JP2005354417A - Device and method for recording reproduction and program recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable an image of -1 time (E dit-) to be outputted by phase locking so as to trace transmission reproduction special-purpose data arranged in a predetermined position according to a fixed rule in a device recording digital data to the track of a magnetic tape by a rotating head. <P>SOLUTION: In the capstan servo calculator 71 of a reproduction system 20; a present position is specified, a phase error is obtained from a value of Block 0, a value of Block 0, and/or Block 0 reproduced intermittently from a track of a magnetic tape at -1-speed by a phase error calculation portion 82, a phase error obtained by the phase error calculation porion 82 is added to a speed error from a speed error calculator 81 by an adding portion 85, and phase servo is applied, thereby performing a control of a reproduction by tracing the search data by phase locking at -1-speed and by the rotating head. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording / reproducing apparatus, a recording / reproducing method, and a program recording medium for recording / reproducing digital data through an inclined track of a magnetic tape using a rotary head.

  In a digital video tape recorder, image data is compressed by, for example, an MPEG (Moving Picture Experts Group) method and recorded on a magnetic tape. FIG. 1 shows an example in which 15 frames out of stream data of image data are GOP (Group of Picture) and the image data is compressed by the MPEG system. (A) in FIG. 1 shows original image data in which image data is arranged in time series. 0 to 14 indicate the numbers of the frames of the image data.

  In FIG. 1B, the image data A in FIG. 1A is converted into MPEG as three types of pictures: an I picture (Intra Coded Picture), a P picture (Predictive Coded Picture), and a B picture (Bidirectionally Coded Picture). The image data compressed by the method is shown. The numbers at the lower right of each of I, P, and B in the image data B indicate the frame numbers of the original image data A.

  An I picture is image data compressed only with image data in a frame. That is, for example, the I picture I2 of the image data B located in the leftmost column in FIG. This is image data obtained by compressing only the second image data.

  A P picture is image data compressed using image data of a past I picture or P picture in addition to image data in a frame. That is, for example, the P picture P5 of the image data B has the frame No. 5 and image data compressed using the image data of the previous I picture I2.

  A B picture is image data compressed using image data of I and P pictures preceding and following in time in addition to image data in a frame. That is, for example, the B picture B0 of the image data B has a frame No. This is image data obtained by compressing 0 image data by using image data of an I picture I2 that is earlier than that in time and a P picture P5 that is later than that in terms of time.

  Thus, since the I picture is compressed from the image data of a single frame, the decompression process can be performed only from the I picture. On the other hand, the P picture and B picture decompression process requires one or both of the preceding and following I picture and P picture data, and cannot be decompressed independently.

  As described above, after the image data A in FIG. 1 is compressed as indicated by the image data B, the image data is recorded on the magnetic tape and read out in the order recorded by the magnetic head when reproduced.

  By the way, when the image data compressed by the MPEG method on the magnetic tape is played back at a variable speed, the magnetic head reads out the image data across a plurality of tracks having different azimuth angles, so that the reproduced image data is intermittent. Signal. For this reason, when image data such as the P picture or B picture described above, which cannot be expanded independently, is intermittently read from the magnetic head, the image cannot be reproduced because there is no image to be referred to. Become.

  That is, as shown in FIG. 2, the two rotary heads 1 a and 1 b are mounted at predetermined positions with respect to the central axis of the drum 1 with a predetermined azimuth angle. Here, it is assumed that the rotary head 1a has a positive azimuth angle, and the rotary head 1b has a negative azimuth angle. Further, as shown in FIG. 3, data is recorded on the magnetic tape 2 in each strip-like track. In FIG. 3, the numbers given to the belt-shaped portions indicate the track numbers, and the + and − attached below the track numbers are recorded and reproduced by the rotary head 1a having an azimuth angle of + in the case of +. In the case of-, the track recorded / reproduced by the rotary head 1b having an azimuth angle of-is shown. The rotary heads 1a and 1b are so-called magnetic heads, and during normal reproduction, tracks corresponding to the azimuth of each track are sequentially reproduced. For example, when reproducing at 9 times speed, the feeding speed of the magnetic tape 2 is normally Since the speed is higher than that during reproduction, in the case of the rotary head 1b with the azimuth angle shown in FIG. 3 as shown in FIG. 3, the magnetic head 2 moves in the direction of the arrow shown in FIG.

  At this time, the rotary head 1b detects the signal recorded on the magnetic tape 2 across the signal with the azimuth angle added in the + direction and the signal attached in the-direction alternately. For this reason, the RF (Radio Frequency) signal detected by the rotary head 1b is a signal as shown in FIG.

  Assuming that, for example, a signal that is reduced by about 6 dB among RF signals as shown in FIG. 4A can be reproduced as data, the reproduced data signal is intermittent as shown in FIG. Signal. Therefore, at the time of variable speed reproduction, the B picture and P picture are in a state in which information necessary for the expansion process cannot always be read out.

  Therefore, at the time of variable speed reproduction, only the image data of the I picture is arranged at a predetermined position on the magnetic tape as the image data for variable speed reproduction, and the magnetic head is controlled to read out only the I picture continuously. , Variable speed playback is made. At this time, the video tape recorder detects the rotation period of the capstan motor that drives the magnetic tape, finds a deviation between the detected rotation period and a pre-stored reference period, that is, a speed error. The rotational speed of the capstan motor is controlled so that the magnetic head detects only the image data of the I picture on the magnetic tape.

  As described above, in a conventional recording apparatus that records image data compressed by the MPEG method or the like on a tape, search image data is searched in order to enable reproduction at a speed other than normal reproduction, so-called search reproduction. It is recorded at a position where the rotating head can trace during reproduction. Thus, when search reproduction is performed at a predetermined speed, the recorded search image data is read and a search image is displayed. Note that at -1 times, an image can be produced using -8 times the search data. In that case, the update rate is worse than 8 times.

  Further, as a method of applying tracking, there is a method of using a phase servo system ATF of 1 × speed of normal reproduction. In that case, there is a problem that the amount of change on software such as PPG data for determining ATF error sampling timing and the amount of track shift becomes large.

  The track pair number TrpNo. And sync block number SBNo. There is a method of performing phase-locking for variable speed reproduction (8 times, 24 times) by knowing the current trace position and target position from (see, for example, Patent Documents 1 and 2).

JP 2003-169285 A JP 2003-169286 A

  By the way, when the search data is traced and an image is output, the phase lock is performed by using data string information intermittently obtained from the recording medium. The data string is reset and stored in Blocks 0 to 2 at the rising edge of the head switching pulse (SWP). At 8 × speed or 24 × speed, since three or more data strings can be reproduced intermittently from the recording medium, one data line (Block 2) can be taken. Therefore, a track included in Block 2 at the time of variable speed reproduction. Pair number TrpNo. And sync block number SBNo. Thus, phase lock can be performed by knowing the current trace position and target position.

  However, in the case of -1 times, there is one (Block 0) data string intermittently reproduced from the recording medium, or two data strings ((Block 0, 1)) missing in the middle. Phase locking cannot be performed by the same method as the double speed phase locking method.

  Accordingly, an object of the present invention is to provide a recording / reproducing apparatus for recording / reproducing digital data through an inclined track of a magnetic tape by a rotary head in view of the conventional problems as described above. An object of the present invention is to make it possible to produce an image of -1 times (Edit-) by phase-locking the arranged variable speed reproduction dedicated data so as to be traced.

  Other objects of the present invention and specific advantages obtained by the present invention will become more apparent from the description of embodiments described below.

  In the present invention, in a recording / reproducing apparatus for recording / reproducing digital data via an inclined track of a magnetic tape by a rotary head, in order to produce an image of -1 times (Edit-), a predetermined position is set according to a certain rule. The phase lock is performed so as to trace the arranged variable speed reproduction dedicated data.

  The present invention provides a recording / reproducing apparatus for recording / reproducing digital data via an inclined track of a magnetic tape by a rotary head, first generation means for generating image data by encoding an input image signal, and the above image A recording system comprising: second generating means for generating search data based on the data; recording means for recording the image data and the search data on an inclined track of the magnetic tape; and recording on the inclined track of the magnetic tape Using the normal reproducing means for reproducing the image data and the search data, and the positional information of one or two data strings intermittently reproduced from the track of the magnetic tape at -1 times speed. The current scan position of the inclined track of the magnetic tape is specified, and the phase is locked at -1 times speed and the above-mentioned search data is read by the rotary head Tracing the data, characterized in that it consists of a reproducing system and a variable speed reproduction control means for controlling to reproduce.

  According to the present invention, the input image signal is encoded to generate image data, search data is generated based on the image data, and the image data and the search data are recorded on an inclined track of a magnetic tape by a rotating head. The recording / reproducing method performs recording / reproduction via the position of one or two data strings that are intermittently reproduced from the track of the magnetic tape at -1 times speed. The present scan position of the inclined track is specified, the phase is locked at -1 times speed, and the search data is traced and reproduced by the rotary head.

  Further, according to the present invention, image data is generated by encoding an input image signal, search data is generated based on the image data, and the image data and the search data are recorded on an inclined track of a magnetic tape by a rotating head. Is a program recording medium on which a control program for recording and reproduction is recorded so as to be readable and executable by a computer, and one or two data strings reproduced intermittently from the track of the magnetic tape at -1 times speed The current scan position of the inclined track of the magnetic tape by the rotary head is specified using the position information of the rotary head, the phase is locked at -1 times speed, and the search data is traced and reproduced by the rotary head. The control program is recorded so that it can be read and executed by a computer.

  The recording / reproducing apparatus, recording / reproducing method, and program recording medium according to the present invention can perform reproduction at -1 times speed using search data at 8 times speed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Needless to say, the present invention is not limited to the following examples, and can be arbitrarily changed without departing from the gist of the present invention.

  The present invention is applied to a video tape recorder including a recording system 10 configured as shown in FIG. 5 and a reproducing system 20 configured as shown in FIG.

