||||||lllllllllllIllllIllll|||||Illllllllllllllllllllllllllllllllllllllllll
`USOO5134499A
`
`United States Patent
`Sata et al.
`
`[191
`
`[11] Patent Number:
`
`5,134,499
`
`[45] Date of Patent:
`
`Jul. 28, 1992
`
`[54] VIDEO RECORDING APPARATUS HAVING
`CONTROL MEANS PROVIDED THEREIN
`FOR INDEPENDENTLY CONTROLLING
`THE WRITING HEAD AND THE READING
`HEAD
`
`[75]
`
`Inventors:
`
`Takeo Sata; Kenzahuro lijima;
`Xatsufumi Kondo; Nobuji Kato, all of
`Hamamatsu, Japan
`
`[73] Assignee: Yamaha Corporation, Hamamatsu,
`Japan
`
`[21] App1.No.: 388,831
`
`[22] Filed:
`
`Aug. 3, 1989
`
`Foreign Application Priority Data
`[30]
`Aug. 4, 1988 [JP]
`Japan ................................ 63-195129
`Aug. 26, 1988 [JP]
`Japan
`63-211793
`Aug. 26, 1988 [JP]
`Japan ................................ 63-211794
`
`Int. Cl.5 ............................................. .. H04N 5/76
`[51]
`[52] U.S. Cl. .................................. .. 358/342; 358/335;
`358/314; 358/327; 358/336; 369/32; 369/54
`[58] Field of Search ............. .. 358/314, 327, 335, 336,
`358/339, 342; 369/32, 54; 360/5, 6, 31, 33.1,
`36.2, 38.1, 72.1, 78.04, 78.11
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4,805,162
`4,905,093
`
`............................ 369/447
`2/1989 Stahl et al.
`2/1990 Satoh ................................. .. 358/335
`
`Assistant Examiner—Robert Chevalier
`Attorney, Agent, or Fz'rm—Burns, Doane, Swecker &
`Mathis
`
`ABSTRACI‘
`[57]
`A video recording apparatus used for a television sys-
`tem and the like writes video information on a track
`formed on a recording medium in a writing direction
`which directs from a predetennined start position to a
`predetermined end position of track by use of a head.
`Thereafter, the video information is read from a desir-
`able designated positon of the track in the writing direc-
`tion. The read video information is reproduced and then
`its corresponding pictures are displayed on a display
`unit of the television system. This video information is
`not outputted from the recording medium in a period
`while the head returns to the predetermined start posi-
`tion of the track after the video information at the pre-
`determined end position of the track is read out. So, this
`video recording apparataus can provide a memory
`which stores the video information and then outputs the
`video information during such period. Thus, the video
`information can be continuously obtained. Preferably,
`the recording medium is constructed by an optical disk
`or an magneto-optical disk, the memory is constructed
`by a semiconductor memory such as a random-access
`memory (RAM), and the predetermined start and end
`positions are innermost side and outermost side of the
`track.
`
`Primary Examiner———Roy N. Envall, Jr.
