|
Digital Camera Patent Abstract
A digital camera includes a CPU (34). The CPU (34) is a multitasking
CPU for executing in parallel an imaging task, a file recording
task, and a file transmitting task. When a shutter button (32) is
operated, JPEG data corresponding to an object scene is written
to an SDRAM (22) by the imaging task. An image file including the
JPEG data stored in the SDRAM (22) is recorded in a CF memory of
a memory/LAN cartridge (30) by the file recording task. The image
file recorded in the CF memory is applied to a wireless LAN card
of the memory/LAN cartridge (30) by the file transmitting task.
Digital Camera Patent Claims
1. A digital camera that processes an image signal of an object
scene imaged by an imaging means by a processor mounting a multitasking
OS, wherein a plurality of tasks to be executed by said processor
includes a first task for writing the image signal from said imaging
means to an internal memory, a second task for recording the image
signal stored in said internal memory in a recording medium, and
a third task for applying the image signal recorded in said recording
medium to a communication means.
2. A digital camera according to claim 1, wherein said third task
includes a first transfer process for transferring the image signal
recorded in said recording medium to said internal memory, and a
second transfer process for transferring the image signal stored
in said internal memory to said communication means.
3. A digital camera according to claim 2, wherein said third task
further includes a determination process for determining whether
or not it is possible to communicate by said communication means,
and said first transfer process and said second transfer process
are validated when a determination result by said determination
means is affirmative.
4. A digital camera according to claim 2, wherein said third task
further includes a restriction process for restricting said second
task prior to said first transfer process, and a canceling process
for canceling the restriction placed on said second task after said
second transfer process.
5. A digital camera according to claim 4, wherein each of said
first transfer process and said second transfer process is a process
transferring a predetermined number of screens of image signals.
6. A digital camera according claim 2, wherein said third task
further includes an encryption process for performing encryption
on the image file transferred to said internal memory by said first
transfer process, and said second transfer process is a process
to transfer the encrypted image file by said encryption process
to said communication means.
7. A digital camera according to claim 1, wherein said recording
medium and said communication means are stored in a detachable cartridge.
8. A digital camera according to claim 3, wherein said third task
further includes a restriction process for restricting said second
task prior to said first transfer process, and a canceling process
for canceling the restriction placed on said second task after said
second transfer process.
9. A digital camera according claim 3, wherein said third task
further includes an encryption process for performing encryption
on the image file transferred to said internal memory by said first
transfer process, and said second transfer process is a process
to transfer the encrypted image file by said encryption process
to said communication means.
10. A digital camera according claim 4, wherein said third task
further includes an encryption process for performing encryption
on the image file transferred to said internal memory by said first
transfer process, and said second transfer process is a process
to transfer the encrypted image file by said encryption process
to said communication means.
11. A digital camera according claim 5, wherein said third task
further includes an encryption process for performing encryption
on the image file transferred to said internal memory by said first
transfer process, and said second transfer process is a process
to transfer the encrypted image file by said encryption process
to said communication means.
12. A digital camera according claim 8, wherein said third task
further includes an encryption process for performing encryption
on the image file transferred to said internal memory by said first
transfer process, and said second transfer process is a process
to transfer the encrypted image file by said encryption process
to said communication means.
13. A digital camera according to claim 8, wherein each of said
first transfer process and said second transfer process is a process
transferring a predetermined number of screens of image signals.
14. A digital camera according claim 13, wherein said third task
further includes an encryption process for performing encryption
on the image file transferred to said internal memory by said first
transfer process, and said second transfer process is a process
to transfer the encrypted image file by said encryption process
to said communication means.
15. A digital camera according to claim 2, wherein said recording
medium and said communication means are stored in a detachable cartridge.
16. A digital camera according to claim 3, wherein said recording
medium and said communication means are stored in a detachable cartridge.
17. A digital camera according to claim 4, wherein said recording
medium and said communication means are stored in a detachable cartridge.
18. A digital camera according to claim 5, wherein said recording
medium and said communication means are stored in a detachable cartridge.
19. A digital camera according to claim 6, wherein said recording
medium and said communication means are stored in a detachable cartridge.
Digital Camera Patent Description
TECHNICAL FIELD
[0001] The present invention relates to a digital camera. More
specifically, the present invention relates to a digital camera
for transmitting an image signal of an imaged object scene to the
outside through a communication circuit.
