conflict avoiding process to be executed in taking out the cartridges  50  has been concluded as mentioned above. 
     Incidentally, in the second embodiment, in the case that execution of drawing-out of the cartridge  50  from the instructed cell  21  has been tried two times and has ended in failure two times, it is judged that abnormality has occurred. However, the number of times is not limited to two and execution of drawing-out of the cartridge  50  may be tried three or more times. 
     Next, a management information changing process will be described. 
     The management information changing process is executed using the library management device  10  every time one cartridge  50  is taken out of the drive device  40 . 
       FIG. 12  is a diagram illustrating an example of a flowchart of a management information changing process. 
     [Step S 11 ] 
     The main control unit  110  controls the robot to draw one cartridge  50  out of the drive device  40 . Then, the process proceeds to step S 12 . 
     [Step S 12 ] 
     The main control unit  110  judges whether another cartridge  50  is present in an arbitrary cell  21  in which the cartridge  50  which has been drawn out of the drive device  40  has been ever contained before it is carried to the drive device  40 . In the case that another cartridge  50  is not present in the cell  21  (No at step S 12 ), the main control unit  110  terminates execution of the management information changing process. On the other hand, in the case it is judged that another cartridge  50  is present in the cell  21  (Yes at step S 12 ), the process proceeds to step S 13 . 
     [Step S 13 ] 
     The main control unit  110  judges whether a cell  21  containing no cartridge is present in the rack. In the case that it is judged that the cell  21  containing no cartridge is present in the rack (Yes at step S 13 ), the process proceeds to step S 14 . On the other hand, in the case that the cell  21  containing no cartridge is not present in the rack (No at step S 13 ), execution of the process illustrated in  FIG. 12  is terminated. 
     [Step S 14 ] 
     The main control unit  110  instructs the robot control unit  120  to insert the cartridge  50  which has been drawn out of the drive device  40  into the cell  21  containing no cartridge. Then, the process proceeds to step S 15 . 
     [Step S 15 ] 
     The main control unit  110  updates management information. Specifically, the main control unit  110  reads the bar code of the cartridge  50  which has been drawn out of the drive device  40  and rewrites the information which is stored in the storage unit  130  in a state in which the kinds of the cartridges  50  are indicated in correspondence with the positions where the cartridges  50  are contained on the basis of the information in the bar code so read. Then, the main control unit  110  makes the monitor  104   a  display a screen indicating that the position where the cartridge  50  is contained has been changed. By displaying the above mentioned screen, the main control unit  110  informs the user of change of the position where the cartridge  50  is contained. Then, the main control unit  110  terminates execution of the management information changing process. 
     The management information changing process has been described as mentioned above. 
     Next, a conflict avoiding process to be executed in inserting the cartridges  50  into an arbitrary cell will be described. 
     This process is executed using the library management device  10  in the case that both the user and the robot try to insert cartridges  50  into one cell  21 . 
       FIG. 13  is a diagram illustrating an example of a flowchart of the conflict avoiding process to be executed in inserting the cartridges  50 . 
     [Step S 21 ] 
     The main control unit  110  which has received an instruction to draw a cartridge  50  out of the drive device  40  and to insert the drawn-out cartridge  50  into a predetermined cell  21  from the host device  300  instructs the robot  30  to draw the cartridge  50  out of the drive device  40 . 
     Then, the main control unit  110  controls to situate the robot  30  that holds the cartridge  50  which has been drawn out of the drive device  40  in the front of a cell  21  which has been instructed from the host device  300  so as to insert the cartridge  50  into it. Then, the process proceeds to step S 22 . 
     [Step S 22 ] 
     The main control unit  110  controls the robot  30  so as to try to insert the cartridge  50  into the cell  21  so instructed from the host device  300  so as to insert the cartridge  50  into it. Then, the process proceeds to step S 23 . 
     [Step S 23 ] 
     The main control unit  110  judges whether insertion of the cartridge  50  into the cell  21  so instructed from the host device  300  has been successfully performed. When cartridge insertion has been successfully performed (Yes at step S 23 ), execution of the conflict avoiding process to be executed in inserting the cartridges  50  is terminated. On the other hand, when cartridge insertion has not been successfully performed (No at step S 23 ), the process proceeds to step S 24 . 
