Method and system for reading and assembling audio and image information for transfer out of a digital camera

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A method of transmitting audiovisual information out of an electronic camera, comprising the steps of:

reading, from a memory of the camera, information describing a relationship between image information and audio information;

reading the image information and the audio information, using the information describing the relationship;

transmitting the image information and the audio information without the information describing the relationship;

receiving the image information and the audio information by an external device;

writing the image information and the audio information in a memory of the external device; and

writing information, in the memory of the external device, describing the relationship between the image information and the audio information.

2. A method according to claim 1, further comprising the step of:

detecting, by the external device, the relationship between the image information and the audio information, before the step of writing the information describing the relationship.

3. A method according to claim 2, wherein:

the step of detecting the relationship determines that the image information is to be presented at a same time as the audio information is presented.

4. A method according to claim 3, wherein:

the step of detecting the relationship determines that the image information is to be presented at the same time as the audio information is presented because the transmitting step transmits the image information along with the audio information.

5. A method according to claim 1, further comprising the steps of:

capturing an image corresponding to the image information and audio corresponding to the audio information; and

writing the image information and the audio information into the memory of the camera, along with the information describing the relationship between the image information and the audio information.

6. A method according to claim 5, further comprising the step of:

compressing the image information and the audio information before writing the image information and the audio information into the memory of the camera.

7. A method according to claim 6, further comprising the step of:

storing the image information and audio information which has been compressed into a first in first out (FIFO) memory, before the step of writing the image information and the audio information into the memory of the camera,

wherein the step of writing the image information and the audio information into the memory of the camera includes transferring the image information and the audio information from the FIFO memory to the memory of the camera.

8. A method according to claim 7, wherein:

the step of writing the image information and the audio information writes into a flash memory.

9. A method according to claim 8 wherein:

the step of writing the image information and the audio information transfers from the FIFO memory to the flash memory in a plurality of transfer operations.

10. A method according to claim 9, wherein:

the step of writing performs a number of said transfers which is an integral multiple of a transfer size of said flash memory.

11. A system for transferring information, comprising:

an electronic camera including:

a lens;

a light sensor for sensing images through the lens;

a microphone for sensing audio;

a memory for storing image information obtained by the light sensor, audio information obtained by the microphone, and information describing a relationship between the image information and the audio information;

means for reading, from the memory of the camera, the information describing the relationship between the image information and the audio information;

means for reading the image information and the audio information, using the information describing the relationship; and

a transmitter which transmits out of the electronic camera, the image information and the audio information without the information describing the relationship, and

an external device which is external to the camera and connected to the camera, including;

a memory;

a receiver which receives the image information and the audio information;

means for writing the image information and the audio information in the memory of the external device; and

means for writing information, in the memory of the external device, describing the relationship between the image information and the audio information.

12. A system according to claim 11, wherein the external device further comprises:

means for detecting the relationship between the image information and the audio information, before the means for writing writes the information describing the relationship.

13. A system according to claim 12, wherein:

the means for detecting the relationship determines that the image information is to be presented at a same time as the audio information is presented.

14. A system according to claim 13, wherein:

the means for detecting the relationship determines that the image information is to be presented at the same time as the audio information is presented because the transmitter transmits the image information along with the audio information.

15. A system according to claim 11, wherein the camera further comprises:

means for writing the image information and the audio information into the memory of the camera, along with the information describing the relationship between the image information and the audio information.

16. A system according to claim 15, wherein the camera further comprises:

means for compressing the image information and the audio information before writing the image information and the audio information into the memory of the camera.

17. A system according to claim 16, wherein the camera further comprises:

a first in first out memory (FIFO) which stores the image information and audio information which has been compressed, before writing the image information and the audio information into the memory of the camera,

wherein the means for writing the image information and the audio information into the memory of the camera includes means for transferring the image information and the audio information from the FIFO memory to the memory of the camera.

18. A system according to claim 17, wherein the memory of the camera is a flash memory card.

19. A system according to claim 18, wherein:

the means for transferring transfers from the FIFO memory to the flash memory in a plurality of transfer operations.