PRIOR ART
[0002] An example of such a kind of conventional digital camera
is disclosed in Japanese Patent Laying-open No. 2002-199121 laid-open
on Jul. 12, 2002. The prior art is directed to transmit image data
stored in a memory unit to a home server when a digital camera comes
within a radio communication area. Thus, it is possible to store
the image data in the home server without performing a troublesome
operation. However, in the prior art, once that transmission is
started, an imaging operation is invalidated until the transmission
of all the image data is completed. Thus, in the prior art, there
is a problem of being short of operability.
SUMMARY OF THE INVENTION
[0003] Therefore, it is a primary object of the present invention
to provide a digital camera capable of improving operability.
[0004] A digital camera according to the present invention is a
digital camera that processes an image signal of an object scene
imaged by an imaging means by a processor mounting a multitasking
OS, and a plurality of tasks to be executed by the processor includes
a first task for writing the image signal from the imaging means
to an internal memory, a second task for recording the image signal
stored in the internal memory in a recording medium, and a third
task for applying the image signal recorded in the recording medium
to a communication means.
[0005] The image signal of the object scene imaged by the imaging
means is processed by the processor mounting the multitasking OS.
More specifically, the image signal from the imaging means is written
to the internal memory by the first task, the image signal stored
in the internal memory is recorded in the recording medium by the
second task, and the image signal recorded in the recording medium
is applied to the communication means by the third task.
[0006] Due to the multitasking property, the first task and the
third task are operated in parallel with each other. Accordingly,
even if an imaging operation is performed by the imaging means at
a time that the second task or the third task is activated, the
image signal from the imaging means is immediately written to the
internal memory by the first task. Thus, it is possible to improve
operability.
[0007] It is preferable that third task includes a first transfer
process for transferring the image signal recorded in the recording
medium to the internal memory, and a second transfer process for
transferring the image signal stored in the internal memory to the
communication means.
[0008] It is noted that in a case that the third task further includes
a determination process for determining whether or not it is possible
to communicate by the communication process, the first transfer
process and the second transfer process may be validated when the
determination result by the determination means is affirmative.
In this case, if it is impossible to communicate, the third task
is substantially a suspended state, and only the first task and
the second task becomes an execution state.
[0009] The third task may further include a restriction process
for restricting the second task prior to the first transfer process,
and a canceling process for canceling the restriction placed on
the second task after the second transfer process. In this case,
the state of the second task is controlled by the third task.
[0010] If each of the first transfer process and the second transfer
process is a process to transmit a predetermined number of screens
of image signals, the second task is limited by a unit of the predetermined
number of screens.
[0011] In a case that the third task further includes an encryption
process for performing encryption on the image file transferred
to the internal memory by the first transfer process, the second
transfer process is a process to transfer the image file encrypted
by the encryption process to the communication means.
[0012] It is preferable that the recording medium and the communication
means are housed in a detachable cartridge.
[0013] The above described objects and other objects, features,
aspects and advantages of the present invention will become more
apparent from the following detailed description of the present
invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a block diagram showing one embodiment of the
present invention;
[0015] FIG. 2 is an illustrative view showing a mapping state of
an SDRAM to be applied to FIG. 1 embodiment;
[0016] FIG. 3 is a block diagram showing one example of a memory/LAN
card to be applied to FIG. 1 embodiment;
[0017] FIG. 4 is a flowchart showing a part of operation of FIG.
1 embodiment;
[0018] FIG. 5 is a flowchart showing another part of the operation
of FIG. 1 embodiment;
[0019] FIG. 6 is a flowchart showing the other part of the operation
of FIG. 1 embodiment; and
[0020] FIG. 7 is a flowchart showing a further part of the operation
of FIG. 1 embodiment.
BEST MODE FOR PRACTICING THE INVENTION
[0021] Referring to FIG. 1, a digital camera 10 of this embodiment
includes an image sensor 12. An optical image of an object scene
is irradiated onto a light-receiving surface of the image sensor
12 via an optical lens (not shown). On the light-receiving surface,
a plurality of light receiving elements (not shown) are arranged.
Through the photoelectronic conversion of the light receiving elements,
a raw image signal (electric charge) corresponding to the optical
image of the object scene is generated.
[0022] When a shutter button 32 is operated, an imaging process
is executed. First, a CPU34 applies a reading instruction to a TG
(Timing Generator) 14, applies a processing instruction to a signal
processing circuit 18, and applies a compression instruction to
a JPEG codec 24. The TG 14 applies a timing signal to the image
sensor 12 in order to read the raw image signal generated in the
light receiving elements. The raw image signal is read from the
image sensor 12 in a raster scan manner, and is subjected to a series
of processes such as noise rejection, gain adjustment, and A/D conversion
in a CDS/AGC/AD circuit 16. The raw image data output from the CDS/AGC/AD
circuit 16 is subjected to a signal process such as color separation,
white balance adjustment, YUV conversion, etc. by the signal processing
circuit 18. YUV data thus generated is applied to a memory controller
20 via a bus B1, and thereby written to a YUV data storing area
22a (see FIG. 2) of the SDRAM 22.
