Abstract:
A digital camera having a plurality of adjustable memory card fullness icons to visually indicate the amount of memory space that is available for storage in a plurality of corresponding removable memory cards insertable into the digital camera is disclosed. The digital camera includes an arrangement for capturing and digitizing image data, a display, and a processor for constructing the memory card fullness icon on the display. Each memory card fullness icon includes an inner portion that can be adjusted to graphically display the relative amount of memory space that is available for storage in its corresponding removable memory card. The digital camera further includes circuitry for transferring the digitized image data into a selected removable memory card. The processor determines the relative amount of available memory space in the selected memory card and modifies the adjustable inner portion of the memory card fullness icon on the display to visually indicate in graphic format the present relative amount of available memory space in the selected memory card.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the field of electronic imaging, and in particular, to digital cameras having memory cards. 
     BACKGROUND OF THE INVENTION 
     Typical digital cameras include a memory card onto which captured digital images can be stored. Many digital cameras provide an indication of the approximate number of images that could be stored on a memory card. However, this number depends on the resolution level and compression mode, which can be confusing to a user. This can be difficult for the user to determine whether the memory card is nearly empty or nearly full. 
     Some new digital cameras provide two memory card slots, which enable images to be stored on either card, or transferred from one card to another. This increases a user&#39;s difficulty in determining the amount of memory space that is available for storage in each of the memory cards. 
     U.S. Pat. No. 5,481,303 discloses an electronic still camera which uses a memory card for storing captured images. The camera includes an indicator light and detects the remaining capacity on the memory card, and causes the indicator light to flash when the available memory space on the memory card is close to capacity. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a visual indication which can quickly determine how much space has been used on each memory card, and how much available memory space is remaining. 
     It is a further object of the present invention to provide a digital camera having an adjustable memory card fullness icon which visually indicates in graphic format the relative amount of available memory space on a removable memory card. 
     These objects are achieved by a digital camera having an adjustable memory card fullness icon to visually indicate in graphic format the amount of memory space that is available for storage in a removable memory card insertable into the digital camera, comprising: 
     (a) means for capturing and digitizing image data; 
     (b) a display; 
     (c) a processor coupled to the display for constructing the memory card fullness icon on the display, the memory card fullness icon having a graphical representation of a memory card, and including an inner portion that can be adjusted to graphically display the relative amount of memory space that is available for storage in the removable memory card; 
     (d) means for receiving the removable memory card; 
     (e) means for transferring the digitized image data into the removable memory card; and 
     (f) the processor including means responsive to the data transfer means for determining the relative amount of available memory space in the removable memory card and for modifying the adjustable inner portion of the memory card fullness icon on the display in accordance with the determined relative amount of available memory space to visually indicate in graphic format the present relative amount of available memory space in the removable memory card. 
     These objects are also achieved by a digital camera having a plurality of memory card fullness icons to visually indicate the amount of memory space that is available for storage in a plurality of corresponding removable memory cards insertable into the digital camera, comprising: 
     (a) means for capturing and digitizing image data; 
     (b) a display; 
     (c) a processor coupled to the display for constructing the plurality of memory card fullness icons on the display, each memory card fullness icon having an inner portion that can be adjusted to display in graphic format the relative amount of memory space that is available for storage in its corresponding removable memory card; 
     (d) means for receiving the plurality of removable memory cards; 
     (e) means for selecting one of the plurality of removable memory cards for storage; 
     (f) means for transferring the digitized image data into the selected removable memory card; and 
     (g) the processor including means responsive to the data transfer means for determining the relative amount of available memory space in the selected removable memory card and for modifying the adjustable inner portion of the corresponding memory card fullness icon on the display in accordance with the determined relative amount of available memory space on the selected removable memory card to visually indicate in graphic format the present relative amount of available memory space in the selected removable memory card. 
     ADVANTAGES 
     It is an advantage of the present invention to provide a digital camera having a simple, easily understood visual indication of the approximate amount of memory remaining on a removable memory card. In this manner, a user would know whether an additional memory card is needed, or whether captured images should be downloaded to a computer for storage. 
