Digital Camera Patent AbstractA digital camera reduces the possibility that a user's release operation
is disabled and performs photographing operations at the appropriate
times. The digital camera (1) can load a memory card (40a) and a
magnetic disk card (40b) as a plurality of recording media, wherein
a CPU (17) can independently make accesses to the memory card (40a)
and the magnetic disk card (40b). The CPU (17) performs a plurality
of tasks in parallel, whereby a captured image is recorded on either
one of the memory card (40a) and the magnetic disk card (40b) while
predetermined processing is performed on the other. In such a configuration,
a captured image which is stored in image memory (21) through a
photographing operation can be recorded at an early stage on one
of the recording media. This enables continuous photographing and
the like even in such a condition that recording on a recording
medium which is selected as a subject of recording is not allowed.
Digital Camera Patent ClaimsWhat is claimed is:
1. A digital camera, comprising: a plurality of media provided
for recording and storing a captured image generated in response
to a photographing operation; and a controller capable of performing
a plurality of tasks in parallel, said controller when performing
a first task to record said captured image on a medium which is
selected as a subject of recording out of said plurality of media,
performing a second task which is different from said first task
to perform predetermined processing on a medium which is not said
subject of recording, wherein said predetermined processing is formatting
of a medium which is not said subject of recording.
2. A digital camera comprising: a plurality of slots capable of
loading a plurality of media for recording and storing a captured
image generated in response to a photographing operation; and a
controller capable of performing a plurality of tasks in parallel,
said controller when performing a first task to record said captured
image on a medium which is selected as a subject of recording out
of said plurality of media loaded in said plurality of tasks, performing
a second task which is different from said first task to perform
predetermined processing on a medium which is not said subject of
recording, wherein said predetermined processing is formatting of
a medium which is not said subject of recording.
3. The digital camera according to claim 1, wherein the plurality
of media include media employing magnetic recording and media employing
a semiconductor memory.
4. The digital camera according to claim 2, wherein the plurality
of media include media employing magnetic recording and media employing
a semiconductor memory. Digital Camera Patent DescriptionThis application is based on application No. 11-359156 filed in
Japan, the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital camera with a plurality
of media for recording captured images, and an image recording system.
2. Description of the Background Art
General digital cameras are configured to be able to load a removable
recording medium for recording and storing captured images. Recently,
in order to increase the number of captured images that can be recorded,
digital cameras with two card slots which can load two recording
media are being prepared for the market.
In photographing a subject, a user selects, for example by operation
of a changeover switch, one recording medium on which images are
recorded out of those loaded in first and second slots; therefore,
images obtained through photographing are recorded on the selected
recording medium. That is, conventional digital cameras are configured
to record captured images on a user-selected recording medium.
Conventionally, the dominating removable recording media for such
digital cameras have been memory cards composed of semiconductor
memory and the like, but magnetic disk cards each comprising a built-in
magnetic disk device with high recording capacity are also being
used in recent years.
For recording of captured images on a magnetic disk card, however,
a predetermined starting time is necessary after activation of the
magnetic disk card is started before captured images can be recorded.
Thus, a captured image obtained in response to a photographing operation
cannot be recorded immediately. When the digital camera is configured
to start the activation of a magnetic disk card after a user's release
operation for photographing, recording of captured images is not
allowed during a period of time required for the activation and
thus the next release operation is disabled. Accordingly, continuous
photographing or the like becomes impossible.
Here, the magnetic disk card may always be placed in the active
state to be able to record captured images all the time; however,
such a configuration raises new problems about endurance of and
power consumption in the magnetic disk card and thus it is not easily
adaptable to transportable digital cameras.
Even if only one of two recording media which can be loaded in
a digital camera is a magnetic disk card, the same problems as above
described arise when a user selects the magnetic disk card as a
subject of recording of captured images.
When not only the magnetic disk card but also any one of two recording
media selected as a subject of recording is temporarily unusable
because of being processed (e.g., being formatted), the recording
of captured images is not allowed until that process is completed,
and therefore the user's release operation is disabled.
To prevent the release operation from being disabled, a large-capacity
buffer memory for temporarily recording a large number of captured
images may be built in a digital camera on the precedent stage of
a recording medium selected as a subject of recording. This, however,
brings up another problem of increasing the product cost of digital
cameras.
Although some digital cameras are provided with an interface for
establishing a connection with external equipment (e.g., a printer
or another digital camera), conventional digital cameras can only
selectively perform either a photographing operation, or image data
communications with the external equipment. Thus, the user's release
operation is disabled during data communications with the external
equipment.
The aforementioned problems result from the fact that even with
a digital camera loading two recording media, only one user-selected
recording medium is always to be accessed for recording or the like.
SUMMARY OF THE INVENTION
The present invention is directed to a digital camera.
According to an aspect of the present invention, the digital camera
comprises: a temporary memory for temporarily storing a captured
image generated in response to a photographing operation; a first
medium for recording and storing the captured image; a second medium
with a higher recording speed than the first medium, for recording
and storing the captured image; and a controller for, when recording
the captured image from the temporary memory to the first medium,
recording the captured image once from the temporary memory to the
second medium and then from the second medium to the first medium.
According to another aspect of the present invention, the digital
camera which can load media comprises: a temporary memory for temporarily
storing a captured image generated in response to a photographing
operation; a first slot capable of loading a first medium for recording
and storing the captured image; a second slot capable of loading
a second medium for recording and storing the captured image; and
a controller for, when recording the captured image from the temporary
memory to the first medium on the condition that the second medium
has a higher recording speed than the first medium, recording the
captured image once from the temporary memory to the second medium
and then from the second medium to the first medium.
As above described, the digital camera is configured such that
when a captured image is recorded from the temporary memory to the
first medium, the image is recorded once on the second medium with
a high recording speed and then recorded from the second medium
to the first medium. The captured image in the temporary memory
can thus be recorded at a relatively high recording speed on one
of the media. This frees the temporary memory at a relatively early
stage, thereby reducing the possibility that a user's release operation
is disabled.
Herein, the term "release", which is used in the description
of film cameras, is also used in the description of digital cameras
and refers to the start of photographing or the indication to start
photographing in the case of digital cameras.
