United States Patent (19)
`Kawasaki et al.
`
`54) VIDEO RECORDING DEVICE FOR
`RETROACTIVELY REPRODUCING AVIDEO
`IMAGE OF AN EVENT WHILE ALSO
`RECORDING IMAGESIN REAL TIME
`
`75 Inventors: Kaoru Kawasaki; Minoru Ozaki;
`Fumio Matsuda; Kazuya Sato, all of
`Tokyo, Japan
`
`73 Assignee: Mitsubishi Denki Kabushiki Kaisha,
`Tokyo, Japan
`
`21 Appl. No.: 08/965,042
`22 Filed:
`Nov. 5, 1997
`30
`Foreign Application Priority Data
`Nov. 7, 1996
`JP
`Japan .................................... 8-295009
`51 Int. CI.7
`H04N 5/91
`
`52 US C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 38646,386/124; 386/125;
`52)
`O X
`O
`-- O
`- - - - - - - - - - - - - - - - - - - - - - - - - - - -
`s
`360 5. 348/1 53
`
`s
`58 Field of Search .............................. 38/46, 117,
`386/12, 15, 129, 45; 365, 7; 369/32,
`50; 348/152-155, 143; H04N 5/91
`
`56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`360/5
`::: 3.E.
`tal
`" ...
`5,025,324
`6/1991 Hashimoto ...
`... 360/5
`5,140,436 8/1992 Blessinger ...
`5,184,215 2/1993 Barker ......................................... 360/5
`
`Y--
`
`CIC Clal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`
`USOO6167186A
`Patent Number:
`11
`(45) Date of Patent:
`
`6,167, 186
`Dec. 26, 2000
`
`5,345,430 9/1994 Moe ............................................ 360/7
`5,455,561 10/1995 Brown ....................
`... 348/155
`5,920,673 7/1999 Yasukohchi et al. ..
`... 386/46
`5,973,867 10/1999 Yamamoto .................................. 360/5
`FOREIGN PATENT DOCUMENTS
`2132599 5/1990 Japan.
`42.19090 8/1992 Japan
`
`Primary Examiner Wendy Garber
`ASSistant Examiner Vincent F. Boccio
`Attorney, Agent, or Firm Sughrue, Mion, Zinn, Macpeak
`& Seas, PLLC
`ABSTRACT
`57
`An input image is digitized The corresponding digital Video
`data are reproduced while they are Successively recorded on
`a magnetic video device. A Successive recording control unit
`manages at which position of a Successive recording area the
`
`digital data are to be Successively recorded to realize the
`endless recording in a limitative recording area. When an
`
`event occurs, the control unit manages to exclude the
`recorded image before and after the corresponding eVent
`image from the endleSS recording area So that the event
`image can be held as an event recording image. Since the
`monitored image can be reproduced while it is recorded, it
`can be reproduced timely retroactively, and the image before
`and after an event occurs can also be reproduced instanta
`neously. Further, Since the recording is continued while the
`image is reproduced, event images corresponding to plural
`events can be left.
`5 Claims, 9 Drawing Sheets
`
`
`
`7
`
`EVENT
`SIGNAL
`INPUT
`UNIT
`
`
`
`
`
`
`
`
`
`
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`
`
`
`
`
`
`
`
`
`
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`
`
`A-D
`CONVERTING
`UNIT
`
`DIGITAL
`VIDEO
`DATA
`INPUT
`UNIT
`
`
`
`TEMPORARY
`MEMORY
`
`
`
`
`
`SUCCESSIVE
`RECORDING
`CONTROL
`UNIT
`END ESS
`RECORDING
`TABLE
`EVENT
`RECORDING
`TABLE
`EVENT
`MANAGEMENT
`TABLE
`
`61
`
`62
`
`DISPLAY
`UNIT
`
`
`
`
`
`SUCCESSIVE
`RECORDING
`UNIT
`
`

`

`U.S. Patent
`
`Dec. 26, 2000
`
`Sheet 1 of 9
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`6,167,186
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`U.S. Patent
`U.S. Patent
`
`Dee.26, 2000
`Dec. 26, 2000
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`Sheet 2 of 9
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`6,167,186
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`Motorola v. Stellar
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`Motorola Exhibit 1008
`Page 003
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`6,167, 186
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`U.S. Patent
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`Dec. 26, 2000
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`6,167, 186
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`Dec. 26, 2000
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`U.S. Patent
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`Dec. 26, 2000
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`U.S. Patent
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`Dec. 26, 2000
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`6,167,186
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`U.S. Patent
`
`Dec. 26, 2000
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`Sheet 8 of 9
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`6,167, 186
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`FIG.8
`
`85
`
`VIDEO
`MEMORY
`
`
`
`83
`
`DISPLAY
`
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`CAMERA
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`

`

`Sheet 9 of 9
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`Dec. 26, 2000
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`Motorola Exhibit 1008
`Page 010
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`

`

`1
`VIDEO RECORDING DEVICE FOR
`RETROACTIVELY REPRODUCING AVIDEO
`IMAGE OF AN EVENT, WHILE ALSO
`RECORDING IMAGES IN REAL TIME
`
`BACKGROUND OF THE INVENTION
`The present invention relates to a Video recording device
`for recording a digitized Video image inputted from a camera
`into a digital Storage memory, and more particularly to a
`Video recording device which is capable of retroactively
`reproducing a video image (event video image) generated
`when any event occurs while it records a Video image
`monitored in real time.