`
`15 Claims, 5 Drawing Sheets
`
`WRITE
`HEAD
`DRIVING
`
`BINARY
`CIRCUIT
`
`Unified Patents Exhibit 1005, p. 1
`
`

`
`U.S. Patent
`
`Sheet 1 of 5
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`Unified Patents Exhibit 1005, p. 2
`
`

`
`U.S. Patent
`
`July 23, 1992
`
`Sheet 2 of 5
`
`5,134,499
`
`SYSTEM
`CONTROLLER
`
`FOCUS/TRACKING
`SERVO CIRCUIT
`
`FEED SERVO
`CIRCUIT
`
`DRIVE
`INTERFACE
`
`WRITE DATA
`
`DRIVE
`INTERFACE
`
`SERVO
`CIRCUIT
`
`FEED SERVO
`CIRCUIT
`
`FOCUS/TRACKING
`SERVO CIRCUIT
`
`SYSTEM
`CONTROLLER
`
`CONTROL
`
`°°“””‘D
`*
`
`Unified Patents Exhibit 1005, p. 3
`
`

`
`U.S. Patent
`
`July 28, 1992
`
`5,134,499
`
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`
`Unified Patents Exhibit 1005, p. 4
`
`

`
`U.S. Patent
`
`’82V.1HJ
`
`29911
`
`Sheet 4 of 5
`
`5,134,499
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`Unified Patents Exhibit 1005, p. 5
`
`

`
`U.S. Patent
`
`July 28, 1992
`
`Sheet 5 of 5
`
`5,134,499
`
`REPRODUCING CIRCUIT
`
`éq
`3%(DD
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`
`EXPANSION
`
`CONTROL
`
`Unified Patents Exhibit 1005, p. 6
`
`

`
`1
`
`5,134,499
`
`VIDEO RECORDING APPARATUS HAVING
`CONTROL MEANS PROVIDED THEREIN FOR
`INDEPENDENTLY CONTROLLING THE
`WRITING HEAD AND THE READING HEAD
`
`BACKGROUND or THE INVENTION
`1. Field of the Invention
`The present invention relates to a video recording
`apparatus, and more particularly to a video recording
`apparatus which is suitable to be used for recording/re-
`producing picture information of a television system.
`2. Prior Art
`In order to record/reproduce the video information
`of the television programs, a video tape recorder (VTR)
`or video cassette recorder (VCR) is used in general. In
`order to play the _recorded video information after re-
`cording the television program, the video tape is re-
`wound back and then the video information is repro-
`duced from its start part.
`In some cases, it is demanded that the precedingly
`recorded video information is reproduced even in the
`middle of the recording. However, the VTR can not
`reproduce the recorded video information in the re-
`cording normally. So, in order to watch the precedingly
`recorded video information in the middle of the record-
`ing, the recording of the VTR must be broken. Mean-
`while, people sometimes want to break the recording of
`the television program, for example. In this case, how-
`ever, certain recorded part of the television program
`which people want to watch must be reproduced after
`the television program ends.
`In the VTR, the rewinding of the video tape requires
`much time. So, in the case where the certain recorded
`part is repeatedly reproduced, it is disadvantageous in
`that
`the conventional video recording apparatus re-
`quires much time.
`SUMMARY OF THE INVENTION
`
`It is accordingly a primary object of the present in-
`vention to provide a video recording apparatus which
`does not require much time when repeatedly reproduc-
`ing the desirable recorded part.
`In a first aspect of the present invention, there is
`provided a video recording apparatus capable of re-
`cording at least video information on a recording me-
`dium comprising:
`(a) write control means for controlling a motion of a
`head to write the video information on a track
`formed on the recording medium in a writing di-
`rection which directs from a predetermined start
`position to a predetermined end position in the
`track, the write control means returning the head
`to the predetermined start position of the track
`when the head reaches at the predetermined end 55
`position of the track; and
`(b) read control means for controlling the motion of
`the head to read the video information from a des-
`ignated position of the track in the writing direc-
`tion.
`In a second aspect of the present invention, there is
`provided a video recording apparatus capable of re-
`cording at least video information on a recording me-
`dium comprising:
`(a) write control means for controlling a motion of a
`head to write the video information on a track
`formed on the recording medium in a writing di-
`rection which directs from a predetermined start
`
`2
`position to a predetermined end position in the
`track, the write control means returning the head
`to the predetermined start position of the track
`when the head reaches at the predetermined end
`position of the track;
`(b) read control means for controlling the motion of
`the head to read the video information from a des-
`ignated position of the track in the writing direc-
`tion;
`(c) memory means for storing the video information
`during a period between a first time when the head
`writes the video information at the predetermined
`end position of the track and a second time when
`the head starts to write the video information at the
`predetermined start position of the track; and
`(d) means for outputting the video information read
`from the memory means instead of the video infor-
`mation read from the recording medium in a period
`between a third time when the video information at
`the predetermined end position of the track is out-
`putted and a fourth time when the video informa-
`tion at the predetermined start position of the track
`is started to be outputted.
