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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an image data recording apparatus including a
digital electronic still video camera, in which digital video data
representing a still picture imaged by the camera is recorded on a freely
loadable/unloadable memory cartridge, and a device for extracting one
frame of a still video signal from an inputted moving video signal,
converting the extracted video signal into a digital signal, and recording
the digital signal on the memory cartridge in the same manner as the
digital still video camera.
2. Description of Related Art
An example of a digital electronic still video camera of the
above-mentioned kind is described in the specification of Japanese Patent
Application Laid-Open (KOKAI) No. 57-14260. The electronic camera is
equipped with a memory having a plurality of memory cells (storage areas)
each storing one frame of data for a subject, so that it is possible to
select the memory cell for storing the image data. In a case where the
memory cell selected has data recorded therein, the previously recorded
image data will be erased when the new image data is written in such a
memory cell. Accordingly, the electronic camera is equipped with a sensing
circuit for sensing whether each memory cell is used or unused, and a
display device for displaying the results of the sensing operation
performed by the sensing circuit. The display device includes a display
for indicating whether each memory cell is used or unused.
With an arrangement of this kind, the user of the electronic still video
camera is prevented from accidentally recording newly taken image data in
a used memory cell.
However, there are times when it is desired to intentionally record newly
taken image data in a used memory cell. Examples of these times are when
the user fails to shoot a previous scene properly and wishes to retake the
picture, and when image data in the used memory cell is no longer needed.
When the camera is used in this way, the order in which the memory cells
are arrayed fails to coincide with the order in which pictures are taken.
The order or sequence in which pictures are taken, namely the order in
which image data is recorded, is a very important factor in terms of
utilizing the image data at a subsequent time. For example, when a number
of pictures that have been taken are to be subsequently compiled based on
a fixed plan, information regarding the order in which the pictures are
stored is vitally important. One solution to this problem is to write down
information identifying the photographed subject, etc. each time in
correlation with the order in which the pictures were taken, but this is a
very troublesome task, and the user may forget to make entries or make
inaccurately.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an image data recording
apparatus that enables the order in which plural items of image data are
recorded to be ascertained without requiring any labor for this purpose.
According to the present invention, the foregoing object is attained by
providing an image data recording apparatus comprising first code
generating means for generating a recording-finished code representing the
fact that image data has been recorded in a freely loadable/unloadable
memory cartridge having a memory capable of recording image data
constituting a plurality of pictures, second code generating means for
generating a recording sequence code incremented whenever image data is
recorded, and control means operative, when image data is recorded in the
memory of the memory cartridge, for storing the recording-finished code
and recording sequence code generated by the first and second code
generating means in a predetermined area of the memory in correspondence
with the image data recorded. The memory cartridge referred to here is one
in which a semiconductor memory is incorporated in a case or cartridge,
and may include a memory card.
In accordance with the present invention, the recording sequence code is
incremented whenever image data far being recorded is stored to correspond
with recorded image data when this data is recorded. Since the code
indicating the recording sequence is stored automatically in
correspondence with the recorded image data, the user is capable of
subsequently ascertaining the order in which the items of image data were
recorded without performing any additional operations. In a case where new
image data is recorded in an area already recorded on and this previous
image data is erased as a result, the previous recording sequence code is
also erased and a new recording sequence code is stored in its place.
Though the previous recording sequence code that has been erased becomes a
missing number, no problem is encountered in ascertaining the prevailing
sequence because the relative sizes of the numerals represented by the
recording sequence codes are preserved which correspond exactly to the
recording sequence.
In accordance with the invention, when plural items of image data are
stored, the codes representing the recording sequence are preserved
whenever image data is stored, even if storing of the items of image data
involves rewriting the memory. Thereby, it is possible to ascertain the
recording sequence at a subsequent time. Accordingly, the invention is
useful for picture compilation as well as other purposes.
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.
The present invention will become more fully understood from the detailed
description given hereinbelow and the accompanying drawings which are
given by way of illustration only, and thus, are not limitative of the
present invention, and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the electrical construction of an
electronic still video camera and a memory cartridge;
FIG. 2 is a view illustrating data recorded in the image memories of a
memory cartridge, as well as a procedure for erasing and re-recording
data;
FIG. 3 is a view illustrating a processing procedure for reassigning
recording sequence codes in image memories; and
FIG. 4 is a view illustrating a table prepared in a case where a display is
presented in accordance with a recording sequence in a playback apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates the electrical construction of a digital electronic
still video camera 10 and a memory cartridge 1 that is freely loadable and
unloadable to and from the camera 10.