     [Step S 24 ] 
     In the case that insertion of the cartridge  50  into the cell  21  has not been successfully performed, the robot control unit  120  keeps the robot  30  waiting for a fixed time period. Owing to the above mentioned operation, conflict which would occur in the case that the user tries again to insert an arbitrary cartridge  50  into that cell  21  while the robot control unit  120  is keeping the robot  30  waiting may be avoided. Then, the process proceeds to step S 25 . 
     [Step S 25 ] 
     The main control unit  110  judges whether a cartridge  50  is present in the instructed cell  21  (which has been instructed from the host device  300  so as to insert the cartridge  50  into it). In the case that the cartridge  50  is present in the instructed cell  21  (Yes at step S 25 ), the processes at step S 13  and succeeding steps of the management information changing process are executed. On the other hand, when any cartridge  50  is not present in the instructed cell  21  (No at step S 25 ), the process proceeds to step S 26 . 
     [Step S 26 ] 
     The robot control unit  120  controls the robot  30  so as to try to insert a cartridge  50  into the instructed cell  21 . Then, the process proceeds to step S 27 . 
     [Step S 27 ] 
     The robot control unit  120  judges whether insertion of the cartridge  50  into the instructed cell  21  has been successfully performed. When cartridge insertion has been successfully performed (Yes at step S 27 ), execution of the conflict avoiding process to be executed in inserting the cartridges  50  is terminated. On the other hand, when cartridge insertion has not been successfully performed (No at step S 27 ), the process proceeds to step S 28 . 
     [Step S 28 ] 
     In the case that insertion of the cartridge  50  into the cell  21  has not been successfully performed, the robot control unit  120  judges that abnormality has occurred in the instructed cell  21  and sends the main control unit  110  a notification that abnormality has occurred. Then, execution of the conflict avoiding process to be executed in inserting the cartridges  50  is terminated. The main control unit  110  that has received the notification controls the monitor  104   a  to display a screen indicative of occurrence of abnormality. 
     Explanation of the conflict avoiding process to be executed in inserting the cartridges  50  has been concluded. 
     As described above, the library management device  10  according to the second embodiment is configured to execute the conflict avoiding process to be executed in taking out the cartridges  50  and the conflict avoiding process to be executed in inserting the cartridges  50 . As a result, it may become possible to avoid conflict which may occur between the user and the robot  30  and hence the operability of the user who utilizes the library system  100  may be increased. 
     In addition, owing to provision of the rack  20  having different access surfaces, one for the user and the other for the robot  30 , the user is allowed to freely insert an arbitrary cartridge  50  into an arbitrary cell  21  while the robot  30  is working. 
     In addition, the access surface for the user is different from that for the robot  30 , so that contact between the user and the robot  30  may be avoided and hence the user is allowed to gain access to each cell  21  more safely. 
     Further, safety may be further increased by disposing the door  211  on each cell  21 . 
     In addition, the user is allowed to manually put an arbitrary cartridge  50  into an arbitrary cell  21 , so that the cartridges  50  may be readily put in order, for example, by classifying positions where the cartridges  50  are contained in accordance with applications of the respective cartridges  50 . For example, in the case that a series of data is separately stored in the plurality of cartridges  50 , data missing and data duplication may be visually grasped by putting the cartridges  50  that hold the series of data in the rack in a mass. 
     In addition, owing to provision of the rack  20 , use of the CAS may be eliminated and hence the operability of the user may be increased. 
     For example, in a library system including the CAS, in the case that data which is stored in a plurality of cartridges  50  and is of the size which is so large as not to be retained in the CAS at one time is to be backed-up or restored, it may be unavoidable to divide the cartridges  50  to be put into the CAS into groups, or to temporarily stop the operation of the library management device and then to open the door of the rack in which the cartridges  50  are contained to gain access to an arbitrary cell. However, in the library system  100  according to the second embodiment, it may become possible to put the plurality of cartridges  50  into the respective cells  21  without stopping the operation of the library management device  10 . 
     In addition, the user is allowed to gain access to each cartridge  50  from the side opposite to the side on which the robot  30  is disposed with the rack  20  interposed between them and hence each cartridge  50  may be readily put into each cell  21  and put out of each cell  21 . 
     In addition, in the case that the library system  100  is to be commonly used by a plurality of users, for example, the library system  100  may be used in the following manner. 
     The range of cells used may be determined on a user by user basis or on a section by section basis. 
     It may be also possible to determine the range of cells used on an application (kind of data) by application basis, or on a date (or year and month) by date basis. As examples of kinds of data, for example, document data, still image data, moving image data, voice data, housekeeping book data, health maintenance data and the like may be given. 