`In a third aspect of the present invention, there is
`provided a video recording/reproducing apparatus
`capable of recording/reproducing at least a video infor-
`mation on a recording medium comprising:
`(a) compressing means for compressing digitized
`video data indicative of the video information into
`compressed video data;
`(b) write means for generating a write signal based on
`the compressed video data, the write means con-
`trolling a motion of a head to write the write signal
`on a track formed on the recording medium in a
`writing direction which directs from a predeter-
`mined start position to a predetermined end posi-
`tion in the track, the write means returning the
`head to the predetermined stan position of the
`track when the head reaches at the predetermined
`end position of the track;
`(c) read means for controlling the motion of the head
`to read the compressed video data from a desig-
`nated position of the track in the writing direction;
`(d) reproducing means for reproducing the com-
`pressed video data based on an output signal of the
`read means; and
`(e) expanding means for expanding the compressed
`video data from the reproducing means,
`whereby the video information is to be reproduced
`based on video data outputted from the expanding
`means.
`
`In a fourth aspect of the present invention, there is
`provided a video recording/reproducing apparatus
`capable of recording/reproducing at least a video infor-
`mation on a recording medium comprising:
`(a) compressing means for compressing digitized
`video data indicative of the video information into
`compressed video data;
`(13) write means for generating a write signal based on
`the compressed video data, the write means con-
`trolling a motion of a head to write the write signal
`on a track formed on the recording medium in a
`writing direction which directs from a predeter-
`mined start position to a predetermined end posi-
`tion in the track, the write means returning the
`head to the predetermined start position of the
`
`Unified Patents Exhibit 1005, p. 7
`
`

`
`5,134,499
`
`20
`
`50
`
`60
`
`3
`track when the head reaches at the predetermined
`end position of the track;
`(c) read means for controlling the motion of the head
`to read the compressed video data from a desig-
`nated position of the track in the writing direction;
`(d) reproducing means for reproducing the com-
`pressed video data based on an output signal of the
`read means;
`(e) expanding means for expanding the compressed
`video data from the reproducing means;
`(i) memory means for storing the compressed video
`data during a period between a first time when the
`head writes the write signal at the predetermined
`end position of the track and a second time when
`the head starts to write the write signal at the pre-
`determined start position of the track; and
`(g) means for outputting the compressed video data
`from the memory means to the expanding means
`instead of the compressed video data from the
`reproducing means in a period between a third time
`when the read means reads out the compressed
`video data at the predetermined end position of the
`track and a fourth time when the read means starts
`to read out the compressed video data at the prede-
`termined start position of the track,
`whereby the video» information is continuously repro-
`duced based on video data outputted from the
`expanding means.
`In a fifth aspect of the present invention, there is
`provided a television system employing a video recor-
`ding/reproducing apparatus capable of recording/re-
`producing at least video information outputted from a
`television tuner on a recording medium comprising:
`(a) write control means for controlling a motion of a
`head to write the video information on a track
`formed on the recording medium in a writing di-
`rection which directs from a predetermined start
`position to a predetermined end position in the
`track, the write control means returning the head 40
`to the predetermined start position of the track
`when the head reaches at the predetermined end
`position of the track;
`(b) read control means for controlling the motion of
`the head to read the video information from a des- 45
`ignated position of the track in the writing direc-
`tion; and
`(c) selecting means for selectively outputting one of
`the video information from the television tuner and
`the video information read by the read control
`means,
`whereby a display unit the television system displays
`pictures corresponding to the video information
`outputted from the selecting means.
`In a sixth aspect of the present invention, there is
`provided a television system employing a video recor-
`ding/reproducing apparatus capable of recording/re-
`producing at least video information outputted from a
`television tuner on a recording medium comprising:
`(a) write control means for controlling a motion of a
`head to write the video information on a track
`formed on the recording medium in a writing di-
`rection which directs from a predetermined start
`position to a predetermined end position in the
`track, the write control means returning the head
`to the predetermined start position of the track
`when the head reaches at the predetermined end
`position of the track;
`-
`
`4
`(b) read control means for controlling the motion of
`the head to read the video information from a des-
`ignated position of the track in the writing direc-
`tion;
`(c) memory means for storing the video information
`during a period between a first time when the head
`writes the video information at the predetermined
`end position of the track and a second time when
`the head starts to write the video information at the
`predetermined start position of the track;
`(d) means for outputting the video information read
`from the memory means instead of the video infor-
`mation read from the recording medium in a period
`between a third time when the video information at
`the predetermined end position of the track is out-
`putted and a fourth time when the video informa-
`tion at the predetermined start position of the track
`is started to be outputted; and
`(e) selecting means for selectively outputting one of
`the video information from the television tuner and
`the video information from the read control means
`or the means,
`whereby a display unit the television system displays
`pictures corresponding to the video information
`outputted from the selecting means.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Further objects and advantages of the present inven-
`tion will be apparent from the following description,
`reference being had to the accompanying drawings
`wherein preferred embodiments of the present inven-
`tion are clearly shown.
