JPS5938911A - Tape width dividing recorder - Google Patents

Abstract

PURPOSE:To realize the sound recording for a long period of time with a VTR which records the sound signal on one of two divided tracks and the video signal on the other track respectively, by dividing the video signal track into plural parts. CONSTITUTION:A track 2 is divided into plural tracks 7-12. Then the sound signal is recorded only to a channel 3' after driving a tape. Hereafter channels 8'-12' are successively recorded in the same way. This equals to the fact that the width of a tape is cut into seven parts and then recording is carried out to these seven parts after joining them together. Thus it is possible to record sounds for a long period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention utilizes the head and running system of a VTR to
The present invention relates to a method suitable for exclusively recording and reproducing CM signals.

FIG. 1 is an explanatory diagram of a recording pattern on an 8-video tape to which the present invention is applied. Compared to the recording pattern on conventional video cassette tapes, the feature is that the audio and video signals are recorded at separate locations on the trunk.

1 is the tape, and 2 is one of the tracks recorded helically. The arrows labeled lJ#vt+Va indicate the respective directions of the tape feed speed and the head movement speed. Track 2 is divided into two parts, and its -force track 6 has P
A commercial audio signal is recorded, and the other trunk 4 records a video signal.

This tape 1. is wound around a rotating head drum in the same way as a conventional consumer VTR, and diagonal recording is performed by the rotating head as shown in the figure. For example, as shown in the figure, the angles are 26 degrees and 180 degrees, and a gap of 4 degrees is provided between them.

FIG. 2 shows the recording method of a Philips cassette VTR. The tape width of tape 1 is divided into two, and the signal is recorded helically as shown in track 5 on channel 5' first.When recording of channel 5' is completed, channel 6
’ is also recorded on the top. Tracks 5 and 6 are similar to trunk 3.4 in Figure 1 in that the tape width is divided into two to create two channels.However, the audio and video signals are not separated and are composite. Trunk 5 as a signal,
The points recorded in 6 are different from those in FIG.

The purpose of the present invention is 8II! To provide an audio-only tape recorder which is compatible with an 11 video compact cassette, is capable of long-time recording, has good editing performance, and is capable of auto-reversing.

The content of the present invention is basically to provide a PCM-dedicated recorder that repeatedly records a PCM signal similar to that on track 6 on video track 4 in FIG. .

FIG. 3 is an example of a recording pattern diagram on a tape showing the basics of the present invention. Track 2 is divided into a plurality of trunks as shown in numbers 7 to 12.

3', 7' to 12' indicate tape splits corresponding to each divided track, which will hereinafter be referred to as channels. As a recording method, first, a tape is run and an audio signal is recorded only on channel 6'. Then, channel /I/7' is recorded in the same manner.

Channels /l/8' to 12' are recorded in the same manner.

Therefore, this recording method is equivalent to cutting the tape into seven pieces, splicing them together, and recording from the end.

In this way, an 8m video VTR can be converted into an audio-only long-time recording tape recorder.

The second feature of this system is that the video tape recorded as shown in FIG. 1 and the channel 3' have the same signal format, so that they can be played back. In other words, audio is compatible with videotape.

The sixth feature is that auto-reverse recording and playback is possible. That is, for example, in FIG. 3, after recording channel 3', the tape running direction is reversed and channel 7' is recorded. Then, the tape running direction is reversed and channel 8' is recorded. In this way, channels from channel 6' to channel 12' can be recorded continuously without rewinding the tape.

A fourth feature is that the quality of the audio signal recorded on channel 3' can be improved using, for example, channel 7'. In the 8+m++ video recording format shown in Figure 1, an 8-bit quantized PCM signal is expected to be recorded on the audio track 6', but 14-16 pit quantization is required for high-fidelity recording. Therefore, the quality of the audio signal on track 3' is naturally insufficient. Therefore, if a corrected quantization signal is recorded to compensate for the rough quantization in channel 7'K and track 3', the signal on track 3' can be compensated for.

The fifth feature, which will be described in detail later, is that it can be edited.

To summarize the above, 1. Long-time (PCM) audio recording 2. Audio from video tapes can also be played back, maintaining compatibility.

3 Auto reverse possible 4 High quality audio is possible 5. Can be edited 05 points are the features of the present invention.