Photography in the digital electronic still video camera 10, transfer of
the resulting image data, recording-finished code and recording sequence
codes to the memory cartridge 1, and other processing operations are
controlled by a system controller 20. The system controller 20 includes a
CPU, a ROM for storing the execution program of the CPU, and a RAM for
storing the required data.
An image of a subject is focused on an image sensor 12 via an optical
system 11, and the image sensor 12 outputs a video signal indicative of
the image. After being subjected to the required signal processing
operations such as amplification, exposure adjustment and white balance
adjustment by a signal processing circuit 13, the video signal is
converted into a digital signal by an A/D converter circuit 14. This
digital signal is subjected to further necessary processing operations,
such as separation the digital signal into color components by a signal
processing circuit 15. The result is as image data sent from the circuit
15 to a data selector 16.
A recording-finished code generating circuit 21 generates a predetermined
recording-finished code having a prescribed number of bits. This code is
applied to the data selector 16 in response to a command from the system
controller 20.
A recording sequence code generating circuit 22, which may, for example,
include a counter, generates a recording sequence code incremented each
time image data is written in the memory cartridge 1. This code indicates
a numeral representing a recording sequence. The operation for
incrementing the recording sequence code in the generating circuit 22 and
the transfer of the generated recording sequence code to the data selector
16 are controlled by the system controller 20.
A decision circuit 23 decodes the recording-finished code (or a code
indicating that an image memory is blank) and the recording sequence code
read out of the memory cartridge 1 which is received via a connector 5 and
the data selector 16. The system controller 20 is provided with the
results of the decoding operation, namely data indicating whether a
recording has been made as well as the number of the recording sequence.
The functions of the circuits 21, 22 and 23, namely the generation of the
recording-finished code, the generation of the recording sequence code and
the decoding of these codes, are performed by the CPU in the system
controller 20.
An input unit 17 includes push-buttons which provides an instruction for
playing back video data recorded in the memory cartridge 1 in a view
finder (not shown), and an instruction for erasing the image data when
this operation is necessary. The view finder includes a display device for
displaying output image data from the signal processing circuit 15 and
image data read out of the memory cartridge 1. An example of the view
finder is a liquid crystal display device. The display of a recorded image
(the image read out of the memory cartridge) in the view finder may be
carried out in accordance with a fixed sequence (e.g. the order of memory
addresses), or the input unit can be provided with a keyboard for allowing
the operator to designated the identification number of a picture to be
played back.
The data selector 16, which is controlled by the system controller 20,
sends the above-mentioned image data, the recording-finished code or the
recording sequence code to the memory cartridge 1, depending upon which is
designated.
The foregoing is a description of processing and flow operations relating
mainly to data (i.e. a description of the data bus). However, the
electronic still video camera 10 naturally includes an address bus as
well, a portion of which is indicated as a bus from the system controller
20 to the connector 5. This is for designating an address at which image
data is to be written in the memory of the memory cartridge 1 or an
address from which image data is to be read out of the memory.
Upon being loaded in the camera 10, the memory cartridge 1 is electrically
connected to the abovementioned circuitry in the camera 10 by the
connector 5. The connector 5 includes a connector provided on the camera
side and a number of terminals provided on the cartridge.
The memory cartridge 1 internally incorporates several image memory chips,
an address designating circuit 3 for decoding the address signal provided
by the system controller 20 of camera 10 and designating the memory area
specified by the decoded signal, and a battery (not shown) for supplying
the memories with operating power. Each image memory chip stores one or
plural frames of image data, depending upon the capacity of the memory
chip. For the sake of the description, an area or memory chip which stores
one frame of image data shall be referred to as an image memory 2 in FIG.
1. If the memory chip is non-volatile, the image memory 2 will not require
the afore-mentioned battery. Depending upon the particular case, it is
also possible to adopt an arrangement in which operating power is supplied
from the side of camera 10 via the connector 5 in order to operate other
required circuitry.
The image memories 2 are connected to the data selector 16 of camera 10 by
the data bus. Each image memory 2, in addition to having an area for
storing image data, is also equipped with a location for storing a
recording-finished code and a location for storing a recording sequence
code. The image memories 2 are provided with numbers M.sub.1, M.sub.2, . .