     An important feature of the present invention is that a digital camera can have two memory cards and a user can select the appropriate memory card for image storage. A user can determine how much memory space is available on each card by viewing the graphical display on the icon. This is particularly useful for applications such as sports photography, where the photographer would like to know whether a memory card is nearly empty or nearly full before a major event is about to occur. A user can also transfer images from one card to another within the digital camera. This is particularly useful for image management in situations, for example, where a user is taking pictures for multiple clients. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is block diagram of a digital camera including a single memory card in accordance with a first embodiment of the present invention; 
     FIG. 2A depicts an image display on the digital camera of FIG. 1 which has a memory card fullness icon that graphically displays that the memory card does not contain any image data; 
     FIG. 2B depicts the same image display as FIG. 2A, but shows the memory card fullness icon as indicating that the memory card is one third full; 
     FIG. 2C depicts the same image display as FIG. 2B, except that the memory card fullness icon indicates that the memory card is two thirds full; 
     FIG. 3A depicts another embodiment of the present invention wherein the memory card fullness icon is shown on a status display on the digital camera of FIG. 1; 
     FIG. 3B depicts the memory card fullness icon as being a status liquid crystal display; 
     FIG. 4 is block diagram of another embodiment of a digital camera including two memory cards; 
     FIG. 5 depicts an image display on the digital camera of FIG. 4 which has two memory card fullness icons that graphically display the availability of memory storage on/he two memory cards, respectively; and 
     FIG. 6 depicts an alternative embodiment of the two memory card fullness icons on the image display of FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Because imaging devices employing electronic sensors are well known, the present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. Elements not specifically shown or described herein may be selected from those known in the art. 
     Referring to FIG. 1, a block diagram of an exemplary digital camera  10  in accordance with a first embodiment of the present invention is shown, such as, for example, the Kodak DCS 315™ digital camera sold by the Eastman Kodak Company. As shown in FIG. 1, the digital camera  10  includes a lens  12  which directs image light from a subject (not shown) through an aperture/shutter controller  13  upon an image sensor  14  having a discrete number of photosites or pixels arranged in a two-dimensional array to form individual photosites corresponding to the pixels of the image. The image sensor  14  can be a charge coupled device (CCD) sensor, such as, for example, the Kodak KAF-1600 full-frame sensor having 1536 columns and 1024 rows of photosites, or a complementary metal oxide semiconductor (CMOS) imager. The photosites of the image sensor  14  convert the incident photons of light into electron charge packets. Each photosite is overlaid with a color filter array (CFA), such as the Bayer CFA described in commonly-assigned U.S. Pat. No. 3,971,065, the disclosure of which is herein incorporated by reference. The Bayer CFA has 50% green pixels in a checkerboard mosaic, with the remaining pixels alternating between red and blue rows. The photosites respond to the appropriately colored incident light illumination to provide an analog signal corresponding to the intensity of illumination incident on the photosites. 
     The analog output of each pixel is amplified and analog processed by an analog signal processor (ASP)  16  to reduce the image sensor&#39;s output amplifier noise. The output of the ASP  16  is converted to a digital image signal by an analog-to-digital (A/D) converter  18 , such as, for example, an 8 bit A/D converter which provides an 8 bit signal in the sequence of the Bayer CFA. 
     The digitized image signal is temporarily stored in a frame memory  20 , and is then processed and compressed by a digital signal processor (DSP)  22 . The image processing includes white balance, color correction, tone correction, and image sharpening. The DSP  22  also decimates (or resamples) the digitized image signal for each still image to produce a thumbnail image having fewer pixels (i.e., lower resolution) than the original captured image as described in commonly-assigned U.S. Pat. No. 5,164,831 to Kuchta et al., the disclosure of which is herein incorporated by reference. The image file containing both the full resolution image and the thumbnail image is stored in a data memory  26 , and then transferred through a memory card interface  32  to a memory card  28  that is present in a memory card slot  30  of the digital camera  10 . The thumbnail image is also sent to an image display  24 , such as a Seiko Epson Model LB18-B000 312×230 pixel color liquid crystal display (LCD), through an LCD controller  25  where the user can view the image. The image display  24 , which is shown in more detail in FIGS. 2A-2C and which will be discussed later, includes a conventional arrangement for displaying the captured image. The image display  24  may, alternatively, utilize many other types of raster image displays, including miniature CRT&#39;s, organic light emitting diode (LED) arrays, or field emission displays. 
     The memory card  28  can be adapted to the PCMCIA card interface standard, such as described in the  PC Card Standard, Release  2.0, published by the Personal Computer Memory Card International Association, Sunnyvale, Calif., September 1991. The memory card  28  can also be adapted to the Compact Flash interface standard, such as described in the  CompactFlash Specification Version  1.3, published by the CompactFlash Association, Palo Alto, Calif., Aug. 5, 1998. 
     Electrical connection between the memory card  28  and the digital camera  10  is maintained through a card connector (not shown) positioned in the memory card slot  30 . The memory card interface  32  and the card connector provide, e.g., an interface according to the aforementioned PCMCIA card or CompactFlash interface standard. The image file may also be sent to a host computer (not shown), which is connected to the digital camera  10  through a host computer interface  34 . 