  As shown in FIG. 5, a recording system 10 in this video tape recorder includes an A / D (Analog / Digital) converter 11 that converts an input image signal from an analog signal to a digital signal. Compression processing unit 12 to which the converted input image data is supplied, variable speed reproduction data generation unit 13 and data multiplexing unit 14 to which the input image data compressed by the compression processing unit 12 is supplied, and this data multiplexing unit 14, an error correction code adding unit 15 to which a multiplexed signal obtained by 14 is supplied, and a SYNC / ID (Synchronized Signal / Identified Number) to which a multiplexed signal to which an error correction code is added is supplied by the error correction code adding unit 15 The recording signal obtained through the SYNC / ID adding unit 16 is amplified by the recording amplifier 17 and is magnetically generated by the rotating head 18. It is adapted to be recorded on the tape 35.

  In this recording system 10, the compression processing unit 12 performs DCT (Discrete Cosine Transformation) conversion on the input image data digitized by the A / D converter 11, and then covers a plurality of frames, for example, 15 frames by the MPEG method. The compressed compressed image data is supplied to the variable speed reproduction data generation unit 13 and the data multiplexing unit 14.

  The variable speed reproduction data generation unit 13 uses only I-picture data consisting only of intra-frame compression that can be decompressed alone, among MPEG compressed image data supplied from the compression processing unit 12, and is dedicated to variable speed reproduction. Image data is generated and supplied to the data multiplexing unit 14.

  The data multiplexing unit 14 multiplexes the image data supplied from the compression processing unit 12 or the variable speed reproduction data generation unit 13 with audio data, subcodes, other system data, and the like, and generates an error correction code as a multiplexed signal. This is supplied to the adding unit 15.

  The error correction code addition unit 15 adds an error correction code to the multiplexed signal supplied from the data multiplexing unit 14 and supplies the multiplexed signal to the SYNC / ID addition unit 16.

  The SYNC / ID adding unit 16 generates a recording signal in which a synchronization signal and an ID are added to the input signal for each sync block, and supplies the recording signal to the rotary head 18 via the recording amplifier 17.

  Here, the ID includes a Synchronized Block Number (hereinafter abbreviated as SB No.) composed of a number indicating the sync block number in the track, and the number of the track on which the signal is recorded. (Track Number: hereinafter abbreviated as Tr No.). In general, recording of digital signals is performed in units of sync blocks (hereinafter referred to as SB). For this reason, this SB No. And Tr No. Is used as an address for writing to the buffer memory.

  The recording amplifier 17 amplifies the recording signal supplied from the SYNC / ID adding unit 16 and supplies the amplified recording signal to the rotary head 18.

  Then, the rotary head 18 records the recording signal supplied from the recording amplifier 17 on the magnetic tape 35.

  Further, the reproduction system 20 in this video tape recorder has a SYNC / ID detection in which a reproduction signal obtained by reading the signal recorded on the magnetic tape 35 by the rotary head 18 is supplied via the reproduction amplifier 21, as shown in FIG. Unit 22, error correction unit 23 and microcomputer 31 connected to SYNC / ID detection unit 22, data separation processing unit 24 and signal connected to error correction unit 23, and variable speed reproduction memory 25, data separation processing unit 24 And a decompression processing unit 27 that is selectively connected to the variable speed reproduction memory 25 via a switch 26, a D / A (Digital / Analog) converter 28 connected to the decompression processing unit 27, and the microcomputer 31. A driver 32 connected to the capstan motor 3 driven by the driver 32 to drive the magnetic tape 35 A capstan motor rotation detecting unit 34 for detecting the rotation of the capstan motor 33, a drum rotation detecting unit 37 for detecting the rotation of the rotating drum 36, a head switching pulse generating unit 38 connected to the drum rotation detecting unit 37, etc. The microcomputer 31 controls the rotation of the capstan motor 33 to control the traveling direction and traveling speed of the magnetic tape 35, thereby performing normal reproduction and variable speed reproduction.

  In the reproduction system 20, the SYNC / ID detection unit 22 receives the SYNC / ID detection request data supplied from the microcomputer 31, and among the reproduction signals supplied via the reproduction amplifier 21, this SYNC / ID detection request. The SB corresponding to the data is detected, and the Tr No. And SB No. Is stored in a register for each block, and then supplied to the microcomputer 31 as SYNC / ID detection data, and the image data is supplied to the error correction unit 23.

  The SYNC / ID detection request data and the SYNC / ID detection data will be described in detail later. Tr No. May be recorded in units of track pairs made up of two pairs corresponding to azimuth angles of + and −. In this case, Tr No. Instead of Trp (Track Pair) No. The two tracks may be identified by + and − of the azimuth angle. In the following description, Tr No. Instead of Trp No. An example when using is described.

  The error correction unit 23 performs error correction processing on the reproduction data supplied from the SYNC / ID detection unit 22. The error correction unit 23 supplies the reproduction data subjected to the error correction processing to the data separation processing unit 24 at the time of normal reproduction, and supplies the image data for variable speed reproduction to the variable speed reproduction memory 25 at the time of variable speed reproduction. To do.

  The data separation processing unit 24 separates image data and audio data, subcodes and other system data included in the reproduction data (multiplexed signal) supplied from the SYNC / ID detection unit 22.

  The audio data separated from the reproduction data by the data separation processing unit 24 is supplied to an audio processing circuit (not shown), and the subcode and system data are supplied to the microcomputer 31. The image data separated from the reproduction data by the data separation processing unit 24 is supplied to the decompression processing unit 27 via the switch 26 during normal reproduction.

  The variable speed reproduction memory 25 is a buffer memory used at the time of variable speed reproduction, and temporarily stores image data for variable speed reproduction supplied from the error correction unit 23. At the time of variable speed reproduction, the variable speed reproduction image data temporarily stored in the variable speed reproduction memory 25 is sequentially read in the order of reproduction and supplied to the expansion processing unit 27 via the switch 26.

  Here, the variable speed reproduction memory 25 temporarily stores the input image data and reads it at a frame cycle, and reads it every time a frame image signal is stored. There are two types, either type.

  The switch 26 selects normal reproduction image data obtained by the data separation processing unit 24 during normal reproduction, and the variable reproduction image data temporarily stored in the variable reproduction memory 25 during variable reproduction. Switching is controlled by the microcomputer 31 so as to select.

  The decompression processing unit 27 performs decompression processing on the compressed image data supplied via the switch 26, that is, image data compressed by the MPEG method, further performs inverse DCT conversion on the decompressed image data, and reproduces the reproduced image. The data is supplied to the D / A converter 28 as data.

  The D / A converter 28 converts the reproduced image data supplied from the decompression processing unit 27 into an analog signal, and outputs it as an original image signal to a television receiver (not shown) or the like to display a video.

  The microcomputer 31 receives the Trp No. included in the SYNC / ID detection data supplied from the SYNC / ID detection unit 22. And SB No. In addition, a PWM (Pulse Width Modulation) signal for controlling the rotation of the capstan motor 34 is generated based on the capstan motor rotation detection pulse supplied from the capstan motor rotation detection unit 33 and supplied to the driver 32.

  The driver 32 drives the capstan motor 34 based on the PWM signal supplied from the microcomputer 31.

  Here, details of the microcomputer 31, the driver 32, the capstan rotation detection unit 33, the capstan motor 34, and the head switching pulse generation unit 38 will be described with reference to FIG.

  The SYNC / ID detection unit 22 corresponds to the SYNC / ID detection request data supplied from the latch data generation unit 62 of the microcomputer 31 and the SB No. of the image signal input from the reproduction amplifier 21. And Trp No. Is output to the latch data generation unit 62 as SYNC / ID detection data.

  A CPU (Central Processing Unit) 61 of the microcomputer 31 controls the overall operation of the microcomputer 31, and in the arithmetic processing, a cap stored in a ROM (Read Only Memory) 202 connected to the bus 201. The contents (program) of the stun servo calculation unit 71 are read and executed. Further, the CPU 61 reads various programs stored in an HDD (Hard Disk Drive) 204 into the RAM 203 or directly executes them as necessary. Further, the CPU 61 reads and executes programs stored in the magnetic disk 211, the optical disk 212, the magneto-optical disk 213, and the semiconductor memory 214 mounted on the drive 205 as necessary.

  The latch data generation unit 62 indicates the request contents of data required for the driver 32 to control the rotation of the capstan motor 32 during variable speed reproduction. SYNC / ID detection request data having a data structure as shown in FIG. To the SYNC / ID detection unit 22, and the SYNC / ID detection data corresponding to the SYNC / ID detection request data is received from the SYNC / ID detection unit 22, and latch data is generated based on the SYNC / ID detection data to generate a capstan servo. The result is output to the calculation unit 71. Further, the latch data generation unit 62 obtains an average value of the latch data (stores it by itself), and when the SYNC / ID detection data corresponding to the SYNC / ID detection request data is not complete, that is, the data is insufficient. If there is, latch data is generated using the average value. The average value may be a predetermined fixed value.

  As shown in FIG. 8, the SYNC / ID detection request data is composed of a total of 16 bits. In the upper 8 bits of FIG. 8, the SB No. indicating the data acquisition start position is shown as the data acquisition range. In A, the lower 5 bits (0 to 4 bits) in the lower part of FIG. 8, continuous data N (the number of consecutive SBs) for designating the number of SBs in the data block to be detected is the upper part of the lower part in FIG. In 2 bits (6, 7 bits), interpolation data M (interpolation SB number −1) indicating the number of SBs that can be interpolated when a loss occurs among SBs consecutive as a data block is recorded. Here, the data block indicates a block of SBs composed of continuous SBs, for example, a part from the rising edge to the falling edge shown in FIG. 4B.

  The data acquisition range (SB No. A) is information indicating a data acquisition start position by the SYNC / ID detection unit 22, and the A-th time after the head switching pulse rises, that is, the rotary head 18 starts reading data. This is information requesting to start detection from SB. Specifically, SB No. A designates a position before the SB (SB in which I picture data necessary for variable speed reproduction is recorded) to be detected by the SYNC / ID detector 22, and SB No. SB before A indicates that it is not necessary to read substantially. The latch data generation unit 62 also supplies the head switching pulse supplied from the head switching pulse generation unit 38 to the SYNC / ID detection unit 22. This SB No. The value of A varies depending on how many times the speed reproduction process is performed.