`An example of the means for recording digitized Video
`information and reproducing the pertinent Video image at
`any timing on demand is a Video on-demand System. With
`Video information previously Stored in a Storage device of a
`Video Server System, when a demand for transmitting the
`Video image comes from the reproducing terminal device,
`the Video on-demand System reads the Video information
`according to the demand and Sends it to the reproducing
`terminal device.
`An example of the means for recording a Video image
`which is not digitized but inputted in real time is a Videotape
`recorder (VTR). Particularly, a “time lapse VTR” has a
`purpose of monitoring by Video image and intends to review
`later the Video image when any event occurs.
`FIG. 8 is a block diagram of a video recording device
`disclosed in JP-A-2-132599. FIG. 9 is a timing chart of the
`operation of the device. In this video recording device, a
`Video image inputted from a camera is recorded in a Video
`memory 85 and the recording of the video memory 85 is
`Stopped at a timing responding to an input from a Sensor 84,
`and the Video image before and after the Sensor 84 produces
`an event detecting Signal that can be displayed. However,
`Since the recording is stopped in response to the Signal from
`the Sensor, when the next events occur Successively, the
`Video image before and after the event cannot be Stored.
`Generally, the video on-demand System, before Video
`Service is started, previously records and Stores Video infor
`mation in the Storage device of a Video Server System. Upon
`completion of the recording of the Video information, the
`Video on-demand System makes video on-demand Service.
`Therefore, the Video on-demand System cannot reproduce
`the video data while they are recorded.
`The time lapse VTR, when any event occurs for an object
`being monitored, can perform its rewind operation to con
`firm circumstances of the event. In this case, however, the
`VTR cannot record video data during the rewind operation.
`Therefore, when another event occurs during the rewind
`operation, the time lapse VTR cannot have the video data
`recorded. In addition, generally, the time lapse VTR is not
`designed for the purpose of reproducing the Video data
`instantaneously. Rather, after the recording for a week or So
`is completed, it is used to analyze an event if any event
`occurred during the period.
`Although the device disclosed in JP-A-2-132599 can
`review the Status before and after the event, it cannot deal
`with another Subsequent event Since it stops recording
`during the period.
`
`SUMMARY OF THE INVENTION
`The present invention has been accomplished to Solve the
`above problem and intends to provide a device which can
`always record the Video image inputted in real time and
`
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`reproduce the image recorded last without Stopping the
`recording. The present invention also intends to provide a
`System which can preserve the video image (recorded event
`image) before and after the event recorded in the video
`recording device has occurred, as historical record of Video
`information for a long time.
`The Video recording device according to the present
`invention comprises a digital Video information inputting
`unit for inputting digital Video data in real time, a temporary
`Storage unit for temporarily Storing the Video data inputted
`form the digital Video data inputting unit, a Successive
`recording unit for intermittently reading out the Video data
`from the temporary Storage unit and overwriting the Video
`data for recording, and a Successive recording control unit
`for controlling a recording area in the Successive recording
`unit. In the Video recording device, the Successive recording
`control unit records the Video data from the temporary
`memory unit in endleSS recording mode and in accordance
`with an external event Signal, it excludes a recording area
`correlated with the event Signal from the area Subjected to
`the endless recording So that it is managed as an event
`recording area.
