JP3211249B2 - Information recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording apparatus, and more particularly to an apparatus for recording an index signal.

2. Description of the Related Art A so-called 8-mm video VTR is one type of rotary head helical scan type recording / reproducing apparatus. In this 8 mm video system VTR, for example, 180
Two magnetic heads having different azimuths are mounted so as to face each other, and these magnetic heads alternately scan the magnetic tape obliquely to sequentially record video signals.

FIG. 4 shows a recording format of the 8 mm video system. From the tip where the magnetic head starts to contact the magnetic tape
36 minutes corresponds to the audio PCM signal recording area AP, and the subsequent 185 minutes corresponds to the video signal recording area AV. Audio PCM signal recording area A
The first 5 ゜ of P is the head entry, and the first half is 2.9.
4 ゜ is the scanning start area, the latter half 2.06 ゜ (corresponding to 3H. 1
(H is one horizontal synchronization period) is a preamble for clock run-in synchronized with the following PCM data. After the preamble, a recording area for the PCM data of the time-axis-compressed audio signal is provided over 26.32 mm, the postamble as the back margin against the recording position shift during after recording is 2.06 mm (3H), and the guard area is 2.62 ゜ is provided. Following the guard area, a recording area for a one-field video signal is provided over 180 °, and thereafter, a scanning end area is provided for 5 °.

In the PCM data area, audio data for one field and related index data are interleaved, encoded, and recorded confusedly. The index data is various data such as a recording date, an absolute address, a program number, and time information (a so-called time code), and is used for cueing and editing during reproduction.

However, since the index data is interleaved with the audio data and coded, it cannot be extracted without deinterleaving and decoding the PCM data. Therefore, conventionally, there is a disadvantage that the processing time is long when used for cueing and editing. Further, at the time of search reproduction, the rotary head scans obliquely across the recording track, so that it was difficult to reproduce index data correctly.

To solve these problems, it has been proposed to record index data having the same content as index data in PCM data in the postamble area of the PCM signal recording area AP. FIG. 5 shows the index format of the postamble area in this case. Fifth
As shown in FIG. 7A, the postamble area following the PCM data area is 2.65H, and the subsequent 1.5H is an index area. And the guard area 2.
65H.

1.26H from the head of the 1.5H index area is a header area, and the following 0.24H is a coding data area. In the header area, "0" is written when an index signal is recorded in the index area, and "1" is written when the signal is not recorded or erased. Coding data area is 5th
It is divided into eight blocks as shown in Fig. (C). The first one block has a code start marker, the next five blocks have an 8-bit ID code, and then a CRC for error detection.
Code, last code end marker.

As described above, if the index data is recorded in an area different from the PCM data, there is an advantage that only the index data can be separately recorded later on the recorded track.

[Problems to be Solved by the Invention] However, in the above-mentioned index format, in order to perform a screen search or the like with high accuracy, a capture, a frame number, and the like are written in a coding data area of an index section from the beginning of the tape. It is necessary to record continuously. In addition, "0" in the header section must be written continuously for a predetermined time or longer (for example, 10 seconds) in order to enable reproduction at the time of search reproduction, and a fine search is not possible.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an apparatus capable of quickly performing a search using an index signal.

[Means for Solving the Problems] An information recording apparatus according to the present invention is an apparatus for generating a large number of parallel tracks on a tape-shaped recording medium and recording a main information signal and an index signal, In response to an instruction to record the index signal, the index signal is recorded for a predetermined period from the designated track, and the distance from a specific track among a large number of tracks in the predetermined period in which the index signal is recorded is set. Recording means for recording the distance information on the track of the predetermined period, the recording means further comprising: a recording instruction of the index signal newly for any of the tracks of the predetermined period in which the index signal is recorded. The index signal is recorded according to the index signal and the new instruction. And recording the distance information relating to a distance from a specific track among the tracks during the predetermined period.

