Patent Publication Number: US-2002002619-A1

Title: Computer system

Description:
[0001] This application claims a priority based on Japanese Patent Application No. 2000-197085 filed on Jun. 29, 2000, the entire contents of which are incorporated herein by reference for all purposes.  
       BACKGROUND OF THE INVENTION  
       [0002] The present invention relates to a computer system including a computer connected through a computer network such as the Internet or the like.  
       [0003] When computers are connected to a computer network [e.g., Local Area Network (LAN), Metropolitan Area Network (MAN), Wide Area Network (WAN), the Internet or the like], data transmission can be carried out among the plurality of computers through the computer network. For example, when there is a connection between a host computer and a terminal computer through the computer network, the terminal computer can access the host computer having a database, and read data stored in the database of the host computer.  
       SUMMARY OF THE INVENTION  
       [0004] When the computer network to which the computers are connected is, for example, the Internet, a third party may access one of the computers (e.g., host computer) through the Internet, illegally read or rewrite data stored in the computer or a mass storage device (hard disk drive or the like) which is connected to the computer, or even destroy the data.  
       [0005] To prevent such illegal data reading or rewriting, or data destruction, generally, the security management of the computer has been carried out by use of a password or the like to put limitations on the access to the computer or by enciphering the data.  
       [0006] Even if such methods are used, however, because of the electrical connection of the computer to the computer network, there is still a possibility that the computer having the data is accessed through the computer network due to a password leakage or data deciphering, and illegal data reading or rewriting, or data destruction may be carried out.  
       [0007] Therefore, an object of the present invention is to provide a computer system configured to make it difficult to have a direct access to a computer having a storage unit, which stores data, through a computer network, whereby making it difficult to illegally read or rewrite the data and to destroy the data.  
       [0008] In a first aspect of the present invention, a computer system comprises a first computer, and a second computer which is connected to a computer network. A storage unit, a data recording unit, and a recording medium carrier are connected to the first computer. A data reproducing unit is connected to the second computer.  
       [0009] The first computer controls the data recording unit to record data stored in the storage unit into a recording medium. Then, the first computer controls the recording medium carrier to carry the recording medium from the data recording unit to the data reproducing unit.  
       [0010] On the other hand, the second computer controls the data reproducing unit to reproduce the data recorded in the recording medium. Then, the second computer transmits the reproduced data through the computer network.  
       [0011] In this case, the date recording unit may initialize the recording medium before recording the data thereinto.  
       [0012] In a second aspect of the present invention, a computer system comprises a first computer, and a second computer which is connected to a computer network. A storage unit, a first data recording and reproducing unit and a recording medium carrier are connected to the first computer. A second data recording and reproducing unit is connected to the second computer.  
       [0013] The first computer controls the first data recording and reproducing unit to record the data stored in the storage unit into a recording medium and also to reproduce the second computer information indicating a data reproducing state of the second computer recorded in the recording medium. Then, the first computer controls the recording medium carrier to carry the recording medium from the first data recording and reproducing unit to the second data recording and reproducing unit.  
       [0014] On the other hand, the second computer controls the second data recording and reproducing unit to reproduce the data recorded in the recording medium, and also record the second computer information into the recording medium. Then, the second computer transmits the reproduced data through the computer network.  
       [0015] In this case, the first data recording and reproducing unit may initialize the recording medium and record the data thereinto after the reproduction of the second computer information. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0016]FIG. 1 is an exemplary view schematically showing a configuration of a computer system to which an embodiment of the present invention is applied.  
     [0017]FIG. 2 is a flowchart illustrating a data transmission operation in the computer system to which an embodiment of the present invention is applied.  
     [0018]FIG. 3 is an exemplary view schematically showing a configuration of a computer system to which another embodiment of the present invention is applied.  
     [0019]FIG. 4 is a flowchart illustrating a data transmission operation in the computer system to which another embodiment of the present invention is applied. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0020] Next, the preferred embodiments of the present invention will be described.  
     [0021] According to the present invention, as a recording medium, various storage media can be used such as: an optical information recording medium such as an optical disk, a magneto-optical disk, or the like; a magnetic information recording medium such as a magnetic disk, a magnetic tape or the like; a semiconductor memory or the like. However, the embodiments will be described assuming that a recording medium is an optical disk.  
     [0022] In addition, at a data recording unit and first and second data recording and reproducing units described later, data recording includes the storing of data into a semiconductor memory, and data reproducing includes the reading of data from the semiconductor memory.  
