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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a digital electronic still-video camera for
imaging a subject, converting the video signal thus obtained into digital
image data and recording the image data in a memory cartridge capable of
being loaded and ejected at will, and to a playback apparatus for playing
back and displaying the image data resulting from the imaging operation of
the digital electronic still-video camera. The memory cartridge mentioned
here has the shape of a case or card incorporating a semiconductor memory.
The term is intended to cover means such as a memory card.
2. Description of the Related Art
A camera of the kind described in the specification of Japanese Patent
Publication (KOKOKU) No. 62-21310 is a known example of a recent
electronic still-video camera. This known electronic still-video camera is
adapted to convert a video signal representing the image of a subject into
a digital quantity and to store the digital quantity as image data in an
internal memory incorporated in the body of tile camera. At playback, the
image data is read out of the internal memory and sent to a playback
apparatus via a connector. The playback apparatus converts the provided
image data into a video signal and applies the video signal to a display
unit. As a result, a still picture is displayed on the display unit.
In another example of an electronic still-video camera described in the
specification of Japanese Patent Application Laid-Open (KOKAI) No.
59-183582, the image data is recorded in a memory cartridge capable of
being loaded in and ejected from the camera body at will.
The first example of the electronic still-video camera mentioned above is
convenient because it is unnecessary for the user to carry about a
separate memory cartridge. However, the number of frames capable of being
photographed is limited by the storage capacity of the internal memory of
the camera, and it is not possible to perform photography beyond the
number of frames decided by the storage capacity of the internal memory.
Using an internal memory having a large storage capacity permits more
photography but raises the cost of the camera. In addition, there is a
limit also upon the storage capacity of the internal memory, and therefore
in practical use there is no assurance that the internal memory will
always have the capacity to preserve all of the frames desired to be shot.
In the second example of the electronic still-video camera described above,
an advantage is that preparing the necessary number of memory cartridges
makes it possible to perform photography without any limitation being
imposed on the number of frames that can be shot. However, the user must
carry about a memory cartridge even if the number of frames planned on
being shot is small. Furthermore, after a memory cartridge has been filled
to capacity with the image data, photography cannot be performed unless
the memory cartridge is exchanged for a new one.
Further, with the first example of the electronic still-video camera, a
separate playback apparatus is necessary in order to read and reproduce
the image data from the internal memory of the camera. Likewise, the
second example of the electronic still-video camera requires a separate
playback apparatus in order to read and reproduce the image data obtained
by the camera and stored in the memory cartridge.
A disadvantage encountered above is that the playback apparatus for the
first example of the electronic still-video camera and the playback
apparatus for the second example of the electronic still-video camera have
connectors of different types, and therefore the cameras cannot share the
same playback apparatus. Accordingly, in a case where two types of
electronic still-video cameras are used for photography, two types of
playback apparatus also are required. This is inconvenient and
disadvantageous in terms of handling and storage space. In addition, the
fact that two types of playback apparatus must be purchased is costly and
is a serious drawback economically speaking.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an
easy-to-carry electronic still-video camera capable of performing
photography without any limitation upon the number of frames.
Another object of the present invention is to provide an electronic
still-video camera in which, even if the number of recordable frames left
in a memory cartridge has become zero, at least one more frame can be shot
without replacing the memory cartridge.
A further object of the present invention is to provide a playback
apparatus capable of being used to reproduce image data stored in both the
internal memory and external memory (a memory cartridge) of an electronic
still-video camera.
An electronic still-video camera according to a first aspect of the present
invention comprises image pick-up means for picking up an image of a
subject and outputting a video signal representing the image of the
subject obtained, recording signal processing means for converting the
video signal outputted by the image pick-up means into digital image data
suited for storage in a memory, an internal memory for storing the image
data, a first connector in and from which a memory cartridge is capable of
being loaded and unloaded at will, the memory cartridge incorporating an
external memory for storing the image data, and write control means for
writing the image data, which has been outputted by the recording signal
processing means, in either the internal memory or the external memory.
In an embodiment of the invention, the image data is written first in the
internal memory until the internal memory is filled to capacity, and then
in the external memory, by the write control means.