20. A system according to claim 19 wherein:

the means for transferring performs a number of said transfers which is an integral multiple of a transfer size of the flash memory.

21. A method according to claim 1, wherein:

the step of reading the information describing a relationship comprises reading, from the memory of the camera which stores a file including information describing a plurality of relationships between image information and corresponding audio information, a first relationship between a first set of the image information and audio information corresponding thereto,

the step of reading the image information and the audio information comprises reading the first set of the image information and the corresponding audio information, using the first relationship; and

the step of transmitting comprises transmitting the first set of the image information and the corresponding audio information without the information describing the relationship.

22. A method according to claim 21, further comprising the steps of:

reading information describing a second relationship between a second set of the image information and the audio information corresponding thereto;

reading the second set of the image information and the audio information corresponding thereto; and

transmitting the second set of the image information and the audio information without the information describing the second relationship.

23. A method according to claim 22, wherein the second set of the image information and the audio information includes a plurality of images, and

the step of transmitting the second set of the image information and the audio information comprises:

transmitting the second set of the image information which includes the plurality of images and the audio information without the information describing the second relationship.

24. A system according to claim 11, wherein:

the means for reading the information describing the relationship comprises means for reading, from the memory of the camera which stores a file including information describing a plurality of relationships between image information and corresponding audio information, a first relationship between a first set of the image information and audio information corresponding thereto,

the means for reading the image information and the audio information comprises means for reading the first set of the image information and the corresponding audio information, using the first relationship; and

the means for transmitting comprises means for transmitting the first set of the image information and the corresponding audio information without the information describing the relationship.

25. A system according to claim 24, further comprising:

means for reading information describing a second relationship between a second set of the image information and the audio information corresponding thereto;

means for reading the second set of the image information and the audio information corresponding thereto; and

means for transmitting the second set of the image information and the audio information without the information describing the second relationship.

26. A system according to claim 25, wherein the second set of the image information and the audio information includes a plurality of images, and

the means for transmitting the second set of the image information and the audio information comprises:

means for transmitting the second set of the image information which includes the plurality of images and the audio information without the information describing the second relationship.

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CROSS-REFERENCES TO RELATED APPLICATIONS

This application is related to commonly owned co-pending U.S. patent application Ser. No. 08/535,378 entitled "Digital Electronic Camera Having an External Input/Output Interface Through Which the Camera is Monitored and Controlled" and U.S. patent application Ser. No. 08/535,562 entitled "A Digital Electronic Still Camera Which Receives an Input/Output Control Program Through a Detachable Communication Interface Card", both of which were filed on Sep. 28, 1995 and are incorporated herein by reference. This application is also related to commonly owned co-pending U.S. patent application Ser. Nos. 08/606,196 entitled "Digital Camera Which Detects a Connection to an External Device", and 08/603,583 entitled "External Communication Interface for a Digital Camera", each concurrently filed with the present application and incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a digital electronic camera and the interfacing of the camera to an external processing device which monitors, receives images and/or audio, and/or controls the camera through an input/output interface. The invention is more particularly related to a digital electronic camera which automatically detects a connection to the external processing device.

Discussion of the Background

Conventional cameras which use light sensitive film have been known for a long time and the manner of generating images is well-known; light sensitive photographic film is exposed to light which passes through a lens and a shutter. The film is then taken to a developing center and processed into photographic prints.

Digital electronic cameras which electronically capture images or images along with audio are also known. However, this field of technology is relatively new and there is not a universal standard for exporting or producing images from digital cameras. When designing the camera corresponding to the present invention, the inventors have discovered various problems in communicating information out of the camera. These problems include the connection of the camera to an external device such as another camera or a general purpose computer. The present inventors have sought to overcome problems pertaining to the actual connection of the camera to the external device, the conversion of signal levels from a level used by the processor within the camera to a level compatible with a communication interface, the detection of a connection of the camera to the external device, and the manner of assembling the information to be transmitted.