  The continuous data N is information for designating the number of continuous SBs as a constituent requirement of the data block to be read by the rotary head 18 on one track, and N is data indicating a value obtained by subtracting 1 from the number of continuous SBs. . The latch data generation unit 62 has the SB No. described above. Since latch data is generated from three data blocks consisting of SBs detected continuously after A, the SYNC / ID detector 22 determines the number of SBs detected continuously and the value of this continuous data N. By comparing, it is determined whether or not a data block is formed.

  The interpolation data M is data indicating the number of SBs that can be interpolated when an SB is missing, that is, an SB that could not be detected in the above-described data block, and 1 is added to the number of interpolation SBs. It is the value. Note that the lower fifth bit in FIG. 8 (the sixth bit with the right side in FIG. 8 as the head) is a reserved area.

  Next, the SYNC / ID detection data will be described with reference to FIG.

  The SYNC / ID detection data is output from the SYNC / ID detection unit 22 to the microcomputer 31 in response to the SYNC / ID detection request data shown in FIG. The SYNC / ID detection data is detected first by starting detection of SB from SB No. A, starting with the first 16-bit data block from the top in FIG. Information of the first position of the data block), information of the last position, and the second data block (in this case, indicated as Block1: SB No. A starts detection of SB and data detected secondly Information of the first position of the block), information of the last position, and the third data block (in this case, indicated as Block 2: SB No. A starts detection of SB and data block detected third ) Of the first position and the information of the last position. In the data indicating the information of the head position of each data block located in the first, third, and fifth stages from the top in FIG. , The next 5 bits are Trp No. Further, a 2-bit reserved area is provided. Furthermore, the last bit located in the leftmost column in FIG. 9 is an error flag, and 1 is recorded when the data is detected, and 0 is recorded otherwise. Further, in the data indicating the information on the final position of the data block located at the second, fourth, and sixth stages from the top in FIG. , The next 5 bits are Trp No. Further, a reserved area of 3 bits is provided.

  Based on such SYNC / ID detection request data, the SYNC / ID detection unit 22 determines whether the SB No. Reading is started from the position where the SB of A is detected, three data blocks consisting of SBs continuous in track pair units are detected, and the Trp No. of the start position and the final position of each data block is detected. And SB No., for example, SB No. In the case of the X-th data block counted from the SB of A (the initial value of X is 0), it is stored in the register FX at the head position and the register LX at the last position, and finally the register FX of three data blocks , SYNC / ID detection data is generated based on LX and output to the latch data generation unit 62.

  The PWM generation unit 63 performs pulse width modulation processing (PWM: Pulse Width Modulation) on output data for controlling the rotation of the capstan motor 34 input from the capstan servo calculation unit 71 and outputs the output data to the driver 32 as a PWM output. For example, when reproducing at n-times speed, the frequency divider 64 generates a pulse waveform obtained by dividing the capstan motor rotation detection pulse input from the capstan motor rotation detection unit 33 by n, and outputs the pulse waveform to the time detection unit 65.

  The drum rotation detection unit 37 detects the rotation of the drum 36 and outputs a detection signal to the head switching pulse generation unit 38. The head switching pulse generator 38 generates a head switching pulse indicating the timing at which the rotating head is switched from the signal input from the drum rotation detector 37 and outputs the head switching pulse to the time detector 65.

  The time detection unit 65 detects the time data of the rising edges of the divided pulse input from the frequency divider 64 and the head switching pulse input from the head switching pulse generation unit 38, and the capstan Output to the servo calculation unit 71. The time detector 65 is actually composed of counter values that circulate at relatively long intervals. In FIG. 7, time data A indicates time data of the rising edge of the pulse obtained by dividing the capstan motor rotation detection pulse by the frequency divider 64, and time data B indicates time of the rising edge of the head switching pulse. Data are shown.

  The capstan servo calculation unit 71 is a program stored in advance in the ROM 202, and the SB information (SB No. at the start position and SB No. at the final position) supplied from the latch data generation unit 62 for the above-described three blocks. A signal for controlling the rotation of the capstan motor 34 is generated from the latch data generated based on No.) and the time data of the edges of various pulses input from the time detector 65.

  Next, with reference to FIG. 10 to FIG. 12, the principle of servo processing when the microcomputer 31 performs variable speed reproduction of the capstan motor 34 will be described. For example, when executing a 24 × speed reproduction process, as shown in FIG. 10, ideally, the rotary head 18 having a negative azimuth angle moves on the scan phase T toward the upper right direction in FIG. 10. However, only the data recorded on the magnetic tape 35, that is, the SB on the track having the azimuth angle of-in each track pair is read.

  In addition, SB No. Is attached from the bottom in FIG. 10 and the target SB to be read is Trp No. 6 SB No. 6 from the bottom above. Let SB of J (SB at the center position in the vertical direction in FIG. 10). Also, the head switching pulse, the RF signal, and the reproduction data signal at this time are shown in FIGS. 11A, 11B, and 11C, respectively. The squares on the track shown in FIGS. 10 and 12 indicate data blocks. That is, Trp No. 6 SB No. 6 from the bottom above. SB of J is the Trp No. of FIG. It is located at the center of the 6th square.

  Thus, in the case shown in FIG. 10, as shown in FIG. J's SB is Trp No. The data is read out at the central position of the central data block on the track having the azimuth angle indicated by 6. However, in practice, this scan phase T may be shifted in the left-right direction in the figure, which results in an error.

  Therefore, the microcomputer 31 sets the target SB No. Trp No. 3 of the three data blocks including the preceding and succeeding data blocks including J SB. And SB No. located in the center thereof. Based on the Trp No. of the read data. Unit deviation width and SB No. By calculating the deviation width of the unit and controlling the capstan motor 34 according to any deviation width, Trp No. The position of the scan phase T is controlled in units (ie, data block units) or SB units.

  As shown in FIG. A, Trp No. 5 is set as the SB of the first position read first on the data block corresponding to 5. Accordingly, for example, as shown in FIG. 12, when the rotary head 18 scans along the scan phase T ′ shifted to the right in the drawing from the scan phase T shown in FIG. In this state, when the data reading is delayed in time), the reading position is delayed as shown in FIGS. 11D and 11E, so the Ath (SB No. A) counted from the head switching pulse. SB of Trp No. SB is later than the SB at the head position of the data block corresponding to No. 5, and similarly, the target J-th SB No. J, Trp No. 6 is read out as a SB at a position later than the peak position of the data block (center position of the data block). As a result, the position of the data block to be read is downward, that is, as shown by the arrow in FIG. Will slide in the direction of decreasing.

  Therefore, the microcomputer 31 controls the capstan motor 34 so as to decelerate the traveling speed of the magnetic tape 35 from the deviation width of the data block. More specifically, in the case shown in FIG. 12, the microcomputer 31 has a target SB No. as shown in FIGS. Although the SB of J deviates from the center position of the target data block, the rotation of the capstan motor 34 is controlled corresponding to the shift width in units of SB when within the data block. Also, for example, the target SB No. When the SB of J is detected outside the range of the target data block (the data block on Trp No. 6), the microcomputer 31 detects the data block unit, that is, Trp No. Control in units.

  FIG. 13 shows the read timing of the RF signal and reproduction signal according to the traveling speed of the magnetic tape 35, and the SB No. Unit or Trp No. The example of the pattern with unit control is shown. FIG. 13A shows a head switching pulse, and shows that the SB read at the timings t0 to t1 is reproduction data. 13B to 13N show timing charts showing the respective timings from the left, and the control method (Trp for Trp No. units, SB for SB No. units) is shown on the right side thereof. ) And TrpNo. In which the SB currently being read is present on the right side. It is shown. In the figure, the number given to the RF signal or the reproduction signal (SB detection signal) is the corresponding Trp No. It is.

  For example, in FIG. 13B, since the traveling speed of the magnetic tape 35 is delayed, reading is quick, and Trp No. SB in the data block corresponding to 4 is read as the SB of the target position. At this time, the deviation of the reading position is equal to or greater than the width of Trp (the width of the data block). Unit.

  13C to 13F, the traveling speed of the magnetic tape 35 is delayed, but the reading is delayed as compared with FIG. The SB in the block corresponding to 5 is read as the SB of the target position. Also at this time, the deviation of the reading position is equal to or greater than the width of Trp. Unit.

  In FIG. 13G, although the running speed of the magnetic tape 35 is delayed, the read delay is small compared to FIGS. 13B to 13F, and the target Trp No. SB in the block corresponding to 6 is read out. Accordingly, the deviation of the reading position is within the width of Trp. Unit.

  In FIG. 13H, the SB of the target position is read at the target timing.

  FIGS. 13I and 13J show a state in which the reading timing is delayed because the traveling speed of the magnetic tape 35 is too fast. However, the target Trp No. Since the SB in the block corresponding to 6 is read and the deviation of the read position is within the width of Trp, the control is performed as SB No. Unit.

  13 (K) to 13 (N), the traveling speed of the magnetic tape 35 is further increased, and its reading is delayed as compared with FIGS. 13 (I) and 13 (J). The SB in the block corresponding to 7 is read as the SB of the target position. At this time, the deviation of the reading position is equal to or greater than the width of Trp. Unit.

  Next, the control configuration of the capstan servo calculation unit 71 will be described with reference to the control block diagram of FIG. In this specification, an example in which the capstan servo calculation unit 71 is configured by a program will be described. However, the configuration is not limited to this, and hardware having a similar function is used. It can also be configured.

  The capstan servo calculation unit 71 includes a speed error calculation unit 81, a phase error calculation unit 82, and a normal reproduction phase error calculation unit 84.

  The speed error calculation unit 81 detects the actual rotation cycle (speed) of the capstan motor 34, calculates a difference from the reference rotation cycle, and calculates this as a servo signal for the capstan motor 34. The speed error calculation unit 81 inputs the time data A input from the time detection unit 65 to the buffer 101 and the subtraction unit 102. The buffer 101 delays the input time data by a predetermined time (the time from the previous process to the current process) and outputs the delayed time data to the subtracting unit 102.

  The subtraction unit 102 calculates the difference between the time data A input from the time detection unit 65 and the time data A (the previous time data A) input from the buffer 101, thereby obtaining a current cap. The rotation period of the stun motor 34 is calculated and output to the subtraction unit 103.

  The subtraction unit 103 is the current rotation cycle of the capstan motor 34 input from the subtraction unit 102 and the rotation cycle of the reference capstan motor 34 stored in advance in the ROM 202 (reference cycle (constant) serving as a reference). And outputs this to the adder 85 as a speed error.