`Furthermore, in the Video recording device according to
`the present invention, the recording area correlated with the
`event Signal is defined as a recording area from a predeter
`mined time before to a predetermined time after the event
`Signal is inputted.
`Furthermore, in the Video recording device according to
`the present invention, the Successive recording control unit
`divides the recording area into blocks, assigns block num
`bers for each blocks, and controls the recording area using
`the block numbers as pointers.
`Moreover, in the Video recording device according to the
`present invention, the Successive recording control unit
`monitors the recording capacity of the endleSS recording
`area from which the event recording area is excluded, and
`when the recording capacity is short for the recording period
`of the endleSS recording, it restores the event recording areas
`as endleSS recording areas Successively in order of older
`Setting or lower priority.
`Still further, the Video recording device according to the
`present invention further comprises a long-term Storage unit,
`and in that the recording contents of the event recording area
`is transferred to the long-term Storage unit So that the event
`recording area is restored as an endleSS recording area.
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a block diagram of a Video recording device
`according to an embodiment of the present invention;
`FIG. 2 is an explanation view of the magnetic disk
`medium of a magnetic disk device;
`FIG. 3 is a time chart for explaining the access to a
`Successive recording unit;
`FIG. 4 is a conceptual view for explaining the manage
`ment of endleSS recording and event recording;
`FIG. 5 is a conceptual view for explaining the manage
`ment of endleSS recording and event recording;
`FIG. 6 is a block diagram of a video recording device
`according to an embodiment of the present invention;
`FIG. 7 is a block diagram of a video recording device
`according to an embodiment of the present invention;
`FIG. 8 is a block diagram of a prior art; and
`FIG. 9 is a time chart showing the operation of FIG. 8.
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`Embodiment 1
`An explanation will be given of the first embodiment of
`the present invention. In FIG. 1, reference numeral 1 denotes
`
`

`

`3
`a camera; 2, an A-D (analog-digital) converting unit for
`converting an input Video image into a digital Signal; 3, a
`digital Video data inputting unit; 4, a temporary memory
`constructed of e.g. a Semiconductor memory; 5, a Successive
`recording unit constructed of a magnetic disk device, 6, a
`Successive recording control unit for managing and control
`ling the recording and reproducing processes of the Succes
`Sive recording unit, 7, an event Signal inputting unit for
`inputting event signals from various kinds of Sensors, and 8,
`a Video display unit for displaying the digital image repro
`duced from the Successive recording unit 5 and the input
`image Supplied directly from the temporary memory unit 4.
`Reference numeral 61 denotes an endleSS recording table for
`recording a pointer indicative of an area Subjected to the
`endleSS recording, 62, an event recording table for recording
`a pointer indicative of an area Subjected to event recording;
`and 63, an event management table for managing the occu
`pying State of the endless recording table 61 and event
`recording table 62.
`A detailed explanation will be given of the operation of
`the Successive recording unit 5. Generally, the Successive
`recording unit 5 is constructed of e.g. a magnetic disk
`device, and records the digital Video data on a large number
`of concentric trackS 22 of a magnetic disk medium 21 as
`shown in FIG. 2. One circle of each track is recorded so as
`to be divided into predetermined units called sectors 23.
`Therefore, the recording is executed after a magnetic head is
`shifted to a recording track position (seek processing) and
`arrives at a desired Sector 23. The reproducing processing is
`also executed after the magnetic head arrives at the Sector
`from which the data is to be reproduced, thereby reproduc
`ing desired digital information. When the recording and
`reproducing are repeated for each Sector unit, if the record
`ing Sector 24 and the reproducing Sector 25 are separate, the
`time for Seeking will be longer than those for recording and
`reproducing. In order to enhance the performance of the
`recording and reproducing processing Speed in the magnetic
`disk device, the digital information must be continuously
`recorded on or reproduced from continuous Sectors.
`The digital Video information is continuously inputted.
