Abstract:
A storage device is provided that includes a first interface unit configured to connect to an external apparatus; a second interface unit configured to connect to a network; and a control unit which controls the storage device. The control unit determines whether a predetermined command is received from the external apparatus. The control unit selects a first operating mode where the storage device is used by the external apparatus and the second interface unit is disabled, if the control unit determines that the predetermined command is received from the external apparatus. The control unit selects a second operating mode where the storage device operates as a file server and the second interface unit is enabled, if the control unit determines that the predetermined command is not received from the external apparatus.

Description:
This is a divisional of prior application Ser. No. 10/774,862, filed Feb. 9, 2004, now pending. The prior application is incorporated herein by reference in its entirety. 

   CLAIM OF PRIORITY 
   The present application claims priority under 35 U.S.C. §119 from Japanese Patent Application No. 2003-033781, entitled “A Storage Apparatus and A Processing Method Therefor” and filed on Feb. 12, 2003, the entire contents of which are hereby incorporated by reference herein. 
   FIELD OF THE INVENTION 
   This invention relates to a storage device that operates as a storage device of a video apparatus, and to a processing method in this storage device. 
   BACKGROUND OF THE INVENTION 
   An external storage device for a video apparatus such as a digital video camera is known in the art, the storage device storing digital video data that has been output from the video apparatus. (For example, see the specification of Japanese Patent Application Laid-Open No. 8-116481). 
   Even though the conventional storage device is capable of operating as a storage device exclusively for a video apparatus, it cannot operate in the manner of an NAS (Network Attached Storage). NAS is a storage device capable of being connected directly to a network and can operate as a file server. If the storage device could operate in the manner of the NAS, then merely connecting it to a network would make it possible to supply a network device in the network with digital video data that has been stored in the storage device. However, the conventional storage device cannot operate in this fashion. 
   Further, the conventional storage device cannot be switched automatically between an operating mode in which it operates as a storage device exclusively for a video apparatus and an operating mode in which it operates as a file server. 
   SUMMARY OF THE INVENTION 
   Accordingly, an object of the present invention is to provide a storage device that can operate as a storage device exclusively for a video apparatus and also as a file server. 
   By way of example, there is provided a storage device comprising: 
   a first interface unit configured to connect to an external apparatus; 
   a second interface unit configured to connect to a network; and 
   a control unit which controls the storage device, 
   wherein the control unit determines whether a predetermined command is received from the external apparatus, 
   the control unit selects a first operating mode where the storage device is used by the external apparatus and the second interface unit is disabled, if the control unit determines that the predetermined command is received from the external apparatus, and 
   the control unit selects a second operating mode where the storage device operates as a file server and the second interface unit is enabled, if the control unit determines that the predetermined command is not received from the external apparatus. 
   Further, by way of example, there is provided a processing method in a storage device, comprising the steps of: 
   determining whether a predetermined command is received from the external apparatus; 
   selecting a first operating mode where the storage device is used by the external apparatus and the second interface unit is disabled, if it is determined that the predetermined command is received from the external apparatus; and 
   selecting a second operating mode where the storage device operates as a file server and the second interface unit is enabled, if it is determined that the predetermined command is not received from the external apparatus. 
   Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
       FIGS. 1A and 1B  are diagrams illustrating modes of use of a storage device according to a first embodiment of the present invention; 
       FIG. 2  is a block diagram illustrating the main structure of a storage device according to the first embodiment; 
       FIG. 3  is a flowchart illustrating operating-mode changeover processing executed in the storage device of the first embodiment; 
       FIGS. 4A and 4B  are diagrams illustrating modes of use of a storage device according to a second embodiment of the present invention; 
       FIG. 5  is a block diagram illustrating the main structure of a storage device according to the second embodiment; and 
       FIG. 6  is a flowchart illustrating operating-mode changeover processing executed in the storage device of the second embodiment. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will now be described with reference to the drawings. 
   First Embodiment 
   First, an example of modes of use of a storage device  10  according to a first embodiment will be described with reference to  FIGS. 1A and 1B .  FIG. 1A  is a diagram illustrating an example in which the storage device  10  is utilized in a DAS (Direct Attached Storage) mode, and  FIG. 1B  is a diagram illustrating an example in which the storage device  10  is utilized in an NAS (Network Attached Storage) mode. 
