Abstract:
Embodiments of the data storage apparatus provide a system and method for storing data in a disconnectably coupled device. Briefly described, one embodiment is a data storage apparatus arranged to be disconnectably coupled to a host device, the data storage apparatus comprising: a first data storage device arranged to store data received from the host device; and a data transfer device arranged to receive a removable data storage medium and arranged to store data received from the host device on the removable data storage medium, wherein the data storage apparatus is arranged to store data selectively on at least one of the first data storage device and the removable data storage medium.

Description:
CLAIM TO PRIORITY  
       [0001]     This application claims priority to copending United Kingdom utility application entitled, “Data Storage Aparatus,” having serial no. GB 0315692.4, filed Jul. 4, 2003, which is entirely incorporated herein by reference.  
       TECHNICAL FIELD  
       [0002]     Embodiments are generally related to data storage and, more particularly, is related to a system and method for storing data in a disconnectably coupled device.  
       BACKGROUND  
       [0003]     With the increasing use of digital devices, including digital still and video cameras and personal digital assistants, there is a corresponding increasing demand for removable digital data storage devices. One example of such removable digital storage is the Flash card. A Flash card is a solid state memory device on to which data can be written and subsequently retrieved. However, the cost of such solid state memory cards is relatively high such that they are not perceived by the majority of users as being suitable for long term data storage. Rather, the majority of users perceive solid state memory cards as temporary data storage, with the data stored thereon being transferred or copied to a long term data storage device relatively soon after it has been stored on the memory card. The original data is then deleted from the memory card such that new data may be stored thereon, or the new data simply overwrites the previous data. This is in contrast to a video cassette or conventional 3.5 inch diskette. From a user&#39;s point of view, these latter devices are cheap enough for data to be recorded thereon once only to provide permanent storage for the data. Hence from a user&#39;s perspective, the two types of data storage medium are not comparable.  
         [0004]     A further inhibition from a user&#39;s perspective against solid state memory cards is the time overhead necessary in downloading the data stored on the memory cards to the subsequent data storage device that the user has denoted as long term storage. One example of this is the use of memory cards in digital cameras. Although each memory card can store tens of still digital photographs, the user is still required to download the stored photographs from the memory card to a further memory storage device, for example the hard disk of a personal computer, to allow fresh data to be stored on the memory card. As stated previously, the cost of the memory card prejudices the user against treating it as Read Only Memory.  
         [0005]     The problem is exacerbated for the use of such memory cards for digital video as the amount of video footage that can be stored on such memory cards is generally very limited. Attempts have been made to overcome this disadvantage. For example, digital video cameras have been provided having both a conventional tape drive and a solid state memory card. The reasoning behind such devices is that the conventional tape is used to store the video footage, with the solid state memory card being used to store still photographs. However, this solution has its own disadvantages in that there is a significant cost overhead in providing the separate read/write mechanisms and associated control logic within the host device for both the memory card and video tape. Additionally, the choice of available data formats for the stored data is restricted to those suitable to be stored on the memory card or video tape, or whatever additional storage medium is provided. The two data storage mediums supported by the host device are alternatives to one another and there is no flexibility in the manner in which the data is stored.  
         [0006]      FIG. 1  illustrates a digital video camera according to the prior art. The camera  2  is capable of taking both conventional video footage and also digital still photographs. A conventional magnetic video tape  4  can be inserted into the tape drive  6  in the camera  2  to allow video footage to be stored on the video tape  4 . Additionally, a solid state memory card  8  capable of storing, for example, but not limited to, 128 MB of data can be inserted into a memory card slot  10  in the camera  2  to allow digital photographs to be stored on the memory card  8 .  
       SUMMARY  
       [0007]     The data storage apparatus provides a system and method for storing data. Briefly described, one embodiment is a data storage apparatus arranged to be disconnectably coupled to a host device, the data storage apparatus comprising: a first data storage device arranged to store data received from the host device; and a data transfer device arranged to receive a removable data storage medium and arranged to store data received from the host device on the removable data storage medium, wherein the data storage apparatus is arranged to store data selectively on at least one of the first data storage device and the removable data storage medium.  