[0023] The JPEG codec 24 reads the YUV data from the YUV data storing
area 22a through the bus B1 and the memory controller 20, and performs
a JPEG compression on the read YUV data. Compressed YUV data thus
generated, that is, JPEG data is applied to the memory controller
20 through the bus B1, and thereby written to a JPEG data storing
area 22b of the SDRAM 22.
[0024] Succeeding to such an imaging process, the CPU 44 creates
a file header by itself, reads the JPEG data stored in the JPEG
data storing area 22b through the bus B1 and the memory controller
20, and applies an image file including the file header and the
JPEG data to a memory/LAN cartridge 30 loaded into a slot 28. The
image file is first recorded in a CF memory 30b (see FIG. 3) of
the memory/LAN cartridge 30.
[0025] In a case a digital camera 10 is within a communication
range, the image file recorded in the CF memory 30b is read by the
CPU 44, and written to a transmitted file storing area 22c of the
SDRAM 22 by the memory controller 30. The image file is then subjected
to an encrypt process by the CPU 44, and the encrypted image file
is applied to a wireless LAN card 30c of the memory/LAN cartridge
30 through the bus B1. The wireless LAN card 30c transmits the applied
image file to a server (not shown) with a desired address.
[0026] Referring to FIG. 3, the memory/LAN cartridge 30 includes
an I/F 30a that is connected to the bus B1 when being attached to
the slot 28. The I/F 30a connects a switch SW1 to a terminal S1
when recording the image file and when encrypting the image file,
and connects a switch SW to a terminal S2 when transmitting the
image file.
[0027] At a time of record, the image file input from the bus B1
is applied to the CF memory 30b via the I/F 30a and the switch SW1,
and recorded in a memory area 302b by a controller 301b. At a time
of encryption, the image file recorded in the memory area 302b is
read by the controller 301b, and output to the bus B1 via the switch
SW1 and the I/F 30a. At a time of transmission, the image file input
from the bus B1 is applied to the wireless LAN card 30c via the
I/F 30a and the switch SW1, and transmitted to the server with the
desired address by a communication circuit 302c under the control
of the controller 301c.
[0028] The CPU34 is a multitasking CPU mounting a multitasking
OS such as the .mu. ITRON, and executes an imaging task shown in
FIG. 4, a file recording task shown in FIG. 5, and a file transmitting
task shown in FIG. 6-FIG. 7 according to a control program stored
in a flash memory 26.
[0029] Referring to FIG. 4, in the imaging task, first, the switch
SW1 of the memory/LAN card 30 is connected to the terminal S1 in
a step S1, and "0" is set to variables File_Num, BG_ListNum,
and BG_Suspend in a step S3. Here, the variable File_Num is a variable
showing the number of the image files that has been created and
has not been transmitted, and the variable BG_ListNum is a variable
showing the number of instructions set to an instruction list 34a.
Furthermore, the variable BG_Suspend is a variable showing whether
or not the instruction set to the instruction list 34a is executable.
The BG_Suspend=0 means "executable", and the BG_Suspend=1
means "unexecutable".
[0030] In a step S5, it is determined whether there is an operation
of the shutter button 32 or not, and if YES, generation of a vertical
synchronization signal is waited in a step S7 and then, an imaging
process is executed in a step S9. One frame of JPEG data is reserved
in the JPEG data storing area 22b of the SDRAM 22 by the imaging
process. In a step S11, a recording instruction of the image file
including the reserved JPEG data is set to the instruction list
34a. After completion of the setting, the variables File_Num and
BG_ListNum are incremented in a step S13, and then, the process
returns to the step S5.
[0031] Referring to FIG. 5, in the file recording task, first,
the variable BG_Suspend is determined in a step S21. Here, if BG_Suspend=1,
by regarding that it is impossible to execute the instruction set
to the instruction list 34a, an identifier SPD is set to a variable
BG_State in a step S23, and then, the process returns to the step
S21. On the contrary thereto, if BG_Suspend=0, by regarding that
the instruction set to the instruction list 34a is executable, an
identifier RUN is set to the variable BG_State in a step S25, and
then, the process proceeds to a step S27. It is noted that the variable
BG_State is a variable for determining a state of the file recording
task, and the identifier SPD shows a suspended state, and the identifier
RUN shows an execution state.