  Based on the latch data supplied from the latch data generating unit 62, the phase error calculation unit 82 is a target data area for variable speed reproduction (data area in which an image signal of an I picture to be read is recorded) during variable speed reproduction. : The above-mentioned block) and a phase error consisting of a positional deviation between actually detected data are calculated in Trp units or SB units. That is, as shown in FIG. 13, when the difference in position between the target SB and the detected SB is equal to or greater than the Trp width, the phase error calculation unit 82 detects a phase error in units of Trp. That is, the switch 113 is connected to the terminal 113 a, and the subtracting unit 111 sets the Trp No. as a target position read from the ROM 202. And Trp No. of the track including the SB detected based on the latch data. And is output to the gain adjustment unit 114 and the addition unit 116 via the switch 113 as a phase error in Trp units. In FIG. 13, the target Trp No. Trp No. For example, in the case of FIG. 13B, the phase error in Trp units is 2 (= 6-4), and in FIGS. 13C to 13F, 1 (= 6-5). 13G to J, 0 (= 6-6), and in FIGS. 13K to 13N, -1 (= 6-7).

  Further, when the Trp to which the detected SB belongs and the target Trp are aligned by the above-described processing, that is, in the above example, in the case of FIGS. 13G to 13J, the switch 113 is changed from the terminal 113a to the terminal. The phase error is calculated in units of SB. At this time, the subtractor 112 determines the SB No. of the target SB based on the latch data. SB No. in the center of the detected data block. And a phase error that is a deviation in SB units is calculated from the difference and output to the gain adjusting unit 114 and the adding unit 116 via the switch 113.

  The gain adjusting unit 114 adjusts the gain of the phase error signal input from the subtracting unit 111 or the subtracting unit 112 and outputs the signal to the integration calculating unit 115. The integral calculation unit 115 performs an integral calculation process on the input signal and outputs it to the addition unit 116. The addition unit 116 adds the signal input from the subtraction unit 111 or the subtraction unit 112 and the signal input from the integration calculation unit 115 and outputs the result to the gain adjustment unit 117. The gain adjustment unit 114, the integration calculation unit 115, and the addition unit 116 function as an LPF (Low Pass Filter), and smooth the phase error signal input from the subtraction unit 111 or the subtraction unit 112. The gain adjusting unit 117 adjusts the gain of the signal input from the adding unit 116 and outputs the adjusted signal to the adding unit 85 via the switch 83.

  The normal reproduction phase error calculation unit 84 generates an error signal required during normal reproduction and outputs the error signal to the addition unit 85 via the switch 83. The switch 83 is connected to the terminal 83a at the time of variable speed reproduction, and outputs the phase error at the time of variable speed reproduction supplied from the phase error calculation unit 82 to the adder 85, and is connected to the terminal 83b at the time of normal reproduction, and is connected to the terminal 83b. The error signal for normal reproduction from the calculation unit 84 is output to the addition unit 85.

  The addition unit 85 is supplied from the phase error for variable speed reproduction input from the phase error calculation unit 82 or from the phase error and speed error calculation unit 81 for normal reproduction input from the phase error calculation unit 84 for normal reproduction. The speed error to be added is added and output to the gain adjustment unit 86.

  The gain adjustment unit 86 adjusts the gain of the speed error and phase error addition signal input from the addition unit 85 and outputs the gain to the integration calculation unit 87 and the addition unit 89. The integral calculation unit 87, the gain adjustment unit 88, and the addition unit 89 smooth the signal input from the gain adjustment unit 86 and output the smoothed signal to the PWM generation unit 63 as servo data.

  Next, with reference to the flowchart of FIG. 15, servo processing during variable speed reproduction by the microcomputer 31 and the SYNC / ID detection unit 22 will be described.

  In step S1, it is determined whether or not variable speed regeneration is commanded, and the process is repeated until variable speed regeneration is commanded. For example, when an operation button (not shown) is operated by the user to instruct variable speed reproduction, the process proceeds to step S2.

  In step S <b> 2, the latch data generation unit 62 transmits SYNC / ID detection request data to the SYNC / ID detection unit 22. In step S <b> 3, the SYNC / ID detection unit 22 executes a SYNC / ID detection process based on the SYNC / ID detection request data from the latch data generation unit 62.

  Here, the SYNC / ID detection processing by the SYNC / ID detection unit 22 will be described with reference to the flowchart of FIG.

  In step S21, the SYNC / ID detection unit 22 determines whether or not SYNC / ID detection request data has been transmitted, and repeats the process until it is transmitted. For example, if it is determined that the SYNC / ID detection request data has been transmitted from the latch data generation unit 62 by the process in step S2 of FIG. 15, the process proceeds to step S22.

  In step S22, the SYNC / ID detector 22 receives the transmitted SYNC / ID detection request data, and initializes a counter j of the detected data block. That is, the counter j is initialized to j = 0, for example.

  In step S23, the SYNC / ID detector 22 determines whether or not the head switching pulse supplied from the latch data generator 62 is Hi, and repeats the processing until it is determined that it is Hi. For example, when the head switching pulse is switched to Hi as at the timing of time t11 shown in FIG. 17A, it is determined that it has become Hi, and the processing proceeds to step S24. Here, FIG. 17A shows the head switching pulse, FIG. 17B shows the RF signal, and FIG. 17C shows the SB detection signal.

  In step S24, the SYNC / ID detector 22 determines whether or not SB has been detected. For example, when SB11 is detected as shown in FIG. 17C, it is determined that SB has been detected. The process proceeds to step S25. In this case, as shown in FIG. 17A, the head switching pulse rises at time t11, and thereafter, as shown in FIG. After A, SB11 is first detected.

  In step S25, the SYNC / ID detector 22 determines whether or not data is recorded in the register Fj that stores the information of Block 0 First SB in FIG. In this case, since j = 0, it is determined whether or not data is recorded in the register F0. At this time, since there is no SB detected before SB11, no data is recorded in the register F0, and the process proceeds to step S26.

  In step S26, the SYNC / ID detection unit 22 determines the SB No. of SB11 based on the ID of SB11. And Trp No. Are stored in the register F0. In step S27, the SYNC / ID detector 22 determines whether or not the head switching pulse is in a Hi state. For example, in FIG. 17A, since the head switching pulse is Hi at the timing when SB11 is detected, the process proceeds to step S24.

  In step S24, it is determined whether or not SB is detected. If SB is detected after SB11 as shown in FIG. 17B, the process proceeds to step S25. In step S25, it is determined whether or not data is recorded in the register Fj. In this case, since the data of SB11 is recorded in F0, it is determined that there is data, and the process proceeds to step S28.

  In step S28, the SYNC / ID detector 22 detects the SB No. of the SB detected this time. And the SB No. of the SB detected last time. And whether or not the value is larger than the interpolation data M is determined. When the number of interpolation SBs is 1, the interpolation data M is 2 (= number of interpolation SBs + 1), so it is determined whether or not the difference is greater than 2. For example, when SB is continuously detected as shown in FIG. 17C, the difference is 1, so it is determined that the difference is not greater than 2, and the process proceeds to step S29.

  In step S29, the SYNC / ID detector 22 stores the SB No. of the SB detected subsequent to SB11 on the basis of the detected ID in the register Lj (register L0 in this case). And Trp No. Is recorded, and the process proceeds to step S27. In step S27, it is determined whether or not the head switching pulse is in a Hi state. In this case, as shown in FIG. 17A, since the head switching pulse is in the Hi state, the process proceeds to Step S24.

  In step S24, it is determined whether or not SB is detected again. If SB is continuously detected as shown in FIG. 17C, the process proceeds to step S25. In step S25, it is determined whether or not data is recorded in the register F0. At this time, since data is recorded in the register F0, it is determined that the data is recorded. Proceed to step S28.

  In step S28, the SYNC / ID detector 22 detects the SB No. of the SB detected this time. And the SB No. of the SB detected last time. And whether or not the value is larger than the interpolation data M is determined. In this case, since SB is continuously detected, the difference is 1 and is smaller than the interpolation data M = 2, so the process proceeds to step S29. That is, when the head switching pulse is in the Hi state, unless the SB cannot be continuously detected beyond the number of interpolated SBs, in step S26, after the first SB data is stored in F0, the step S24 is performed. Through the processing from S29 to S29, the data in the register L0 is sequentially overwritten on the data in the subsequent SB.

  In step S24, for example, as shown in FIG. 17C, when it is determined that SB is not detected at the timing after SB12, the process proceeds to step S30. In step S30, the SYNC / ID detector 22 determines whether SB has not been detected continuously for M-1 times or more. That is, for example, as shown in FIG. 17C, since SB is not continuously detected at the timing after SB12, M-1 (1 (= M-1 = 2-1 in this example)). The case where SB is not detected continuously more times than the number of times is determined. For example, since SB12 to SB13 in FIG. 17C are not continuously detected more than once, the process proceeds to step S31.

  In step S31, the SYNC / ID detector 22 detects the SB No. recorded in the register Lj. SB No. recorded in the register Fj. Of the SB No. of the register L0 is equal to or greater than the continuous data N (= number of consecutive SBs−1). Is the boundary value SB No. For example, in the example of FIG. 17C, it is determined that SB11 to SB12 are equal to or greater than a predetermined number of consecutive SBs, and the SB No. of register L0 is determined. Is the boundary value SB No. If it is determined that the number is greater than or equal to A, that is, if it is determined that a data block including a predetermined number or more of consecutive SBs is configured, the process proceeds to step S32.

  In step S32, the SYNC / ID detector 22 determines whether or not the counter j is equal to or greater than the initial value +2. In this case, since the counter j is an initial value, the process proceeds to step S33. In step S33, the SYNC / ID detector 22 increments the counter j by 1, and the process returns to step S27.

  That is, the data of the first block is acquired by the processing of step S33, the acquisition processing of the data stored in the registers F0 and L0 ends, and the value is determined (increment) As a result, data is stored in the registers F1 and L1 corresponding to the next block). In addition, the values of the registers F0 to F2 and L0 to L2 are obtained by repeating the processes of steps S24 to S34 described above.