SUMMARY OF THE INVENTION

Accordingly, one object of the present invention is to provide an electronic camera which can efficiently transmit information to an external device such as a computer. It is a further object of the invention for the camera to transmit both image and audio information out of the camera. It is another object of the invention to transmit image and audio information out of the camera without transmitting specific data which defines the relationship between the image and audio information.

These and other objects are accomplished by an electronic camera for connection to an external device such as a personal computer. The electronic camera first obtains image and audio information by detecting light which passes through a lens of the camera by a light sensor such as a charge couple device (CCD) and audio information using a microphone. The image and audio are separately compressed by the camera and stored within the camera. Also, information describing that the audio information is related to the image is stored in a memory of the camera.

When transmitting the image and audio out of the camera, the information describing the relationship is read to obtain the correspondence between the image and audio files. The desired image and audio files are then grouped together and transmitted out of the camera without any information describing the relationship between the audio and image.

When an external device such as a personal computer receives the combined image and audio, the image and audio are separated and stored in a memory of the computer. Further, information indicating the relationship between the image and audio are stored in the memory of the external device. Because the image and audio are transmitted together, the external device can determine that the image and audio are related to each other.

Preferably, the camera includes a first in first out (FIFO) memory which is used to temporarily store the information before it is transmitted. The FIFO memory can be used as a buffer both as the image and audio are being read from a memory of the camera so that the image and audio can be transmitted, and also before the image and audio information are written into the memory of the camera. The memory of the camera can be implemented using flash memories. In order to make the flash memories have a high storage speed, high speed buffers such as SRAM memories which are smaller in size than the flash memories can be utilized as buffers.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1A illustrates a perspective view of the front and top of a digital camera according to the present invention;

FIG. 1B illustrates another perspective view of the digital camera of FIG. 1A viewed from the bottom and rear;

FIGS. 2A-2C illustrate perspective views of an external communication interface of the camera;

FIG. 3A illustrates a top view of a latching mechanism of the external communication interface;

FIG. 3B illustrates a cross-sectional view of the latching mechanism of the external communication interface;

FIG. 4A illustrates a view from the top of a pivoting latch member of the latching mechanism;

FIG. 4B illustrates a cross-sectional view of the pivoting latch member;

FIG. 5A illustrates the manner of inserting a latch 196 of the pivoting latch member into a receiving member;

FIG. 5B illustrates the latch 196 after being inserted through and latched to the receiving member;

FIG. 6A illustrates a top view of the latch locked into the receiving member;

FIG. 6B illustrates the pivoting latch member in a release position in which the pivoting latch member has rotated about pivot point 214;

FIG. 7 is an exploded view of the internal components of the external communication interface;

FIG. 8 is a functional block diagram of the electrical aspects of the digital camera;

FIG. 9 illustrates the details of the CPU 23 of the camera;

FIG. 10, illustrates a functional block diagram of the memory card 16 employing four flash memories;

FIG. 11 is a flowchart illustrating the process of capturing an image and audio by the camera;

FIG. 12 illustrates the manner of storing files within the memory card 16 and the format of information to be transmitted out of the camera;

FIG. 13A illustrates a single switch which controls both whether the camera is recording, playing or is off along with whether the camera is receiving or transmitting when connected to an external device;

FIG. 13B illustrates two switches; one for placing the camera in a receive or a transmit mode and the other for setting the camera to a record mode, play mode or turning the camera off;

FIG. 14 illustrates a flowchart of the communication process of the camera with an external device;

FIG. 15 illustrates the manner of transmitting information of the camera to an external device;

FIG. 16 is a flowchart illustrating the specific steps for receiving and storing by the camera data from an external device;

FIG. 17 is a functional block diagram of the electrical components within the external communication interface; and