According to another aspect of the present invention, the digital
camera comprises: a plurality of media provided for recording and
storing a captured image generated in response to a photographing
operation; and a controller capable of performing a plurality of
tasks in parallel, the controller when performing a first task to
record the captured image on a medium which is selected as a subject
of recording out of the plurality of media, performing a second
task which is different from the first task to perform predetermined
processing on a medium which is not the subject of recording.
According to still another aspect of the present invention, the
digital camera which can load media comprises: a plurality of slots
capable of loading a plurality of media for recording and storing
a captured image generated in response to a photographing operation;
and a controller capable of performing a plurality of tasks in parallel,
the controller when performing a first task to record the captured
image on a medium which is selected as a subject of recording out
of the plurality of media loaded in the plurality of tasks, performing
a second task which is different from the first task to perform
predetermined processing on a medium which is not the subject of
recording.
As above described, the digital camera is configured to perform
a plurality of tasks in parallel, i.e., to perform another second
task, which is different from a first task, for predetermined processing
on a medium which is not the subject of recording. In this case,
the predetermined processing performed on a medium which is not
the subject of recording permits effective continuation of a photographing
operation rather than delaying that operation, which results in
a reduction in the possibility that the release operation is disabled.
The present invention is also directed to an image recording system.
According to one aspect of the present invention, the image recording
system comprises: a first digital camera; a second digital camera;
and a transmission medium for providing a connection between the
first and second digital cameras to make data communications possible,
wherein the first digital camera comprises a controller capable
of performing a plurality of tasks in parallel and performing a
first task related to a photographing operation or recording of
a captured image while performing a second task for data communications
with the second digital camera through the transmission medium.
As above described, the first digital camera can perform a plurality
of tasks in parallel and is configured so as to performs one task
related to a photographing operation or recording of a captured
image while performing another task for data communications with
the second digital camera through the transmission medium. A user
can thus establish data communications while continuing a release
operation.
According to another aspect of the present invention, the image
recording system is comprised of a digital camera and external equipment
connected with each other. This digital camera comprises first and
second media for recording a captured image and performs, in parallel,
a task of recording the captured image on the first medium and a
task of establishing data communications with the external equipment.
The digital camera is configured to perform, in parallel, a task
of recording a captured image on the first medium and a task for
data communications with external equipment. A user can thus establish
data communications while continuing a release operation.
An object of the present invention is thus to provide a digital
camera that can reduce the possibility that a user's release operation
is disabled and can perform photographing operations at the appropriate
times, and to provide an image recording system.
These 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
FIGS. 1A, 1B, 2A, and 2B are external views of a digital camera
according to a preferred embodiment of the present invention;
FIG. 3 is a schematic diagram of an internal structure of the digital
camera;
FIG. 4 is a block diagram of a functional structure of the digital
camera;
FIG. 5 shows an example of screen displayed in a camera-function
display unit;
FIG. 6 schematically shows a form of functions achieved by a CPU;
FIG. 7 is a flow chart of processing when a magnetic disk card
is selected as a subject of recording;
FIGS. 8 to 10 are flow charts of processing when a card selected
for recording is being formatted;
FIGS. 11 to 15 show examples of processing on a recording medium
which is not the subject of recording;
FIG. 16 shows a digital camera in displaying a card selection screen;
FIG. 17 shows a construction of an image recording system; and
FIG. 18 shows an image recording system having a printer connected.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, preferred embodiments of the present invention will be described
with reference to the drawings.
<1. Construction of Digital Camera>
FIGS. 1A, 1B, 2A, and 2B are external views of a digital camera
1 according to a preferred embodiment of the present invention.
FIG. 1A is a front view of the digital camera 1; FIG. 1B is a rear
view thereof; FIG. 2A is a top view thereof; and FIG. 2B is a side
view thereof.
On the front of the digital camera 1, a lens unit 3 for forming
a subject image, an optical viewfinder 7 for determining the range
of photography, and a flash 8 for shedding light on a subject are
provided. On the back thereof, there are provided the optical viewfinder
7, a monitor 25 composed of, e.g., a color liquid crystal display
for confirmation of a captured image, a setting selection switch
6b for selecting a recording medium 40 to be a subject of recording,
and 4-way keys 6c, 6d, 6e, and 6f for use in scrolling captured
images or changing various settings.
Further, a shutter start button 6a for use in capturing a subject
image and a camera-function display unit 9 are provided on the top
of the digital camera 1. The camera-function display unit 9 has
a display function of displaying shooting or photographing conditions
for the digital camera 1, card names for a plurality of recording
media 40 loaded in the digital camera 1, and the like and allowing
a user to visually identify which of the recording media 40 is selected
as a subject of recording of captured images. The camera-function
display unit 9 is composed of a monochrome display mode of compact
liquid crystal display or the like and is provided aside from the
monitor 25, which is for use in confirmation of captured images,
so that a user can visually identify the photographing conditions
and the selection of a recording medium 40 during photographing.
As shown in FIG. 2B, the digital camera 1 has in the side surface
a plurality of slots 41a and 41b for loading the plurality of recording
media 40, and an external interface 20 for establishing a connection
between the digital camera 1 and external equipment.
In this preferred embodiment, a so-called slot indicates where
a single medium is loaded. That is, the same opening which can load
a plurality of media at the same time means that a plurality of
slots are formed in that opening.
The plurality of slots 41a and 41b each can load a single recording
medium 40. The recording medium 40 is a medium for recording a captured
image generated through a photographing operation of the digital
camera 1 and the like, which may be a memory card with a built-in
semiconductor memory such as flash memory, or a magnetic disk card
with a built-in magnetic disk device employing a magnetic recording
system.
This preferred embodiment gives a case where mainly, the recording
medium 40 loaded in the first slot 41a is a memory card 40a and
the recording medium 40 in the second slot 41b is a magnetic disk
card 40b.
For convenience of description, this preferred embodiment gives
an example of two slots for loading recording media, but the number
of slots is not limited thereto and it may be three or more. Further,
on the surface around the respective slots 41a and 41b for recording
media, characters such as "slot A" for the slot 41 a and
"slot B" for the slot 41b are engraved so that a user
can discriminate between those slots.
The external interface 20 is for communications in compliance with
a USB (universal serial bus) or IEEE-1394 standard or the like,
which allows input/output of captured image data from/to external
equipment through a transmission medium such as a cable connected
to the external interface 20.