     [0023]FIG. 1 is an exemplary view schematically illustrating the configuration of a computer system to which an embodiment of the invention is applied.  
     [0024] In FIG. 1, a data recording unit  102  is electrically connected to a first computer  101 , and a data reproducing unit  104  is electrically connected to a second computer  103 . The data recording unit  102  and the data reproducing unit  104  are physically connected to each other through a recording medium  110  by a recording medium carrier  105 .  
     [0025] In the described embodiment, the first computer  101  is connected to a local network  108 , which is not connected to the Internet  109 .  
     [0026] The second computer  103  is not connected to the local network  108 , but connected to the Internet  109 . The second computer  103  may be connected to any other network, which is not connected to the local network  108 .  
     [0027] A first storage unit  106  capable of storing mass data, such as a hard disk drive or the like, is connected to the first computer  101 . The first computer  101  and the first storage unit  106  are, for example, host computers having databases.  
     [0028] The first computer  101  transmits data stored in the first storage unit  106  to the second computer  103  by controlling the data recording unit  102  and the recording medium carrier  105  described later. In this case, the first computer  101  controls the data recording unit  102  and the recording medium carrier  105  based on the later-described first status information and second status information.  
     [0029] Note that the first computer  101  can also transmit the data, which is stored in other devices connected to the local network  108  to the second computer  103 .  
     [0030] At the data recording unit  102 , based on the control of the first computer  101 , data outputted from the first computer  101  is recorded into the recording medium  110  loaded by the later described recording medium carrier  105 . Then, from the data recording unit  102 , information indicating the loading/unloading of the recording medium  110  is outputted as first status information to the first computer  101 .  
     [0031] A second storage unit  107  capable of storing mass data, such as a hard disk drive or the like, is connected to the second computer  103 . The second storage unit  107  temporarily stores data obtained from the first computer  101 .  
     [0032] In the described embodiment, the data obtained from the fist computer  101  is stored into the second storage unit  107 . However, the second computer  103  may store such data into a built-in storage unit (not shown) and, as described later, read the data from the storage unit and transmit it to the Internet  109 .  
     [0033] The second computer  103  temporarily stores the data reproduced from the recording medium  110  by the later described data reproducing unit  104  into the second storage unit  107 , and then transmits the data to the Internet  109  therefrom.  
     [0034] The data reproducing unit  104  reproduces the data recorded in the recording medium  110  loaded by the later described recording medium carrier  105 . The reproduced data is then transmitted to the second computer  103 . Then, from the data reproducing unit  104 , information indicating the loading/unloading of the recording medium  110  is outputted as second status information to the first computer  101 .  
     [0035] Based on the control of the first computer  101 , the recording medium carrier  105  carries the recording medium  110  between the data recording unit  102  and the data reproducing unit  104 .  
     [0036] Connections are made respectively between the first computer  101  and the first storage unit  106 , between the first computer  101  and the data recording unit  102 , between the second computer  103  and the second storage unit  107 , and between the second computer  103  and the data reproducing unit  104  through interfaces, for example, Small Computer System Interface (SCSI) or the like.  
     [0037] Connections are also made respectively between the first computer  101  and the data recording unit  102 , and between the first computer  101  and the data reproducing unit  104  through interfaces for serial data transmission, for example, Recommended Standard 232C (RS232C) or the like.  
     [0038] The first computer  101  can accurately detect the operational states of the data recording unit  102  and the data reproducing unit  104  (whether or not the recording medium  110  is loaded, whether or not the recording medium  110  is being reproduced, and so on), based on the first status information sent from the data recording unit  102 , and the second status information sent from the data reproducing unit  104 .  
     [0039]FIG. 2 is a flowchart illustrating a data transmission operation in the computer system to which an embodiment of the present invention is applied.  
     [0040] When the first computer  101  transmits data to the second computer  103 , first, the first computer  101  decides the data to be transmitted among data stored in the first storage unit  106  (step  201 ). Then, the first computer  101  controls the recording medium carrier  105  to load the recording medium  110  in the data recording unit  102  (step  202 ).  
     [0041] Subsequently, the first computer  101  monitors the first status information of the data recording unit  102  at every constant interval of time, and is placed on standby until the recording medium  110  is loaded in the data recording unit  102  (step  203 ).  
     [0042] Upon detecting the completion of the loading of the recording medium  110  based on the first status information, the first computer  101  transmits the data to the data recording unit  102 . Then, the data recording unit  102  is controlled to record the data into the recording medium  110  loaded in the data recording unit  102  based on a predetermined format (step  204 ).  