         [0008]     Another embodiment is a data storage device for providing storage of data from a digital device, the data storage device comprising; an interface configured to enable the data storage device to be disconnectably coupled to a digital device; a first data storage medium coupled to the interface and arranged to selectively store data received from the digital device via the interface; and a data transfer device coupled to the interface and configured to receive a second, removable, data storage medium, the data transfer device being arranged to selectively store data received from the digital device via the interface on the second, removable, data storage medium.  
         [0009]     Another embodiment is a storage apparatus for providing storage of data from a host device, the data storage apparatus comprising: an interface providing means for disconnectably coupling the data storage apparatus to the host device; a first data storage device arranged to selectively store data received from the host device; a data transfer device configured to removably receive a second data storage device and arranged to selectively store data received from the host device on the second data storage device; and a data controller arranged to control the selection of each of the first data storage device and the data transfer device and control the storage of data received from the host device thereon.  
         [0010]     Another embodiment is an image capture device, comprising: an interface arranged to be disconnectably coupled to either a data storage apparatus and a conventional memory device; a processor configured to discover if the image capture device is coupled to the data storage apparatus or the conventional memory device; and a data controller arranged to control the flow of data from the image capture device in accordance to at least one criteria when the image capture device is coupled to the data storage apparatus, wherein the data storage apparatus comprises a first data storage device and a data transfer device arranged to receive a removable data storage medium, and wherein the data storage apparatus stores the data received from the image capture device selectively into one of the first data storage device and the removable data storage medium depending upon the criteria.  
         [0011]     Another embodiment is a method for storing data received from an image capture device into a storage apparatus disconnectably coupled to the image capture device, comprising: receiving data from the image capture device; determining a characteristic of the received data; storing the received data into a solid state memory medium when the determined characteristic corresponds to a first predefined characteristic; and storing the received data into a removable memory medium when the determined characteristic corresponds to a second predefined characteristic. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     Embodiments of the present invention will be described below, by way of illustrative example only, with reference to the accompanying figures, of which:  
         [0013]      FIG. 1  schematically illustrates a prior art digital video camera having both a video tape drive and a memory card slot;  
         [0014]      FIG. 2  schematically illustrates a data storage apparatus according to an exemplary embodiment;  
         [0015]      FIG. 3  schematically illustrates the use of the data storage device shown in  FIG. 2  with a digital video camera; and  
         [0016]      FIG. 4  is a flow chart illustrating a process used by the data storage apparatus of  FIG. 2 . 
     
    
     DETAILED DESCRIPTION  
       [0017]     A data storage apparatus  100  according to an exemplary embodiment is shown in  FIG. 2 . The apparatus  100  is housed in a casing  12  that has the same physical dimensions as a conventional solid state memory card.  
         [0018]     An example of such a conventional memory card is a solid-state floppy-disk card (SSFDC), more commonly known as SmartMedia (Registered as a Trademark to the Toshiba Corporation), and available in memory capacities from 2-128 MB. The external dimensions of a SSFDC are 45 mm long, 37 mm wide and less than 1 mm thick. A further example is a CompactFlash card, as developed by Scandisk. These are slightly physically larger than SmartMedia having external dimensions of 43 mm wide, 36 mm long and either 3.3 mm or 5.5 mm depth. Of course it will be appreciated that other solid state memory devices may be utilised, although it is preferable for them to conform to the technical standards set by the Personal Computer Memory Card International Association (PCMCIA).  
         [0019]     Integrated within the data storage apparatus  100  is a conventional solid state memory  14 , as is found within a conventional solid state memory card. An input/output interface (I/O)  16  is provided such that the data storage apparatus  100  can be used with a conventional solid state memory card interface.  
         [0020]     In addition to the integrated memory  14 , there is also provided a data transfer device  18  for use with removable storage media. For example, the data transfer device  18  may be an optical disk drive for use with mini optical disks. In one embodiment, the data transfer device is arranged to receive a removable data storage medium having a greater data storage capacity than the first data storage device  14 .  
         [0021]     In various embodiments, the data transfer device is that the associated storage medium is sufficiently inexpensive such that it is viewed by users as write once memory. Hence any appropriate storage device may be used, such as a magnetic disk drive or a solid state memory read/write device.  