  If it is determined in step S32 that the value of the counter j is equal to or greater than the initial value +2, in step S34, the SYNC / ID detector 22 in this case is the respective values of the registers F0 to F2 and the registers L0 to L2. Is transmitted to the latch data generation unit 62 as SYNC / ID detection data, and the process ends. That is, in the example of FIG. 17C, TrpNo. Belonging to the data blocks from SB11 to SB12. And SB No. of SB11. Are TRP Nos. Belonging to the data blocks SB11 to SB12 as data of Block0FirstSB (data stored in the register F0) of the SYNC / ID detection data of FIG. And SB No. of SB12. , As data of Block 0 Last SB (data stored in the register L 0), Trp No. belonging to the data blocks from SB 13 to SB 14 is stored. And SB No. SB13. , As data of Block1FirstSB (data stored in the register F1), Trp No. belonging to the data blocks from SB13 to SB14. And SB No. SB14. Are Trp No. belonging to the data blocks SB15 to SB16 as data of Block1LastSB (data stored in the register L1). And SB No. of SB15. However, as data of Block2FirstSB (data stored in the register F2), Trp No. belonging to the data blocks from SB15 to SB16. And SB No. of SB16. Are recorded as data of Block 0 Last SB (data stored in the register F 2).

  When it is determined in step S30 that the SB is not detected continuously for M-1 times or more, that is, the number of times that the SB cannot be detected is within the range of the interpolation data M, the process is as follows. Returning to step S27, the subsequent processing is repeated. That is, as shown in FIGS. 18A to 18C, for example, when the number of SBs that could not be detected is one, such as SB34 to S35 belonging to the central data block, the number of SBs that can be interpolated is as follows. Since there is, the process of step S24 thru | or S34 will be repeated. That is, in FIG. 18C, three data blocks SB31 to SB32, SB33 to SB36, and SB37 to SB38 are detected. Here, FIG. 18A shows a head switching pulse, FIG. 18B shows an RF signal, and FIG. 18C shows an SB detection signal.

  In step S31, the predetermined number of consecutive SBs is not exceeded, or the SB No. Is the boundary value SB No. If it is determined that the value is not A or more, the process proceeds to step S35.

  In step S35, the SYNC / ID detector 22 resets the registers Fj and Lj, and the process returns to step S27. That is, for example, as shown in FIGS. 18D and 18E, SB cannot be detected more than the number of interpolation SBs (in this case, SB number 1 or more) as between SB54 and SB55 belonging to the central block. Or in step S28, the SB No. of the SB detected this time. And the SB No. And when the data block cannot be regarded as a state in which the data block is configured based on the continuous data N, the registers Fj and Lj stored so far are determined. Reset the value of. That is, in the case of FIGS. 18D and 18E, when SB55 is detected, the interval between SB54 and SB55 is equal to or greater than the number of interpolation SBs, and the number of consecutive SBs of SB53 to SB54 is not equal to or greater than N. , SB53 to SB54 are regarded as not constituting a data block and are discarded.

  Also, SB55 to SB56 are reset in the same manner because the number of consecutive SBs is equal to or less than the prescribed number N of consecutive SBs. As a result, in the case of the SB detection signal as shown in FIGS. 18D and 18E, only two blocks SB51 to SB52 and SB57 to SB58 are detected. Further, the number of data blocks detected in this way may not necessarily be three, but in that case, the SYNC / ID detection data of FIG. 9 is stored in a row. Here, FIG. 18D shows an RF signal, and FIG. 18E shows an SB detection signal.

  In the case of FIGS. 18F and 18G, in the central block, the interval between SB73 and SB74 is equivalent to one SB, so that interpolation is performed. However, the number of SBs between SB75 and SB76 is 2 Interpolation is impossible because there are intervals for each. As a result, in FIGS. 18F and 18G, SB73 to SB75 are regarded as central blocks. The SB 76 is discarded by the process of step S35. Here, FIG. 18F shows the RF signal, and FIG. 18G shows the SB detection signal.

  Further, in step S31, the SB No. of L0. Is the boundary value SB No. Even when it is determined that it is not equal to or greater than A, the process proceeds to step S35, and the data in the registers Fj and Lj are discarded as described above. That is, as shown in FIG. When a data block composed of SB is detected near the boundary of A (SB-F is the SB at the head position of the data block in the figure and SB-L is the SB at the final position), this SB-L is not detected.

  As shown in FIG. 19B, the data block is SB No. Under the condition of straddling the SB of A, if the number of consecutive SBs of the SB-F that is the SB at the head position and the SB-L that is the last position is satisfied, it is handled as a data block.

  Furthermore, as shown in FIG. When the data block is configured to straddle both the SB of A and the head switching pulse, the detection of the SB is started from the state in which the head switching pulse becomes Hi, so the head of the data block in FIG. The SB-X existing at the position is not detected, the first SB after the time t11 when the head switching pulse rises is detected as the SB-F at the head position, and the SB-L at the final position is detected. A range from SB-F to SB-L is read as a data block.

  Furthermore, when the block is configured to straddle the time t12 when the head switching pulse falls as shown in FIG. 21, the SB is detected only when the head switching pulse is in the Hi state. The SB-F and the SB-L immediately before the time t12 are detected, and the SB-Y that is the SB at the actual final position of the data block is not detected.

  FIG. 22 schematically shows the processing of the flowchart described in FIG. Here, FIG. 22A shows a head switching pulse, FIG. 22B shows an SB detection signal, FIG. 22C shows the state of the register Lj, FIG. 22D shows the state of the register Fj, and FIG. 22 (E) shows the states of the registers F0 and L0, FIG. 22 (F) shows the states of the registers F1 and L1, and FIG. 22 (G) shows the states of the registers F2 and L2, respectively. The numbers in FIGS. 22B to 22C are numbers for identifying SB.

  As shown in FIG. 22A, when the head switching pulse rises at time t11, the process is started (the process of step S23), and the first detected data of SB201 is stored in the register F0 and then detected. The SB 202 is stored in the register L0 (step S29), and then the SB data sequentially read is overwritten in the register L0 (steps S24 to S29).

  After the time t21 when the SB 250 is detected, the SB is not continuously detected. Therefore, the condition for the continuous data N and the SB No. of the register L0. SB No. When it is satisfied that A is greater than or equal to A (the process of step S31), the counter j is incremented (step S33), and the registers F0 and L0 are determined as shown in FIG.

  Subsequently, when the SB 301 is detected at time t22, the data is stored in the register F1, the next detected SB 302 is stored in the register L1 (the process of step S29), and then the SB data sequentially read is stored. The register L1 is overwritten (steps S24 to S29).

  After the time t23 when the SB 350 is detected, the SB is not continuously detected, so that the number of consecutive SBs and the register L1 are SB No. When it is satisfied that A is greater than or equal to A (processing in step S31), the counter j is incremented (step S33), and the registers F1 and L1 are determined as shown in FIG.

  Further, when SB401 is detected at time t24, the data is stored in the register F2, the next detected SB402 is stored in the register L2 (the process of step S29), and then the SB data sequentially read is stored. The register L2 is overwritten (the processing in steps S24 to S29).

  After the time t25 when the SB 450 is detected, since the SB is not continuously detected, the number of consecutive SBs and the register L2 are SB No. When it is satisfied that A is greater than or equal to A (the process in step S31), the counter j is incremented (step S33), and the registers F2 and L2 are determined as shown in FIG. In the example of FIG. 22, the case where the number of consecutive SBs in one data block is 50 is described, but the number of SBs in one data block is not limited to this number.

  Now, the description returns to the flowchart of FIG.

  In step S4, the latch data generation unit 62 receives the SYNC / ID detection data transmitted from the SYNC / ID detection unit 22 by the process of step S3. In step S5, the latch data generation unit 62 executes a process of generating latch data based on the SYNC / ID detection data.

  Here, the latch data generation processing of the latch data generation unit 62 will be described with reference to the flowchart of FIG. In the following description, the data of Block 0 First SB included in the SYNC / ID detection data is detected data F 0, the data of Block 0 Last SB is detected data L 0, the data of Block 1 First SB is detected data F 1, the data of Block 1 Last SB is detected data L 1, and Block 2 FirstBs. This data is referred to as detection data F2, and the data of Block2LastSB is referred to as detection data L2.

  In step S51, the latch data generation unit 62 determines whether or not the detection data F0 to F2 and L0 to L2 are included based on the SYNC / ID detection data. That is, as described with reference to the flowchart of FIG. 15, the SYNC / ID detection data may not necessarily detect data corresponding to the three data blocks, so there is an undetected data block. It is determined whether or not to do so. More specifically, by checking the error flag of the SYNC / ID detection data, when all the error flags are 1, it is confirmed that all of the SYNC / ID detection data is possible. If data exists for all blocks, that is, if it is determined that the detected data F0 to F2 and L0 to L2 are included, the processing proceeds to step S52.

  In step S52, the latch data generation unit 62 treats the detection data F0 to F2 and L0 to L2 as they are as the processing data F0 to F2 and L0 to L2, and cumulatively adds the processing data F0 to F2 and L0 to L2. The average value is obtained and stored.

  In step S53, the latch data generation unit 62 refers to the processing data F0 to F2 and L0 to L2, and detects the detected SB No. The SB No. of each SB at the head position and the last position of the data block including SB No. which is the average of And the Trp No. to which the data block belongs. Is output to the capstan servo calculation unit 71 as latch data.

  If it is determined in step S51 that all the detection data F0 to F2 and L0 to L2 are not included, the process proceeds to step S54.

  In step S54, the latch data generation unit 62 determines whether or not the detection data F0, L0, F1, and L1 are included in the SYNC / ID detection data. For example, when it is determined that the detection data F0, L0, F1, and L1 are included, the process proceeds to step S55.

  In step S55, the latch data generation unit 62 determines whether or not the detection data F0 and L0 of the SYNC / ID detection data is a value close to the average value of the processing data F0 and L0 stored therein. For example, when it is determined that the detection data F0 and L0 are not close to the average value of the processing data F0 and L0 stored in the self, the latch data generation unit 62 determines that the SYNC / ID detection data in step S56. Among these, the detection data F0, L0, F1, and L1 are used as the processing data F1, L1, F2, and L2, and the processing data F0 and F0 use the average value, and the processing proceeds to step S53.