Furthermore, we will discuss the sixth feature. In digital records, protection against data errors as well as the ability to correct them is important. For this reason, a data error detection word is generally added and multiple data writing is performed. Although signal processing theory for this purpose has been developed and is applied to each audio channel in the present invention, its capability is limited by the channel capacity, that is, the number of bits that can be written in one channel. In the present invention, seven channels can be used in the example shown in FIG. Therefore, the signal of one channel can be written to other channels as well. That is, multiple writing becomes possible, and data reliability can be significantly improved. For example, if the data error rate of one channel is 10-3,
This can be improved to about 10-0 by 2-channel multiplex writing.

FIG. 4 shows an embodiment of the multichannel recording method according to the present invention shown in FIG. 16 is a drum. 13 is divided into a rotating drum and a stationary drum, and a magnetic head 14 and another magnetic head 14' facing the magnetic head 14 are attached to the rotating drum.

The rotation of the rotating drum causes the magnetic heads 14 and 14' to sweep the tape width diagonally as shown at 2.

During recording, it is necessary to detect that the magnetic head has reached the end of the tape width and then start writing to the track. At this point, a pulse generator is attached to the rotating drum shaft. 15, 16° and 17 are its constituent elements. 1
5 is a support plate attached to the drum shaft 18, 16 is a permanent magnet piece mounted on the support plate 15, and 17 is an element for detecting the magnetic field of the permanent foundation stone piece 16. 19 is drum 1
6. A motor that rotates the support plate 15 and the like.

The rotation speed and phase of the motor 19 are determined by a reference frequency generator 20.
is locked. 21 is a control circuit for the motor rotation speed and phase. Next, the operation of specifying a predetermined channel and recording and reproducing based on the output of the element 17 will be explained. This will be explained using the time chart shown in FIG. 41 is an output waveform of the magnetic field detection element 17, which generates one pulse per one rotation of the drum. Output pulse 4
1 is waveform-shaped and delayed by the waveform shaping circuit 23 and output as a ζ pulse 42. This delay amount corresponds to the time difference from when the pulse 41 is generated until the magnetic head 14 reaches the end of the track 2. Normally, since there is a mounting angle deviation between the magnetic head 14 and the element 16, the waveform shaping circuit 26 It is adjusted by a variable resistor etc. Pulse 42 is further delayed by delay circuit 25 to become pulse 43. The required amount of delay at this time will be explained. For example, in the multi-channel recording example according to the present invention shown in FIG. 3, the number of channels is seven. Now, if channel 8' is to be recorded, it is necessary to record only the width of channel 8' from the time when the magnetic head finishes scanning channels 6' and 7'. The pulse indicating the beginning of channel 3' is 42. The pulse 46 is delayed by the delay circuit 25 by the time span required to scan the tracks 6 and 7 from the pulse 42.

The channel designation signal is sent to the delay circuit 2 from the terminal 39 in FIG.
5 to specify the above delay amount.

The pulse 43 is input to the pulse generating circuit 26 and is converted into a pulse 44 having a scanning time width of channel 8' in the above example to control the switch 27. Below the pulse 44 in FIG. 5, there is a scale indicating the scanning order of the main channels and the scanning time width. Pulse 44'&'j Channel 6' on the next track (Fig. 3 2') by another force of mountain air
・\This is a control pulse applied to the switch circuit 27' to perform similar writing.

The pulse 46 is applied to the motor control circuit 21 and compared in phase with the output of the reference frequency generator 20, and the motor rotation speed is controlled in proportion to the phase difference, so that the pulse 42 is correctly phase-locked to the reference frequency generator 20. .

A recording signal to the magnetic head is applied to terminal 31, which is, for example, an audio signal. 60 is a digital conversion and digital processing circuit for this voice signal, and the input analog signal is digitally encoded into a predetermined format. The output of the processing circuit 30 is connected by a switch 29 to the R side during recording and to the P side during playback. During reproduction, the output of the magnetic head 14 is taken into the processing circuit 30 and converted into an analog signal.

It is output to terminal 32. The output of the switch circuit 29 is input to the terminal A of the next switch circuit 27.

Terminal B is grounded. The switch circuit 27 is connected to the terminal A during the middle period of the pulse 44 by the pulse 44 shown in FIG.
, and is connected to B during other periods. Therefore, track 8 is recorded as described above.