     &lt;Third Embodiment&gt; 
     Next, a library system according to a third embodiment will be described. 
     In the following, different points of the library system according to the third embodiment from those of the library system according to the second embodiment will be described and description of the same points as those in the second embodiment will be omitted. 
       FIG. 14A  to  FIG. 14F  are diagrams illustrating examples of a cell according to the third embodiment. 
     As illustrated in the example in  FIG. 14A , a cell  21   a  according to the third embodiment includes a door  213  disposed on its front surface side, and a stopper  214  for restricting rotation of the door  213  toward its rear surface side. 
     The door  213  rotates about a fulcrum (not illustrated in the drawing) as in the case of the door  211 . 
     The stopper  214  may be situated at a position (an engagement position) where it engages with the door  213  and a position (a release position) where it does not engage with the door  213 . 
     The transversal length of the cell  21   a  is made longer than that of each cartridge  50  such that the door  213  may be closed in a state in which each cartridge  50  is contained in each cell  21   a.    
     Next, insertion of an arbitrary cartridge  50  into an arbitrary cell  21   a  will be described. 
     First, operations of respective parts performed when an arbitrary cartridge  50  is inserted into an arbitrary cell  21   a  from the font surface side of the cell  21   a  will be described. 
     In inserting an arbitrary cartridge  50  into an arbitrary cell  21   a  from the front surface side of the cell  21   a , the stopper  214  is situated at the release position (see  FIG. 14A ). When a user inserts the cartridge  50  into the cell  21   a  from the front surface side of the cell  21   a  (see  FIG. 14B ), the door  213  is pushed into the cell  21  toward its rear surface side. 
     Then, when the entire of the cartridge  50  is positioned within the cell  21   a , an end surface  50   b  of the cartridge  50  comes into abutment against the door  211 . The stopper  212  is in abutment against the door  211 , so that further movement of the cartridge  50  toward the rear surface side of the cell  21   a  is restricted. In the above mentioned situation, the door  213  goes back to its original position by gravity (see  FIG. 14C ). 
     Next, taking-out of an arbitrary cartridge  50  using the robot  30  will be described. 
     The main control unit  110  specifies a cell  21   a  in which a cartridge  50  to be taken out using the robot  30  is disposed on the basis of information in which the kinds of respective cartridges  50  are indicated in correspondence with the positions where the respective cartridges  50  are contained. 
     Then, the main control unit  110  controls the stopper  212  of the specified cell  21   a  so as to move to the release position (see  FIG. 14D ). Simultaneously with controlling the stopper  212  to move to the release position or before controlling the stopper  212  to move to the release position, the main control unit  110  controls the stopper  214  so as to move to the engagement position. Owing to the above mentioned operations, conflict which would occur between the user and the robot  30  may be avoided. 
     Then, the robot  30  rotates the door  211  and draws the cartridge  50  out of the cell  21   a  (see  FIG. 14E ). 
     After the cartridge  50  has been drawn out of the cell  21   a , the door  211  goes back to its original position by gravity. The main control unit  110  confirms that the cartridge  50  has been drawn out of the cell  21   a  and then controls the stopper  212  so as to return to the position where it engages with the door  211  (see  FIG. 14F ). 
     Incidentally, in the example illustrated in  FIG. 14A  to  FIG. 14F , the main control unit  110  controls such that the user is permitted to open the door  211  to take out an arbitrary cartridge  50  until the robot  30  starts taking out of the cartridge  50 . However, a manner of controlling the operations of respective parts is not limited to the above and a controlling operation may be performed such that after the user has inserted an arbitrary cartridge  50  into an arbitrary cell  21   a  once, taking-out of that cartridge  50  by the user is forbidden (locked). 
     Next, an example of a method of controlling the doors  211  and  213  will be described in detail. 
       FIG. 15  is a diagram illustrating an example of a manner of controlling the doors  211  and  213 . 
     A door control table  215  illustrated in  FIG. 15  is stored in, for example, the HDD  103  and the main control unit  110  is allowed to read it to be used. 
     In the door control table  215 , as states of access to each cell  21   a , four access states, that is, “Before Insertion of Cartridge”, “After Insertion of Cartridge”, “Access to Cartridge from Robot”, and “After Bringing-back of Cartridge to Cell Using Robot” are indicated. 