  That is, when only two data blocks are included in the SYNC / ID detection data, the detection data F0, L0 and the detection data F1, L1 are not interchanged in time series, so that the detection data F0 , L0 does not take a value close to the average value of the processing data F0, L0, as shown in FIGS. 24 (A) to (C), it corresponds to the first data block (Trp No. 5, 6, 7). If it is a block, it is considered that data of a block corresponding to Trp No. 5 has not been detected. Therefore, in the case of FIGS. 24A to 24C, the processing data corresponding to SBs 91 and 92 are the processing data F0 and L0, and therefore these are generated using the average values stored by themselves. The subsequent processing data F1, L1, F2, and L2 of the SBs 93, 94, 95, and 96 use the detection data F0, L0, F1, and L1 based on the SYNC / ID detection data. For comparison with the average value, for example, the absolute value of the difference between the average value of the detection data and the processing data is obtained. If the absolute value is equal to or less than the threshold value, the absolute value is close. It may be determined that it is not.

  24A is a head switching pulse, FIG. 24B is an RF signal, FIG. 24C is an SB detection signal, FIG. 24D is an RF signal, and FIG. Indicates an SB detection signal, FIG. 24F shows an RF signal, and FIG. 24G shows an SB detection signal.

  If it is determined in step S55 that the detection data F0 and L0 of the SYNC / ID detection data are close to the average value of the processing data F0 and L0 stored in the SYNC / ID detection data, the latch data generation unit 62 is determined in step S57. Determines whether or not the detection data F1 and L1 of the SYNC / ID detection data are close to the average value of the processing data F1 and L1 stored therein. For example, when it is determined in step S57 that the detection data F1 and L1 of the SYNC / ID detection data are not close to the average value stored in the SYNC / ID detection data, the detection data F1 and L1 of the SYNC / ID detection data are As shown in FIGS. 24D and 24E, Trp No. No block corresponding to 6 is detected, and Trp No. 7, it is assumed that the block corresponding to 7 is detected, and in step S58, the latch data generation unit 62 converts the detection data F0, L0, F1, and L1 of the SYNC / ID detection data into the processing data F0, L0, F2, and L2. And the average value is used for the processing data F1, L1, and the processing proceeds to step S53. That is, in the examples of FIGS. 24D and 24E, the processing data F0 and L0 are the detection data F0 and L0 of the SYNC / ID detection data corresponding to SB111 and SB112, and the processing data F1 and L1 are The average values of the processing data F1 and L1 corresponding to SB113 and SB114 are used, and the detection data F1 and L1 of the SYNC / ID detection data corresponding to SB115 and SB116 are used as the processing data F2 and L2. .

  If it is determined in step S57 that the data F1 and L1 of the SYNC / ID detection data are close to the average value stored in the SYNC / ID detection data, as shown in FIGS. 24 (F) and 24 (G), Trp No. In step S59, the latch data generation unit 62 regards the detection data F0, L0, F1, L1 of the SYNC / ID detection data as the processing data F0, L0, F1, and L1 are used, and the average value is used for the processing data F2 and L2, and the process proceeds to step S53. That is, in the examples of FIGS. 24F and 24G, the processing data F0 and L0 are the detection data F0 and L0 of the SYNC / ID detection data corresponding to SB121 and SB122, and the processing data F1 and L1 are , Detection data F1 and L1 of SYNC / ID detection data corresponding to SB123 and SB124 are used, and average values of the processing data F2 and L2 corresponding to SB125 and SB126 are used as the processing data F2 and L2. .

  If it is determined in step S54 that the processing data F0, L0, F1, and L1 are not included in the SYNC / ID detection data, the process proceeds to step S60. In step S60, the latch data generation unit 62 determines whether or not the detection data F0 and L0 are included. For example, if it is determined that they are included, the process proceeds to step S61.

  In step S61, the latch data generation unit 62 determines whether or not the detection data F0 and L0 of the SYNC / ID detection data is close to the average value of the processing data F0 and L0. The process proceeds to step S62.

  In step S62, the latch data generation unit 62 regards the detection data F0 and L0 of the SYNC / ID detection data as data of the first data block, and uses the detection data F0 and L0 of the SYNC / ID detection data as processing data. The average values are used as the processing data F1, L1, F2, and L2, and the processing proceeds to step S53.

  If it is determined in step S61 that the detection data F0 and L0 of the SYNC / ID detection data are not close to the average value of the processing data F0 and L0, the processing proceeds to step S63. In step S63, the latch data generation unit 62 determines whether or not the detection data F0 and L0 of the SYNC / ID detection data are close to the average value of the processing data F1 and L1, and are close to each other, for example. If it is determined, the process proceeds to step S64.

  In step S64, the latch data generation unit 62 regards the detection data F0 and L0 of the SYNC / ID detection data as data of the second data block, and processes the detection data F0 and L0 of the SYNC / ID detection data. The average value is used as the processing data F0, L0, F2, and L2, and the processing proceeds to step S53.

  When it is determined in step S63 that the detection data F0 and L0 of the SYNC / ID detection data are not close to the average value of the processing data F1 and L1, in step S65, the latch data generation unit 62 detects the SYNC / ID detection. The detection data F0 and L0 of the data are regarded as data of the third data block, and the detection data F0 and L0 of the SYNC / ID detection data are used as the processing data F2 and L2, and the processing data F0, L0 and F1 are used. , L1 is used as the average value, and the process proceeds to step S53.

  If it is determined in step S60 that the data F0 and L0 are not included, in step S66, the SYNC / ID detection data is regarded as including no data block data, and the processing data F0 is processed. Through F2 and L0 through L2 are all used from the average value, and the process proceeds to step S53.

  As described above, since the detection data F0 to F2 and L0 to L2 (SYNC / ID detection data) may not be detected as described above, the latch data generation unit 62 may detect the detection data F0 to F2 and L0. From L2 to L2, processing data F0 to F2 and L0 to L2 corresponding to detection data of three data blocks are generated, and latch data is generated.

  Now, the description returns to the flowchart of FIG.

  In step S6, the capstan servo calculation unit 71 determines whether or not the detected SB is within the target Trp (in the data block) based on the latch data supplied from the latch data generation unit 62. . That is, for example, as described with reference to FIG. 13, in the case of 24 × speed reproduction processing, the detected SB (SB detected Jth from the rising edge of the head switching pulse) is the target Trp No. 6 is determined. Therefore, in step S6, whether or not the latch data is in the state of FIGS. 13G to 13J (FIGS. 13B to 13F and FIGS. 13K to 13N). ) Is determined.

  When it is determined in step S6 that the detected SB is within the target Trp, that is, for example, in the case of a 24 × speed reproduction process, when it is determined that the state shown in FIGS. The process proceeds to step S7.

  In step S7, the capstan servo calculation unit 71 determines whether or not the switch 113 is connected to the terminal 113b. If it is determined that the switch 113 is connected, the process returns to step S1 and is connected to the terminal 113b. If it is determined that the switch 113 is not connected, the switch 113 is connected to the terminal 113a. Therefore, in step S8, the terminal 113a is switched to the terminal 113b.

  If it is determined in step S6 that the detected SB is not within the target Trp, that is, for example, in the case of a 24 × speed reproduction process, FIGS. 13 (B) to (F) and FIGS. 13 (K) to (N) ), The process proceeds to step S9.

  In step S9, it is determined whether or not the switch 113 is connected to the terminal 113a. If it is determined that the switch 113 is connected, the process returns to step S1 and it is determined that the switch 113 is not connected to the terminal 113a. In this case, since the switch 113 is connected to the terminal 113b, in step S8, the terminal 113b is switched to the terminal 113a.

  Through the above processing, the capstan servo calculation unit 71 determines at which timing the detected SB (the currently read SB) is read based on the latch data, and is in the Trp. In this case, the switch 113 is connected to the terminal 113b so that the phase error can be calculated in units of SB, and if not in the Trp, the switch 113 is connected to the terminal 113a so that the phase error can be calculated in units of Trp. .

  Next, with reference to the flowchart of FIG. 25, the error calculation process at the time of variable speed reproduction of the capstan servo calculation unit 71 will be described.

  In step S91, the capstan servo calculation unit 71 connects the switch 83 to the terminal 83a.

  In step S92, the speed error calculation unit 81 and the phase error calculation unit 82 calculate a speed error and a phase error, respectively, the speed error calculation unit 81 adds the speed error to the addition unit 85, and the phase error calculation unit 82 The phase error is output to the adding unit 85 via the switch 83 and added.

  Here, processing of the speed error calculation unit 81 and the phase error calculation unit 82 will be described.

  First, the speed error calculation process by the speed error calculation unit 81 will be described with reference to the flowchart of FIG. In step S <b> 111, the buffer 101 stores the time data A input from the time detection unit 65 and outputs the previously stored time data to the subtraction unit 102. For example, when the capstan motor rotation detection pulse input from the capstan motor rotation detection unit 33 is the pulse shown in FIG. 27A, as shown in FIG. A pulse divided by 10 is generated. The time of the rising edge detected by the time detector 65 is time data B. If it is now time t102, the time data at time t102 is input to the buffer 101 and the subtraction unit 102, and the buffer 101 subtracts the time data at time t101 stored before that. 102 to be output.

  In step S112, the subtraction unit 102 takes the difference between the time data input from the buffer 101 and the time data input from the time detection unit 65, and outputs the difference to the subtraction unit 103 as the current rotation period of the capstan motor. That is, in this case, the time (t102−t101), which is the difference between the time t101 that is the time data input from the buffer 101 and the current time t102, is sent to the subtraction unit 103 as the current rotation cycle of the capstan motor. Is output.

  In step S113, the subtraction unit 103 takes the difference between the reference rotation cycle stored in advance in the ROM 202 and the current rotation cycle of the capstan motor (in this case (t102-t101)), and obtains this as a speed error. To the adder 85.

  Note that the processing of the speed error calculation unit 81 is executed at the rising time of the capstan rotation detection pulse in FIG. 27B, and as shown in FIG. ) Is executed at the timing of the rising edge of the divided pulse.

  Next, phase error calculation processing by the phase error calculation unit 82 will be described with reference to the flowchart of FIG.

  In step S131, it is determined whether or not the switch 113 is connected to the terminal 113a. If it is determined that the switch 113 is connected to the terminal 113a, that is, a phase error is calculated in units of Trp. If so, the process proceeds to step S132.