FIG. 18 illustrates a timing diagram showing how power to the communication circuitry is reduced in order to conserve the life of a camera battery.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIG. 1A thereof, a perspective view showing the front and top of a digital electronic camera according to the present invention is illustrated. The camera, referred to as a digital camera or electronic camera, captures images and/or audio and writes this information into a memory in digital form. The use of photographic film is not necessary and the camera may capture a series of consecutive still images to provide video with movement or motion. The camera 100 illustrated in FIG. 1A contains a button 102 for turning the flash 20 on and off and changing the flash mode, a button 104 for setting the recording mode such as whether audio is to be captured, whether a series of consecutive images are to be captured, etc. A display 22 is a LCD display which displays the state and settings of the camera such as the flash mode, record mode, battery state, number of images taken and other features of the camera. Switch 108 is used to set the self timer and switch 110 is used to turn the camera off and on and also sets whether the record mode or play mode is to be used. This switch in one embodiment is also used to set whether the camera will be in a transmit or receive mode when connected to an external device. There is a red LED 112 which indicates that an image is being recorded or that the self timer is operating. The windows designated by 114 are used to perform automatic focusing and the viewfinder window is designated by 116. Images are captured through the lens 7, and there is a window 118 for receiving commands from an infrared remote control (not illustrated) which can be used to instruct the camera to capture images and/or audio and also control the functions of the camera. There is also a clip 120 which holds a camera strap. A slidable lever 122 is used to zoom the lens and the camera also includes a shutter release button 124.

FIG. 1B illustrates a perspective view of the bottom and back of the camera 100. There is knob 130 to adjust the visibility, a cover 132 which covers an opening for a small button type battery used to maintain the setting of parameters in memory, a view finder 134, a date button 136 and time button 138 which controls the operation of the date and time functions of the camera, a microphone 140, and a switch 142 for controlling the image quality or resolution. There is a hole 146 for receiving a bolt from a tripod, and a lever 148 for releasing memory or I/O cards from the camera body through the slot 160.

The camera according to the present invention allows images and audio in a digital format to be transmitted from and received by the camera to and from an external communication interface which connects to a connecting portion 150 of the camera. The connecting portion 150 includes concave protrusions 152, each protrusion having a hole 154. Within each hole is a receiving member 156 which, due to its position within the hole 154, cannot be seen in FIG. 1B and is more clearly illustrated in FIGS. 5A and 5B which are described below. These receiving members 156 are metal and also serve to provide grounding connections between the camera and the external communication interface. There are also electrical contacts 158 which allow an electrical connection between the camera 100 and an external communication interface. Because of the existence of the slots 160 for receiving various types of cards (e.g., memory or communication PCMCIA cards) there is very little depth for the connection portion 150. This requirement resulted in the design of a novel connection mechanism described in further detail below. Additionally, a conductive ribbon cable which is thin and flexible is used to feed power and receive and transmit signals through the contacts 158.

The camera also includes contacts 162 on the side of the camera and connectors 164 which allow connection of a video display and a speaker to display images and audio generated by the camera.

FIGS. 2A-2C illustrate perspective views of an external communication interface 180. The interface 180 includes, as illustrated in FIG. 2A, a sliding release button 182, a DIN 8 pin RS-422 interface for connection to a modem port of a Macintosh computer and a 9 pin D connector 188 which communicates according to the RS-232 format to an IBM compatible personal computer. Images and/or audio are communicated between the connected computer and camera in either direction. The interface 180 also includes nuts 186 for receiving screws from a pin connector which plugs into the D-9 pin connector 188. FIG. 2B is a perspective view showing the underside of the communication interface 180 which connects to the camera 100. A clearer view of this connection portion 190 is seen in FIG. 2C.

The connection portion 190 includes convex indentations 194 which match with the concave protrusions 152 of the camera. The convex indentations 194 include pivoting latches 196 which latch with the receiving member 156. The communication interface also includes pins 192 which correspond to the contacts 158 of the camera.

FIG. 3A illustrates a latching mechanism 200 located within the external communication interface 180 which is used to connect the external communication interface 180 to the camera 100. The latching mechanism 200 includes a frame 202. On the frame is mounted a spring connector 204 which is used to mount a spring which is connected to a sliding release unit which is illustrated in FIG. 7. There is a pivoting latch member 210 which includes the latch 196 and is resiliently held in place via a spring 206.