FIG. 3 is a schematic diagram of the internal structure of the
above-described digital camera 1. As shown in FIG. 3, the digital
camera 1 has located therein the lens unit 3, a diaphragm 4, and
an image sensor 5 and can hold the memory card 40a and the magnetic
disk card 40b.
The image sensor 5 is a photoelectric device having a plurality
of pixels in a plane (image surface) normal to the optical axis
and being composed of an all-pixel-readout CCD area sensor or the
like. On the image surface side of the image sensor 5, primary-color
(red (R), green (G), and blue (B)) transmitting filters are placed
on a pixel-by-pixel basis in checkered patterns, each pixel having
sensitivity to each color component of a captured image which enters
through the optical lens unit 3 and the diaphragm 4. Such an image
sensor 5 corrects the amount of exposure by controlling a charge
storage time.
Now, a functional structure of the digital camera 1 will be discussed.
FIG. 4 is a block diagram of the functional structure of the digital
camera 1.
Image signals which are photoelectric-converted in the image sensor
5 are shifted to a lightproof transmission path (not shown) in the
image sensor 5 and then read out from this transmission path in
sequence on a pixel-by-pixel basis through a buffer. The image signals
obtained through the image sensor 5 are transmitted to an image
processor 10 through a correlated double sampling (CDS) circuit
36, an automatic gain controller (AGC) 37, and an A/D converter
38. More specifically, the CDS circuit 36 samples the image signals
to reduce the noise in the image sensor 5 and the AGC 37 makes sensitivity
compensation. The A/D converter 38 is for example a 10-bit A/D converter,
which converts normalized analog signals obtained from the AGC 37
into digital signals. Therefore, the image signals to be transmitted
to the image processor 10 are digital signals.
For control of each structural unit in the digital camera 1, a
camera control CPU (central processing unit) 31 is provided. This
camera control CPU 31 is configured to control a photographing operation
or the like during image capture or the like and to make setting
changes for effecting various setting changes by a user. The CPU
31 also sends control signals to a diaphragm driver 32, a timing
generator 33, and the like during photographing or the like.
An f-number of the diaphragm 4 and a storage time in the image
sensor 5 are obtained through computations in the camera control
CPU 31. According to the result of computations, the camera control
CPU 31 gives control signals to the diaphragm driver 32 and the
timing generator 33, thereby achieving a control system that allows
the image sensor 5 to attain the appropriate amount of exposure
in photographing.
According to the control signals from the camera control CPU 31,
the diaphragm driver 32 drives the diaphragm 4 to adjust an aperture
and the timing generator 33 controls the storage time, which is
defined by storage start/stop timing, in the image sensor 5.
The camera control CPU 31 also gives to the camera-function display
unit 9 the contents of display of the photographing conditions and
the names for the memory card 40a and the magnetic disk card 40b
obtained from the image processor 10. The camera-function display
unit 9 thus serves as information display.
A control switch 6 is for input operations for a user to allow
settings of the photographing conditions and to perform a photographing
operation (release operation). This switch 6 includes all of the
shutter start button 6a, the setting selection switch 6b, and the
4-way keys 6c, 6d, 6e, 6f, described above.
The setting selection switch 6b is a three-position slide switch
as shown in FIG. 1B. The "up" position thereof is a position
to select the memory card 40a loaded in the first slot 41a as a
subject of recording of captured images; the "central"
position is a position to select the magnetic disk card 40b loaded
in the second slot 41b as a subject of recording of captured images;
and the "down" position is a position to select external
equipment connected to the external interface 20 as a subject of
recording.
Based on the input from the control switch 6, the camera control
CPU 31 makes settings of various photographing conditions, or it
specifies a recording medium to be a subject of recording out of
the memory card 40a and the magnetic disk card 40b, then transmits
the contents of those settings to the image processor 10 and displays
the same in the camera-function display unit 9 on top of the digital
camera 1.
FIG. 5 shows the contents of screen displayed in the camera-function
display unit 9, when viewing the digital camera 1 from the above.
The camera-function display unit 9 displays the names for the memory
card 40a and the magnetic disk card 40b loaded in the two slots
41a and 41b, the name for external equipment connected, an indication
that which of the above three is selected as a subject of recording
or readout, and the photographing conditions. The names for cards
and external equipment and the indication of selection are displayed
in a subject-of-access display area in the upper right hand of the
camera-function display unit 9, and the photographing conditions
are displayed in a segment display format in the other display area
of the camera-function display unit 9.
As to the display of card names, as shown in FIG. 5, the name for
the memory card 40a loaded in the slot 41a, i.e., "CARD 1",
is displayed in the upper column, and the name for the magnetic
disk card 40b loaded in the slot 41b, i.e., "CARD 2",
is displayed in the middle column. Such display of the card names
allows a user to readily and visually identify the slot in which
each card is loaded even if the user loads each of the cards 40a
and 40b without discriminating between the slots 41a and 41b. Further,
the name for external equipment connected, i.e., "EXT 1",
is displayed in the lower column.
The indication of selection of a subject to be accessed, e.g.,
a subject of recording, is given by placing a predetermined mark
or the like (the closed circle in the example of FIG. 5) on the
right side of the name for a card or external equipment which is
selected by a user by operation of the setting selection switch
6b as above described. Such display of the indication of selection
allows a user to always check which of the memory card 40a, the
magnetic disk card 40b, and the external equipment is being selected
as a subject of recording or the like.
When the shutter start button 6a included in the control switch
6 is fully pressed (i.e., when the release operation is performed),
the camera control CPU 31 performs an image capturing operation
by control of the diaphragm 4 and the image sensor 5 as above described.
The image processor 10 for performing a plurality of kinds of processing
on digitized image signals is implemented for example in a single
chip of IC (integrated circuit) and comprises, as its internal functions,
a pixel interpolation circuit 11, a color balance controller 12,
a gamma correction circuit 13, an image compressor 14, a video encoder
15, card drivers 16a and 16b, a CPU 17, a ROM (read only memory)
18, and a RAM (random access memory) 19, all of which are connected
with each other through a data bus 29 and configured to be able
to access an image memory 21 which serves as a temporary memory
for temporarily storing captured images obtained with the image
sensor 5. The image memory 21 is configured to be able to store
a single frame of captured image generated through a photographing
operation in response to a release operation.