In another embodiment of the invention, the electronic still-video camera
further comprises memory selecting means for selecting either the internal
memory or the external memory. The image data is written in the memory
selected by the memory selecting means.
The electronic still-video camera also comprises means for displaying the
number of recordable frames left in the internal memory or the external
memory, and means for displaying the number of frames of image data stored
in the internal memory or external memory.
In a preferred embodiment, the electronic still-video camera according to
the first aspect of the present invention further comprises read control
means for reading out the image data stored in the internal memory or the
external memory, playback processing means for converting the image data
read out by the read control means into a video signal suited for display,
and outputting this video signal, and a second connector, to which an
external display unit is capable of being connected, for supplying the
display unit with the video signal outputted by the playback processing
means.
In another preferred embodiment, the electronic still-video camera
according to the first aspect of the present invention additional
comprises read control means for reading out the image data stored in the
internal memory or the external memory, and a third connector, to which an
external playback apparatus is capable of being connected, for supplying
the playback apparatus with the image data read out by the read control
means.
An electronic still-video camera according to a first aspect of the present
invention comprises an internal memory for storing image data, a first
connector, in and from which a memory cartridge is capable of being loaded
and unloaded at will, the memory cartridge incorporating an external
memory for storing the image data, read control means for reading out the
image data stored in the internal memory or the external memory, playback
processing means for converting the image data read out by the read
control means into a video signal suited for display, and outputting this
video signal, and a second connector, to which an external display unit is
capable of being connected, for supplying the display unit with the video
signal outputted by the playback processing means.
In another embodiment of the invention, the electronic still-video camera
further comprises memory selecting means for selecting either the internal
memory or the external memory. The image data is read out of the memory
selected by the memory selecting means.
The electronic still-video camera also comprises means for designating a
frame number of the image data to be read out of the memory.
The electronic still-video camera additionally comprises a third connector,
to which an external playback apparatus is capable of being connected, for
supplying the playback apparatus with the image data read out by the read
control means.
An electronic still-video camera according to a first aspect of the present
invention comprises an internal memory for storing image data, a first
connector, in and from which a memory cartridge is capable of being loaded
and unloaded at will, the memory cartridge incorporating an external
memory for storing the image data, read control means for reading out the
image data stored in the internal memory or the external memory, and a
second connector, to which an external playback apparatus is capable of
being connected, for supplying the playback apparatus with the image data
read by the read control means.
In a preferred embodiment, the electronic still-video camera further
comprises memory selecting means for selecting either the internal memory
or the external memory. The image data is read out of the memory selected
by the memory selecting means.
The electronic still-video camera further comprises means for designating a
frame number of the image data to be read out of the memory.
The electronic still-video camera also comprises playback processing means
for converting the image data read out by the read control means into a
video signal suited for display, and outputting this video signal, and a
third connector, to which an external display unit is capable of being
connected, for supplying the display unit with the video signal outputted
by the playback processing means.
In accordance with the first aspect of the present invention, a memory
cartridge incorporating an external memory is loaded in the camera,
thereby making it possible to shoot a number of frames beyond the storage
capacity (the number of photographable frames) of the internal memory. In
a case where the volume of image data for the required number of
photographic frames is less than the capacity of the internal memory, it
is unnecessary for the user to bring along a memory cartridge.
Accordingly, the electronic still-video camera is highly portable. In
addition, since it is unnecessary to rely solely upon the internal memory
in order to shoot all of the desired number of photographic frames, it is
possible to hold down the price of the camera. At playback, image data
stored not only in the internal memory but also in the external memory can
be played back by the playback processing means and reproduced on the
display screen of the display unit. Of course, it is possible also to read
the image data out of the external memory or internal memory and send this
image data to the external playback apparatus.
A playback apparatus for an electronic still-video camera according to a
second aspect of the present invention comprises a first connector capable
of being connected to the electronic still-video camera for accepting
image data outputted upon being read out of a memory of the electronic
still-video camera, a second connector capable of being connected to a
memory cartridge for accepting image data outputted upon being read out of
a memory within the memory cartridge, playback means for converting the
image data, with which it has been provided, into a video signal suited
for display, and connector selecting means for selecting either the first
connector or the second connector and providing the playback means with
the image data supplied through the connector selected.