  In step S132, the subtraction unit 111 of the capstan servo calculation unit 71 includes a Trp No. including the detected SB (for example, SB No. J in FIG. 13) based on the latch data. And the target Trp No. stored in the ROM 202. And is output to the gain adjustment unit 114 and the addition unit 116 via the switch 113 as a phase error signal.

  Here, the phase error in Trp units will be described with reference to FIG. FIG. 29 shows the structure of data for variable speed reproduction of 8 × speed reproduction. The data block A1 is a data block in which SB data for 8 × speed reproduction is recorded. When the rotary head 18 having an azimuth angle of − along the scan phase A scans in the arrow direction, the Trp No. The target data block A1 on the track recorded with a azimuth angle of −6 is passed through. The data for 8 × speed reproduction is arranged at the same position in units of 8 Trp (block A2 in the figure is also arranged in the same manner), and variable speed reproduction is realized by reading these continuously. Yes.

  However, if the scan phase shifts depending on the running state of the magnetic tape 35, for example, when the rotary head 18 scans along the scan phase B, the Trp No. 5 data blocks A'1. Accordingly, the phase error of the scan phase A and the scan phase B is represented by E1 in the figure, and E1 = Trp No. 6 (target Trp No.)-Trp No. 5 = 1 Trp. In addition, for example, when the magnetic head scans along the scan phase C, Trp No. 7 data block A ″ ″ 1. Therefore, the phase error of the scan phase A and the scan phase C is represented by E0 in the figure, and E0 = Trp No. 6 (target Trp No.)-Trp No. 7 = −1Trp. That is, the phase error in units of Trp is output.

  In step S <b> 133, the gain adjustment unit 114, the integration calculation unit 115, and the addition unit 116 smooth the phase error signal input from the subtraction unit 111 and output the signal to the gain adjustment unit 117.

  In step S <b> 134, the gain adjusting unit 117 adjusts the gain of the input phase error signal and outputs the adjusted signal to the adding unit 85 via the switch 83.

  If it is determined in step S131 that the switch 113 is not connected to the terminal 113a, that is, if the switch 113 is connected to the terminal 113b and is in a state of calculating a phase error in units of SB, the processing is as follows. The process proceeds to step S135.

  In step S135, the subtraction unit 112 of the capstan servo calculation unit 71 detects the SB No. of the detected SB (for example, the SB of SB No. J in FIG. 13) based on the latch data. And the target SB No. stored in the ROM 202. And is output to the gain adjusting unit 114 and the adding unit 116 via the switch 113 as a phase error signal.

  That is, as described in the flowchart of FIG. Since the detection of the unit phase error is when the data block including the detected SB is detected in the target Trp, it represents the phase error of the SB unit in the target Trp. become.

  FIG. 30 shows the relationship between the phase error in Trp units and the phase error in SB units for each scan phase. FIG. 30A shows blocks A1 to A3 (tracks scanned by a magnetic head having a −azimuth angle) including scan phases and SBs for 8 × speed variable speed reproduction, and a thick line indicates a rotating head 18 having a −azimuth angle. Indicates the scan phase when scanning. Further, the thin line indicates the scan phase when the rotary head 18 having a + azimuth angle scans. FIG. 30B shows a Trp No. that intersects the center line of the scan phase of the rotary head 18 having an azimuth angle indicated by a bold line. The transition of the phase error in units of Trp for each scan phase is shown with the horizontal axis. Here, the vertical axis indicates the number of Trp indicating a phase error. As shown in FIG. 30B, the scan phase changes periodically, and Trp No. In the range of 6 to 2, the case where the traveling speed of the magnetic tape 35 is high is shown. In the range of 2 to 6, the case where the running speed of the magnetic tape 35 is slow is shown.

  FIG. 30C shows a phase error in SB units. In this example, the target Trp No. 6 is shifted by 1 Trp around the track of the azimuth angle, and the upper limit value (Max) and the lower limit value (Min) are fixed values. That is, since it is only necessary to show the transition within the target Trp, it is sufficient that the upper limit value and the lower limit value are set to be equal to each other in absolute value. The capstan servo process is executed so that the phase error becomes zero.

  FIG. 31 shows the timing of the above processing. FIG. 31A shows a head switching pulse, TD1 to TD3 indicate detected blocks, and SD1 to SD3 indicate target data blocks. FIG. 31B shows the processing timing. FIG. 31C shows the timing of the rising pulse of the time data A (frequency-divided pulse).

  That is, as shown in FIG. 31 (A), when the head switching pulse rises at times t11, t13, and t15, the SYNC / ID detector 22 performs timings t121, t123, and t125, which are the centers of the pulses. Data in the blocks TD1, TD2, and TD3 are read out and transferred to the latch data generation unit 62 as SYNC / ID detection data at timings t12, t14, and t16.

  Based on the SYNC / ID detection data, the latch data generation unit 62 performs timing data at times t131, t133, and t135, as shown in FIG. 31B, that is, time data as shown in FIG. Latch data is generated at timings t155, t162, and t169 when the A pulse rises, and transferred to the capstan servo calculation unit 71. Based on the latch data, the capstan servo calculation unit 71 sets the target SB No. stored in advance. (Corresponding times t122, t124, t126) and the detected SB No. From a comparison with (corresponding times t121, t123, 125), a phase error is calculated at timings t132, t134, t136, and the rotation of the capstan motor 34 is controlled. By this process, the result of the capstan servo calculation process based on the latch data is reflected at the timings t156, t163, and t170, which is the timing immediately after the rotation of the capstan motor 34 is controlled.

  Now, the description returns to the flowchart of FIG.

  In step S <b> 93, the addition unit 85 adds the speed error from the speed error calculation unit 81 to the phase error from the phase error calculation unit 82 and outputs the result to the gain adjustment unit 86. In step S <b> 94, the gain adjustment unit 86 adjusts the gain of the input signal and outputs the adjusted signal to the integration calculation unit 87 and the addition unit 89. In step S95, the integral calculation unit 87, the gain adjustment unit 88, and the addition unit 89 constitute an LPF, smooth the signal input from the gain adjustment unit 86, and output the smoothed signal to the PWM generation unit 63. Then, the process of step S92 is performed again. Return to, and the subsequent processing is repeated.

  With the above processing, only by detecting data of three data blocks in the vicinity of the target SB, a phase error in Trp units is obtained, and capstan servo processing in Trp units is executed by that processing. When the block on the target Trp can be read, a phase error in SB units is continuously obtained, and target data can be acquired in SB units by the corresponding capstan servo processing.

  In the above example, the case where the detection position of the target data block is the central portion of the magnetic tape has been described. However, as shown in FIG. 32, the data blocks B1 to B3 are separated from the data blocks A1 to A3. As described above, target data blocks may be set at different positions even on the same scan phase. By setting in this way, even when a linear shift that may occur due to a mechanical problem occurs on the data blocks A1 to A3, for example, the target position is switched to the data blocks B1 to B3. Can be suppressed. Also, data blocks C1 to C3 for reverse speed shift reproduction may be recorded.

  Further, as shown in FIG. 33, target data blocks A1 to A3 are represented by data blocks A1-1 to A1-3, data blocks A2-1 to A2-3, and data blocks A3-1 to A3-3. In addition, by recording the same data block a plurality of times (for example, three times) on one track, the range that can be read by the rotary head 18 can be set wide, and as a result, the occurrence of errors can be suppressed. be able to. Also at this time, the target position may be set on another track that can be detected on the same scan phase as shown in FIG. 32. In this case, the number of data block recordings is changed as shown in FIG. (Blocks B1 to B3 in FIG. 33 are twice). Further, the data for reverse speed shift reproduction may be recorded a plurality of times as in data blocks C1-1 and C1-2. As a matter of course, the number of times the same block is recorded on the same track is not limited to the above-described one to three times, and may be any other number.

  In the above description, Trp No. In the above description, the capstan servo calculation process is executed according to Tr No .. Thus, the capstan servo calculation process may be executed.

  According to the above, since the servo processing by the SB unit is executed after executing the servo processing by the phase error in the Trp unit, the image signal recorded on the tape-shaped recording medium can be reproduced even during the variable speed reproduction. It is possible to reproduce stably and further shorten the processing time until the reproduction state is stabilized. Further, in the SB reading process, it is not necessary to read out all the SBs by reading out only the SBs on the Trp near the Trp including the SB to be read. Therefore, the configuration necessary for the SB reading process is simplified. In addition, the cost can be reduced and the processing speed can be improved.

  In this way, at 8 × speed or 24 × speed, since three or more data strings are intermittently reproduced from the recording medium, one data line (Block 2) in which all the data is collected can be taken. Track pair number TrpNo. And sync block number SBNo. Thus, phase lock can be performed by knowing the current trace position and target position.

  However, at -1 times speed, there are one data string intermittently reproduced from the recording medium (Block 0) or two data strings missing in the middle ((Block 0, 1)). Phase locking cannot be performed by the same method as the double speed phase locking method.

  Therefore, in the present invention, phase-locking is performed so that the variable speed reproduction dedicated data arranged at a predetermined position in accordance with a certain rule is traced, so that reproduction at -1 times speed is performed using search data at 8 times speed.

Here, FIG. 34 shows an area where search data of 8 × speed is recorded. In -1 × speed reproduction, phase lock is applied to trace this search data. In order to display an image, it is necessary to trace the search data of TrpNo0 and Trp1, and they are locked at a position slightly shifted from the center. That is, since the data of Trp0 and Trp2 are the same, it is sufficient to obtain either one. )
As shown in FIG. 35 for the trace pattern, the data required for the phase lock is obtained from the data string in the section where the head switching pulse (SWP) is H.

  In a section where SWP is H, there are one or two effective areas in which the data string can be obtained when the signal level of the reproduction RF signal is equal to or higher than a predetermined level.

  That is, in the case of -1 traveling, it can be locked using either one or two data strings obtained.

  Hereinafter, a case where locking is performed by using a data string having a larger amount of data will be described.

  Here, the first and last SBs of the data string are referred to as First SB and Last SB.

  First, as shown in FIG. 36, when only a block 0 has a data string, all the data is prepared, and therefore, the middle SBNo of First SB and Last SB is set as the current position.