The digitized image signals entering the image processor 10 are
once stored in the image memory 21. The image stored in the image
memory 21 undergoes pixel interpolation in the pixel interpolation
circuit 11, white balance control in the color balance controller
12, predetermined conversions in the gamma correction circuit 13,
and the like, and is then stored back in the image memory 21.
The pixel interpolation circuit 11, after reading out stored image
data from the image memory 21 and masking that data in the filter
pattern of the primary-color transmitting filters, performs average
interpolation between predetermined peripheral pixels for each color
component.
The color balance controller 12 adjust white balance by separately
providing gain control for image signals of each color component
generated by pixel interpolation. More specifically, a portion of
a subject which is considered to be essentially in white is estimated
from luminance, saturation, and the like and the gain of each color
component is determined according to R, G, B colors in that portion.
Then, the gain obtained is used to compensate for each color component,
whereby white balance is automatically adjusted (automatic white
balance control).
The gamma correction circuit 13 performs nonlinear conversion,
which complies with output equipment (e.g., the monitor 25), on
the white-balanced image data.
The image compressor 14 performs image compression in the JPEG
format or the like on the image data, which is stored in the image
memory 21 after going through a variety of image processing as above
described, thereby to reduce the amount of image data to be recorded
on the memory card 40a or the magnetic disk card 40b.
The image memory 21 has a capacity for a single frame in this example.
In situations where the image data in the image memory 21 has not
yet been processed, the next photographing (release) operation is
disabled.
The card drivers 16a and 16b are electrically connected to the
two slots 41a and 41b for loading recording media, respectively.
These drivers are configured to access the memory card 40a and the
magnetic disk card 40b loaded respectively in the slots 41a and
41b under control of the CPU 17 and to record or read out captured
images or other data on or from those cards. The memory card 40a
and the magnetic disk card 40b are removable from the respective
slots 41a and 41b.
For individual access to the memory card 40a loaded in the slot
41a and the magnetic disk card 40b loaded in the slot 41b, the card
drivers 16a and 16b are provided respectively for the slots 41a
and 41b. This allows the CPU 17 to perform access processing individually
and in parallel on the memory card 40a and the magnetic disk card
40b.
The video encoder 15 encodes image data, which describes an image
stored in the image memory 21 or in the memory card 40a and the
magnetic disk card 40b, in NTSC or PAL format data, thereby to display
that image on the monitor 25. The monitor 25 thus serves as display
for captured images.
The CPU 17, which is configured to be able to access the ROM 18
and the RAM 19, is a controller for achieving various functions
by reading out and executing a program stored in the ROM 18. It
exercises control over recording and any other operations when recording
a captured image on a user-selected recording medium as a subject
of recording.
FIG. 6 schematically shows a form of functions achieved by the
CPU 17. The CPU 17 carries out functions of first task execution
17a, second task execution 17b, and so on. The above task execution
is implemented to operate in parallel in a time-division multiplexed
system. That is, the CPU 17 is configured to be able to perform
a plurality of tasks in parallel in a time-division multiplexed
system; therefore, it can perform a plurality of processing operations
at once, e.g., one task of making access to the memory card 40a
and another task of making access to the magnetic disk card 40b.
In short, the CPU 17 as a controller can perform a plurality of
processing operations in parallel at the same time.
The CPU 17 controls the operation of each of the above-described
circuits or sections such as the pixel interpolation circuit 11
and causes a captured image, which has been generated through a
photographing operation in response to a user's release operation
and stored in the image memory 21, to be recorded on the memory
card 40a or the magnetic disk card 40b according to the set position
of the setting selection switch 6b so that the captured image can
be stored in the user-selected recording medium for the long term.
With such a configuration of the CPU 17 that can perform a plurality
of tasks in parallel, even when the digital camera 1 loads a plurality
of recording media 40, execution of one task enables access to one
recording medium selected as a subject of recording while execution
of another task enables access to another recording medium. Further,
execution of one task allows selection of one of the plurality of
recording media 40 as a subject of access, while execution of another
task allows any desired processing to be performed in parallel.
Such a configuration of the CPU 17 that can perform a plurality
of tasks further reduces the length of time that the user's release
operation is disabled. The following description gives how the CPU
17, serving as a controller, provides operating control for concrete
recording processing of captured images.
<2. Parallel Processing for Magnetic Disk Card as Subject of
Recording>
Now, a recording task when the magnetic disk card 40b is selected
as a subject of recording is discussed. Herein, the term "task"
refers to the overall process steps shown in FIG. 7, while the term
"processing" refers to a concrete procedure in each step
of the task.
When the magnetic disk card 40b is selected as a subject of recording
and the activation thereof is performed after photographing, the
long starting time is required before recording is enabled, and
thus a captured image stored in the image memory 2 which is a temporary
memory cannot be deleted until the activation is completed. If the
captured image in the image memory 21 cannot be deleted, image data
generated through subsequent photographing cannot be stored therein
and the next photographing operation is disabled. In continuous
photographing or the like, therefore, a captured image which is
temporarily stored in the image memory 2 should preferably be recorded
onto another recording medium as soon as possible. In this preferred
embodiment, when the magnetic disk card 40b is selected as a subject
of recording, the memory card 40a which can record a captured image
at a higher speed than the magnetic disk card 40b is used as a temporary
buffer, thereby to enable early deletion of the captured image from
the image memory 21.
FIG. 7 is a flow chart of recording processing when the memory
card 40a is used as a buffer and the magnetic disk card 40b is selected
as a subject of recording.
This task is performed on the condition that the release operation
is not disabled. In step S101, a user performs a release operation.
The execution of the release operation is transmitted from the camera
control CPU 31 to the CPU 17 in the image processor 10.
The process goes to step S102, in which the CPU 17 determines whether
the memory card 40a is usable or not. Herein, the memory card 40a
being usable indicates the condition that the memory card 40a is
loaded in the slot 41a of the digital camera 1 and has enough free
space for recording a captured image. The CPU 17 thus determines
whether the memory card 40a is loaded in the card slot 41a and whether
it has enough free space. If so ("YES"), the process goes
to step S103, in which case the memory card 40a is used as a temporary
buffer before recording on the magnetic disk card 40b. If not ("NO"),
the memory card 40a cannot be used as a buffer and the process goes
to step S112 to record a captured image on the magnetic disk card
40b selected as a subject of recording.