     In addition, two control modes are set in the door control table  215 . The main control unit  110  is allowed to select one of the above mentioned two control modes. One mode is a mode (a first mode) in which the user is allowed to freely take out a cartridge  50  that the user has put into an arbitrary cell  21   a  and the other mode is a mode (a second mode) in which the user is not allowed to freely take out a cartridge  50  that the user has put into an arbitrary cell  21   a.    
     Incidentally, in the example of the table illustrated in  FIG. 15 , “Front Door” indicates the door  211  and “Rear Door” indicates the door  213 . “Unlocked” in the column for the front door indicates that the stopper  212  is situated at the release position, and “Locked” in the column for the front door indicates that the stopper  212  is situated at the engagement position. Likewise, “Unlocked” in the column for the rear door indicates that the stopper  214  is situated at the release position, and “Locked” in the column for the rear door indicates that the stopper  214  is situated at the engagement position. 
     In the first mode, the door  213  is locked only when the robot  30  gains access to an arbitrary cartridge  50 . Owing to the above mentioned operation, conflict which would occur in taking out a cartridge  50  may be avoided. 
     On the other hand, in the second mode, the door  213  is locked when an arbitrary cartridge  50  is inserted into an arbitrary cell  21   a . Owing to the above mentioned operation, security of the cartridges  50  may be increased. 
     According to the library system of the third embodiment, the same effects as those obtained by the library system of the second embodiment may be obtained. 
     Then, according to the library system of the third embodiment, after an arbitrary cartridge  50  has been inserted into an arbitrary cell  21   a , the stopper  214  of the cell into which the cartridge  50  has been inserted is moved to the engagement position to lock the door  213  by setting the mode to the second mode. Thus, the possibility that a third person opens the door without leave to take the cartridge  50  away may be avoided and hence the safety in management of the cartridges  50  may be increased. 
     In addition, conflict which would occur between the user and the robot  30  may be readily avoided. 
     &lt;Fourth Embodiment&gt; 
     Next, a library system according to a fourth embodiment will be described. 
     In the following, different points of the library system according to the fourth embodiment from those in the library system according to the third embodiment will be described and description of the same parts as those in the third embodiment will be omitted. 
       FIG. 16  is a diagram illustrating an example of a library system according to the fourth embodiment. 
     The library system according to the fourth embodiment includes a touch panel  71  and a cartridge ejection part  72 . 
       FIG. 17  is a diagram illustrating an example of a display image on the touch panel  71 . 
     On the touch panel  71 , an operable area  71   a  indicating a state in which the cartridges  50  are contained in the respective cells  21   a  and an area in which the user is allowed to take an arbitrary cartridge  50  into an arbitrary cell  21   a  and out of an arbitrary cell  21   a . In the example illustrated in  FIG. 17 , a shaded part indicates the area where any cartridge  50  is not contained. 
     Each grid displayed on the touch panel  71  corresponds to each cell  21   a.    
     The operable area  71   a  may be configured such that, for example, different areas are allocated to different users or different sections of a company. As an alternative, the operable area  71   a  may be configured such that an area to be used is determined in accordance with the application of each piece of data or the date (or year and month) of each piece of data. 
     The user is allowed to change the position where each cartridge  50  is disposed in the operable area  71   a  by operating the touch panel  71 . 
     Description will be further made returning to the example in  FIG. 16 . 
     The cartridge ejection part  72  is a part through which each cartridge  50  is ejected. The cartridge  50  to be ejected may be carried to the cartridge ejection part  72  and then may be taken out of the library system under the operation of the touch panel  71  by the user. 
     The library system according to the fourth embodiment is configured such that in the case that the user designates an arbitrary cartridge  50  by operating the touch panel  71  or inserts an arbitrary cartridge  50  into an arbitrary cell  21   a , a pop-up menu is displayed on the touch panel  71  in response to the above mentioned operation. 
       FIG. 18  is a diagram illustrating an example of a pop-up menu. 
     The content of an arbitrary cartridge  50  which has been designated under the operation of the touch panel  71  or the directory structure of data stored in an arbitrary cartridge  50  which has been inserted into an arbitrary cell  21   a  is displayed on a pop-up menu  73 . 
     In the case that the cartridge  50  so inserted is to be taken out of the cell  21   a , an instruction to eject the cartridge  50  is sent to the main control unit  110  by selecting “Eject Cartridge” on the pop-up menu  73 . 