   The storage device  10 , which has the DAS mode and the NAS mode, implements these modes selectively. The DAS mode is an operating mode in which the storage device  10  is caused to operate as a storage device dedicated to a video apparatus  20 . The DAS mode is an operating mode selected automatically and implemented when the storage device  10  is loaded in the video apparatus  20  or connected to the video apparatus  20  via a cable. The NAS mode is an operating mode in which the storage device  10  is connected to a network automatically via an access point  30  and caused to operate as a file server. In other words, the NAS mode is an operating mode in which the storage device  10  is caused to operate as NAS (Network Attached Storage). The NAS mode is an operating mode selected automatically and implemented when the storage device  10  is disconnected from the video apparatus  20 . When the storage device  10  is in the NAS mode, network devices  40  are capable of utilizing the storage device  10  via the access point  30 . The video apparatus  20  is an apparatus such as a digital video recorder or a digital video camera. When the storage device  10  has been connected to the video apparatus  20 , digital video data from the video apparatus  20  is stored in the storage device  10 . The access point  30  is one in a wireless network such as a wireless LAN. 
   This embodiment has been described taking a video apparatus as an example of an apparatus to which the storage device  10  is connected. However, this does not impose any limitation upon the present invention and the apparatus may be any that executes prescribed data processing. 
   The main structure of the storage device  10  according to the first embodiment will now be described with reference to  FIG. 2 . 
   In  FIG. 2 , a device interface unit  101  makes it possible to communicate with the video apparatus  20 , and a wireless interface unit  102  makes it possible to communicate with the access point  30  in the wireless network. A storage unit  103  executes processing for writing digital video data obtained from the device interface unit  101  or wireless interface unit  102  to a randomly accessible storage medium, and processing for supplying digital video data, which has been read out of a randomly accessible storage medium, to the device interface unit  101  or wireless interface unit  102 . The storage unit  103  is also capable of providing the function of a file server via the wireless interface unit  102 . A CPU (Central Processing Unit)  104  controls the functions of the storage device  10  and performs management in accordance with a program stored in a program memory  105 . 
   Processing for changing over the operating mode implemented in the storage device  10  will now be described with reference to the flowchart of  FIG. 3 . It should be noted that in processing for changing over the operating mode, it is assumed that the processing in the CPU  101  is executed in accordance with the program stored in the program memory  105 . 
   Step S 301 : If the user has connected the storage device  10  to the video apparatus  20 , then the device interface unit  101  detects this fact electrically or by using a switch and notifies the CPU  104  of the fact that the storage device  10  has been connected to the video apparatus  20 . In accordance with this notification from the device interface unit  101 , the CPU  104  determines whether the storage device  10  has been connected to the video apparatus  20 . If it is determined that the storage device  10  has been connected to the video apparatus  20 , then control proceeds to step S 302 . On the other hand, if it is determined that the storage device  10  has not been connected to the video apparatus  20 , then control proceeds to step S 305 . 
   Step S 302 : The CPU  104  switches the operating mode of the storage device  10  to the DAS mode. 
   Step S 303 : The CPU  104  disables the function of the wireless interface unit  102  and disconnects the storage device  10  from the network. The CPU  104  then controls the storage device  10  in such a manner that the storage device  10  will operate as a storage device exclusively for the video apparatus  20 . 
   Step S 304 : If the user has removed the storage device  10  from the video apparatus  20 , the device interface unit  101  detects this fact electrically or by using a switch and notifies the CPU  104  of the fact that the storage device  10  has been disconnected from the video apparatus  20 . In accordance with such notification from the device interface unit  101 , the CPU  104  determines whether the storage device  10  has been disconnected from the video apparatus  20 . It is determined that the storage device  10  has been disconnected from the video apparatus  20 , control proceeds to step S 305 . 
   Step S 305 : The CPU  104  switches the operating mode of the storage device  10  to the NAS mode. 
   Step S 306 : The CPU  104  enables the function of the wireless interface unit  102  and connects the storage device  10  to the network via the access point  30 . The CPU  104  then controls the storage device  10  in such a manner that the storage device  10  will operate as a file server connected directly to the network. By execution of such processing, each network device  40  is capable of utilizing the storage device  10  via the access point  30 , desired digital video data can be read out of the storage unit  103 , and desired digital video data can be written to the storage unit  103 . 
   As will be understood from the flowchart of  FIG. 3 , even if the storage device  10  is operating in the NAS mode, it will switch over to the DAS mode automatically if it is connected to the video apparatus  20 . Accordingly, this embodiment is such that the DAS mode has a higher priority than the NAS mode. By thus giving the DAS mode a higher priority than the NAS mode, a switch will be made to the DAS mode even in an environment in which the NAS mode is capable of operating. This is very convenient in that by merely connecting the storage device  10  to the video apparatus  20 , the user can make the changeover without being aware of the changeover. It should be noted, however, that the above does not negate the possibility of making the NAS mode higher in priority than the DAS mode; it is possible to change the priority by a setting. 
   Thus, in accordance with the storage device  10  of the first embodiment, the storage device  10  can operate as a storage device dedicated to the video apparatus  20  and also as a file server connected directly to a network. 