In step S103, the CPU 17 starts the activation of the magnetic
disk card 40b. Thereby, a magnetic disk in the magnetic disk card
40b starts rotating and begins an operation for activation. Once
the CPU 17 starts the activation of the magnetic disk card 40b,
the process goes to step S104. If the activation of the magnetic
disk card 40b has already been started, the processing of step S103
is skipped.
In step S104, the CPU 17 transmits to the camera control CPU 31
a notification that an exposure operation in response to the release
operation is enabled, whereby the camera control CPU 31 controls
drive functions of the diaphragm 4, the image sensor 5, and the
like to perform a photographing operation. Consequently, a captured
image generated through the photographing operation in response
to the release operation is stored in the image memory 21. Then,
the captured image is subjected to image processing such as pixel
interpolation as necessary so that it becomes recordable on the
magnetic disk card 40b which is the subject of recording, and is
temporarily held in the image memory 21.
The process then goes to step S105, in which the CPU 17 checks
whether or not the magnetic disk card 40b activated in step S103
becomes usable. Herein, the magnetic disk card 40b being usable
indicates the condition that the starting time for the magnetic
disk card 40b has elapsed and the magnetic disk card 40b can perform
a recording operation with stability. The CPU 17 goes to step S106
when "YES", i.e., when the magnetic disk card 40b can
immediately record a captured image, while going to step S107 when
"NO", i.e., when the starting time for the magnetic disk
card 40b has not yet elapsed and thus a captured image cannot immediately
be recorded on the card.
In step S107, the CPU 17 records the captured image stored in the
image memory 21, being a temporary memory, on the memory card 40a.
Since the memory card 40a is a medium employing a semiconductor
memory, it generally has a higher recording speed than the magnetic
disk card 40b and can complete the recording processing in a shorter
time than would be possible in the case where the captured image
is directly recorded on the magnetic disk card 40b.
Immediately after the completion of the recording processing of
captured image on the memory card 40a, the CPU 17 deletes the temporarily
stored image from the image memory 21. This frees the image memory
21 as a temporary memory at an early stage and enables the start
of the next photographing operation.
In the next step S108, the CPU 17 determines, as in step S105,
whether the magnetic disk card 40b becomes usable or not. The processing
of step S108 is repeated until the magnetic disk card 40b becomes
usable, and the captured image recorded on the memory card 40a as
a temporary buffer is held as it is.
When the magnetic disk card 40b becomes usable, the process goes
to step S109 in which the CPU 17 performs a task of recording the
captured image stored in the memory card 40a onto the magnetic disk
card 40b. That is, the processing of step S109 corresponds to the
copying of captured image data from the memory card 40a into the
magnetic disk card 40b.
In step S110, the captured image on the memory card 40a is deleted
therefrom since the copying in step S109 makes unnecessary the captured
image data which has been temporarily recorded on the memory card
40a.
Now, when step S105 judges the magnetic disk card 40b as being
usable and the process goes to step S106, the captured image stored
in the image memory 21 is recorded on the magnetic disk card 40b.
The recording processing on the magnetic disk card 40b takes a longer
time than that on the memory card 40a; however, when the activation
of the magnetic disk card 40b is completed and a stable recording
operation is possible, the captured image in the image memory 21
is recorded on the magnetic disk card 40b soon after exposure.
Immediately after the completion of the recording processing of
captured image on the magnetic disk card 40b, the CPU 17 deletes
the temporarily stored image from the image memory 21. This frees
the image memory 21 which is a temporary memory at an early stage
and enables the start of the next photographing operation.
Next described is processing when the CPU 17 selects "NO"
in step S102 because the memory card 40a is not loaded in the slot
41a or does not have enough free space.
In this case, the CPU 17 starts the activation of the magnetic
disk card 40b in step S112. In step S113, the release operation
is disabled until the time required for the activation of the magnetic
disk card 40b has elapsed, during which the camera control CPU 31
cannot obtain permission for photographing.
In step S114, the CPU 17 checks whether the magnetic disk card
40b activated in step S112 becomes usable or not. The CPU 17 goes
to step S115 when "YES", i.e., when the magnetic disk
card 40b can immediately record a captured image, while returning
to step S113 when "NO", i.e., when the starting time for
the magnetic disk card 40b has not yet elapsed and thus a captured
image cannot immediately be recorded on the card.
When the activation of the magnetic disk card 40b is completed
and a stable recording operation becomes possible, the CPU 17 in
step S115 transmits to the camera control CPU 31 a notification
that an exposure operation in response to the release operation
is allowed. Thereby, the camera control CPU 31 controls drive functions
of the diaphragm 4, the image sensor 5, and the like to perform
a photographing operation. Consequently, a captured image generated
through the photographing operation is stored in the image memory
21.
The process then goes to step S106 to record the captured image
stored in the image memory 21 on the recordable magnetic disk card
40b and deletes that captured image from the image memory 21, thereby
to enable the start of the next photographing operation.
This will complete the recording processing of captured image when
the magnetic disk card 40b is selected as a subject of recording.
The next photographing operation can be started at the time when
the image memory 21 is freed in step S107 or S106. The CPU 17 performs,
in response to the release operation, a plurality of tasks as shown
in FIG. 7 in parallel. Thus, even if processing for a first photographing
operation continues loop iterations when "NO" in step
S108, processing for the next photographing operation can proceed
as another task from step S101 in sequence as long as there is free
space in the image memory 21.
In this case, the processing of steps S109 and S110 for "YES"
in step S108 is performed in the background of the next photographing
operation.
Once the activation of the magnetic disk card 40b is completed
and the magnetic disk card 40b is made recordable, there is no need
to reactivate the magnetic disk card 40b for recording of captured
images obtained through subsequent photographing operations. Thus,
the captured images can directly be recorded on the magnetic disk
card 40b from the image memory 21. That is, for first several images,
the process goes through the procedures from steps S101 to S105
and then from steps S107 to S110. On the other hand, in continuos
photographing or the like after the completion of the activation
of the magnetic disk card 40b, the process goes through the procedures
from steps S101 to S106.
Therefore, when the memory card 40a is usable as above described,
the use thereof as a temporary buffer during the activation of the
magnetic disk card 40b allows a reduction in the length of time
that the user's release operation is disabled.
In step S113, the magnetic disk card 40b is under activation and
the release operation is disabled. In this case, the memory card
40a cannot be used and the same processing as before is performed.