     [0043] After the end of the recording of the data into the recording medium  110 , the first computer  101  controls the data recording unit  102  to unload the recording medium  110  from the data recording unit  102  (step  205 ).  
     [0044] Subsequently, the first computer  101  monitors the first status information of the data recording unit  102  at every constant interval of time, and is placed on standby until the recording medium  110  is unloaded from the data recording unit  102  (step  206 ).  
     [0045] Upon detecting the unloading of the recording medium  110  from the data recording unit  102  based on the first status information, the first computer  101  controls the recording medium carrier  105  to carry the recording medium  110  unloaded from the data recording unit  102  to the data reproducing unit  104  (step  207 ). Then, the recording medium  110  is loaded in the data reproducing unit  104  (step  208 ).  
     [0046] On the other hand, the second computer  103  accesses the data reproducing unit  104  at every constant interval of time to confirm whether the recording medium  110  is loaded in the data reproducing unit  104  or not. The first computer  101  detects the completion of the loading of the recording medium  110  in the data reproducing unit  104  based on the second status information of the data reproducing unit  104 .  
     [0047] Upon confirming the loading of the recording medium  110  in the data reproducing unit  104 , enabling the data to be reproduced (step  209 ), the second computer  103  controls the data reproducing unit  104  to reproduce the data from the recording medium  110 , and stores the reproduced data into the second storage unit  107  (step  210 ).  
     [0048] After the completion of the data storing in the second storage unit  107 , the second computer  103  transmits the data stored in the second storage unit  107  through the Internet  109 . At the same time, the second computer  103  controls the data reproducing unit  104  to unload the recording medium  110  (step  211 ).  
     [0049] In this case, when the second computer  103  cannot control the unloading of the recording medium  110  from the data reproducing unit  104 , the first computer  101  controls the recording medium carrier  105  after being placed on standby for a period of time necessary for data reproduction at the data reproducing unit  104 , and unloads the medium from the data reproducing unit  104 .  
     [0050] The first computer  101  monitors the second status information sent from the data reproducing unit  104 . Then, upon confirming the completion of the unloading of the recording medium  110  from the data reproducing unit  104  based on the second status information (step  212 ), the first computer  101  notifies a data transmission state by use of a monitor or the like (step  213 ).  
     [0051] In the case of continuing the process, the first computer  101  executes the processes from step  201  to step  213  (step  214 ). In the case of finishing the process, the first computer  101  controls the recording medium carrier  105  to hold the recording medium  110 , and places the carrier on standby. Thus, the process comes to an end.  
     [0052] As can be understood from the foregoing, according to the embodiment, the first and second computers  101  and  103  are not electrically connected to each other through a network or the like. Instead, these computers are connected to each other physically through the recording medium  110  carried by the recording medium carrier  105 . Accordingly, it is impossible to make direct access to the first computer  101  from the Internet  109  through the second computer  103 .  
     [0053] In addition, the data reproducing unit  104  connected to the second computer  103  is permitted only to reproduce the data recorded in the recording medium  110  and not to record the data. Thus, it is impossible to modify the data stored in the recording medium  110  from the Internet  109  through the second computer  103  and the data reproducing unit  104 .  
     [0054] Therefore, since no direct access is possible from the Internet  109  to the first computer  101 , the data stored in the first computer  101  itself or the data stored in the first storage unit  106  can be prevented from being illegally read, rewritten or destroyed.  
     [0055]FIG. 3 is an exemplary view schematically illustrating the configuration of a computer system to which another embodiment of the present invention is applied.  
     [0056] The computer system shown in FIG. 3 is configured by making a few changes in the computer system shown in FIG. 1. Specifically, the data recording unit  102  is changed to a first data recording and reproducing unit  111 ; and the data reproducing unit  104  to a second data recording and reproducing unit  112 . Other configurations are similar to those of the computer system shown in FIG. 1, and thus detailed description thereof will be omitted.  
     [0057] The first data recording and reproducing unit  111  records data into the recording medium  110 , and reproduces second computer information recorded in the recording medium  110 .  
     [0058] The second data recording and reproducing unit  112  reproduces the date recorded in the recording medium  110 , and records the second computer information into the recording medium  110 .  
     [0059] The first computer  101  determines whether the data has been normally transmitted or not based on the second computer information recorded in the recording medium  110 . In addition, the first computer  101  controls the recording of the data into the recording medium  110  by the first data recording and reproducing unit  111 , and the carriage of the recording medium  110  by the recording medium carrier  105 .  