`In the drawings:
`FIG. 1 is a block diagram showing a whole configu-
`ration of a television system employing the video re-
`cording apparatus according to a first embodiment of
`the present invention;
`FIG. 2 is a block diagram showing an essential part of
`the video recording apparatus shown in FIG. 1;
`FIG. 3 is a block diagram showing the video record-
`ing apparatus according to a modified example of the
`first embodiment;
`FIG. 4 is a block diagram showing a whole configu-
`ration of a television system employing the video re-
`cording apparatus according to a second embodiment;
`and
`FIG. 5 is a block diagram showing the video record-
`ing apparatus according to a modified example of the
`second embodiment.
`
`DESCRIPTION OF PREFERRED
`EMBODIMENTS OF THE PRESENT
`INVENTION
`
`Next, description will be given with respect to the
`preferred embodiments of the present invention by re-
`ferring to the drawings, wherein like reference charac-
`ters designate like or corresponding parts throughout
`the several views.
`
`[A] FIRST EMBODIMENT
`(1) Configuration Of First Embodiment
`
`FIG. 1 is a block diagram showing the whole config-
`uration of the television system employing the video
`recording apparatus according to the first embodiment
`of the present invention. In FIG. 1, 1 designates a televi-
`sion tuner which outputs a video/audio signal of the
`channel to be tuned. This video/audio signal is fed to a
`
`Unified Patents Exhibit 1005, p. 8
`
`

`
`5,134,499
`
`5
`frequency modulation (FM) circuit 2 wherein this sig-
`nal is modulated and then fed to a write head driving
`circuit 3. Meanwhile, Tl designates a terminal to which
`the video signal is fed from an external device such as
`the VTR. This video signal fed to the terminal T1 is also
`modulated in the FM circuit 2 and then fed to the write
`head driving circuit 3.
`The write head driving circuit 3 is configured as
`shown in FIG. 2. In FIG. 2, 10 designates a drive inter-
`face which mixes the FM audio signal and FM picture 10
`signal from the FM circuit 2. Then, the amplitude of
`such mixed signal is limited by a limiter (not shown) and
`then fed to a optical head 11 as write data. In addition,
`the drive interface 10 is designed to supply a control
`command to a system controller 12. Based on this con-
`trol command, the system controller 12 controls the
`drive system of a magneto-optical disk 4. The optical
`head 11 controls the laser radiation based on the write
`data so that the pits are desirably formed along the track
`on the magneto-optic disk 4. This optical head 11 is
`driven to move in the radius direction of the disk 4 by a
`feed motor 13. Thus, the optical head 11 will move to
`accurately trace the track on the disk 4 from the inner-
`most side to the outer side. The position data indicative
`of the tracking (or tracing) position of the optical head
`11 is fed back to the system controller 12. Based on the
`feedback signal (i.e., position data to be fed back), a
`servo control signal is made. The servo control signal is
`fed to a feed servo circuit 14, which will control the
`revolution of the feed motor 13 based on the servo
`control signal. Thus, the optical head 11 will trace the
`track on the disk 4 with accuracy. After the optical
`head 11 traces the outermost side track,
`the system
`controller 12 supplies the control signal to the feed
`servo circuit 14 such that the optical head 11 will return
`and then begin to trace the track from the innermost
`side. As described above, the optical head 11 and its
`drive system are designed such that the optical head 11
`will record the video/audio information on the disk 4
`endlessly.