[Operation] The track to be searched to which the index signal is added can be easily detected based on the identification information and the distance information.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an index according to an embodiment of the present invention.
An example of an area signal is shown. Usually, “1” is recorded in the header, but “0” is recorded as a cue index for 10 seconds after the field to be searched. In this embodiment, five blocks of coding data WD0, WD1,
WD2, WD3, WD4 are defined as follows. That is, WO0 indicates the mode. For example, if the search mode is indicated by 20,
The search is executed only in the track having the index area block WD0 of 20.

WD1 indicates an arbitrary search index number. The index number is input from a ten key (not shown) or the like, and is recorded in an index section where the header is “0”. This index number will be used in later searches.

WD2 indicates the number of frames from the track where the target specific field to be searched is recorded. Thereby, the number of frames (or the number of tracks) from a plurality of tracks (or fields) where the index numbers to be searched are recorded to the target field can be known.

WD3 is a block for recording the previously defined index number when there is a specific field to be searched further while the header is "0", that is, when two indexes overlap. If there is no index number defined, "0" is recorded, and if so, the index number is recorded.

WD4 indicates the number of frames from a specific field with an index number defined in advance when there is a specific field to be further searched while the header is "0". This allows the index to be defined later,
The disappearance of the previously recorded index can be prevented.

FIG. 2 is a block diagram showing the configuration of this embodiment. In FIG. 2, reference numerals 10a and 10b denote rotating heads.
It is installed facing 80 ゜. Switches 14a and 14b are connected to the R contact during recording and are connected to the P contact during reproduction. 16a and 16b are recording amplifiers. 18a and 18b are reproduction amplifiers.
Is a head selection switch that selects the heads 10a and 10b during recording, 22 is a head selection switch that selects the heads 10a and 10b during reproduction, and 24 is a recording process that processes the video signal from the input terminal 26 and supplies it to the switch 20 during recording. At the time of reproduction, the video signal processing circuit reproduces the reproduction signal from the switch 22 and outputs the reproduced video signal to the output terminal 28.

Reference numeral 30 denotes a PCM audio signal for converting the right and left channel audio signals into PCM data from the input terminals 32R and 32L, outputting the PCM data, demodulating the reproduced PCM data, and outputting the right and left channel reproduced audio signals to the output terminals 34R and 34L. It is a processing circuit. 36 is an input terminal for index information, 38 is an input terminal for a signal designating the code of the header of the index area, 40 is a header corresponding to the input signal of the input terminal 38, and an input terminal 36
Coding data according to index information from
An index encoder that forms WD0 to WD4.
For example, an on / off signal of a cue index switch (not shown) is input to an index encoder 40 via an input terminal 38, and the index encoder 40
Over a predetermined number of tracks, the header is "0" and the coding data WD0 to WD4 output a signal having the above-described predetermined content. 42 is a switch for selecting the output of the index encoder 40 in the index area of FIG.
Is a modulation circuit for recording.

Reference numeral 46 designates the reproduced signal from the switch 22 as "0" or "1".
A demodulation circuit for demodulating to a decimal value, 48 is an output of the demodulation circuit 46,
A gate circuit 50 for extracting a signal from the index area shown in FIG. 5 is an index decoder, which outputs a header to a "0" discriminating circuit 52 described later, and outputs coding data to a system control circuit 66 described later. 52 is “0” which determines whether the header from the index decoder 50 is “0” or not.
A discriminating circuit, 54 is a counter that counts the discrimination result for each bit by the "0" discriminating circuit 52, 56 is a comparing circuit that compares the count value of the counter 54 with a predetermined threshold TH, and 60 is a comparing result of the comparing circuit 56. Is a cueing determination circuit that determines whether or not it is a cueing position according to the following.

62 is a pulse generating circuit that generates a PG pulse indicating the rotation phase of the drum 12, 64 is a switching signal forming circuit that generates a switching control signal RFSW according to the PG pulse from the pulse generating circuit 62, and 66 is a system control circuit that controls the whole And 68, a gate signal forming circuit for generating a gate signal to the gate circuit 48 at a timing synchronized with the switching control signal RFSW under the control of the system control circuit 66. The switches 20, 22 are switched by a switching control signal RFSW. The signal RFSW is also supplied to the system control circuit 66 and the PCM audio processing circuit 30.