At this time, if the memory card 40a which does not have enough
free space is used as a buffer, the captured image(s) stored in
the memory card 40a may be damaged. Disabling the release operation
is to avoid such a situation.
As above described, when the magnetic disk card 40b is the subject
of recording, the use of the memory card 40a as a temporary buffer
frees the image memory 21 as a temporary memory at a relatively
early stage after photographing. The digital camera 1 can thus cope
with even continuous photographing. With such a configuration that
the removable memory card 40a is used as a buffer, the digital camera
1 does not build therein a high-capacity buffer memory as an ante-stage
component for recording on the magnetic disk card 40b. This keeps
down the product cost of the digital camera 1.
While the above description gives the case where the magnetic disk
card 40b is selected as a subject of recording, the same applies
to the case where an optical magnetic disk card or the like is loaded
to the digital camera 1. Further, even if the magnetic disk card
40b is recordable after the completion of the activation, there
may be a remarkable difference in recording speed between the magnetic
disk card 40b and the memory card 40a and such a difference could
be a problem to direct recording of a captured image on the magnetic
disk card 40b. In such a case, the memory card 40a should always
be used as a buffer when recording a captured image on the magnetic
disk card 40b.
In other words, when two media loaded in the digital camera 1 have
a high recording speed and a low recording speed, respectively,
and a captured image is recorded from the image memory 21 onto the
medium with a low recording speed, the digital camera 1 should be
configured to record the image once from the image memory 21 onto
the medium with a high recording speed and then from that medium
onto the other with a low recording speed. By so doing, the recording
of image from the image memory 21 can be performed at a higher recording
speed. As a result, the image memory 21 can be freed at a relatively
early stage, which allows efficient and effective use of resources
in the digital camera 1.
If the digital camera 1 is configured to record a captured image
once on the memory card 40a and then on the magnetic disk card 40b
by performing a plurality of tasks, the copying of the captured
image can be performed in parallel in the background of a main task
performed by a user operation or the like. This eventually enables
the user-transparent recording of the captured image on the selected
magnetic disk card 40b.
Further, the captured image stored in the memory card 40a serving
as a temporary buffer is deleted therefrom after copying into the
magnetic disk card 40b is completed. The use of the memory card
40a as a buffer is thus transparent to the user, and even if the
memory card 40a is selected as a subject of recording thereafter,
it would allow the same free space as it had before being used as
a buffer.
<3. Parallel Processing When Card as Subject of Recording is
in Use>
Next, we will discuss parallel processing when the recording medium
selected as a subject of recording is in use (i.e., when it is being
processed in a task other than that shown in FIG. 7).
If a recording medium selected as a subject of recording is being
processed in another processing when recording processing of a captured
image is performed, the captured image which is generated through
a photographing operation cannot be recorded on the recording medium
which is the subject of recording from the image memory 21 and therefore
that captured image stored in the image memory 21 which is a temporary
memory cannot be deleted until the processing on the recording medium
is completed. In continuous photographing or the like, the captured
image which is temporarily stored in the image memory 21 should
preferably be recorded on another recording medium as soon as possible.
In this preferred embodiment, when the recording medium selected
as a subject of recording is being used for any processing, another
recording medium is used as a temporary buffer, thereby allowing
early deletion of the captured image from the image memory 21.
The following description gives, as an example, a case where the
magnetic disk card 40b, which is selected as a subject of recording,
is being formatted.
FIGS. 8 to 10 are flow charts of parallel processing when the card
selected for recording is being formatted. FIGS. 8 and 9 are flow
charts of a task of recording a captured image; and FIG. 10 is a
flow chart of a task being performed on the magnetic disk card 40b
selected for recording.
First of all, the magnetic disk card 40b is being formatted in
accordance with the flow chart of FIG. 10. More specifically, physical
formatting takes place in step S214 and logical formatting in step
S215. In physical formatting, tracks and sectors are allotted to
the disk. In logical formatting, data management information is
generated.
In parallel with the task shown in FIG. 10, the task shown in FIGS.
8 and 9 is carried out.
When a user performs a release operation (step S202) during formatting
on the condition that the image memory 21 has free space, the execution
of the release operation is transmitted from the camera control
CPU 31 to the CPU 17 in the image processor 10.
The process goes to step S203, in which the CPU 17 determines whether
the other-than-selected memory card 40a is usable or not. More specifically,
the CPU 17 determines whether the memory card 40a is loaded in the
card slot and whether it has enough free space. If so ("YES"),
the process goes to step S204, in which case the memory card 40a
is used as a temporary buffer until the formatting of the magnetic
disk card 40b is completed. If not ("NO"), the memory
card 40a cannot be used as a buffer and the process goes to step
S208.
In step S204, the CPU 17 sends to the camera control CPU 31 a notification
that an exposure operation in response to the release operation
is allowed. With this permission of the release operation, the camera
control CPU 31 in step S205 controls drive functions of the diaphragm
4, the image sensor 5, and the like to perform a photographing operation.
Consequently, a single captured image generated through the photographing
operation in response to the release operation is stored in the
image memory 21. That captured image is then subjected to image
processing such as pixel interpolation as necessary so that it becomes
recordable on the magnetic disk card 40b which is the subject of
recording, and is temporarily held in the image memory 21.
In step S207, the CPU 17 records the captured image stored in the
image memory 21 on the memory card 40a. Immediately after the recording
processing of captured image on the memory card 40a is completed,
the CPU 17 deletes the temporarily stored captured image from the
image memory 21.
This frees the image memory 21 which is a temporary memory at an
early stage even if the magnetic disk card 40b selected as a subject
of recording is being formatted, thereby permitting the start of
the next photographing operation.
The process then goes to step S208 which determines whether the
formatting of the selected magnetic disk card 40b is completed or
not. When the formatting is completed ("YES"), the process
goes to step S210. If not ("NO"), the process goes to
step S209 to wait for the next release operation. With the next
release operation ("YES" in step S209), the process returns
to step S203.
In step S210, the CPU 17 determines whether the other-than-selected
card, i.e., the memory card 40a, has recorded a captured image or
not. At this time, a measure of judgment is the presence or absence
of a captured image recorded in step S207 and other captured images
are not taken into consideration. That is, the focus of judgment
is the captured image which was stored in the memory card 40a when
that card 40a is used as a buffer during the formatting of the magnetic
disk card 40b, not any other captured images which had been recorded
before the memory card 40a was used as a buffer. With the presence
of a captured image corresponding to the focus of judgment in the
memory card 40a ("YES"), the process goes to step S211.