`Next, under control of the system controller 12, a
`focus/tracking servo circuit 15 performs the focusing
`and tracking servo control of the optical head 11. In
`addition, 16 designates a disk motor which drives to
`revolve the magneto-optic disk 4. The data indicative of 45
`the revolution number of this disk motor 16 is fed back
`to the system controller 12. Based on this data, the
`system controller 12 generates and then supplies a servo
`signal to a disk servo circuit 17. Based on this servo
`signal, this disk servo circuit 17 controls the disk motor
`16 such that its revolution number will become con—'
`stant. Such constant revolution control of the disk
`motor 16 must be required because the optical head 11
`must write the video data on the disk 4 at the constant
`angular speed. The above is the detailed description of 55
`the write head driving circuit 3.
`Next, description will be given with respect to a read
`pick-up drive 5 which is configured as shown in FIG. 2.
`The configuration of this read pick-up drive 5 is similar
`to that of the write head driving circuit 3 except that the
`disk motor 16 and its drive system are not used. In short,
`20 to 25 respectively corresponds to 10 to 15. However,
`this read pick-up drive 5 is activated when read com-
`mand data is supplied thereto. Further, the system con-
`troller 22 is supplied with track designating data, by
`which the initial reading position of the optical head 21
`is controlled. After the optical head 21 reaches at the
`track designated by the track designating data,
`it
`is
`
`6
`controlled to move in the outer side of the track. After
`reading the data from the outermost side of the track
`(hereinafter, referred to as outermost track), the optical
`head 21 returns to the innermost side of the track (here-
`inafter, referred to as innermost track). Thereafter, the
`optical head 21 re-starts to read the data from the inner-
`most side of the track.
`The above-mentioned read designating data and track
`designating data to be fed to the system controller 22
`are both generated when an operator console (not
`shown) is operated. The data read by the optical head
`21 is fed to a demodulation circuit 6 shown in FIG. 1 as
`the output signal of the read pick-up drive 5. The de-
`modulation circuit 6 demodulates this signal to thereby
`generate the video signal and audio signal. Then, these
`signals are fed to an externally provided television 7 via
`an output To. Incidentally, 8 designates a VTR which is
`used for storing the output signal of the demodulation
`circuit 6.
`Next, 30 designates a binary circuit which converts
`the output signal of FM circuit 2 into binary data, which
`is then written into arandom-access memory (RAM)
`31. This binary circuit 30 operates in the period while
`the optical head 21 moves from the innermost track to
`the outermost track. The RAM 31 has the storage ca-
`pacity by which all of the output signals of FM circuit
`2 can be stored in the above period. The data stored in
`the RAM 31 is read out by a read control circuit 32 and
`then fed to the demodulation circuit 6. This read control
`circuit 32 is activated while the optical head 21 moves
`from the outermost track to the innermost track. There-
`fore, the video data which is not recorded on the disk 4
`in the above period is outputted from the RAM 31
`under control of the read control circuit 32. By the
`above-mentioned binary circuit 30, RAM 31 and read
`control circuit 32, the video data can be continuously
`stored and then outputted without any break.
`
`(2) Operation Of First Embodiment
`Next, description will be given with respect to an
`operationof the first embodiment.
`As an example, the television 7 is connected to the
`output terminal To, and the same channel is tuned in
`both of the television tuner I and television 7. As de-
`scribed before, the write head driving circuit 3 performs
`the writing operation endlessly. Therefore, the magne-
`to-optic disk 4 continuously records the video data
`concerning the television program of the channel tuned
`by the television tuner I. In this case, when the video
`data is overwritten on the disk 4, the previously written
`video data is erased. For this reason, the amount of
`video data which can be recorded on the disk 4 depends
`on the size of disk or track density of disk. In the case
`where the present embodiment uses the optical disk
`made from Tb-Fe-Co materials and having the diameter
`of 30 cm, it is possible to record the video data of 30-
`minute television program. In the meantime, the RAM
`31 writes and renews the video data during the period
`when the write head driving circuit 3 can not write the
`video data on the disk 4 as described before.