[0032] In the step S27, a variable BG_ListNum is determined. Here,
if BG_ListNum=0, it is regarded that the instruction to be executed
is not set to the instruction list 34a, and then, the process returns
to the step S21. On the contrary thereto, if BG_ListNum>0, the
instruction in the instruction list 34a is executed in a step S29.
The recording instruction set to the instruction list 34a by the
process in the step S11 shown FIG. 4 is executed here. Thus, the
JPEG data is read from the JPEG data storing area 22b of the SDRAM
22, the file header is created, and the image file including the
JPEG data and the file header is applied to the CF memory 30b of
the memory/LAN cartridge 30. The image file is recorded in the memory
area 302b by the controller 301b. After completion of recording,
in a step S31, the variable BG_ListNum is decremented, and then,
the process returns to the step S21.
[0033] Referring to FIG. 6-FIG. 7, in the file transmitting task,
first, a variable File_Num is determined in a step S41, the variable
BG_ListNum and the variable File_Num are compared with each other
in a step S43, and it is determined whether or not it is possible
to communicate in a step S45. If File_Num>0, it is regarded that
at least one frame of JPEG data is reserved in the JPEG data storing
area 22b shown in FIG. 2. Furthermore, if BG_ListNum=File_Num, it
is regarded no image file is present in the CF memory 30b, and if
BG_ListNum<File_Num, at least one image file is present in the
CF memory 30b. Furthermore, whether it is possible to communicate
or not is determined on the basis of a radio sensitivity detected
by the wireless LAN card 30c.
[0034] If File_Num>0 and BG_ListNum<File_Num are satisfied,
and it is possible to communicate, "1" is set to the variable
BG_Suspend in a step S47 in order to prohibit the instruction set
in the instruction list 34c from being executed. When the identifier
SPD is set to the variable BG_State in the step S23 shown in FIG.
5, in response thereto it is regarded that the file recording task
shifts to the suspended state, and then, the process proceeds from
a step S49 to the step S51. In the step S51, one image file that
has been recorded in the CF memory 30b and has not yet been transmitted
is transferred to the transmitted file storing area 22c of the SDRAM
22. After completion of transfer, the switch SW1 is connected to
the terminal S2 in a step S53.
[0035] In a step S55, the image file stored in the transmitted
file storing area 22c is encrypted, and in a succeeding step S57,
the encrypted image file is transferred from the SDRAM 22 to the
wireless LAN card 30c of the memory/LAN cartridge 30. The transferred
image file is transmitted to the server with the desired address
by the communication circuit 302c under the control of the controller
301c.
[0036] After completion of transmission, the switch SW1 is connected
to the terminal S1 in a step S59, and "0" is set to the
variable BG_Suspend in a step S61 in order to permit executing the
instruction set to the instruction list 34a. When the identifier
RUN is set to the variable BG_State in the step S25 shown in FIG.
5, in response thereto it is regarded that the file recording task
shifts to the execution state, and then, the process proceeds from
a step S63 to a step S65. In the step S65, it is determined whether
or not the transmission process in the step S57 is successful. If
"YES" here, the image file that has already been transmitted
is erased from the CF memory 30b in a step S67, and the variable
File_Num is decremented in a step S69, and then, the process returns
to the step S41. On the contrary thereto, if "NO" is determined
in the step S65, the process after the step S45 is executed once
again.
[0037] As understood from the above description, when the shutter
button 32 is operated, the JPEG data corresponding to the object
scene is written to the SDRAM 22 by the imaging task. The image
file including the JPEG data stored in the SDRAM 22 is recorded
in the CF memory 30b of the memory/LAN cartridge 30 by the file
recording task. The image file recorded in the CF memory 30b is
applied to the wireless LAN card 30c of the memory/LAN cartridge
30 by the file transmitting task.
[0038] Here, the imaging task, the file recording task, and the
file transmitting task are executed in parallel with each other.
Thus, even if the shutter button 32 is operated at a time that the
file recording task or the file transmitting task is activated,
the imaging task is immediately executed to reserve the JPEG data
corresponding to the imaged object scene in the SDRAM 22. Thus,
it is possible to improve operability.
[0039] It is noted that although the JPEG compression process is
executed in the imaging task in this embodiment, the JPEG compression
process may be executed in the file recording task.
[0040] Although the present invention has been described and illustrated
in detail, it is clearly understood that the same is by way of illustration
and example only and is not to be taken by way of limitation, the
spirit and scope of the present invention being limited only by
the terms of the appended claims. |