         [0022]     The casing  12  of the data storage apparatus  100  is provided with an access flap or slot, as is most appropriate for the design of the optical disk drive, to allow the associated storage medium, such as optical disks, to be inserted and removed from the casing  12 .  
         [0023]     Also within the casing  12  there is provided a microprocessor  20  that controls the operation of both the data transfer device  18  and the solid state memory  14 .  
         [0024]     In use, the microprocessor  20  (μp) controls the flow of data between the host device to which the data storage apparatus  100  can be coupled and the solid state memory  14  and the data transfer device  18  of the data storage apparatus. In one exemplary embodiment, the data transfer device  18  is an optical drive, and referred to hereinafter as such for convenience.  
         [0025]     Only a single controller  20  is thus required for both data storage mediums. It is therefore possible to have a single data storage apparatus  100 , or memory module, that allows short term data storage of data received from a host device by virtue of the first data storage device  14 , in an analogous fashion to conventional solid state memory cards, yet also allows a removable data storage medium to be used for long term storage of the data from the host device in an analogous fashion to video tape or computer diskettes.  
         [0026]     In some embodiments, the microprocessor  20  includes some memory that stores the software and data required by the microprocessor  20  to accomplish its controlling functions. Alternatively, an additional dedicated memory, such as, but not limited to, a programmable read only memory (PROM), may be provided for this purpose.  
         [0027]     The microprocessor  20  is programmed in such a fashion that the data storage apparatus  100  appears as a conventional solid state memory card to the host device to which it is coupled. However, the microprocessor  20  controls the flow of data from the host device so as to utilise both the solid state memory  14  and the optical drive  18  in a number of different possible ways. In other words the data from the host device can be stored on either, or both, of the data storage mediums, according to one of a number of possible data flow schemes.  
         [0028]     The provision of the microprocessor  20  within the data storage apparatus  100  allows the data storage apparatus  100  to be essentially self-controlled. This allows the data storage apparatus to be used with existing host devices, such as video or still cameras equipped with an appropriate memory card slot, that themselves do not include a data controller arranged to control the flow of data between the host device and the two data storage mediums present in the data storage apparatus  100 . Additionally, the flow of data may be controlled in accordance with a user initiated control signal.  
         [0029]     For example, the microprocessor  20  may be programmed to distinguish between data having different characteristics, for example video and/or audio data on the one hand and still photography data on the other hand, and to control the flow of data so as to store the video and/or audio data using the optical drive  18 , whilst storing the still photo data on the solid state memory  14 . This provides various advantages. Firstly, as the optical disk used with the optical drive  18  is likely to have a far higher data capacity than the solid state memory  14 , for example up to 1 GB, significantly more video and/or audio data may be stored on the optical disk. Secondly, as the optical disk is removable from the data storage apparatus  100 , it may be used in other consumer devices that are compatible. This would allow the optical disks to be treated in an analogous fashion as conventional video tapes have been in the past. Thirdly, the increased data storage provided by the optical drive  18  on the data storage apparatus  100  enables other user devices capable of being coupled to a conventional memory card to perform improved functionality. For example, a personal digital assistant having a memory card slot could be used to play video footage stored on the optical disk at a significantly lower cost to the user than is currently possible.  
         [0030]     However it will be appreciated that the data stored on the solid state memory  14  and removable data storage medium (optical disk in the described embodiment) may still be mixed. For example, each still photograph may have some text associated with it. Such text may be an ‘aide memoir’ provided by the user relating to the subject of the photograph. Alternatively, or in addition to, the ‘aide memoir’ may be audio data. Consequently, the characteristics of the data used by the microprocessor  20  to differentiate between data need not be restricted only to the data type. The host device may be arranged to add a flag to the data denoting its preferred storage location, either automatically or in response to a user input.  
         [0031]     Equally, the microprocessor  20  may be responsive to control signals initiated by a user via appropriate input means provided on a host device in which the data storage apparatus is inserted. This allows the user to determine which of the first and second data storage devices is used for any given kind of data.  