In a preferred embodiment, the playback apparatus further comprises a third
connector for connecting a display unit provided with the video signal
outputted by the playback means.
The playback apparatus also comprises image designating means for
designating image data to be read out of the memory of the electronic
still-video camera or the memory of the memory cartridge.
The electronic still-video camera comprises an internal memory for storing
the image data, a connector for connecting a memory cartridge which
incorporates an external memory for storing the image data, memory
selecting means for selecting read-out of the image data from the internal
memory or the external memory, and image data reading means for reading
and outputting designated image data from the memory selected by the
memory selecting means.
The playback apparatus further comprises means for commanding read-out of
image data from the internal memory or the external memory of the
electronic still-video camera.
In a preferred embodiment according to the second aspect of the present
invention, the playback apparatus has a first control panel which includes
the connector selecting means, and the electronic still-video camera has a
second control panel for commanding operation of the camera. The playback
apparatus further comprises operation selecting means for enabling an
operating input from one of the first and second control panels and
disabling an operating input from the other of the first and second
control panels, and causing the playback apparatus to perform an
operation, which has been commanded by an operating input, in response to
the operating input from the enabled control panel.
In another embodiment according to the second aspect of the invention, the
playback apparatus further comprises a fourth connector for receiving an
input of an externally applied video signal, and recording means for
converting the video signal inputted from the fourth connector into image
data, and storing the image data in the electronic still-video camera or
the memory of the memory cartridge via the first or second connector.
In accordance with the second aspect of the present invention, the
electronic still-video camera is connected to the first connector, the
memory cartridge is connected to the second connector, and the first or
second connector is connected to the playback means by the connector
selecting means. As a result, the image data read out via the connector
can be played back and displayed on the display unit. Accordingly, the
image data recorded in the electronic still-video camera and in the memory
cartridge can be played back using a single playback apparatus.
In accordance with the embodiment of the second aspect of the invention,
memory selection and playback can be controlled by the user using the
first control panel of the playback apparatus or the second control panel
of the electronic still-video camera.
In accordance with the other embodiment of the second aspect of the
invention, a video signal from a VTR or the like inputted from the fourth
connector is converted into image data, and the image data can be stored
in the electronic still-video camera or the memory cartridge via the first
or second connector. This makes it possible to reproduce the recorded
contents of a video tape of the like.
An electronic still-video camera according to a third aspect of the present
invention comprises image pick-up means for picking up an image of a
subject and outputting a video signal representing the image of the
subject obtained, recording signal processing means for converting the
video signal outputted by the image pickup means into digital image data
suited for storage in a memory, and for compressing the digital image
data, an internal memory for storing the compressed image data, a first
connector in and from which a memory cartridge is capable of being loaded
and unloaded at will, the memory cartridge incorporating an external
memory for storing the compressed image data, and write control means for
writing the compressed image data, which has been outputted by the
recording signal processing means, in either the internal memory or the
external memory.
In an embodiment according to the third aspect of the present invention,
the electronic still-video camera further comprises memory selecting means
for selecting either the internal memory or the external memory. The
compressed image data is written in the memory selected by the memory
selecting means.
It is particularly preferred that the electronic still-video camera also
comprises means for displaying the number of recordable frames left in the
internal memory or the external memory, and means for displaying the
number of frames of image data stored in the internal memory or external
memory.
In another embodiment, the electronic still-video camera comprises read
control means for reading out the compressed image data stored in the
internal memory or the external memory, and playback processing means for
expanding the compressed image data read out by the read control means,
converting the expanded image data into a video signal suited for display,
and outputting this video signal.
The electronic still-video camera further comprises a second connector, to
which an external display unit is capable of being connected, for
supplying the display unit with the video signal outputted by the playback
processing means.
The electronic still-video camera also comprises a display unit for
displaying an image represented by the video signal outputted by the
playback processing means.