. M.sub.n, so that these numbers are in accordance with the order in which
the image memories 2 are arrayed. When it is necessary to distinguish
among these plurality of image memories 2, these numbers will be used.
Rather than storing the recording-finished codes and recording sequence
codes in each of the image memories 2, it is permissible to adopt an
arrangement in which these codes are stored in a separately provided data
memory to correspond to the image memory numbers M.sub.1, M.sub.2, . . .
M.sub.n.
An example of the operation of the digital electronic still video camera
and an example of a playback operation using a playback apparatus will be
described next.
The upper row of FIG. 2 illustrates the manner in which image data, a
recording-finished code and a recording sequence code are stored in each
image memory 2. For the sake of simplicity, it will be assumed that n=5,
so that there are five image memories M.sub.1 through M.sub.5. The code
1010 shall be employed as the recording-finished code. Since image data
will be recorded in the order of the image memories M.sub.1 through
M.sub.5, the recording sequence codes are stored in the image memories as
follows: a recording sequence code 0001 (=1) in the image memory M.sub.1,
a recording sequence code 0010 (=2) in the image memory M.sub.2, and so
on, with a recording sequence code 0101 (=5) being stored in the last
image memory M.sub.5.
More specifically, the content of the recording sequence code generating
circuit 22 in the camera 10 is cleared first of all. When the first frame
of an image has been shot, the image data is stored in the first image
memory M.sub.1 via the data selector 16 and connector 5. The content of
the recording sequence code generating circuit 22 is incremented by +1 to
produce the recording sequence code which, together with the
recording-finished code outputted by the generating circuit 21, is
transferred to the same image memory M.sub.1 to be stored therein. The
address of this storage location is designated by the system controller
20.
When the second frame of video is obtained, the resulting image data is
transferred to the second image memory M.sub.2, and the recording sequence
code, which is updated by being incremented by +1, is transferred to and
stored in the same memory M2 together with the recording-finished code.
The image memories are thereby provided with data as illustrated in the
upper row of FIG. 2.
With the memory cartridge 1 loaded in the camera 10, the user of the camera
is capable of reading the image data out of the image memories in an order
starting from the image memory M.sub.1 to display the data in the view
finder. When a playback command is inputted from the input unit 17, the
system controller 20 first designates the memory M.sub.1 and reads out the
recording-finished code thereof. When the result of the decoding operation
performed by the decision circuit 23 is that the memory M.sub.1 has been
recorded on, a command for reading out this image data is applied.
Accordingly, the read image data is displayed in the view finder. When the
memory M.sub.1 has not been recorded on, a read-out of image data from
this image memory is not performed. When the user applies a forward-feed
command from the input unit, or when a fixed time period elapses, the
image data in the second image memory M.sub.2 is read out and displayed.
If the user enters an erase command from the input unit 17 when still
pictures are thus sequentially displayed in the view finder, the
recording-finished code and the recording sequence code are reset (to
0000) in the image memory corresponding to the picture being displayed.
The middle row in FIG. 2 illustrates the manner in which the codes are
erased from the second memory M.sub.2 and the fourth memory M.sub.4.
It is permissible to adopt an arrangement in which the user is called upon
to input the number of the memory whose image is to be erased or the
recording sequence code. In the latter case, a number indicating the
recording sequence would be displayed in the view finder.
Image data obtained by newly photographing a subject can be recorded by the
user in an image memory erased as set forth above.
The content of the recording sequence code generating circuit 22 is assumed
to be 5. The next time a picture is taken, the code is incremented by +1,
so that the circuit 22 generates a recording sequence code equivalent to
6. This recording sequence code will be recorded in the second image
memory M.sub.2 along with the image data and the recording-finished code.
The system controller 20 stores the numbers of the image memories erased
and designates the image memories in numerical order starting from the
smallest number. When the user takes a picture again, the image data is
stored in the fourth image memory M.sub.4. The recording sequence code at
this time is 7. The image memories in which the new image data and various
codes are thus written are illustrated in the bottom row of FIG. 2.
Looking at the recording sequence codes in the order to the memories
M.sub.1 through M.sub.5, it is found that the codes are 1, 6, 3, 7 and 5.
Though the sequence codes 2 and 4 are no longer present, the recording
sequence is known from the size relationship among the numbers expressed
by the recording sequence codes. In other words, the recording sequence is
preserved. Accordingly, it is possible for still pictures to be displayed
by a playback apparatus in accordance with this recording sequence, as
will be described below by way of example.