   Further, in accordance with the storage device  10  of the first embodiment, the operating mode of the storage device  10  can be selected to be the DAS mode or NAS mode in dependence upon whether the storage device  10  has been connected to a video apparatus. As a result, it is possible to switch automatically between an operating mode in which the storage device operates as a storage device dedicated to the video apparatus  20  and an operating mode in which the storage device operates as a file server connected directly to a network. 
   Further, in accordance with the storage device  10  of the first embodiment, the device can be connected to a network using the wireless interface unit  102 . As a result, the storage device  10  can be connected to the network in simple fashion merely by disconnecting it from the video apparatus  20 . 
   Further, in accordance with the storage device  10  of the first embodiment, the storage device  10  can operate as a file server connected directly to a network when the NAS mode is in effect. This means that digital video data that the video apparatus  20  has stored in the storage device  10  can be supplied to a network device that requests this data. 
   It should be noted that in the storage device  10  of the first embodiment may be so adapted that the area used by the storage unit  103  is split into areas, with a certain area being used when the DAS mode is in effect and another area being used when the NAS mode is in effect. More specifically, the storage unit  103  is divided up into a plurality of areas of use. If the DAS mode is in effect, then an area A, for example, is used. If the mode has been switched from the DAS mode to the NAS mode, then the area used is switched from area A to area B. The area B may be further subdivided into a plurality of areas of use and may be managed on a per-network-device basis. 
   Second Embodiment 
   According to the first embodiment, the arrangement described is such that the DAS mode or NAS mode is changed over in dependence upon whether the storage device has been connected to a video apparatus. According to a second embodiment, an arrangement in which the DAS mode or NAS mode is changed over in accordance with a mode changeover command obtained from a video apparatus will be described. 
   First, an example of modes of use of a storage device  50  according to the second embodiment will be described with reference to  FIGS. 4A and 4B .  FIG. 4A  is a diagram illustrating an example in which the storage device  50  is utilized in a DAS (Direct Attached Storage) mode, and  FIG. 4B  is a diagram illustrating an example in which the storage device  50  is utilized in an NAS (Network Attached Storage) mode. 
   The storage device  50 , which has the DAS mode and the NAS mode, implements these modes selectively. The DAS mode is an operating mode in which the storage device  50  is caused to operate as a storage device dedicated to a video apparatus  60 . The DAS mode is an operating mode selected automatically and implemented in accordance with a mode changeover command transmitted from the video apparatus  60  to the storage device  50 . The NAS mode is an operating mode in which the storage device  50  is connected to a network automatically via an access point  70  and caused to operate as a file server. In other words, the NAS mode is an operating mode in which the storage device  50  is caused to operate as NAS (Network Attached Storage). The NAS mode is an operating mode selected automatically and implemented in accordance with the mode changeover command transmitted from the video apparatus  60  to the storage device  50 . When the storage device  50  is in the NAS mode, network devices  80  are capable of utilizing the storage device  50  via the access point  70 . The video apparatus  60  is an apparatus such as a digital video recorder or digital video camera. When the storage device  50  has been connected to the video apparatus  60 , digital video data from the video apparatus  60  is stored in the storage device  50 . Further, the video apparatus  60  sends the storage device  50  the mode changeover command, which is control information for switching the operating mode of the storage device  50  to the DAS mode or NAS mode. The access point  70  is one in a wireless network such as a wireless LAN. 
   The main structure of the storage device  50  according to the second embodiment will now be described with reference to  FIG. 5 . 
   In  FIG. 5 , a device interface unit  401  makes it possible to communicate with the video apparatus  60 , and a wireless interface unit  402  makes it possible to communicate with the access point  70  in the wireless network. A storage unit  403  executes processing for writing digital video data obtained from the device interface unit  401  or wireless interface unit  402  to a randomly accessible storage medium, and processing for supplying digital video data, which has been read out of a randomly accessible storage medium, to the device interface unit  401  or wireless interface unit  402 . The storage unit  403  is also capable of providing the function of a file server via the wireless interface unit  402 . A CPU (Central Processing Unit)  404  controls the functions of the storage device  50  and performs management in accordance with a program stored in a program memory  405 . 
   Processing for changing over the operating mode implemented in the storage device  50  will now be described with reference to the flowchart of  FIG. 6 . It should be noted that in processing for changing over the operating mode, it is assumed that the processing in the CPU  401  is executed in accordance with the program stored in the program memory  405 . 
   Step S 601 : The device interface unit  401  receives the mode changeover command transmitted from the video apparatus  60  to the storage device  50  and supplies the received mode changeover command to the CPU  404 . The latter investigates the content of the mode changeover command supplied by the device interface unit  401  and switches the operating mode of the storage device  50  to the DAS mode or NAS mode. If the mode is switched to the DAS mode, then control proceeds to step S 602 . On the other hand, if the mode is switched to the NAS mode, control proceeds to step S 604 . 