45.46 in FIG. 5 is a control pulse waveform when recording the 8wn video signal shown in FIG. 1. In this case, the audio signal is applied to terminal 31, and a predetermined channel designation signal is applied to terminal 69 so that it is recorded on channel 6'. Further, the video signal is applied to the terminal 65, undergoes predetermined signal processing in the video signal processing circuit 34, and is output to the R terminal of the switch circuit 66.

The switch circuits 29 and 33 are connected to the R side in the recording mode. The audio signal is sent to the channel 5' by the pulse 45 shown in FIG. 5, and the video signal is sent to the channels 7' to 1.
2' is recorded. Therefore, a recording pattern as shown in FIG. 1 is obtained.

Among the helical recording methods, the two-head method is the most common. In this case, the drum 13 has two rotating heads 14.
i4' is taken up, and tracks 2 and 2' are recorded alternately by each head as shown in FIG. The head 14', switch circuit 27', magnetic head drive circuit 28', switch circuit 38, etc. in FIG. Switch circuit 27' is similarly controlled by control pulses 45', 46'.

As mentioned above, (1) long-time recording and playback is possible; (2) recording and playback of the audio track of the videotape (track 6' in Figure 1) is possible, so tape compatibility with respect to audio is maintained; (6) ) Auto-reverse recording/playback is possible, etc.

Next, we will discuss the fourth feature, which is high quality audio.

When recording a video signal, a PCM (pulse code modulation) audio signal is recorded on the trunk 6'. 6th
The figure shows an example of the configuration of a known analog-to-digital converter that is generally used to PCM encode audio analog signals. The audio signal is applied to the terminal 31, sampled and held by a sample and hold circuit 47, and its output 48 is inputted to a comparator 49.

50 is a digital-to-analog converter, and its analog output 51 is applied to the other input of the comparator 49. The comparator 49 compares the magnitude of the outputs 48 and 51 and controls the successive approximation register 52 based on the output. The output of the register 52 is controlled by controlling the converter 50 so that the output 51 approaches the output 48. 1 digital signal is output. 54 shows an example of allocation of the number of quantization bits when the output terminal 53 outputs 16 bits. As is well known, the number of quantization bits indicated by the number 54 is proportional to the number of quantization bits. However, in the Video I8 recording format shown in Figure 1, the number of quantization bits allocated to the audio PCM channel 6' is scheduled to be 8 bits. , high-fidelity recording requires 14 to 16 bits, and 8 pits is insufficient.In the case of 8-pit recording,
For example, the top eight pits from 2-1 to 2-8 shown at 54 are rounded down. According to the invention, 2″ is truncated.

The lower 8 bits up to 2-16 can be recorded in channels 7' to 12' in FIG. Tame.

For example, referring to FIG. 5, the upper 8 pits can be recorded on channel 3' with reference numeral 45, and the lower 8 pits can be recorded on channel 8' with pulse 44.

In this case, writing is not performed by pulses 46, 46', etc. As described above, the present invention allows high quality recording and reproduction of audio.

In reality, various known compression/expansion techniques are applied to compensate for the 8-bit quantization bit number, and although there are cases where the lower bits are not simply truncated as shown in Figure 6, the truncated bits are By supplementing this, the effects of the present invention can be maintained.

Next, a new tape editing method, which is the fifth feature of the present invention, will be explained. Conventionally, when editing tapes, two tape recorders were prepared, and the signal played from one of them was recorded on the second recorder, which had the disadvantage of requiring two tape recorders, and the problem of the beginning of the playback signal. There was a problem in that there was a lack of precision in the so-called tape feed, which was to align the tape on the recording side at a predetermined position at the time of .

For this reason, a countermeasure has been taken in which a conductive memory device is installed or relayed between the reproduction and recording, but the system including the memory device becomes enormous and expensive.

The present invention solves these difficulties.

Editing accuracy refers to the accuracy of signal splicing.

For this purpose, first, it is necessary to accurately know the beginning and end of the reproduced signal to be edited. At the same time, it is also necessary to know exactly where on the tape this should be recorded.