In other words, the capstan servo calculation unit 71 uses the value of Block 0 when Trp and SBNo of Block 1 cannot be picked up.
Current position = (FirstSB + LastSB) / 2
The current position is obtained by the following calculation.

  In addition, as shown in FIG. 37, when the data is lost due to the SWP edge, the current position is obtained by correcting the data value (the number of effective SBs) on the desk to the first or last SB data that has been correctly taken. Calculate

That is, in the capstan servo calculation unit 71, when both Trp and SBNo are picked up for both Block 0 and Block 1, when Block 0 Last SB-Block 0 First SB> Block 1 Last SB-Block 1 First SB, the value of Block 0 is Bck, and B When Block ≦ LastSB−Block1FirstSB, the value of Block1 having a long effective data length of the data string is used, and if LastSB is the right edge (138),
Current position = First SB + number of effective SBs / 2
The current position is obtained by the following calculation. If FirstSB is the left edge (0),
Current position = LastSB-Number of effective SBs / 2
The current position is obtained by the following calculation.

  Here, as shown in FIG. 38, the number of effective SBs is the number of SBs included in an effective area where the signal level of the reproduction RF signal is equal to or higher than a predetermined level and a data string is obtained.

Then, in the phase error calculation unit 82 of the capstan servo calculation unit 71, a deviation from the current position and the target position to be locked (for example, reference SBNo = 90) is obtained as a phase error,
Phase error = current position-reference SBNo (90)
Where the phase error is large, for example, it is pulled in with a fixed error value of 2% of the speed, and if the phase error is within the 20 SB number, the phase is locked by applying a servo using SBNo. The number of switching SBs can be changed, and all can be pulled in with a servo using SBNo.

  The algorithm of the arithmetic processing for the capstan servo in such -1 × speed reproduction is shown in FIG. 39, and the speed error is similar to the control configuration of the capstan servo arithmetic unit 71 shown in FIG. It is executed by the calculation unit 81 and the phase error calculation unit 82. The phase error calculation unit 82 includes a limiter processing unit 118 for pulling in with a fixed error value of 2% of the speed when the phase error is large.

  The speed error calculation unit 81 obtains a reference time period by taking a difference from the data acquired immediately before the time data acquired at the timing of the rising edge of the divided pulse in FIG. The difference from the reference value of the reference time corresponding to the target speed is calculated as a basic speed error. Further, the phase error calculation unit 82 obtains the phase error obtained by specifying the current position from the values of Block 0, Block 0 and / or Block 0. Then, the phase error obtained by the phase error calculation unit 82 is added to the speed error from the speed error calculation unit 81 by the addition unit 85, and the gain output is adjusted by the gain adjustment unit 86, and the integration calculation unit 87, gain adjustment is performed. The data is output to the PWM generation unit 63 via the LPF configured by the unit 88 and the addition unit 89.

  That is, in the capstan servo calculation unit 71 of the playback system 20, the phase error calculation unit 82 specifies the current position from the values of Block0, Block0 and / or Block0 that are intermittently reproduced from the track of the magnetic tape at -1 × speed. Then, the phase error is obtained, and the phase error obtained by the phase error computing unit 82 is added to the speed error from the speed error computing unit 81 by the adding unit 85, and the phase servo is applied to lock the phase at -1 times speed. The rotary head 18 performs control to trace and reproduce the search data.

  The series of processes described above can be executed by hardware, but can also be executed by software. When a series of processing is executed by software, a program constituting the software can execute various functions by installing a computer or various programs incorporated in dedicated hardware. For example, it is installed from a recording medium in a general-purpose personal computer.

  As shown in FIG. 7, this recording medium is not limited to the HDD 204 in which the program is recorded, but is distributed to provide the program to the user separately from the computer. Flexible disk), optical disk 212 (including compact disk-read only memory (CD-ROM), DVD (digital versatile disk)), magneto-optical disk 213 (including MD (mini-disk)), or semiconductor memory 214 Consists of package media (including Memory Stick).

  In this specification, the step of describing the program recorded on the recording medium is not limited to the processing performed in time series in the order described, but of course, it is not necessarily performed in time series. Or the process performed separately is included.

It is a figure explaining compression of an MPEG system. It is a figure explaining a drum. It is a figure explaining the operation | movement which the rotary head reads the image signal recorded on the magnetic tape. It is a figure explaining RF signal detected by a rotating head. It is a figure which shows the structure of one Embodiment of the recording system of the digital video tape recorder to which this invention is applied. It is a figure which shows the structure of the reproduction | regeneration system of the digital video tape recorder to which this invention is applied. It is a block diagram around the microcomputer provided in the video tape recorder. It is a figure which shows the structure of SYNC / ID detection request data. It is a figure which shows the structure of SYNC / ID detection data. It is a figure explaining the scan of the data on the magnetic tape by a rotating head. It is a figure which shows a detection signal when the data on the magnetic tape are scanned by the rotating head. It is a figure explaining the scan of the data on the magnetic tape by a rotating head. It is a figure explaining the pattern of a phase error when scanning the data on the magnetic tape by a rotary head. It is a control block diagram of a capstan servo calculation unit in the video tape recorder. It is a flowchart explaining the servo processing at the time of variable speed reproduction. It is a flowchart explaining a SYNC / ID detection process. It is a figure explaining a SYNC / ID detection process. It is a figure explaining a SYNC / ID detection process. It is a figure explaining a SYNC / ID detection process. It is a figure explaining a SYNC / ID detection process. It is a figure explaining a SYNC / ID detection process. It is a figure which illustrates a SYNC / ID detection process typically. It is a flowchart explaining a latch data generation process. It is a figure explaining a latch data generation process. It is a flowchart explaining error calculation processing at the time of variable speed reproduction. It is a flowchart explaining a speed error calculation process. It is a timing chart explaining speed error calculation processing. It is a flowchart explaining a phase error calculation process. It is a figure explaining a phase error calculation process. It is a figure explaining a phase error calculation process. It is a timing chart explaining a phase error calculation process. It is a figure explaining a phase error calculation process. It is a figure explaining a phase error calculation process. It is a figure which shows the area where the search data of 8 times speed is recorded. It is a figure which shows the data string obtained intermittently and the reproduction | regeneration RF signal of -1 time. It is a figure which shows the state from which a data sequence is obtained only in Block0 at the time of -1 times-speed reproduction. It is a figure which shows the state which fell on the edge of SWP at the time of -1 times-speed reproduction | regeneration, and data was missing. It is a figure for demonstrating the number of effective SB. It is a figure which shows the control structure of the capstan servo calculating part which performs the algorithm of the calculation process for the capstan servo in -1 time speed reproduction | regeneration.

Explanation of symbols

  10 recording system, 20 playback system, 31 microcomputer, 32 driver, 33 capstan motor rotation detector, 34 capstan motor, 35 magnetic tape, 36 drums, 37 drum rotation detector, 38 head switching pulse generator, 51 RF Envelope detector, 52 comparator, 61 CPU, 62 latch data generator, 63 PWM generator, 64 frequency divider, 65 time detector, 71 capstan servo calculator, 81 speed error calculator, 82 phase error calculator

Claims (9)

In a recording / reproducing apparatus for recording / reproducing digital data through an inclined track of a magnetic tape by a rotating head,
First generation means for encoding the input image signal to generate image data; second generation means for generating search data based on the image data; and the image data and the search data on the magnetic tape A recording system comprising recording means for recording on the inclined track of
Normal reproduction means for reproducing the image data and search data recorded on the inclined track of the magnetic tape, and positions of one or two data strings intermittently reproduced from the track of the magnetic tape at -1 × speed Variable speed reproduction control means for performing control to specify the current scan position of the inclined track of the magnetic tape by the rotary head using the information, phase lock at -1 × speed, and trace and reproduce the search data by the rotary head A recording / reproducing apparatus comprising: a reproduction system comprising:   The variable speed playback control means specifies the current scan position of the inclined track of the magnetic tape by the rotary head using the one having the larger data amount of the two data strings, and performs phase lock at -1 times speed. The recording / reproducing apparatus according to claim 1.   The variable speed reproduction control means specifies the current scan position of the inclined track of the magnetic tape by the rotating head by correcting the obtained data when the data is not all in the two data strings, 2. The recording / reproducing apparatus according to claim 1, wherein phase locking is performed at -1 times speed. The input image signal is encoded to generate image data, search data is generated based on the image data, and the image data and the search data are recorded and reproduced by the rotating head via the inclined track of the magnetic tape. A recording / playback method,
Using the position information of one or two data strings that are intermittently reproduced from the track of the magnetic tape at -1 times speed, the current scan position of the inclined track of the magnetic tape by the rotary head is specified,
A recording / reproducing method comprising: phase-locking at -1 times speed and tracing and reproducing the search data by the rotary head.   5. The current scan position of the inclined track of the magnetic tape by the rotary head is specified using the larger data amount of the two data strings, and phase locked at -1 times speed. Recording and playback method.   When all the data in the two data strings are not complete, the obtained data is corrected to identify the current scan position of the inclined track of the magnetic tape by the rotary head, and phase lock is performed at -1 times speed. The recording / reproducing method according to claim 4. The input image signal is encoded to generate image data, search data is generated based on the image data, and the image data and the search data are recorded and reproduced by the rotating head via the inclined track of the magnetic tape. Is a program recording medium in which a control program for reading and recording is executed by a computer,
Using the position information of one or two data strings that are intermittently reproduced from the track of the magnetic tape at -1 times speed, the current scan position of the inclined track of the magnetic tape by the rotary head is specified,
A program recording medium on which a control program is recorded so as to be read and executable by a computer, wherein the search data is traced and reproduced by the rotary head after phase locking at -1 times speed.   A control program is characterized in that the current scan position of the inclined track of the magnetic tape by the rotary head is specified by using the larger one of the two data strings, and the phase is locked at -1 times speed. 8. The program recording medium according to claim 7, wherein the program recording medium is recorded so as to be readable and executable.   When all the data in the two data strings are not complete, the obtained data is corrected to identify the current scan position of the inclined track of the magnetic tape by the rotary head, and phase lock is performed at -1 times speed. 8. The program recording medium according to claim 7, wherein the control program is recorded so as to be readable and executable by a computer.

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