   Step S 602 : The CPU  404  switches the operating mode of the storage device  50  to the DAS mode. 
   Step S 603 : The CPU  404  disables the function of the wireless interface unit  402  and disconnects the storage device  50  from the network. The CPU  404  then controls the storage device  50  in such a manner that the storage device  50  will operate as a storage device exclusively for the video apparatus  60 . 
   Step S 604 : The CPU  404  switches the operating mode of the storage device  50  to the NAS mode. 
   Step S 605 : The CPU  404  enables the function of the wireless interface unit  402  and connects the storage device  50  to the network via the access point  70 . The CPU  404  then controls the storage device  50  in such a manner that the storage device  50  will operate as a file server connected directly to the network. By execution of such processing, each network device  80  is capable of utilizing the storage device  50  via the access point  70 , desired digital video data can be read out of the storage unit  403 , and desired digital video data can be written to the storage unit  403 . 
   Thus, in accordance with the storage device  50  of the second embodiment, the storage device  50  can operate as a storage device dedicated to the video apparatus  60  and also as a file server connected directly to a network. 
   Further, in accordance with the storage device  50  of the second embodiment, the operating mode of the storage device  50  can be switched to the DAS mode or NAS mode in accordance with a mode changeover command transmitted from the video apparatus  60 . As a result, it is possible to switch automatically between an operating mode in which the storage device operates as a storage device dedicated to the video apparatus  60  and an operating mode in which the storage device operates as a file server connected directly to a network. 
   Further, in accordance with the storage device  50  in the second embodiment, the device can be connected to a network using the wireless interface unit  402 . As a result, the storage device  50  can be connected to the network in simple fashion. 
   Further, in accordance with the storage device  50  in the second embodiment, the storage device  50  can operate as a file server connected directly to a network when the NAS mode is in effect. This means that digital video data that the video apparatus  60  has stored in the storage device  50  can be supplied to a network device that requests this data. 
   It should be noted that in the storage device  50  of the second embodiment may be so adapted that the area used by the storage unit  403  is split into areas, with a certain area being used when the DAS mode is in effect and another area being used when the NAS mode is in effect. More specifically, the storage unit  403  is divided up into a plurality of areas of use. If the DAS mode is in effect, then an area A, for example, is used. If the DAS mode has been switched to the NAS mode, then the area used is switched from area A to area B. The area B may be further divided into a plurality of areas of use and may be managed on a per-network-device basis. 
   Thus, in accordance with the present invention, it is possible to provide a storage device that can operate as a storage device exclusively for a video apparatus and also as a file server. 
   Other Embodiments 
   Note that the present invention can be applied to an apparatus comprising a single device or to system constituted by a plurality of devices. 
   Furthermore, the invention can be implemented by supplying a software program, which implements the functions of the foregoing embodiments, directly or indirectly to a system or apparatus, reading the supplied program code with a computer of the system or apparatus, and then executing the program code. In this case, so long as the system or apparatus has the functions of the program, the mode of implementation need not rely upon a program. 
   Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the claims of the present invention also cover a computer program for the purpose of implementing the functions of the present invention. 
   In this case, so long as the system or apparatus has the functions of the program, the program may be executed in any form, such as an object code, a program executed by an interpreter, or scrip data supplied to an operating system. 
   Example of storage media that can be used for supplying the program are a floppy disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a magnetic tape, a non-volatile type memory card, a ROM, and a DVD (DVD-ROM and a DVD-R). 
   As for the method of supplying the program, a client computer can be connected to a website on the Internet using a browser of the client computer, and the computer program of the present invention or an automatically-installable compressed file of the program can be downloaded to a recording medium such as a hard disk. Further, the program of the present invention can be supplied by dividing the program code constituting the program into a plurality of files and downloading the files from different websites. In other words, a WWW (World Wide Web) server that downloads, to multiple users, the program files that implement the functions of the present invention by computer is also covered by the claims of the present invention. 
   It is also possible to encrypt and store the program of the present invention on a storage medium such as a CD-ROM, distribute the storage medium to users, allow users who meet certain requirements to download decryption key information from a website via the Internet, and allow these users to decrypt the encrypted program by using the key information, whereby the program is installed in the user computer. 
   Besides the cases where the aforementioned functions according to the embodiments are implemented by executing the read program by computer, an operating system or the like running on the computer may perform all or a part of the actual processing so that the functions of the foregoing embodiments can be implemented by this processing. 
   Furthermore, after the program read from the storage medium is written to a function expansion board inserted into the computer or to a memory provided in a function expansion unit connected to the computer, a CPU or the like mounted on the function expansion board or function expansion unit performs all or a part of the actual processing so that the functions of the foregoing embodiments can be implemented by this processing. 
   As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.