The above-mentioned processing operations for erasing unnecessary image
data can also be performed by a playback apparatus. The memory cartridge
can be freely loaded and unloaded in and from the playback apparatus. When
the cartridge is loaded, the circuitry in the playback apparatus and the
memory cartridge are electrically connected. The playback apparatus
includes a system controller for controlling the reading and writing of
image data relative to the memory of the memory cartridge, and a display
device (such as a liquid crystal device or CRT) for displaying the read
digital image data directly or following the read digital image data being
converted into an analog signal.
The memory cartridge 1 is unloaded from the camera 10 and loaded in the
playback apparatus. Through a procedure similar to the procedure described
above, a recording-finished code and a recording sequence code
corresponding to unnecessary image data stored in an image memory inside
the memory cartridge 1 are reset by the playback apparatus.
The memory cartridge is subsequently reloaded in the camera 10. When the
system controller 20 of the camera 10 senses loading of the memory
cartridge 1 (as by a loading sensor), the recording-finished codes and
recording sequence codes of all of the image memories are read out, the
numbers of image memories that have not been recorded on are stored, and
the maximum value of a recording sequence code is found. The maximum value
is preset in the recording sequence code generating circuit 22.
Accordingly, when the camera 10 next performs a photographic operation,
the resulting image data are stored in the blank image memories, and
recording sequence codes are assigned to these memories starting from the
afore-mentioned maximum value which has been incremented by one.
When recording is performed again after erasing the recording-finished
codes and the recording sequence codes, the erased recording sequence
codes become missing numbers, as indicated by the bottom row of FIG. 2.
Though the recording sequence is preserved by the relative magnitudes of
the recording sequence codes, the sequence is somewhat difficult to grasp.
Accordingly, the playback apparatus is preferably provided with a function
for processing so that the recording sequence codes will be reassigned
while the recording sequence remains intact. FIG. 3 illustrates an example
of a processing procedure for reassigning recording sequence codes, where
the processing is executed by a CPU in the system controller of the
playback apparatus. In the uppermost row of FIG. 3 it is assumed that the
recording sequence codes are assigned and are the same as the codes
illustrated in the bottom row of FIG. 2 with the exception of the fourth
memory M.sub.4. Because the fourth memory M.sub.4 is blank, the recording
sequence code thereof has been reset. The character E is assigned to this
image memory in FIG. 3.
When the memory cartridge is loaded in the playback apparatus, still
pictures are displayed on the display device in the order of the image
memories. At such a time, the recording sequence code is also displayed by
being superimposed on a portion of the picture.
The CPU of the playback apparatus stores the recording sequence codes in a
predetermined area of the memory in the order in which the pictures are
played back. Next, the recording sequence codes are rearranged in an order
starting from the smallest code (see the second row from the top in FIG.
3). The character E is ignored. (Preferably, the aforementioned display of
still pictures is not performed at this time.) After the codes are
rearranged, the recording sequence codes representing consecutive numbers
devoid of missing numbers are assigned (see the third row from the top in
FIG. 3). Finally, the reassigned recording sequence codes are stored in
the corresponding image memories (see the bottom row in FIG. 3).
When consecutively numbered recording sequence codes are thus assigned to
recorded image data, these recorded data are easily read out and displayed
in accordance with the recording sequence. It is possible to adopt an
arrangement in which the reassignment of the recording sequence codes is
carried out by the electronic still video camera.
The CPU of the playback apparatus prepares a table in a predetermined area
of its memory. As illustrated in FIG. 4, the table includes recording
sequence codes corresponding to the image memories M.sub.1 through
M.sub.5, and the lead addresses of the areas at which the image data are
stored. The CPU retrieves this table using the recording sequence codes as
a key and first reads out the lead address of the recording sequence code
1 and presets this address in an address counter for image memory
read-out. When the counter is successively incremented, one frame of the
image memory data corresponding to the recording sequence code 1 is read
out and this still picture is displayed on the display device. When a
forward-feed command is inputted or a fixed period of time elapses, the
CPU then reads the lead address corresponding to the next recording
sequence code 2 out of the table and executes the display processing in
the same manner. Thus, still pictures are displayed in an order
corresponding to the recording sequence and the display of the picture
assigned with the character E is unnecessary.
As many apparently and widely different embodiments of the present
invention can be made without departing from the spirit and scope thereof,
it is to be understood that the invention is not limited to the specific
embodiments thereof except as defined in the appended claims.
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