Abstract:
An image-capturing apparatus is provided having a memory, a storage medium, and a storage control device. The memory is built in the image-capturing apparatus. The storage medium stores image data. The storage control device stores image data into the memory when the remainder of the storable capacity of said storage medium becomes too small to store image data.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an image-capturing apparatus, in particular to the storage of an image file in a storage medium of the image-capturing apparatus. 
         [0003]    2. Description of the Related Art 
         [0004]    An image-capturing apparatus, for example a digital camera, converts a photography subject input from the lens to image data by utilizing a CCD/AFE. The image data is stored temporarily in a RAM, processed by a DSP, and then stored in a removable external storage medium. On an LCD screen, image data stored in the storage medium, a through image obtained through the lens, and information required for operating a digital camera are displayed either automatically or according to the operation of a switch. 
         [0005]    The storage capacity of the storage medium that stores image data and is removable, for example an SD card™ is limited so that image data cannot be recorded exceeding its capacity. Therefore, the remainder of storable capacity will be diminished during the storing of image data. In this case, the process of storing image data cannot be completed, and the image data is lost. A digital camera which has a backup device located outside of the digital camera body to prevent loss of the image data is disclosed in Japanese Unexamined Patent Publication (KOKAI) No. 2004-153369. 
         [0006]    However, the provision of a backup device external to the digital camera requires a transmitter, which increases the size and power consumption of the digital camera. Moreover, it does not assure the completion of data storage into the backup device because a communication failure may occur during transmission. 
       SUMMARY OF THE INVENTION 
       [0007]    An object of the present invention is to provide an image-capturing apparatus that can avoid the loss of image data in the event that the remainder of the storable capacity is diminished during the storing of image data. 
         [0008]    According to the present invention, there is provided an image-capturing apparatus comprising a memory built in the image-capturing apparatus, a storage medium for storing image data, and a storage control device to enable storage of said image data to said memory when the remainder of storable capacity in the storage medium available for storing image data is diminishing. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which: 
           [0010]      FIG. 1  is a block diagram showing the image-capturing apparatus as an embodiment of the present invention; 
           [0011]      FIG. 2  is a diagram showing how the memory is divided; 
           [0012]      FIG. 3  is a flowchart showing the anterior half of the storing process of the present invention; and 
           [0013]      FIG. 4  is a flowchart showing the posterior half of the storing process of the present invention; 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    The present invention is described below with reference to the embodiments shown in the drawings.  FIG. 1  is a block diagram showing a digital camera which has an image-capturing apparatus that applies to the embodiment of the present invention. 
         [0015]    A photography subject is focused onto the CCD  120  through a lens  110 , an aperture  112 , and shutter  113 . The lens  110 , an aperture  112 , and shutter  113  are controlled by a motor driving circuit  114  receiving instructions from a DSP  124 . The shutter  113  is released by operating a release button (not shown), the CCD  120  converts a focused subject into an analog signal, and then an AFE  122  converts the analog signal received from the CCD  120  into a digital signal. 
         [0016]    The DSP  124  compresses and stores a digital signal of the image data into a memory card  130  (e.g. SD card™) via temporarily storage of it into the memory  126 . A battery  133  is connected to the DSP  124 , to which it provides electric power. The DSP  124  controls the power supply or cutoff to devices provided in the digital camera, and controls the power supply to devices in power saving mode in order that the DSP  124  only provides power to a necessary minimum of devices, according to the operation of the power switch  131 . 
         [0017]    The image data is displayed on an LCD  138 . The LCD  138  may display a still image or a moving image which is received from the AFE  122  before imaging, and may display image data stored in the memory card  130  after imaging. A backlight  136  is provided in the LCD  138 . A backlight control circuit  134  turns the backlight  136  on when receiving an indication from the DSP  124 . 
         [0018]    The memory  126  comprises a DRAM with a refresh circuit  128 . The refresh circuit  128  is a holding device for holding the image data in the memory  126 , and a circuit to make the memory  126  operates in self-refresh-mode. In self-refresh-mode, the memory  126  performs the refresh operation automatically without a clock signal, i.e. a timing pulse provided from an external device. Therefore, the memory  126  can continue to hold a stored data, without a clock signal provided from an external device, with only electrical power provided. This makes it possible to lower the electrical consumption of the digital camera. 
         [0019]    A working memory space  210  is provided in the memory  126  for storing pre-compressed image data, i.e. the raw data (YUV data) temporarily. Three backup spaces, i.e. a first backup space  212 , a second backup space  214 , and a third backup space  216 , are provided for storing compressed image data in memory spaces other than the working memory space  210 . 
         [0020]    The embodiment of the invention is described below with references to  FIGS. 3 and 4 . 