Otherwise ("NO"), the photographing operation is completed.
In step S211, the CPU 17 copies the captured image recorded in
step S207 from the other-than-selected memory card 40a to the magnetic
disk card 40b selected as a subject of recording. Thereby, the captured
image is recorded on the user-selected magnetic disk card 40b which
is the subject of recording.
In step S212, the CPU 17 determines whether the copying is completed
or not. If the copying is completed, the process goes to step S213.
Otherwise, the process returns to step S211 to continue the copying.
In step S213, the captured image which has temporarily been stored
in the memory card 40a is deleted therefrom since the copying in
step S211 makes that image unnecessary. At this time, only the captured
image recorded in step S207 is deleted and any other images in the
memory card 40a are not to be deleted.
This completes the recording processing of captured image when
the magnetic disk card 40b selected as a subject of recording is
being formatted. When the memory card 40a is freed in step S207
and the next photographing operation can be started, the release
operation in step S204 will be allowed even if the formatting of
the magnetic disk card 40b is not completed.
Thus, when the memory card 40a is usable as above described, the
use of the memory card 40a as a temporary buffer during the formatting
of the magnetic disk card 40b can prevent the user's release operation
from being disabled.
When "NO" in step S203, the exposure operation is not
performed and consequently the release operation is disabled. In
this case, the other-than-selected memory card 40a cannot be used
and the same processing as before is performed.
In this fashion, when the magnetic disk card 40b selected as a
subject of recording is being formatted, the memory card 40a is
used as a temporary buffer. This frees the image memory 21 which
is a temporary memory at a relatively early stage after photographing.
The digital camera 1 can thus cope with continuous photographing
even if the magnetic disk card 40b which is subject of recording
is being formatted.
While the above description gives the case where the magnetic disk
card 40b is selected as a subject of recording, the present invention
is not limited thereto and the same applies to the case where the
memory card 40a is selected as a subject of recording.
When a recording medium selected as a subject of recording is being
processed in any desired processing, the use of another recording
medium as a buffer allows a photographing operation to be performed
without waiting for the completion of the processing on the recording
medium selected as a subject of recording. Thus, the digital camera
1 should be configured such that when a recording medium selected
as a subject of recording out of a plurality of recording media
is being processed with one task as in this preferred embodiment,
another recording medium of the plurality of recording media can
temporarily record a captured image with another task. This allows
a photographing operation to be performed without waiting for the
completion of the processing on the recording medium selected as
a subject of recording.
<4. Parallel Processing on Recording Medium being Not Subject
of Recording>
Performing one processing on a recording medium to be a subject
of recording and another processing on another recording medium
in parallel, as above described, is based on the premise that the
CPU 17 serving as a controller can perform a plurality of tasks
in parallel.
Such examples of processing on a recording medium which is not
the subject of recording are now discussed with reference to FIGS.
11 to 15. In the forms of processing shown in FIGS. 11 to 15, the
type of recording medium (whether it is a memory card, a magnetic
disk card, or any other card) is not specifically confined. Thus,
the following description gives the cases where a recording medium
40c is loaded in the first slot 41a of the digital camera 1 and
a recording medium 40d in the second slot 41b, and the recording
medium 40c is selected as a subject of recording by a user.
FIG. 11 shows a form of parallel processing performed on the recording
medium 40d which is not the subject of recording. The CPU 17 performs
the first task execution which is shown in FIG. 7, thereby to record
a captured image, which has been generated in response to a photographing
operation and temporarily stored in the image memory 21, on the
recording medium 40c selected as a subject of recording. On the
other hand, the CPU 17 carries out the second task execution in
parallel with the first task execution on the condition that the
image memory 21 has free space, thereby to perform the task shown
in FIG. 7 in parallel. Such parallel processing enables the execution
of a photographing operation in the background of the task of recording
a captured image on the recording medium 40c which is the subject
of recording.
FIG. 12 shows a form of parallel processing when the formatting
of the recording medium 40d which is not the subject of recording
is performed. The CPU 17 performs the first task execution, thereby
to record a captured image, which has been generated in response
to a photographing operation and temporarily stored in the memory
21, on the recording medium 40c selected as a subject of recording.
On the other hand, the CPU 17 performs the second task execution
in parallel with the first task execution, whereby the recording
medium 40d which is not the subject of recording is formatted. Such
parallel processing enables the formatting of the recording medium
40d which is not the subject of recording, in the background of
the main task.
In the case of FIG. 12, when the recording medium 40d is selected
as a subject of recording, the same processing as shown in the flow
chart of FIG. 8 is performed. That is, when recording a captured
image on the recording medium 40d selected as a subject of recording,
the recording medium 40c which is not the subject of recording is
used as a buffer to temporarily store the captured image.
FIG. 13 shows another form of parallel processing when any desired
image processing is performed on a captured image stored in the
recording medium 40d which is not the subject of recording. The
CPU 17 performs the first task execution, thereby to record a captured
image, which has been generated in response to a photographing operation
and temporarily stored in the image memory 21, on the recording
medium 40c selected as a subject of recording. On the other hand,
the CPU 17 performs the second task execution in parallel with the
first task execution, whereby captured image data previously recorded
on another recording medium 40d which is not the subject of recording
is read out, transmitted to the image compressor 14 where compression
processing is performed at a predetermined compression rate, and
recorded again on the recording medium 40d. Herein, image compression
is given as an example of image processing; however, other image
processing may be performed. Such parallel processing enables the
execution of image processing on the captured image data recorded
on the recording medium 40d which is not the subject of recording,
in the background of the main task.
As previously described, the digital camera 1 is connectable to
other external equipment through the external interface 20. Therefore,
parallel processing of a plurality of tasks in the CPU 17 enables
data communications with external equipment in the background of
the main task.
FIG. 14 shows a form of parallel processing when a captured image
in the recording medium 40d which is not the subject of recording
is outputted to external equipment 60. The CPU 17 performs the first
task execution, thereby record a captured image, which has been
generated in response to a photographing operation and temporarily
stored in the image memory 21, on the recording medium 40c selected
as a subject of recording. The CPU 17 also performs the second task
execution in parallel with the first task execution, whereby a captured
image is read out from another recording medium 40d which is not
the subject of recording, transmitted to the external interface
20, and outputted as output image data to the external equipment
60.