`For example, the data compressed in a moving picture at a
`rate of 20 Kbyte for /30 sec are inputted successively. The
`Seek processing takes a time of 0.1 Sec or So. In this case, in
`order to reduce the number of times of the Seek processing
`as described above, it is recommended to compile the Video
`data into blockS each with e.g. 0.5 Sec or So and intensively
`record and reproduce these data. Although the magnetic disk
`device has a large Storage capacity of e.g. 1 Gbyte, the
`digital Video data, even if compressed, has also a large data
`size of 600 Kbyte/sec as mentioned above. Therefore, the
`magnetic disk device can record the digital Video data on the
`magnetic disk medium for only about 30 minutes or shorter.
`Referring to FIGS. 3 and 4, an explanation will be given of
`the mechanism of making the endleSS recording by the
`Successive recording unit 5 which is an object of the present
`invention. In FIG.3, with a time in its abscissa, the accessing
`Status in the Successive recording unit 5 will be explained for
`the processes of recording and reproducing.
`In FIG. 3, reference numeral 31 denotes digital video
`information Strings at the digital Video data inputting unit 3.
`These Video information Strings are once Stored in the
`temporary Storage unit 4, and read out as intermittent
`recorded information Strings 32. These information Strings
`32 are recorded in the Successive recording unit 5. Although
`it is illustrated in FIG.3 that the recorded information strings
`are recorded endlessly at four points of a, b, c and d, actually,
`they are recorded at more points. On the other hand, refer
`
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`ence numeral 33 denotes one of reproduced information
`Strings. These reproduced information Strings are repro
`duced from the Successive recording unit retroactively by
`any time of the image recorded endlessly. Then, they are
`displayed as Successive reproduced Video information
`Strings 34 in a moving picture on the Video display unit 8.
`In this way, according to this embodiment, while the record
`ing is continued, the reproducing can be executed So that in
`instant response to the event signal, the recorded Video
`image can be reviewed. If there is a further allowance of
`acceSS in the Successive recording unit 5, the image belong
`ing to another time interval can be retroactively read out as
`reproduced information strings 35. The reproduced infor
`mation Strings 35 can be also displayed as Successive
`reproduced Video information StringS 36 in a moving image
`by the video display unit 8. FIG. 3 illustrates that the
`reproduced data disappear on the way. This means that the
`Video image reproduction in the Video display unit has been
`stopped on the way. In the example illustrated in FIG. 3, the
`Video display unit 8 can display the monitored Video image
`which is being inputted at present and two kinds of delayed
`images. In FIG. 3, line 37 represents the status of the
`Successive recording unit. Each of black Square portions 38
`denotes the time taken for the Seek processing. Each of
`Slender lines denotes the time taken for the recording or
`reproducing. Each of open Square portions 39 denotes the
`acceSS allowance time in the Successive recording unit. This
`access allowance time 39 is formed to absorb the varying
`width of the seeking time 38 which may be varied.
`Now referring to FIG. 4. an explanation will be given of
`a method of the processes of recording and reproducing in
`the Successive recording control unit 6. Reference numeral
`41 shows the State where the Successive recording unit 5 is
`divided into a plurality of blocks (30 blocks in this example)
`labeled block numbers (pointers), respectively. Reference
`numeral 51 denotes a time Zone of events which have
`occurred during the Successive recording. The Successive
`recording control unit 6 includes an endless recording table
`61 and an event recording table 62, and manages the
`numbers of the blocks on which the digital Video image is to
`be recorded as shown in part (a) of FIG. 4. The notation
`“1->2” in the part (a) represents that the recording block
`successive to block No. 1 is block No. 2. By provision of
`Such a recording table, the blocks are overwritten in order
`from the block with an older record. Next, an explanation
`will be given of the operation when the Successive recording
`control unit 6 receives an event Signal from the event Signal
`inputting unit 7. Now it is assumed that the event Signal is
`inputted while the recording is made at the position of block
`No. 4. In this case, the video image from block No. 3 with
`a previously recorded image to block No. 6 with a video
`image after the event will be managed as an event video
`image. Since the present invention always executes the
`recording in a manner of endleSS recording, the Video image
`inclusive of the Video image prior to inputting of the event
`Signal can be managed as an event Video image. Thus, event
`No. 1 will be managed on the event recording table as shown
`in part (b) of FIG. 4. Event No. 2 will be managed similarly.