     In operation, a camera microprocessor  36  receives user inputs  48 , such as from a shutter release (not shown), and initiates a capture sequence by signaling a timing generator  38 . The timing generator  38  is connected generally to the elements of the digital camera  10 , as shown in FIG. 1, for controlling the digital conversion, compression, and storage of the image signal. The camera microprocessor  36  also processes a signal from a photodiode  44  for determining a proper exposure, and accordingly signals an exposure driver  46  for setting the aperture and shutter speed via the aperture/shutter controller  13  and triggers a flash unit  42  (if needed). The image sensor  14  is then driven from the timing generator  38  via a sensor driver  40  to produce the image signal. The user inputs  48  are used to control the operation of the digital camera  10  in a well-known manner. 
     Referring now to FIGS. 2A-2C, a memory card fullness icon  52  is provided on the image display  24  in accordance with the present invention. The memory card fullness icon  52  includes a graphical representation of the removable memory card  28 . The memory card fullness icon  52  further includes an inner portion  54  that can be adjusted to graphically display the relative amount of memory space that is available for storage in the removable memory card  28 . The use of the term “graphic” means a non-numeric indication which has an adjustable portion such as a bar or a colored area. For example, the graphical format on the memory card fullness icon  52  (or  66  and  68 ) can be provided by adjustable color portions. One color can indicate the amount of memory availability, while another color can indicate the amount of used memory. In FIG. 2A, the memory card fullness icon  52  indicates that the memory card  28  is empty. In FIG. 2B, the memory card fullness icon  52  indicates that the memory card  28  is one third full. In FIG. 2C, the memory card fullness icon  52  indicates that the memory card  28  is two thirds full. 
     The camera microprocessor  36 , which is coupled to the image display  24  through the LCD controller  25  (see FIG.  1 ), constructs the memory card fullness icon  52  on the image display  24 . The camera microprocessor  36  determines, using the memory card interface  32 , the amount of total memory and available memory in the memory card  28 . The ratio of the available memory to the total memory in the memory card  28  is then calculated by the camera microprocessor  36 . The camera microprocessor  36  then provides appropriate signals to the memory card fullness icon  52  on the image display  24  to cause the modification of the adjustable inner portion  54  of the memory card fullness icon in accordance with the determined ratio of the available memory to the total memory to visually indicate in graphic format the present relative amount of available memory space in the memory card  28 . Other circuit architectures will suggest themselves to those skilled in the art. For example, the data memory  26  can be directly coupled by a bus to the image display  24  under the control of the camera microprocessor  36 . 
     The portion of the memory card fullness icon  52  that is filled is determined by the following ratio: 
     [number of bytes that are currently “used” or recorded on memory card  28 ]/[number of total bytes available for storage on the memory card  28 ]. For example, if the digital camera  10  uses an 8 Mbyte memory card and 2 Mbyte worth of images has been taken, 6 Mbyte are available for storage on the memory card  28  and the memory card fullness icon  52  is 25 percent full. The memory card fullness icon  52  does not assume a specific resolution level or compression; it is independent of both of these settings. Accordingly, it is easier for a user to understand whether the memory card  28  is “mostly” full or “mostly” empty, compared to having only a number of pictures remaining that changes as a function of resolution level and compression mode. 
     Referring again to FIG. 1, a status display  50  is shown which can be used in place of the image display  24  for displaying the memory card fullness icon  52 . FIG. 3A shows the status display  50  in more detail. As shown in FIG. 3A, the status display  50  also displays a conventional battery level indicator  60  and a flash mode indicator  62 . In FIG. 3B, the memory card fullness icon  52  is shown in more detail. As shown, the memory card fullness icon  52  is provided by a series of liquid crystal display (LCD) segments  64  which are controlled to visually indicate in a graphic format the available storage on the memory card  28 . Each LCD segment  64  provides for a different level of storage fullness on the memory card  28 . The LCD segments  64  are driven by the camera microprocessor  36  by way of LCD segment drivers which are understood to be included in the block labeled “camera microprocessor  36 ” on FIG.  1 . The status display  50  could, alternatively, use light emitting diodes (LED&#39;s) or other emissive display technologies. 
     Turning now to FIG. 4, a block diagram similar to FIG. 1 is depicted. The main difference is that this block diagram includes a second memory card  58  that is present in a second memory card slot  56  which is electrically connected to the memory card interface  32 . The operation of the digital camera  10  is similar to FIG. 1 with the exception that the user, through the user inputs  48 , can select which of the memory cards  28  or  58  is to be used for storing captured images. The user can also cause image information to be transferred through the memory card interface  32  from one of the memory cards to another memory card under the control of the camera microprocessor  36 . The image display  24  or the status display  50  now has two memory card fullness icons  66  and  68  which respectively correspond to memory cards  28  and  58  and indicate their respective relative availability of memory storage. FIG. 5 shows the image display  24  with the two memory card fullness icons  66  and  68 . As shown, the memory card fullness icon  66  indicates that the memory card  28  is one third full and the memory card fullness icon  68  indicates that the memory card  58  is two thirds full. 