     [0060] The second computer  103  controls the second data recording and reproducing unit  112  to reproduce the data recorded in the recording medium  110 . Then, when the second data recording and reproducing unit  112  reproduces the data normally, the second computer  103  controls the second data recording and reproducing unit  112  to record the second computer information into the recording medium  110 .  
     [0061] In this case, the second computer information means the information indicating whether the reproduction of data from the recording medium  110  is accurately carried out or not. Such second computer information includes, for example, reproduction completion information indicating the completion of data reproduction, reproduction disability information indicating the disabled reproduction of data due to an error during data reproduction, writing incompletion information indicating the writing failure of data into the second storage unit  107  due to an error during data reproduction, and so on. Other than these, the second computer information also includes data transmission request information inputted to the second computer  103  through the Internet  109 , and so on.  
     [0062]FIG. 4 is a flowchart illustrating a data transmission operation in the computer system according to another embodiment of the present invention.  
     [0063] When the first computer  101  transmits data to the second computer  103  first, the first computer  101  decides the data to be transmitted among data stored in the first storage unit  106  (step  401 ). Then, the first computer  101  controls the recording medium carrier  105  to load the recording medium  110  in the first data recording and reproducing unit  111  (step  402 ).  
     [0064] Subsequently, the first computer  101  monitors first status information sent from the first data recording and reproducing unit  111  at every constant interval of time, and is placed on standby until the recording medium  110  is loaded in the first data recording and reproducing unit  111  (step  403 ).  
     [0065] Upon detecting the completion of the loading of the recording medium based on the first status information, the first computer  101  transmits the data to the first data recording and reproducing unit  111 . Then, by controlling the first data recording and reproducing unit  111 , the first computer  101  records the data into the loaded recording medium  110  based on a predetermined format (step  404 ).  
     [0066] After the end of the data recording into the recording medium  110 , the first computer  101  controls the first data recording and reproducing unit  111  to unload the recording medium  110  from the first data recording and reproducing unit  111  (step  405 ).  
     [0067] Subsequently, the first computer  101  monitors the first status information sent from the first data recording and reproducing unit  111  at every constant interval of time, and is placed on standby until the recording medium  110  is unloaded from the first data recording and reproducing unit  111  (step  406 ).  
     [0068] Upon detecting the completion of the unloading of the recording medium  110  from the first data recording and reproducing unit  111  based on the first status information, the first computer  101  controls the recording medium carrier  105  to carry the recording medium  110  unloaded from the first data recording and reproducing unit  111  to the second data recording and reproducing unit  112  (step  407 ). Then, the recording medium  110  is loaded in the second data recording and reproducing unit  112  (step  408 ).  
     [0069] On the other hand, the second computer  103  accesses the second data recording and reproducing unit  112  at every constant interval of time to verify whether the recording medium  110  is loaded in the second data recording and reproducing unit  112  or not. The first computer  101  detects the loading of the recording medium  110  in the second data recording and reproducing unit  112  based on second status information sent from the second data recording and reproducing unit  112 .  
     [0070] Upon verifying the loading of the recording medium  110  in the second data recording and reproducing unit  112 , enabling the data to be reproduced (step  409 ), the second computer  103  controls the second data recording and reproducing unit  112  to reproduce the data from the recording medium  110 . Then, the reproduced data is stored into the second storage unit  107  (step  410 ).  
     [0071] Subsequently, when all the data reproduced from the recording medium  110  has been stored into the second storage unit  107 , the second computer  103  controls the second data recording and reproducing unit  112  to record second computer information indicating the end of the data reproduction into the recording medium  110  (step  411 ).  
     [0072] After the completion of the recording of the second computer information, the second computer  103  transmits the data stored in the second storage unit  107  through the Internet  109 . At the same time, the second computer  103  controls the second data recording and reproducing unit  112  to unload the recording medium  110  (step  412 ).  
     [0073] In this case, when the second computer  103  cannot control the unloading of the recording medium  110  loaded in the second data recording and reproducing unit  112 , the first computer  101  controls the recording medium carrier  105  to unload the recording medium  110  from the second data recording and reproducing unit  112  after being placed on standbys for a period of time necessary for data reproduction in the second data recording and reproducing unit  112 .  
     [0074] On the other hand, the first computer  101  monitors the second status information sent from the second data recording and reproducing unit  112 . Upon confirming the unloading of the recording medium  110  from the second data recording and reproducing unit  112  (step  413 ), the first computer  101  controls the recording medium carrier  105  to carry the recording medium  110  from the second data recording and reproducing unit  112  to the first data recording and reproducing unit  111  (step  414 ). Then, the recording medium  110  is loaded in the first data recording and reproducing unit  111  (step  415 ).  