FIG. 15 shows a form of parallel processing when an image or the
like received from the external equipment 60 is recorded on the
recording medium 40d which is not the subject of recording. The
CPU 17 performs the first task execution, thereby to record a captured
image, which has been temporarily stored in the image memory 21,
on the recording medium 40c selected as a subject of recording.
The CPU 17 also performs the second task execution in parallel with
the first task execution, whereby an image or the like is received
from the external equipment 60 which is connected through the external
interface 20, and then recorded on the recording medium 40d which
is not the subject of recording.
Such parallel processing enables data communications with the external
equipment 60 in the background of the photographing operation of
the digital camera 1.
The forms of processing as shown in FIGS. 14 and 15 are taken when
a user designates the execution of background processing as above
described. For a user to select which kind of processing is to be
performed in the background, the CPU 17 controls the monitor 25
to display a card selection screen. FIG. 16 shows the digital camera
1 displaying such a card selection screen on the monitor 25.
As shown in FIG. 16, the setting selection switch 6b is placed
in its "central" position; therefore, the recording medium
40c ("CARD 2") loaded in the slot B (i.e., the slot 41b)
is selected as a subject of recording of a captured image. At this
time, the card selection screen as shown in FIG. 16 shall appear
on the monitor 25.
On the card selection screen of FIG. 16, a recording medium ("CARD
1") loaded in the slot 41 a is selected as a destination of
data supply.
When a user operates cursor-control keys (e.g., the down key 6f)
as a decision key with the card selection screen as shown in FIG.
16, the recording medium loaded in the slot 41b is selected as a
subject of recording of a captured image which is generated through
a photographing operation. Also, processing for the input of an
image or the like from the external equipment 60 and the recording
thereof on the recording medium loaded in the slot 41a is selected
as multiple task processing performed in the background of the CPU
17.
Consequently, the processing as shown in FIG. 15 is executed by
the CPU 17.
In this fashion, when recording a captured image on a recording
medium which is selected as a subject of recording out of a plurality
of recording media, any desired processing is performed in parallel
on another recording medium which is not the subject of recording.
This enables the execution of necessary processing on the recording
medium which is not the subject of recording, in the background
of the main task. Such processing on the recording medium which
is not the subject of recording prevents the release operation from
being disabled, thereby allowing photographing operations to be
performed at the appropriate times.
<5. Processing When External Equipment is Another Digital Camera>
In the above descriptions with FIGS. 14 and 15, no mention is made
of what kind of device is the external equipment 60. If another
digital camera is connected as the external equipment 60, an image
recording system that can achieve recording processing of a variety
of captured images can be configured.
FIG. 17 shows a configuration of such an image recording system
100. As shown in FIG. 17, this image recording system 100 is comprised
of a first digital camera 1 and a second digital camera 60a connected
with each other through a cable 2 which is a transmission medium
that makes data communications possible. The first digital camera
1 is a digital camera with the above-described construction, which
can load two recording media 40c, 40d and comprises the CPU 17 that
can perform a plurality of tasks in parallel. When viewed from the
first digital camera 1, the second digital camera 60a corresponds
to the external equipment 60. The second digital camera 60a, on
the other hand, can load at least one recording medium 40e.
In such a configuration of the image recording system 100, for
example, a first captured image, which is obtained through a photographing
operation with the first digital camera 1, is recorded on the recording
medium 40c, and in parallel with that recording, a second captured
image, which is obtained through a photographing operation with
the second digital camera 60a, is input into the first digital camera
1 through the cable 2 and recorded on the recording medium 40d.
Thus, even if the recording medium 40e in the second digital camera
60a is short of free space, both the digital cameras can perform
photographing operations at the appropriate times.
Further, even when a captured image which is recorded on the recording
medium 40c in the first digital camera 1 is copied into the recording
medium 40e in the second digital camera 60a, recording of a first
captured image, which is obtained through a photographing operation
with the first digital camera 1, onto the recording medium 40d can
be performed in parallel with output of captured image data, which
is recorded on the recording medium 40c, to the second digital camera
60a. The first digital camera 1 can thus perform photographing operations
at the appropriate times.
Furthermore, even when a captured image is copied from the recording
medium 40c into the recording medium 40d within the first digital
camera 1, the second digital camera 60a which is the external equipment
60 for the first digital camera 1 should be selected as a subject
of recording. By so doing, a captured image obtained through a photographing
operation with the first digital camera 1 can be recorded on the
recording medium 40e in the second digital camera 60a. Therefore
even if the copying of captured image from the recording medium
40c into the recording medium 40d is being performed, the first
digital camera 1 can perform photographing operations at the appropriate
times.
<6. Processing When External Equipment is Printer>
Next, processing when the external equipment 60 is a printer is
discussed.
FIG. 18 shows an image recording system 200 when a printer 60b
is connected as external equipment. This image recording system
200 comprises the digital camera 1 and the printer 60b connected
with each other through the cable 2. The digital camera 1 has the
aforementioned construction.
In such a system configuration, recording of a captured image,
which is obtained through a photographing operation with the digital
camera 1, on the recording medium 40c can be performed in parallel
with output of captured image data, which is recorded on the recording
medium 40d, into the printer 60b. The digital camera 1 can thus
perform photographing operations at the appropriate times even during
printout of captured image data.
<7. Modifications>
So far, one preferred embodiment of the present invention has been
described; however, it is to be understood that the present invention
is not limited thereto.
For instance, the aforementioned CPU 17 may be located in a unit
other than the image processor 10. Further, although a single CPU
17 performs a plurality of task in parallel in the above description,
the present invention is not limited thereto. In fact, a plurality
of CPUs may be provided to perform a plurality of tasks in parallel
and those CPUs may constitute a controller.
In the above description, each recording medium is removable from
the digital camera 1; however, the present invention is not limited
thereto. Alternatively, the digital camera 1 may have built-in storage
media. In such a case, also, the digital camera 1 would achieve
the same effect of preventing the release operation from being disabled,
thereby permitting continuous photographing and the like.
While the invention has been shown and described in detail, the
foregoing description is in all aspects illustrative and not restrictive.
It is therefore understood that numerous modifications and variations
can be devised without departing from the scope of the invention.
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