`Now if only the event recording table is updated as it is, the
`event Video images are overwritten to disappear at a period
`of endless recording. For this reason, the endleSS recording
`table must be also modified. As shown in the part (b),
`notation “2->7” represents that the block Nos. 3, 4, 5 and 6
`are excluded from the loop of the endleSS recording.
`Likewise, notation “24->29” saves the event video image of
`event No. 2 from the endless recording. In this way, in the
`endless recording area, the recording area correlated with the
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`S
`event Signal will not be thereafter used as an endleSS
`recording and not overwritten So that the event Video image
`will be held for a longer period than the endleSS recording
`period. Generally, a certain Video image can be left as an
`event recording by copying the Video image from the
`endleSS recording unit to the event recording holding area
`while the endless recording is done. However, as Seen from
`the example shown in FIG. 3, Since the access allowance
`time in the Successive recording unit is limited, the present
`invention adopts a technique of avoiding any unnecessary
`copying.
`
`Embodiment 2
`In the above first embodiment, the recording time of the
`event video image has been Set equally for any event. The
`event recording time may be changed according to the kind
`of events in a Such a fashion that a long recording time is
`given to a slowly changing event whereas a short recording
`time is given to an instantaneous event. For example, a
`longer recording time is given to the event Signal from a fire
`Sensor So that the Signal can be managed as an event video
`image from before a fire occurs, and a short event video
`image may be given to an event Such as explosion. Further,
`in the above embodiment, although the block immediately
`before the event Signal occurs has been held as the event
`Video image, the block to be held as the event Video image
`may be further retroactive according to an event circum
`stance. Thus, according to the kind of each of events, an
`event management table representative of the manner of
`holding the event video image (e.g. the block being caused
`to be retroactive before the event signal is inputted, the
`period when it is held as the event video image, etc.) can be
`arranged on the Successive recording control unit 6. Part (a)
`in FIG. 5 shows an example of Such a management table.
`Embodiment 3
`In the above Second embodiment, a manner of managing
`the Successive events has been given. However, where the
`event Signals are Successive So that the corresponding event
`recording times overlap, the endless recording table and the
`event recording table are applied as illustrated as shown in
`part (b) in FIG. 5 so that the event recording time is set as
`a time including the recording times of both event Video
`images. Thus, the Successive events like case B can be
`managed.
`In the first, Second and third embodiments, when an event
`occurs, the corresponding event Video image is not recorded
`on a separate area, but the management table for the block
`numbers being Subjected to the Successive recording is only
`operated. Therefore, it is not necessary to transfer the Video
`image immediately before the event occurs to the above
`Separated area So that without wasting the access time in the
`Successive recording unit, the Video data in the Successive
`recording unit can be reproduced as the event Video image
`with an allowance. Namely, in the example, either one of the
`reproduced information strings 33 and 35 may not be used
`for event recording So that both information Strings can be
`used as independent reproduced information Strings.
`Embodiment 4
`The first to third embodiments described above have an
`advantage that it has only to operate the management table
`to manage the invent video image. However, if events occur
`frequently, as shown in part (c) of FIG. 5, the area to be
`registered for event recording may increase So that the
`endleSS recording area cannot be assured. In order to obviate
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`Such a failure, the event management table 63 manages the
`area for event recording to decide whether or not the endleSS
`recording time can be assured. In this case, if the endleSS
`recording time cannot be assured, the event video images
`which are older or have lower holding priorities can
`removed in order from the event recording table, thereby
`restoring the corresponding areas as endleSS recording areas.
`
`Embodiment 5
`The forth embodiment cannot hold the event video image
`substantially permanently. This embodiment, which has
`been accomplished to Solve this problem, will be explained
`with reference to FIGS. 6 and 3. In FIG. 6, like reference
`numerals except a long-term Storage unit 9 refer to like
`elements in FIG. 1. If the event video image stored in the
`Successive recording unit 5 can be saved into the long-term
`Storage unit 9, the event Video image Stored in the Successive
`recording unit is not necessary. The event Video image can
`be saved into the long-term Storage unit 9 by copying it from
`the Successive recording unit 5 into the long-term Storage
`unit 9 using the access allowance time in the Successive
`recording unit 5 represented by the open Square portion 39
`shown in FIG. 3. The copying operation, which is not an
`operation of reproducing a visual image and So not time
`limited, can be executed Successively using the access
`allowance time in the Successive recording unit 5 as in the
`case of the general copying operation of the digital data. The
`presence or absence of the Saving of the event Video image
`Stored in the Successive recording unit 5 can be managed
`using the event management table 63 of the Successive
`recording control unit 6, or otherwise using another man
`agement table provided Separately in the Video display unit.