     [0075] Then, the first computer  101  monitors the first status information of the first data recording and reproducing unit  111 . Upon confirming the loading of the recording medium  110  in the first data recording and reproducing unit  111  (step  416 ), the first computer  101  controls the first data recording and reproducing unit  111  to reproduce the second computer information from the recording medium  110  (step  417 ).  
     [0076] The first computer  101  then confirms whether the reproduction of the data in the second data recording and reproducing unit  112 , the writing of the data into the second storage unit  107  or the like is completed normally or not based on the second computer information reproduced from the recording medium  110  (step  418 ).  
     [0077] In this case, when the first computer  101  verifies that the data reproduction by the second data recording and reproducing unit  112  and the data writing into the second storage unit  107  are not completed normally, the first computer  101  executes the processes from step  405  to step  418  again. On the other hand, when the first computer  101  verifies that the data reproduction by the second data recording and reproducing unit  112  and the data writing into the second storage unit  107  are completed normally, the first computer  101  notifies a data transmission state by use of a monitor or the like (step  419 ).  
     [0078] In the case of continuing the process, the first computer  101  executes the processes from step  401  to step  419  (step  420 ). In the case of finishing the process, the first computer  101  controls the recording medium carrier  105  to unload the recording medium  110  from the first data recording and reproducing unit  111  (step  421 ). Then, the first computer  101  also controls the recording medium carrier  105  to hold the recording medium  110 , and places the carrier on standby. Thus, the process comes to an end.  
     [0079] As can be understood from the foregoing, according to the described embodiment, the first and second computers  101  and  103  are not electrically connected to each other through a network. Instead, these computers are physically connected to each other through the recording medium  110  carried by the recording medium carrier  105 .  
     [0080] The second computer  103  can only reproduce the data recorded in the recording medium  110  and record the second computer information into the recording medium  110 . The second computer  108  cannot have any direct access to the first computer  101 .  
     [0081] Thus, it is possible to prevent the illegal reading, rewriting, destruction, or the like of the data stored in the first computer  101  itself or stored in the first storage unit  106  by accessing the first computer  101  through the Internet  109 .  
     [0082] In addition, the first computer  101  can detect the failed reproduction of data in the second computer  103  or the failed writing of data into the second storage unit  107  based on the second computer information.  
     [0083] In the above case, the first computer  101  can control the recording medium  110  to stay loaded in the second data recording and reproducing unit  112  until the data reproduction in the second computer  103  and the data writing into the second storage unit  107  are completed normally. Accordingly, it is possible to accurately transmit the data from the first computer  101  side to the second computer  103  side.  
     [0084] Note that, in each of the foregoing embodiments, based on the first status information and the second status information, the first computer  101  controls the data recording unit  102  or the first data recording and reproducing unit  111 , and the recording medium carrier  105 . However, the present invention is not limited to this.  
     [0085] For example, the first computer  101  may output control signals to the data recording unit  102  or the first data recording and reproducing unit  111 , and the recording medium carrier  105 , the signals being used to control these. Then, after the passage of predetermined time, the first computer  101  may output a control signal for controlling a next operation.  
     [0086] In addition, the first computer  101  may control the data recording unit  102  or the first data recording and reproducing unit  111 , and determine whether the recording medium  110  is loaded in the data recording unit  102  or the first data recording and reproducing unit  111  depending on the possibility of data recording into or data reproducing from the recording medium  110  by the data recording unit  102  or the first data recording and reproducing unit  111 . Then, based on the result of the determination, the first computer  101  may output a control signal for controlling a next operation.  
     [0087] Moreover, in each of the foregoing embodiments, the data recording unit  102  may record the data in the recording medium  110  after the initialization of the recording medium  110 . The first data recording and reproducing unit  111  may initialize the recording medium  110  and record the data thereinto after the reproduction of the second computer information. The second data recording and reproducing unit  112  may initialize the recording medium  110  and record the second computer information thereinto after the reproduction of the data.  
     [0088] Accordingly, it is possible to increase the quantity of data to be recorded into the recording medium  110 . Also, it is possible to prevent a reproducing mistake, such as the reproduction of previously recorded data instead of reproducing the data to be reproduced among the data recorded in the recording medium  110 .  
     [0089] As apparent from the foregoing, the present invention is advantageous in that it is difficult to illegally read, rewrite, or even destroy the data by direct access from the computer network side to the computer having the storage unit, which stores the data.