The basic operation at the time of recording will be described. The switches 14a and 14b are connected to the R contact according to a control signal from the system control circuit 66. The video processing circuit 24 processes the video signal from the input terminal 26 and outputs the processed signal to the switch 20. In addition, the PCM audio processing circuit 30 converts the audio signals from the input terminals 32L and 32R into PCM data, and responds to the switching control signal RFSW by using the PCM audio processing circuit shown in FIG.
Output at the timing corresponding to the data section. The index encoder 40 forms an index signal from the input signals at the input terminals 36 and 38 as described above. The switch 42 is normally connected to the output side of the PCM audio processing circuit 42, and the output of the index encoder 40 in the index area (FIG. 5) extending over the postamble and the guard area of the PCM signal recording area AP. To the side. The modulation circuit 44 converts the data from the switch 42, “1” to a 5.8 MHz signal, and “0” to
Each of the 2.9 MHz signals is modulated and output to the switch 20.

The switch 20 is connected to the drum 12 according to the switching control signal RFSW.
The heads 10a and 10b are switched every 1/2 rotation of the same, and on the same track, the output of the modulation circuit 44 is selected for the area AP, and the output of the video signal processing circuit 24 is selected for the area AV. Is switched to. The output of the switch 20 is amplified by the recording amplifier 16a or 16b, and
The voltage is applied to the head 10a or 10b via 4b and recorded on a magnetic tape (not shown).

The basic operation during reproduction will be described. In the case of the 8 mm video system, tracking and tracking are performed using four frequency pilot signals.
Servo is applied, and at the time of recording, a pilot signal for that purpose is superimposed and recorded.

At the time of reproduction, the switches 14a and 14b are connected to the P contact side. The reproduction output of the heads 10a and 10b is supplied to the switch 22 via the switches 14a and 14b and the reproduction amplifiers 18a and 18b. The switch 22 is a switching control signal from the switching signal forming circuit 64
The signal is switched by the RFSW in the same manner as the switch 20, and the reproduction signal from the area AV is supplied to the video signal processing circuit 24, and the reproduction signal from the area AP is supplied to the demodulation circuit 46. The video signal processing circuit 24 reproduces the signal from the switch 22 and outputs it to the reproduced video signal output terminal 28. The demodulation circuit demodulates the bi-phase mark signal into PCM data. The output of the demodulation circuit 46 is applied to the PCM audio processing circuit 30 and the gate circuit 48.

After performing error detection and correction on the reproduced data, the PCM audio processing circuit 30 returns the analog audio signals to the right and left channels and outputs the analog audio signals to the output terminals 34R and 34L.

The gate circuit 48 extracts index data over the postamble and the guard area based on the gate signal from the gate signal forming circuit 68, and supplies the index data to the index decoder 50. The index decoder 50 decodes the coding block and supplies it to the system control circuit 66, and supplies the header to the “0” determination circuit 52. “0” determination circuit
52 determines whether the contents of the header are “0” or “1” for each bit,
The counter 54 counts the determination result, and the comparison circuit 56 compares the count result of the counter 54 with a predetermined threshold TH. When the count value of the counter 54 is equal to or greater than the predetermined value TH, it is determined that a cueing position has occurred, and the cueing determination circuit 60 outputs a determination result signal to the system control circuit 66. System control circuit
66 outputs, for example, a tape running stop control signal in accordance with the output of the determination circuit 60.

In this way, the entire device can be controlled by the index signal recorded between the postamble and the guard area.

FIG. 3 shows a flowchart at the time of recording an index signal recorded between the postamble and the guard area. First, a screen to be indexed is selected by normal reproduction or slow reproduction, and the still reproduction state is set (S1, 2). In still playback, the magnetic tape is stopped, and the rotational speed of the rotary head is made to match the relative speed between the rotary head and the magnetic tape during recording (S3). In this state,
Read the index signal (header and coding data) between the postamble and the guard area (S
Four).