     FIG. 6 depicts an alternative embodiment of the two memory card fullness icons  66  and  68  on the image display  24  of FIG.  5 . The first memory card fullness icon  66  includes a card slot number  80  (indicating the first memory card  28  inserted in the memory card slot  30  shown in FIG. 4) and a card total memory size value  84  (indicating, for example, that the first memory card  28  is an 8 Mbyte capacity card). Similarly, the second memory card fullness icon  68  includes a card slot number  82  (indicating the second memory card  58  inserted in  5  memory card slot  56 ) and a card total memory size value  86  (indicating, for example, that the second memory card  58  is a 4 Mbyte capacity card). 
     In accordance with the present invention, the memory fullness icons  66  and  68 , as shown in FIG. 6, include inner portions  90  and  100 , respectively, that are adjusted to graphically display the amount of memory space that is available for storage in each corresponding memory card, relative to the largest capacity of the two cards (for example, relative to the 8 Mbyte card capacity of the first memory card  28  inserted in the memory card slot  30 ). The inner portion  90  of the first memory card fullness icon  66  includes two regions  92  and  94 , which differ in tone or color. In a preferred embodiment, the upper region  94  is colored green, indicating the relative amount of available (i.e., unused) memory space on the first memory card  28  while the lower region  92  is colored black, indicating the relative amount of memory on the first memory card  28  which is currently storing images. 
     Because the total capacity of the second memory card  58  is less than the total capacity of the first memory card  28 , the inner portion  100  of the second memory card fullness icon  68  includes three regions  102 ,  104 , and  106  which all differ in tone or color. In a preferred embodiment, the upper region  106  is colored red, indicating that the second memory card  58  has a proportionally lower memory capacity than the first memory card  28 . The middle region  104  is colored green, indicating the relative amount of available (i.e., unused) memory space on the second memory card  58 , while the lower region  102  is colored black, indicating the relative amount of memory which is currently storing images. 
     The colored inner portions  90  and  100  of the memory card fullness icons  66  and  68 , respectively, enable the user to easily visualize whether or not it will be possible to copy images from one memory card to another. For example, if the height of the green region  104  of the second memory card fullness icon  68  is larger than the height of the black region  92  of the first memory card fullness icon  66 , all of the images stored on the first memory card  28  can be copied to the second memory card  58  (i.e., the memory card  58  has sufficient available memory space to receive all of the images stored on the memory card  28 ). 
     Alternatively, the memory card fullness icons  66  and  68  for the two different capacity memory cards  28  and  58 , respectively, could be displayed using two different sized icons, rather than using three different regions (i.e., regions  102 ,  104 , and  106 ) for the memory card fullness icon of the smaller capacity card. For example, the memory card fullness icon  68  for the 4 Mbyte memory card could have a smaller vertical height than the memory card fullness icon  66  for the 8 Mbyte card. The memory card fullness icon  68  would then use only two different regions (i.e., regions  102  and  104 ) rather than the three regions depicted in FIG.  6 . This approach would allow use of relative size as a perceptual indicator of used/unused capacity for different capacity memory cards. 
     The invention has been described in detail with particular reference to preferred embodiments thereof. It will be understood that variations and modifications can be effected within the spirit and scope of the invention. 
     PARTS LIST 
       10  digital camera 
       11  lens 
       12  aperture/shutter controller 
       13  image sensor 
       16  analog signal processor 
       18  analog-to-digital converter 
       20  frame memory 
       22  digital signal processor 
       24  image display 
       25  liquid crystal display controller 
       26  data memory 
       28  memory card 
       30  memory card slot 
       32  memory card interface 
       34  host computer interface 
       36  camera microprocessor 
       38  timing generator 
       40  sensor driver 
       42  flash unit 
       44  photodiode 
       46  exposure driver 
       48  user inputs 
       50  status display 
       52  memory card fullness icon 
       54  adjustable inner portion 
       56  memory card slot 
       58  memory card 
       60  battery level indicator 
       62  flash mode indicator 
       64  liquid crystal display segment 
       68  memory card fullness icon 
       80  memory card fullness icon 
       82  card slot number 
       84  card slot number 
       86  card total memory size value 
       90  card total memory size value 
       94  adjustable inner portion 
       100  lower region 
       102  upper region 
       104  adjustable inner portion 
       106  lower region 
     middle region 
     upper region