In another embodiment of the present invention, the electronic still-video
camera additionally comprises means for transferring the compressed image
data from the internal memory to the external memory, or vice versa.
The electronic still-video camera further comprises means for designating
the compressed image data to be transferred.
The transfer means may be adapted to transfer all of the compressed image
data stored in the internal memory or external memory.
An electronic still-video camera according to a third aspect of the present
invention comprises an internal memory for storing compressed image data,
a first connector in and from which a memory cartridge is capable of being
loaded and unloaded at will, the memory cartridge incorporating an
external memory for storing the image data, read control means for reading
out the compressed image data stored in the internal memory or the
external memory, and playback processing means for expanding the
compressed image data read out by the read control means, converting the
expanded image data into a video signal suited for display, and outputting
this video signal.
In a preferred embodiment, the electronic still-video camera further
comprises memory selecting means for selecting either the internal memory
or the external memory. The compressed image data is read out of the
memory selected by the memory selecting means.
In an embodiment according to the third aspect of the present invention,
the electronic still-video camera also comprises a second connector, to
which an external display unit is capable of being connected, for
supplying the display unit with the video signal outputted by the playback
processing means.
According to another embodiment, the electronic still-video camera
additionally comprises a display unit for displaying an image represented
by the video signal outputted by the playback processing means.
An electronic still-video camera according to a third aspect of the present
invention comprises image pick-up means for picking up an image of a
subject and outputting a video signal representing the image of the
subject obtained, recording signal processing means for converting the
video signal outputted by the image pick-up means into digital image data
suited for storage in a memory, and for compressing the digital image
data, an internal memory for storing the compressed image data, a
connector in and from which a memory cartridge is capable of being loaded
and unloaded at will, the memory cartridge incorporating an external
memory for storing the compressed image data, write control means for
writing the compressed image data outputted by the recording signal
processing means in either the internal memory or external memory, and
means for transferring the compressed image data from the internal memory
to the external memory or vice versa.
In a preferred embodiment, the electronic still-video camera further
comprises means for designating the compressed image data to be
transferred.
The transfer means may be adapted to transfer all of the compressed image
data stored in the internal memory or external memory.
accordance with the third aspect of the present invention, photography is
possible without carrying about a memory cartridge, just as in the first
aspect of tile present invention. The data representing the acquired image
is capable of being stored in the internal memory. The image data that has
been stored in the internal memory can be transferred to the external
memory of the memory cartridge and therefore is capable of being preserved
in the external memory. Naturally, in a case where the number of
photographs is large, the memory cartridge is loaded so that the
photographic image data can be preserved in the memory cartridge. Since
the image data is subjected to compression processing, memory capacity can
be utilized very effectively.
An electronic still-video camera according to a fourth aspect of the
present invention comprises image pick-up means for picking up an image of
a subject and outputting a video signal representing the image of the
subject obtained, recording signal processing means having a frame memory
for converting the video signal outputted by the image pick-up means into
digital image data suited for storage in a memory, and for compressing the
digital image data, a connector in and from which a memory cartridge is
capable of being loaded and unloaded at will, the memory cartridge
incorporating an external memory for storing the compressed image data,
sensing means for sensing that the memory cartridge has been connected to
the connector, determining means for determining that compressed image
data can no longer be recorded in the memory cartridge connected to the
connector, and control means, when it has been determined by the
determining means that the compressed image data can no longer be recorded
in the memory cartridge after the digital image data, which has been
obtained by image pick-up performed by the image pick-up means and results
from the conversion performed by the recording signal processing means,
and has been stored in the frame memory, operable for performing control
in such a manner that the image data stored in the frame memory is written
in a new memory cartridge once it has been confirmed based upon
information from the sensing means that the memory cartridge has been
replaced by the new memory cartridge.
In an embodiment according to the fourth aspect of the present invention,
the recording signal processing means includes a Y/C processing circuit
for generating luminance data and color data from the digital image data,
and a compressing circuit for compressing the image data after it has been
subjected to Y/C processing. Once the image data subjected to Y/C
processing has been preserved in the frame memory and replacement of the
memory cartridge has been confirmed, the image data is compressed and then
recorded in the new memory cartridge.
