1. Field of the Invention
The present invention relates generally to digital cameras employed with a computer using an interface for transferring digital images captured by the digital cameras and particularly to employing a digital camera with a computer without the use of a card reader.
2. Description of the Prior Art
In recent years, the use of digital cameras has become more prevalent as a consumer product. Whereas previously, digital cameras were used almost exclusively by professional photographers and perceived by the public-at-large as exotic devices, nowadays, digital cameras are used by amateur photographers and seen in many households.
The rising popularity of the digital cameras is due to a number of factors. First, the quality of pictures taken by low price cameras has improved considerably. Second, printers with higher resolution and greater quality have been introduced to the market at increasingly more affordable prices.
However, there has not been a comparative success in the area of connectivity between the digital camera and a computer (personal computer (PC) or Macintosh). Pictures taken by a digital camera, being in digital format, must be transported in some manner from the removable storage media of the camera to the storage media of the computer. Inside of the computer, the pictures may be viewed, edited and ultimately transferred to a printer for printing. Therefore, the need arises to establish communication between the digital camera and the computer without the use of a card reader device or extra circuitry within the digital camera, in the form of a USB port built into the storage media, in order to transport data therebetween while reducing costs associated with establishing such communication.
Inside of the computer, the pictures may be viewed, edited and ultimately sent to a printer for re-production. Thus, there needs to be a transport mechanism, which can establish communication with both the digital camera and the computer in order to transport data therebetween.
At present, there are several different methods of connecting the digital camera to a computer. FIG. 1 illustrates one such mode of connectivity wherein a digital camera 12 is shown to be connected to a desktop computer 19 through a transmission cable 18. Also shown in FIG. 1 are a Personal Computer/Compact FLASH (PC/CF) card 16 as well as a serial or universal serial bus (USB) port 14. Transmission cable 18 connects the serial or the USB port 14 of the digital camera to the serial or USB port of the computer 19.
The pictures taken by the digital camera 12 are stored into the PC/CF card 16 and subsequently transmitted from the serial or the USB port 14 of the camera 12, through the serial or the USB port of the computer 19 and the transmission cable 18, to the computer 19. The main limitation of the type of connection shown in FIG. 1 is that the camera has to stay on while data is being transferred. Thus, not only the camera cannot be used while data is being transferred but the battery of the camera is being drained during the entire transmission process. Another limitation of the method of data transmission shown in FIG. 1 is the additional cost of the digital camera due to the circuitry and software associated with the implementation of the serial or USB port 14. The additional cost may make the camera 12 more expensive than that which is within the reach of the average consumer.
An alternative method of transferring the digital data from a digital camera storage media to a computer is shown in FIG. 2(a). Therein is shown a PC/CF card 28, a card reader 20, a transmission cable 25 and a computer 29. The card reader 20 comprises a housing 24 for the PC/CF card 28 as well as the USB controller circuitry 26 and the USB port 27. The transmission cable 25 connects the USB port 27 of the card reader 20 to the USB port 22 of the computer 29.
The card reader 20 provides a bridge between the computer 29 and the PC/CF card 28. The latter is inserted into the digital camera (not shown in FIG. 2(a)) and stores digital images, enabling it to transfer data between the computer 29 and the camera. The PC/CF card 28 establishes connection with the card reader housing 24 through the PC/CF interface 23. The card reader 20 communicates with the computer 29 through the USB controller circuitry 26.
There are disadvantages associated with employing the card reader 20 in FIG. 2(a) such as the substantial cost associated therewith. In addition, since the card reader 20 acts like a bridge between the USB bus 22 on the one hand and the PC/CF bus 23 on the other hand, it does not utilize either of the busses fully. Neither can the card reader 20 optimize the interface between the computer 29 and the PC/CF card 28 because of its lack of direct communication with the internal circuitry of the storage media of either of the two devices. Finally, the card reader 20 has the disadvantage of duplicating logic in circuitry 26 since it must have a PC/CF interface as well as a USB interface in order to establish communication between the PC/CF card 28 and computer 29. The PC/CF card 28 also includes the PC/CF interface 23, as shown in FIG. 2(a).
Another limitation of the prior art systems employing card readers is illustrated in FIG. 2(b) wherein a computer screen is depicted with icon 31 indicating that a removable disk F is connected to the computer. However, icon 31 is displayed as soon as the card reader is connected to the computer regardless of whether there is any PC/CF card in the card reader or not. Therefore, it is misleading to the user as to whether or not the PC/CF card is actually connected to the computer by that which is displayed by the icon 31.
Thus, the need arises for coupling a digital camera's storage media to a PC by avoiding the need for an intermediary interface, such as a card reader, thereby reducing costs, avoiding duplicate circuitry and allowing for a direct connection between a PC/CF card and the PC and thereby allowing for efficient utilization of the interface busses used for connecting the PC/CF card to the PC.