FIG. 3B is a cross-sectional view of the latching mechanism 200 illustrated in FIG. 3A. In this figure, it is seen that the frame 202 is not planar but has the center portion thereof raised above a level of the region supporting the pivoting latch member 210. This allows the latching mechanism 200 to be mounted to a board, for example a printed circuit board, having holes to accommodate the end regions of the frame. Only the center region of the frame is mounted on the printed circuit board.

FIG. 4A is a top view of the pivoting latch member 210. The pivoting latch member 210 contains a body 212 which is pivotally mounted at a pivot point 214. Connected to the body 212 is the latch 196 and a pressing surface 216. FIG. 4B is a cross-sectional view of the pivoting latch member 210. This figure clearly shows that the latch 196 is at a level below the level of the body 212. This allows the latch 196 to be inserted into the hole 154 of the camera. Further, the level of the pressing surface 216 is shown to be above the level of the body 212 of the pivoting latch member.

FIGS. 5A and 5B are a perspective view of the operation of connecting the latch 196 of the external communication interface 180 to the receiving member 156 of the connecting portion of the camera. In FIG. 5A, first the latch 196 is pushed downwardly to the level of the receiving member 156. Next, the latch 196 is pushed through the receiving member 156 in order to engage with the receiving member 156 as illustrated in FIG. 5B. Referring to FIG. 5A, as the latch 196 is pushed forward through the receiving member 156, the surface 196A of the latch 196 contacts the surface 156A of the receiving member 156. The rounded surface 196A of the latch 196 causes the latch 196 to pivot and then engage with the receiving member 156, as illustrated in FIG. 5B.

FIGS. 6A and 6B are a top view of the interaction of the pivoting latch member 210 with the receiving member 156. In FIG. 6A, the pivoting latch member 210 is engaged with the receiving member 156 and corresponds to the perspective view illustrated in FIG. 5B. In order to release the latch 196 from the receiving member 156, a force is applied against the pressing surface 216 which pivots the latch member 196 so that the latch member 196 and the entire external communication interface can be slid back so that the latch 196 is no longer under the receiving member 156. Then, the latch 196 along with the entire external communication interface can be separated from the camera by moving the external communication interface away from the camera.

FIG. 7 is an exploded view of the internal components of the external communication interface 180. There is a sliding release unit 222 having ends which engage with the pressing surfaces 216 of the pivoting latch member 210. The exact position of the sliding release button 182 illustrated in FIG. 2A can be seen in FIG. 7. There is a groove 224 in the sliding release unit 222 which mates with and receives the spring connector 204. The spring connector 204 slides along this groove 224. There is also a spring connector 226 on the latching mechanism 222. A spring (not illustrated) connects to the spring connector 204 and the spring connector 226. This keeps the sliding release unit 222 biased away from the pressing surfaces 216. In order to operate the release mechanism, the sliding release unit is pushed towards the pressing surfaces 216 in the direction of the arrow on the sliding release button 182 which causes the latches 196 to pivot inwardly or towards each other.

The frame 202 of the latching mechanism spans the two holes 232 in a printed circuit board 230. Due to the offset levels of the frame 202, the ends of the frame containing the pivoting latch members 210 fit within the holes 232. Mounted on the printed circuit board 230 is a signal level conversion chip 234 which is described in detail below. Connected to the signal level conversion chip 234 are the 8 pin RS-422 connector 236 and the 9 pin D connector for RS-232 signals.

FIG. 8 is a block diagram showing the details of the construction of the camera 100. The microphone 1 is connected to an amplifier/filter 2a, which outputs a signal to an analog-to-digital converter 4. The amplifier/filter 2a reduces the audio signal to the appropriate bandwidth. The analog-to-digital converter 4 operates with an optimum sampling frequency, for instance, at a frequency which is an integer-times of the sub-carrier frequency of an NTSC signal used by the camera. Further, a sampling frequency of the A/D converter 4 is more than two times the necessary bandwidth. An audio data compression/expansion circuit 3 is used to encode and decode audio signals using known methods of audio encoding such as linear PCM, Dolby AC-3, or MPEG-2 audio encoding. The compressed audio signals are trans