If the reproduced header is “1” (S5), the header is “0”, WD0 is “20”, WD1 is an arbitrary index number, and WD2
Is set to "0", and WD3 and WD4 are both set to "0". These signals are stored in the memory in the system control circuit 66 and written to the same track of the magnetic tape (S7, 8, 9). Next, the magnetic tape is slightly rewound (S10) and set to the playback mode (S1).
1) Reproduce an index signal between the postamble and the guard area of each track, and compare the header and coding data with the header and coding data stored in the memory in S8 (S13). The header is set to “0” for 10 seconds from the track following the track that matches the comparison.
WD0 is “20”, WD1 is any index number described above, WD2
Is recorded in the index area of FIG. 5A (S14, 15).

If the header of the index signal reproduced by the still reproduction is "0" (S7), the reproduced WD1 and WD2 are respectively WD.
Copy to 3 and WD4, header is “0”, WD0 is “20”, WD1 is an index number different from the previous index number, WD1
2 is set to "0" and the data is written on the same track of the magnetic tape (S9). Next, rewinding (S10), reproduction (S11, 12) and comparison (S13) are performed. From the next track after the equalized track, the header is set to "0", WD0 is set to "20", and WD1 is set to Other index numbers, WD2 is the number of frames from the track of S9, WD3 is the index number recorded earlier, and WD4 is the signal with the number of frames from the track where the index number of WD3 is recorded first, It is recorded in the index area of FIG. 5A (S14, 15).

In the reproduction using the index signal recorded in this manner, first, the head is searched by searching for a track whose header is "0", and the desired index number is compared with the WD1 of the reproduced coding data. By this, it can be determined whether or not the desired index section,
It is possible to determine whether to search or rewind to the track following the header "0". If the desired index number, the desired field (or track) by WD2
The number of frames up to this point can be accurately known, and by controlling the tape running by the system control circuit 66 while reproducing the WD2, the track on which the target video is recorded can be reproduced.

[Effects of the Invention] As can be easily understood from the above description, according to the present invention, a track to be searched can be easily detected.

[Brief description of the drawings]

FIG. 1 is an example of the contents of an index signal in one embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of this embodiment, FIG. 3 is a flowchart of recording an index signal in this embodiment, and FIG. FIG. 5 shows a video track format, in which an index signal is recorded between a postamble and a guard area. 10a, 10b: rotating head, 12: rotating drum, 14a, 14b: changeover switch, 16a, 16b: recording amplifier, 18a, 18b: reproduction amplifier,
20, 22: head selection switch, 24: video signal processing circuit, 30:
PCM audio processing circuit, 40: index encoder, 42:
Switch, 44: modulation circuit, 46: demodulation circuit, 48: gate circuit, 50: index decoder, 52: "0" discriminating circuit, 5
4: counter, 56: comparison circuit, 60: cue discrimination circuit, 62: pulse generation circuit, 64: switching signal formation circuit, 66: system control circuit, 68: gate signal formation circuit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-119085 (JP, A) JP-A-4-61684 (JP, A) JP-A-63-161582 (JP, A) JP-A-63-164 146290 (JP, A) JP-A-63-883 (JP, A) JP-A-61-162879 (JP, A) JP-A-56-25277 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) G11B 20/12 103 G11B 15/087 101 G11B 27/28

Claims (1)

(57) [Claims] 1. An apparatus for generating a large number of parallel tracks on a tape-shaped recording medium and recording a main information signal and an index signal, wherein the main information signal and the index signal are recorded in response to an instruction to record the index signal. Recording means for recording the index signal over a predetermined period from a track and recording distance information on a distance from a specific track among the tracks of the predetermined period in which the index signal is recorded, on the track of the predetermined period. The recording unit may further include, in response to a new recording instruction of the index signal for one of the tracks in the predetermined period in which the index signal is recorded, the index signal and the new A specific track among the tracks of the predetermined period in which the index signal is recorded according to the instruction Information recording apparatus and the distance information relating to the distance to and recording the track of the predetermined period.