`Next, when the operator console is operated so that
`the read command data and track position designating
`data are fed to the read pick-up drive 5, the read pick-up
`drive 5 starts to read the video data from the track
`position designated by the track position designating
`data on the disk 4. Thereafter, the reading track position
`is sequentially renewed by the read pick-up drive 5 so
`that the reading operation will be continued. In the case
`
`Unified Patents Exhibit 1005, p. 9
`
`

`
`5, 134,499
`
`8
`the terminal T1 and the video/audio signal outputted
`from the television tuner I are fed to the separation
`circuit 102a wherein these signals are separated into the
`video signal and audio signal. This video signal is fed to
`the video signal digitization circuit 102b wherein the
`video signal is digitized into the video data, while the
`audio signal is fed to the audio signal digitization circuit
`102c wherein the audio signal is digitized into the audio
`data. The compression circuit 102d compresses the
`video data. In this compression circuit 102d, several
`kinds of compressions are made based on the spectrum,
`spatial frequency, time and the like. Then, such com-
`pressed video data is fed to a first input of the adder
`102e, while the audio data is fed to a second input of the
`adder 102e, This adder 1022 adds the video data and
`audio data together to generate digital data, which is
`then fed to the foregoing write head driving circuit 3.
`This digital data is also fed to the foregoing write con-
`trol circuit 30 so that the digital data will be stored in
`the RAM 31 as described before.
`Then, as described before in the description of FIG.
`2, the digital data is recorded on the disk 4. Thereafter,
`the recorded digital data is read by the read pick-up
`drive 5. The output signal of this read pick-up drive 5 is
`fed to a digital signal reproducing circuit 9 wherein this
`signal is reproduced into the digital data. In addition,
`the read control circuit 32 reads the digital data from
`the RAM 31.
`The above digital signal is fed to the expansion con-
`trol 106 which includes a separation circuit 106a, an
`expansion circuit 106b, an audio signal decoder 106c and
`a video signal decoder 106d. The separation circuit 106a
`separates the digital data into the foregoing compressed
`video data and audio data. The compressed video data
`is fed to the expansion Circuit 1061:, while the audio data
`is fed to the audio signal decoder 106C. This expansion
`circuit 106b performs the data expansion on the com-
`pressed video data, wherein this data expansion is per-
`formed in accordance with the algorithm correspond-
`ing to the data compression performed by the compres-
`sion circuit 102d. Thus, the compressed video data is
`expanded into the original video data, which is then fed
`to a video signal decoder 106d wherein the video data is
`converted into the analog video signal. This analog
`video signal is outputted to the terminal To. On the
`other hand, the audio signal decoder 106c converts the
`audio data into the analog audio signal, which is then
`outputted to the terminal To. The foregoing television 7
`and VTR 8 can be connected to this terminal To.
`
`7
`where the read command data is not stopped after the
`video data at the outermost track is completely read
`out, the optical head 21 searches the innermost track to
`thereby re-start to perform the reading operation. While
`the read pick-up drive 5 searches out the innermost
`track, the read control circuit 32 reads out the video
`data from the RAM 31. Thus, the demodulation circuit
`6 can output the continuous video signal. When the
`video signal from the television tuner I is changed over
`to the video signal outputted from the demodulation
`circuit 6, the display unit of the television 7 displays the
`pictures corresponding to the video data, wherein these
`pictures retroact to the previous time which is prior to
`the current time by the period corresponding to the
`designated track position. As described above, by selec-
`tively reading out one of the video data recorded on the
`disk 4 and the video data stored in the RAM 31, it is
`possible to watch the previous pictures of maximum 30
`minutes the moment the television tuner 1 tunes and
`outputs the current pictures.
`For example, in contrast to the present embodiment,
`the conventional VTR can not replay the first 15-
`minute part of the 2-hour-program in the case where the
`person wants to record the whole part of this program.
`Because, the conventional VTR can merely record and
`reproduce the video information in serial manner. So, it
`takes a long time to record and then watch the recorded
`video information. In contrast, the present embodiment
`can simultaneously play back and reproduce the previ-
`ous part of the television program the moment the VTR
`8 continuously records the current part of the television
`program. So, the present embodiment does not waste
`the time.