In digital recording, one sample as shown at 54 in FIG. 6 is called a word. Since each word is recorded one after another on the tape, it is necessary to know the beginning of each word, so a synchronization signal is inserted every many words. A group of words that receive this synchronization signal is called a block. In addition, a block code and other data necessary for identifying the pro 7 are added to the synchronization signal section, and these are called prefix blocks. In addition, a trailing block is also added to the end of the block. A block code can be used to distinguish a block from other blocks.

In the present invention, an additional tape recorder is not required for editing. FIG. 7 is a conceptual diagram thereof. The portion 56 recorded in the channel 3' is once stored in the memory device 57.
VC and then to section 58 of channel 8'. Through such operations, the editing results remain in channel 8'. The case where this operation is performed by dividing block codes will be explained using FIG. 8. FIG. 8 shows a case where the amount of data in the portion 56 exceeds the capacity of the memory 57. In addition, the block code placed at the beginning of the data block is used as an editing indicator.

BC the first block code of section 56 of channel 3'
-I3-The end block code is BC-E3.

Portion 56-6 is a data block whose head is block code BC-B3. Block code BC-■3 and block codes B and C-E5 are specified during editing, and from this, the data amount and memory capacity of portion 56 are compared,
If it is determined that the former exceeds the latter, the portion 56 is divided into portions 56-1 and 56-2 (
To divide. BC-M2R is the last block code of portion 56-1, and BC-M3I is the first block code of portion 56-2. In this way, the portion 56 is divided into a size that allows the memory to be relayed, and then transferred to the channel 8'. In the figure, P and R indicate playback and recording data, respectively. B.C.
-I8 is a block code of data already recorded in channel 8' and is designated in advance for recording the portion 56 following this data block 58-1. Therefore block code BC-I 3, portion 56-1, block code BC-
MBE and section 56-4 are each pronk code BC-I3
'Part 56-1', block code BC-, MBE'
is recorded in the section 56-4'. Then, block code BC-M 3 I, portion 56-2, block code BC-E3 and portion 56-6 are transferred in the same manner. At this time, in order to catch the necessary block code, the tape is rewound and forwarded as appropriate, and this tape forwarding operation can also be performed automatically by determining the block code. Also,
Generally, consecutive numbers are assigned to the block code for each successive data block. Therefore, each block code of channel 3' recorded after block code Be-I5 may be recorded by changing to the gauze number assigned to code BC-I8.

FIG. 9 shows an embodiment in which the operation No. 8- is performed.

It consists of parts extracted from Figure 4 and newly added parts. First, the b raw of channel 3', its head and end block codes BC-I3, BC-E3, etc., and the record of channel 8', its head block code Be-l8, etc. are input to the register 59 from the input terminal 60. put in. Next, when START 5W61 is pressed, a motor starting pulse is transmitted to the tape feed control circuit 62, and the motor 66 is started via the drive circuit 68. Further, register contents regarding channel 3' are input to delay circuit 25 and motor 63. In response, delay circuit 25 generates a timing pulse to select channel 3'. The discrimination control circuit 64 initially rotates the reproducing force to a normal amount in response to the starting pulse. The channel 3' has a magnetic head 14. Switch circuit 27.
29. The block code reproduced through the discrimination 1 discrimination control circuit 64 and the data processing circuit 65 and output from the output terminal o6 is compared with the block code Be-l3 in the discrimination control circuit 64, and its context and distance are determined. If it is towards the front, send it directly to the playback capacity, and if it is too far, rewind it. The command signal is sent to the control circuit 62, and the feeding at this time may be via rapid feed. 68 and 69 are a motor drive circuit and its power supply device, respectively. Further, the control circuit 62 receives a stop signal from the discrimination control circuit 64 and stops the motor. The discrimination control circuit 64 uses block code BC-I.
3. Determine the number of blocks between BC and E3 and store the memory 57
If it is thick compared to the capacitance of , a code BC-M 3B is generated, and when this matches the block code from the output terminal 66, a stop signal is sent to the control circuit 62. Next, it is necessary to write reproduction data into the memory device 57 starting from the code BC-I3. Since the code BC-I3 itself cannot be written after detecting the code BC-I3', the block number before that is detected and the writing wait is performed. The determination control circuit 64 uses the block unit Be − input to the register 59.
Convert I 5 to the block number before the -, and connect terminal 6
6 and detects a match. Then, after the data block length, write control pulse W
is generated and the data taken out from the data processing circuit 65 is written into the memory 57. The write control pulse W returns one cheater block length 56-4 after detecting the code BC-M3B. The code BC-M3E determines the interval between the code BC-I5 and the code BC-IE3, and the discrimination control circuit 64
make it inside.