`FIG. 7 is an embodiment in which the digital video image
`inputting unit 3 and the Successive recording unit 5 are apart
`from the video display unit 8 through a transfer path 10. In
`this case, on the Side of the digital video image inputting unit
`3, a transmission processing unit 11 is provided in place of
`the video display unit 8 and is connected to the video display
`unit 8 through the transmission path. The long-term Storage
`unit is connected to the video display unit 8 through the
`transmission path. It is needless to Say that the configuration
`shown in FIG. 7 can provide the same advantage as in that
`of FIG. 6.
`In the embodiments described above, a magnetic disk has
`been adopted as the Successive recording unit. However,
`using other digital recording devices inclusive of a Semi
`conductor memory and an optical disk device can provide
`the same advantage. Further, in the embodiments described
`above, the endleSS recording has been made on the endleSS
`recording table for managing it in the order of block num
`bers. However, it may not be made in the order of block
`numbers. Further, in the embodiments described above, on
`each management table, a next block number was arranged
`in Succession to each block. However, where Successive
`blocks are to be recorded and reproduced, the block numbers
`at the first position and last position have only to be managed
`So that the Successive blockS can be managed using leSS
`amount of information. Furthermore, in the embodiments
`described above, the event recording has been managed for
`each block. However, the data of the event management
`table may be increased So that the bytes inclusive of any
`optional byte on the way of a certain block to that in the
`other block can be managed as the event recording.
`AS described above, in accordance with the present
`invention, Since the Successive recording unit is configured
`to enable the endleSS recording which is Saved from the
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`7
`endleSS recording area as an event video image when an
`event input Signal is received, the Video image inclusive of
`the Video image before the event Signal is received can be
`recorded and Stored as the event Video image. In addition,
`Since the event Video image when an event occurs needs not
`to be transferred to a separate area, the access time in the
`Successive recording unit can be efficiently used So that the
`event Video image can be reproduced with a Sufficient
`allowance.
`What is claimed is:
`1. A video recording device comprising:
`a digital video data inputting unit inputting digital Video
`information in real time;
`a temporary Storage unit for temporarily Storing the Video
`data inputted from Said digital video data inputting unit;
`a Successive recording unit for reading out Said digital
`Video data from Said temporary Storage unit, recording
`the digital Video data in a recording area of Said
`Successive recording unit, Said recording area compris
`ing an event recording area and an endless recording
`area, and for overwriting the recorded digital Video
`data; and
`a Successive recording control unit for controlling Said
`Successive recording unit, wherein Said Successive
`recording control unit controls the recording of the
`digital Video data in endleSS recording from Said tem
`porary Storage unit to Said recording area of Said
`Successive recording unit and,
`in accordance with an external event Signal, Video data is
`recorded in Said event recording area correlated with
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`the event Signal, Said event recording area being
`excluded from Said endless recording area So that the
`Video data is Stored in Said event recording area for a
`longer time than Video data Stored in Said endless
`recording area.
`2. A video recording device according to claim 1, wherein
`the event recording area correlated with the event Signal is
`defined as a recording area from a predetermined time
`before to a predetermined time after the event signal input
`being inputted.
`3. A video recording device according to claim 1, wherein
`Said Successive recording control unit divides the recording
`area into blocks, assigns block numbers for each block, and
`controls the recording area using the block numbers as
`pointers.
`4. A video recording device according to claim 1, wherein
`Said Successive recording control unit monitors the record
`ing capacity of Said endleSS recording area from which Said
`event recording area is excluded, and when Said recording
`capacity is low, Said control unit restores the event recording
`area as an endleSS recording area Successively in order of
`older Setting or lower priority.
`5. A video recording device according to claim 1, further
`comprising a long-term Storage unit for Storing the digital
`Video data, and
`wherein the recording contents of Said event recording
`area is transferred to Said long-term Storage device So
`that Said event recording area is restored as an endless
`recording area.
`
`