`
`(3) Modified Example of First Embodiment
`The first embodiment provides a single pair of the
`write head driving circuit 3 and read pick-up drive 5, by
`which the television program of one channel is to be
`recorded. Instead, it is possible to provide plural pairs,
`by which the television programs of plural channels can
`be simultaneously recorded. For example, as shown in
`FIG. 3, the first embodiment can be re-designed to
`provide plural magneto-optic disks each providing with
`a pair of write head driving circuit and read pick-up
`drive. Further, plural television tuners, FM circuits,
`binary circuits, RAMS and read control circuits can be
`provided. Thus, it is possible to configure the television
`system which can continuously record the plural videos
`of previous 30 minutes in plural channels (e.g., six chan-
`nels).
`Meanwhile, in the case where the video data in the
`non-video-recording period of the write head driving
`circuit 3 is not needed, it is possible to simplify the
`system configuration by omitting the binary circuit 30,
`RAM 31 and read control circuit 32.
`
`[B] SECOND EMBODIMENT
`
`(1) Description of Second Embodiment
`The second embodiment as shown in FIG. 4 is char-
`acterized by providing a compression control 102 and 60
`an expansion control 106 as comparing to the first em-
`bodiment shown in FIG. 1, wherein the description of
`the similar parts between these embodiments will be
`omitted.
`The compression control 102 includes a separation 65
`circuit 102a, a video signal digitization circuit 102b, an
`audio signal digitization circuit 102c, a compression
`circuit 102:! and an adder 1029. At first, the signal fed to
`
`(2) Modified Example of Second Embodiment
`As similar to the modified example of first embodi-
`ment described before, it is possible to provide plural
`pairs of television tuners, compression controls, write
`head driving circuits, magneto-optic disks, read pick-up
`drives, write control circuits, RAMs and read control
`- circuits. In this case, the output signals of read pick-up
`drives 5 are fed to the digital signal reproducing circuit
`9 wherein these signals are reproduced into the digital
`data, which are then fed to the expansion control 106. In
`addition, the digital data outputted from the read con-
`trol circuits 32 are also fed to the expansion control 106.
`This expansion control 106 expands the compressed
`video data within the digital data.
`Above is the description of the preferred embodi-
`ments of the present invention. This invention may be
`practiced or embodied in still other ways without de-
`
`Unified Patents Exhibit 1005, p. 10
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`20
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`40
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`9
`parting from the spirit or essential character thereof as
`described heretofore. Therefore, the preferred embodi-
`ments described herein are illustrative and not restric-
`tive, the scope of the invention being indicated by the
`appended claims and all variations which come within
`the meaning of the claims are intended to be embraced
`therein.
`What is claimed is:
`1. A video recording apparatus capable of recording
`at least video information on a recording medium com-
`prising:
`(a) write control means for controlling a motion of a
`write head to write said video information on a
`track formed on said recording medium in a writ-
`ing direction which directs from a predetermined
`start position to a predetermined end position in
`said track, said write control means returning said
`write head to said predetermined start position of
`said track when said write head reaches at said
`predetermined end position of said track; and
`(b) read control means for controlling the motion of a
`read head which can move independently of said
`write head to read said video information from a
`designated position of said track in said writing
`direction.
`2. A video recording apparatus capable of recording
`at least video information on a recording medium com-
`prising:
`(a) write control means for controlling a motion of a
`head to write said video information on a track
`formed on said recording medium in a writing
`direction which directs from a predetermined start
`position to a predetermined end position in said
`track, said write control means returning said head
`to said predetermined start position of said track
`when said head reaches at said predetermined end
`position of said track;
`(b) read control means for controlling the motion of
`said head to read said video information from a
`designated position of said track in said writing
`direction;
`(c) memory means for storing said video information
`during a period between a first time when said head
`writes said video information at said predetermined
`end position of said track and a second time when
`said head starts to write said video information at
`said predetermined start position of said track; and
`((1) means for outputting said video information read
`from said memory means instead of said video
`information read from said recording medium in a
`period between a third time when said video infor-
`mation at said predetermined end position of said
`track is outputted and a fourth time when said
`video i