In another embodiment, the electronic still-video camera further comprises
means for displaying a memory-cartridge replacement request when it has
been determined by the determining means that compressed image data is no
longer capable of being recorded in the memory cartridge.
In a preferred embodiment, the electronic still-video camera also comprises
means for cancelling automatic turn-off of power when a memory-cartridge
replacement request has been displayed by the display means.
An electronic still-video camera according to a fourth aspect of the
present invention comprises image pick-up means for picking up an image of
a subject and outputting a video signal representing the image of the
subject obtained, recording signal processing means having a frame memory
for converting the video signal outputted by the image pick-up means into
digital image data suited for storage in a memory, and for compressing the
digital image data, a connector in and from which a memory cartridge is
capable of being loaded and unloaded at will, the memory cartridge
incorporating an external memory for storing the compressed image data,
sensing means for sensing that the memory cartridge has been connected to
the connector, and control means which, when it has been sensed by the
sensing means that the memory cartridge has not been connected to the
connector after the digital image data obtained by image pick-up performed
by the image pick-up means and resulting from conversion performed by the
recording signal processing means has been stored in the frame memory,
which is operable for performing control in such a manner that the image
data stored in the frame memory is written in a memory cartridge once it
has been confirmed by the sensing means that the memory cartridge has been
connected to the connector.
In accordance with the fourth aspect of the present invention, a frame
memory essential for digital signal processing within the digital
electronic still-video camera is utilized. As a result, if it is desired
to perform photography beyond an already fixed number of photographic
frames of the memory cartridge, at least one frame can be preserved
temporarily irrespective of the size of the compression ratio. In
addition, even if memory cartridge has not been loaded in the camera,
image data resulting from photography can be preserved in the frame memory
temporarily. By operating the camera in such a manner that the temporarily
preserved image data is recorded in a new memory cartridge when the new
memory cartridge has been loaded in the camera, the operator's task is
simplified greatly.
Other features and advantages of the present invention will be apparent
from the following description taken in conjunction with the accompanying
drawings, in which like reference characters designate the same or similar
parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the electronic circuitry of an
electronic still-video camera according to a first embodiment of the
present invention;
FIG. 2 is an external perspective view of the electronic still-video
camera;
FIGS. 3a through 3c are diagrams illustrating examples of displays which
appear on a liquid-crystal display device of the electronic still-video
camera;
FIG. 4 is a block diagram illustrating the electronic circuitry
incorporated within a playback apparatus for an electronic still-video
camera according to a second embodiment of the present invention;
FIG. 5 is an external perspective view of the electronic still-video camera
and playback apparatus;
FIG. 6 is a block diagram illustrating the electronic circuitry of the
playback apparatus according to a modification of the present invention;
FIG. 7 is a block diagram illustrating the electrical construction of a
digital electronic still-video camera according to a third embodiment of
the present invention;
FIG. 8 is a diagram illustrating a display panel of the digital electronic
still-video camera;
FIG. 9 is a diagram illustrating a control panel of the digital electronic
still-video camera;
FIG. 10 is a block diagram illustrating the electrical construction of a
digital electronic still-video camera according to a fourth embodiment of
the present invention;
FIG. 11 is a flowchart illustrating the operation of the digital electronic
still-video camera; and
FIG. 12 is a diagram showing various areas of an external memory that are
contained in a memory card.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will now be described in detail with
reference to the drawings.
First Embodiment
An electronic still-video camera 10 according to a first embodiment of the
present invention has a photographic lens 8 and a finder lens 9 provided
on its front side, as illustrated in FIG. 2. A shutter-release button 11
and a liquid-crystal display device 12 are provided on the top side of the
electronic still-video camera 10. The display panel of the liquid-crystal
display device 12 is divided into three display sections 12A, 12B and 12C.