         [0021]    A digital camera is powered on in step S 310 , and then, executes an initialization operation in step S 312 . The initialization operation comprises the movement of the lens  110  into a photographing position and the display of a starting sign on the LCD  138 . After the initialization, it is judged whether a counter N is less than 3 or not in step S 314 . The counter N indicates how much image data can be stored into the backup space of the memory  126 . The memory  126  has three backup spaces in this embodiment, so the maximum number of the counter N is three. In the case that the counter N is greater than or equal to three, no image data has been stored in a backup space, so the process moves to step S 328  without copying to the memory card  130 . 
         [0022]    When the counter N is less than three, it shows that the image data is stored in a backup space. A copy process whereby the image data is copied onto the memory card  130  from the memory  126 , is therefore executed. It is judged whether the remainder of storable capacity in the memory card  130  is sufficient to store the image data or not in step S 316 . The judgment is carried out by comparing the size of the image data which is stored in the memory  126  with the remainder of storable capacity in the memory card  130 . If the remainder is sufficient, a message is displayed on the LCD  138 . This message enables the user to select whether the image data is copied onto the memory card  130  or not. Referring to the message, the user makes a choice between copying to the memory card  130  or not using an operation switch  132  in S 318 . When the option to not copy is chosen, the image data stored in the backup space is deleted, and the process moves to step S 322 . When the user chooses the option to copy, all the image data stored in the backup space is copied onto the memory card  130 , and deleted from the backup space in step S 320 . All the image data stored in the backup space is now stored on the memory card, and all of the backup space is cleared, so that three spaces worth of image data can be stored in the backup space. 
         [0023]    The numeral three is set into the counter N in step S 322 . The DSP  124  subsequently recognizes that three images can be stored in the backup space herewith. 
         [0024]    It is judged whether the remainder of storable capacity in the memory card  130  is sufficient storage or not in step S 324 . If the remainder is not large enough, an alert sign, which indicates that the remainder is insufficient, is displayed on the LCD  138  in step S 326 . If the remainder is large enough, the process moves to step S 328 . 
         [0025]    It is judged whether the power switch  131  is activated or not in step S 328 . If the power of the digital camera is switched off by operating the power switch  131 , the process moves to step S 330 . When the power is not switched off, it is judged whether the release switch is pressed halfway or not in step S 332 . If the release switch is not pressed halfway, the process returns to step S 328 . 
         [0026]    When the release switch is pressed halfway, auto-focusing (AF) is executed in step S 334 . It is judged whether the release switch is pressed halfway or not in step S 336 . If the release switch is pressed halfway, it is judged whether the release switch is pressed fully or not in step S 338 . When the release switch is pressed fully, a release process is executed in step S 340 . The release process generates image data by executing processes from imaging to image-compressing using devices including the lens  110  and the CCD  120 . The image data is stored temporary into the working memory space  210  of the memory  126 . 
         [0027]    It is judged whether the remainder of storable capacity in the memory card  130  is sufficient for the storage of data or not in step S 342 . If the remainder is large enough, the numeral three is set into the counter N in step S 344 , and image data generated in step S 340  is stored in the memory card  130 . The photographing action is completed herewith, and the process returns to step S 328 . 
         [0028]    If the remainder of storable capacity in the memory card  130  is not large enough for storage in step S 342 , the image data is stored into a backup space, and 1 is subtracted from the counter N. In the next step S 350 , it is judged whether counter N is greater than 0 or not. If the counter N is greater than 0, i.e. the backup space has some empty space, the process returns to step S 328 . If the counter N is less than or equal to 0, i.e. each backup space contains stored image data, the memory (DRAM)  126  is set to self-refresh-mode in step S 352 . 
         [0029]    In self-refresh-mode, the power supply to the memory  126  is sustained in step S 354 , but the power of the digital camera is switched off in step S 356 . Thus, even if the power of a digital camera is off, the memory  126  and peripheral devices (not shown) are powered by the power supply (not shown) provided in the digital camera. In the case that the remainder of storable capacity in the memory card  130  is not large enough, it is enabled herewith that essential energy consumption of the digital camera is kept to a necessary minimum, and the image data remains in the a memory  126 . 
         [0030]    Note that the number of storage space for storing compressed image data may not only be limited to three, and may be greater than or equal to one. 
         [0031]    The refresh circuit may not be disposed in the memory  128 , but may also be disposed in the digital camera. 
         [0032]    Moreover, the memory card is not limited to being an SD card™, but may also be a removable storage medium such as a Smart Media™, or a Compact Flash™. 
         [0033]    Although the embodiment of the present invention has been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in this art without departing from the scope of the invention. 
         [0034]    The present disclosure relates to subject matter contained in Japanese Patent Application No. 2006-144853 (filed on May 25, 2006), which is expressly incorporated herein, by reference, in its entirety.