For example, if the capacity of the memory 57 is equivalent to N data blocks, the block number is set to the code BC- by using a counter.
Code B using the Nth counter output counting from I3
Make C-M3B. This counter is included in the discrimination control circuit 64.

This completes the first memory writing of channel 6' data. The memorized data is then recorded on channel 8'. The end of the W pulse is detected by the pulse edge detection circuit 67, and the switch 61 is closed via the timing circuit 70. Or generate a start pulse and start the motor 6.
3 is controlled in the same manner as described above. Further, the discrimination control circuit 64 receives the code BC-■ sent from the register 59.
8 and the block code from the terminal 66 and one data block length (5B-1) after they match, a read control pulse R is generated and the contents of the memory 57 are sent to the data processing circuit 71. At the same time, the switch 29 is switched from the reproduction (P) mode to the recording (R) mode by R, and the memory output is transferred to the processing circuits 71, 72, switch circuits 29, 27,
The data is recorded on the channel 8' via the magnetic head drive circuit 28 and the magnetic head 14. At this time, a code indicating channel 8' is sent to delay circuit 25 from register 59. This is sent from the register 59, for example, in synchronization with the second motor start pulse.

As a result, data from code BC-Ix of channel 6' to part 56-4 is transferred to code BC-Ix of channel 8'.
I3 to section 56-4'. Data transfer from the twitching code Be-M3I to the portion 56-3 is performed in the same manner, so a detailed explanation will be omitted. In this case, among the contents of the register 59, the code BC-I3 is replaced with the code HC-M3I, and the code BC-I8 is replaced with the code BGM-3I'.

Blocks that have not yet been explained in FIG. 9 will be explained. Reference numeral 69 denotes a waveform shaping circuit for input data of the reproduction system and a synchronization signal extraction circuit. 65 is a data processing circuit in which block codes are separated and outputted to a terminal 66. Reference numeral 71 denotes a recording system data processing circuit, and a synchronization signal and other signals are added to the output data generation/addition circuit at 72.

Note that the explanation of the second magnetic head 14' and the circuits attached thereto shown in FIG. 4 is too complicated and is similar to the above explanation, so the explanation thereof will be omitted.

Also, in the method 1 above, I edited in blocks,
Editing in the middle of a block length can be done in the same way by appropriately inserting a timing circuit, so the explanation will be omitted.

Although the case of multi-channel helical recording and reproducing has been described in FIGS. 7 to 9, the present invention can be similarly applied to other types, such as a fixed 7-domain multi-trunk force type.

[Brief explanation of the drawing]

Figure 1 is a diagram of an 8mm video tape recording pattern, Figure 2 is a diagram of a tape recording pattern showing the recording method of a Philips VTR, Figure 6 is a diagram of a tape recording pattern according to the present invention, and Figure 4 is a diagram of a tape recording pattern according to the present invention. A block diagram showing an embodiment of the present invention, FIG. 5 is a time chart for recording, FIG. 6 is a block diagram of a well-known analog-to-digital conversion circuit, and FIG. 7 is a conceptual diagram of the tape editing method according to the present invention. FIG. 8 is a supplementary diagram of FIG. 7, and FIG. 9 is a block diagram showing an embodiment of the present invention. 1... Tape 2... Trunk (2'... Adjacent track) 3.
...Audio track 4...Video trunk 5.6...Track 5.6'...Channel 7-12...Tracks 3' and 7'-12 obtained by dividing track 2...Tracks 6. Channel Tt corresponding to 7-12 Figure T + Figure f 5 Diagram of Figure 4 (A) '7'7 Figure f/ 1'8 Figure 1) C-M31

Claims (1)

[Claims] 1. In a video tape recorder that uses a helical recording method and divides the length of the recording track on the tape into two and records the audio signal on one side and the video signal on the other, the video signal track is further divided into a plurality of parts and the length of the recording track is divided into two. A tape subdivision recording recorder characterized by recording audio signals in each subdivision.