Disposed alongside the liquid-crystal display device 12 is a control panel
(indicated by numeral 20 in FIG. 1) which includes a memory selecting
switch 13, a main switch 14, a forward button 16, a reverse button 17 and
an erase button 18. An accommodating recess for a connector 19 which
connects an external playback apparatus 32 (see FIG. 1) is open and shut
by sliding a cover 21.
When the memory selecting switch 13 is set at the position of an indicator
mark 22, an internal RAM 28 incorporated within the camera 10 is selected,
as shown in FIG. 1. When the memory selecting switch 13 is set at the
position of an indicator mark 23, an external RAM 31 within a memory
cartridge 29 is selected. Thus, it is possible for image data to be stored
in or read out of the selected RAM. In this embodiment, the RAMs 28 and 31
each have a storage capacity of 12 photographic frames.
When the main switch 14 is set at the position of an indicator mark 25, the
main electronic circuitry within the camera 10 ceases operating, and
operating power is supplied solely to the minimum required circuitry, such
as a circuit needed to maintain the data stored in the internal RAM 28.
This makes it possible to minimize power consumption. When the main switch
14 is changed over to the position of an indicator mark 26, this
establishes an image playback mode. Changing over the main switch 14 to
the position of an indicator mark 27 establishes an image recording mode.
One side of the electronic still-video camera 10 has an opening 33 into
which the memory cartridge 29 is inserted. Provided within the interior of
the opening 33 is a connector 34 for connecting the memory cartridge 29. A
connector 37 for connecting an external monitor (see FIG. 1) for image
playback is provided alongside the opening 33.
When the shutter-release button 11 is pressed, a timing generator 40 shown
in FIG. 1 generates a clock pulse. In response to the clock pulse, a CCD
38 outputs a video signal representing the image of a subject
photographed. The video signal is converted into digital data by an A/D
converter 39, and the digital data is supplied to a signal processing
circuit 41. The signal processing circuit 41 separates color information
and luminance information of each pixel from the video signal and produces
image data by combining these items of information with address
information of each pixel generated based upon the clock pulse and a dot
clock signal. The image data is directed through an interface 42 to be
stored in the internal RAM 28 or the external RAM 31, depending upon the
setting of the memory selecting switch 13.
The states of the various buttons and switches on the control panel 20 are
constantly being monitored by a CPU 44. If the shutter-release button 11
is pressed when the indicator mark 27 has been selected by the main switch
14, one frame of image data resulting from photography is transferred from
the interface 42 to either the internal RAM 28 or the external RAM 31.
When the indicator mark 25 or 26 has been selected by the main switch 14,
depression of the shutter-release button 11 is considered an invalid
operation and no clock pulse is generated by the timing generator 40.
A cartridge detector circuit 46 connected to the connector 34 detects
loading of the memory cartridge 29 and sends a signal indicative thereof
to the CPU 44. The latter reads the header information of the storage area
of the external RAM 31 in the memory cartridge 29 via the interface 42
and, based upon the header information, recognizes the number of
photographable frames left in the external RAM 31 of the memory cartridge
29 and the number of already photographed frames stored in the external
RAM 31. Power necessary for backing up the external RAM 31 is supplied by
a battery in a power-supply circuit 48 incorporated in the memory
cartridge 29.
FIG. 3a illustrates examples of displays presented on the liquid-crystal
display device 12 when the memory cartridge 29 has not been loaded. In
examples 53, 54 and 55, the number "12" of photographable frames
conforming to the storage capacity of the internal RAM 28 is displayed in
the display section 12A. In examples 54 and 55, the number of photographed
frames already stored in the internal RAM 28 is displayed in display
section 12B. The number of photographed frames is incremented from "0" to
"1", "1" to "2" and so on, up to "12", each time a frame is shot.
When the memory cartridge 29 has been loaded, the display on the
liquid-crystal display device 12 changes over, as shown in FIG. 3b.
In display example 57, the indication "CA 12" in the display section 12A
indicates that the number of photographable frames in memory cartridge 29
is 12. The underlying numeral "0" indicates that the number of shot frames
already stored in the memory cartridge 29 is 0.
The indication "IN 12" which appears in the display section 12B indicates
that the number of ph | | |