     The main control unit  110  specifies the cartridge  50  that stores data on a selected file. Next, the cell  21   a  that contains the specified cartridge  50  is specified. Then, the hand  33  of the robot  30  is actuated under the instruction of the main control unit  110  to nip-hold the cartridge  50  which is contained in the specified cell  21   a . The robot  30  carries the nip-held cartridge  50  to the cartridge ejection part  72 . 
     According to the library system of the fourth embodiment, the same effects as those obtained by the library system according to the third embodiment may be obtained. 
     In addition, according to the library system of the fourth embodiment, in which cell  21   a  in the library system a cartridge  50  that a user wishes to obtain is contained may be more readily grasped. 
     Next, following altered embodiments will be described in addition to the above mentioned first to fourth embodiments. 
     &lt;Altered Embodiments&gt; 
       FIG. 19A  and  FIG. 19B  are diagrams illustrating examples of the library system according to altered embodiments. 
     A display unit that displays various kinds of information may be provided on the door  213  of each cell  21   a.    
       FIG. 19A  is a diagram illustrating an example of the library system according to one altered embodiment in which a display unit is provided on the door  213  of each cell  21   a.    
     An LED  74  is an example of the display unit and displays information indicating the presence/absence of the respective cartridges  50  in the respective cells  21   a  and information indicating that the cell  21   a  that the user intends to operate is which one. 
     Specifically, in the case that a cartridge  50  is contained in a cell  21   a , the LED  74  of the cell  21   a  is turned on. In the case that any cartridge  50  is not contained in a cell  21   a , the LED  74  of the cell  21   a  is turned off. In addition, when one cell  21   a  is selected under the operation of the touch panel  71 , the LED  74  of the selected cell (the cell that the user intends to operate)  21   a  is turned on and off. 
       FIG. 19B  is a diagram illustrating an example of the library system according to another altered embodiment in which a touch panel is provided on the door  213  of each cell  21   a.    
     Information indicating the contents of data in each cartridge  50  which is contained in each cell  21   a  is displayed on a touch panel  75  in addition to the information indicating the presence/absence of the respective cartridges  50  in the respective cells  21   a  and the information indicating that the cell  21   a  that the user intends to operate is which one. In the example illustrated in  FIG. 19B , the ravel name and the file name of the data in each cartridge  50  are displayed as examples of the above mentioned information. 
     In addition, in the case that information other than the above is to be looked at, if the user touches a part on which “UP” or “DOWN” is displayed, the display on the screen will be changed so as to allow the user to look at information other than the above. In addition, if the user touches a part on which “EJECT” is displayed, the main control unit  110  will start execution of an operation of ejecting the cartridge  50  concerned. 
     Although the control program, the control method and the control device of the invention have been described on the basis of the embodiments illustrated in the drawings, the invention is not limited to the above and configurations of respective units may be replaced by arbitrary configurations having the same functions. In addition, other arbitrary structures and steps may be added to the invention. 
     In addition, the invention may be a combination of two or more arbitrary configurations (characteristics) included in the above mentioned embodiments. 
     Incidentally, the above mentioned processing functions may be implemented using a computer. In the above mentioned case, a program in which processing contents of functions that the library management device  10  includes are described is provided. The above mentioned processing functions may be implemented using the computer by executing the above mentioned program using the computer. The program in which the processing contents are described may be recorded in a computer readable storage medium. As examples of the computer readable storage medium, for example, a magnetic recording device, an optical disc, a magnetic-optical recording medium, a semiconductor memory and the like may be given. As examples of the magnetic recording device, for example, a hard disc drive (HDD), a flexible disc (FD), a magnetic tape and the like may be given. As example of the optical disc, for example, a DVD, a DVD-RAM, a CD-ROM, a CD-R/RW and the like may be given. As examples of the magnetic-optical recording medium, for example, an MD and the like may be given. 
     In the case that a program is to be made commercially available, a portable recording medium, for example, such as a DVD, a CD-ROM or the like in which the program is recorded is marketed. As an alternative, the program may be recorded in a memory of a server computer and may be transferred from the server computer to another computer over a network. 
     A computer used to execute a library management program stores the program which is, for example, recorded in a portable recording medium or the program which is transferred from a server computer in its memory. Then, the computer reads the program out of its memory to execute processes according to the program. As an alternative, the computer may read a program directly out of a portable recording medium and execute processes according to the program. In addition, every time a program is transferred from a server computer, the computer may execute processes according to the received program each time. 
     All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.