         [0032]     Furthermore, the microprocessor  20  may be programmed to perform one or more ‘added-value’ functions. For example the microprocessor  20  may be programmed to construct a ‘slide-show’ of still photographs stored on the solid state memory  14  and copy or save it onto an optical disk using the optical disk drive  18  in a format that can be played on a further user device. This would allow the still photographs to be viewed by other users who do not have access to a solid state memory card reader. The programming of the processor  20  may be established at the time of manufacture or may be re-programmable by a user. The latter option allows the functionality of a data storage apparatus to be tailored to individual user&#39;s requirements.  
         [0033]     In other embodiments of the present invention, the microprocessor  20  may utilise the solid state memory  14  to optimise local issues such as power management and the situation of abrupt power removable. For example, the solid state memory  14  may be used as a data buffer to conserve power, with a transfer of data from the solid state memory  14  to the optical disk drive  18  occurring periodically. This is more power efficient than operating the optical drive  18  continuously. The use of the solid state memory  14  as a buffer would also mitigate against data loss in a case of abrupt power removal.  
         [0034]      FIG. 3  illustrates an example of the use of an embodiment of a data storage apparatus  100  with a digital video camera  22  as an exemplary host device. The storage apparatus  24 , of the kind shown in  FIG. 2 , can be inserted into a conventional solid state memory card slot  26  provided in the camera  22 . In the case of the embodiment shown in  FIG. 2 , the processor  20  of the data storage apparatus  24  subsequently controls the flow of data to and from the storage apparatus  24  and the camera  22 . The removable optical disk  28  can subsequently be removed and used in other consumer devices in a conventional manner. In an alternative embodiment, an additional processor  30  may be provided within the camera  22  to control the flow of data to and from the data storage apparatus  24 . However, the processor  20  integrated in the data storage apparatus  24  still controls other basic functions of the apparatus  100 , such as interface functions. The provision of the processor  30  within the camera  22  transfers the “intelligence” from the data storage apparatus  24  to the camera  22  and allows the camera  22  to interrogate any data storage card coupled to the camera to discover if the card is a conventional solid state memory card or is an embodiment of a storage apparatus. The provision of the processor  30  and camera  22  would allow functionality to be provided in the camera  22  giving control of data storage to the user. For example, the user would be able to specify in which of the data storage devices, that is the solid state memory  14  or the optical drive  18 , specific data is to be stored.  
         [0035]     Other uses of embodiments of the data storage apparatus can be envisaged. For example, with a personal digital assistant to provide a data archiving function, with the archived data being stored on the removable data storage media, i.e. the optical disk  28 , which in turn could be safely stored away from the personal digital assistant with the ability to be restored at a later date.  
         [0036]     Although the above described embodiments of the present invention have referred to solid state memory as the ‘integrated’ storage device and an optical disk as the removable data storage medium, other combinations of available data storage devices and mediums may be used. The combination is likely to be selected in dependence on the anticipated characteristics of the data to be stored. For example, if it is expected that large data files will be stored on the removable storage medium a high density storage medium and appropriate data transfer device may be selected.  
         [0037]      FIG. 4  is a flow chart  400  illustrating a process used by the data storage apparatus  100  of  FIG. 2 . The flow chart  400  shows the architecture, functionality, and operation of a possible implementation of the software for implementing the programming operated by the microprocessor  20  ( FIG. 2 ) residing in the data storage apparatus  100 . In this regard, each block may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order noted in  FIG. 4  or may include additional functions. For example, two blocks shown in succession in  FIG. 4  may in fact be executed substantially concurrently, the blocks may sometimes be executed in the reverse order, or some of the blocks may not be executed in all instances, depending upon the functionality involved, as will be further clarified hereinbelow. All such modifications and variations are intended to be included herein within the scope of this disclosure  
         [0038]     The process starts at block  402 . At block  404 , data from the image capture device is received. At block  406 , a characteristic of the received data is determined. At block  408 , the received data is stored into a solid state memory medium when the determined characteristic corresponds to a first predefined characteristic. At block  410 , the received data is stored into a removable memory medium when the determined characteristic corresponds to a second predefined characteristic. The process ends at block  412 .