JP2514182B2 - Magnetic recording device - Google Patents

Description

The present invention relates to a magnetic recording device suitable for use in recording information signals such as PCM audio signals.

[Conventional technology]

Conventionally, a magnetic tape of a tape cassette is obliquely wound around a tape guide drum having a rotary magnetic head, and a plurality of inclined tracks are sequentially formed in opposite directions in both tape areas divided by a center line of the magnetic tape. As described above, a magnetic recording / reproducing apparatus has been proposed in which a PCM audio signal is recorded and reproduced.

4 and 5 show the rotary magnetic head device,
(1) is a magnetic tape of a tape cassette, (2) is a tape guide drum, for example, upper and lower fixed drums (3), (4)
And a rotary drum (5) arranged between them and equipped with a rotary magnetic head (6). The tape guide drum (2) may be composed of a fixed lower drum and a rotating upper drum provided with a rotating magnetic head. (9) is a rotary drum drive motor. (7) and (8) are guides for determining the winding angle of the magnetic tape (1) with respect to the tape guide drum (2), and the magnetic tape (1) of the tape cassette which can be turned inside out has a winding angle of 90 °, for example. Thus, the tape guide drum (2) is obliquely wound around the cylindrical surface.

In this case, a conventional magnetic recording apparatus records information signals in both tape areas of the magnetic tape (1) as shown in FIG.

That is, in FIG. 6, L is the center line, (1A),
(1B) is the two tape areas divided by the center line L of the tape (1), and A and B are the opposite running directions of the tape (1) at the time of recording / reproducing of the both tape areas (1A) and (1B). , T _A , T _B are inclined tracks formed by sequential recording in both tape areas (1A), (1B), and a, b are the scanning directions of the rotary magnetic head (6) with respect to the inclined tracks T _A , T _{B, respectively} . Show. Further, in the inclined tracks T _A and T _B , the time axis direction of the information signal recorded therein is from the hatched area to the non-hatched area. Rotating magnetic head (6)
Scan directions a and b are the same, and the time axis directions of the inclined tracks T _A and T _B are opposite to each other.

To record a magnetic tape (1) having such a recording pattern by a magnetic recording device, the tape running directions are made different in both tape areas (1A) and (1B), but the rotating magnetic head is made to rotate in the same direction.

In this case, there is no problem in the tape area (1B), but in the tape area (1A), the information signal to be recorded, that is, the PCM audio signal is inverted in the time axis for each unit signal section recorded in the one inclined track. There is a need. Therefore, the inverting circuit (20) is shown in FIG. In FIG. 7, (10) is a memory (RAM), which supplies an audio signal from the input terminal (11) to a PCM encoder (12) to convert it into a PCM audio signal, and then to this memory (10). Supply and write. At the time of writing, the address signal from the write address counter (13) is supplied to the memory (10) via the multiplexer (14). The write / read control signal from the input terminal (15) switches the write / read mode of the memory (10) and the write / read address signal of the multiplexer (14) in an interlocking manner.

(16) is a read address counter, which is configured as an up / down counter and is a down counter when recording on the tape area (1A) of the magnetic tape (1) based on a control signal from a control signal input terminal (17). To the up counter when recording on the tape area (1B). The read address signal from the read address counter (16) is supplied to the memory (10) via the multiplexer (14).

Then, if the read output from the memory (10) is supplied to the rotary magnetic head (6) via the amplifier (18), it is possible to change the tape running direction without changing the rotating direction of the rotary magnetic head (6). , Tape area of magnetic tape (1) (1
It is also possible to record the PCM audio signal by quick reverse so that the inclined tracks T _A and T _B are formed in A) and (1B).

A magnetic reproducing device (having a tape guide drum having a rotating magnetic head, similar to the magnetic recording device) for reproducing the magnetic tape (1) shown in FIG. 6 may be either an auto-reverse type or a unidirectional type. , The inverting circuit becomes unnecessary.
However, the scanning direction of the rotary magnetic head (6) at the time of reproducing the inclined track T _A of the tape area (1 _A ) is the opposite direction to a.
Therefore, not only the tape running direction but also the rotating direction of the rotary magnetic head (6) can be switched at the time of reverse of the automatic reverse type magnetic reproducing apparatus.

[Problems to be solved by the invention]

By the way, as described above, in the case of the conventional method in which all the data after modulation for one track is written in the memory and the read address is inverted and recorded, there is no restriction in the modulation / demodulation method and the CRCC is used.
It is possible to generate and inspect normally from the front, but it is necessary to invert a large amount of data for one track (one field) at a high speed and to have a high-speed memory for two tracks per channel. For example, 384 bits ( Number of bits per block) x 2 (for example, when TW = 0.5T) x 128 blocks x 2
A high-speed memory of track x 2 channels = 384K bits was required.

The present invention has been made in view of the above points, does not require a large-capacity high-speed memory, and can be used in a modulation method such as so-called convolutional modulation that can be modulated only before, and
It is intended to provide a recording device capable of serially performing CRCC generation and inspection as usual.

[Means for solving problems]

The magnetic recording apparatus according to the present invention is such that a magnetic tape is obliquely wound around a tape guide drum equipped with a rotary magnetic head,
A plurality of slant tracks are sequentially formed in one tape area divided into two parts by the approximate center line of the magnetic tape by running the tape in one direction, and the other tape area divided into two parts by the approximate center line is formed. In a magnetic recording apparatus in which an information signal is recorded so that a plurality of inclined tracks are sequentially formed by running a tape in a direction opposite to one direction, a unit recorded on the one inclined track generated by an encoder. The rotating magnetic head includes the reversing means (23) for reversing the order of blocks having a predetermined length shorter than the signal section, and the reversing means (30) for reversing the time axis of the output of the reversing means for each block. When recording the information signal on both tape areas of the tape, the rotating magnetic head is rotated in the same direction, and both tape areas are scanned, so that the tape travels in one direction. At the time of recording the information signal on one tape area, the information signal is reversed in block order by the reversing means (23), and then the reversal output is reversed by the reversing means (3
The time axis is inverted for each block by 0) and is supplied to the rotary magnetic head, and at the time of recording the information signal in the other tape area by the tape running in the reverse direction, the information signal is inverted by an inversion means (30). The information signal is supplied to the rotary magnetic head without passing through and the information signals are sequentially recorded in both the tape areas.

[Action]

Since the data to be recorded on the recording medium (1) is inverted on the time axis for each block of a certain length in the inversion means (30),
Quick reverse is possible, and a large amount of high-speed memory is unnecessary.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.
A detailed description will be given with reference to FIG.

FIG. 1 shows a circuit configuration of this embodiment. An audio analog signal from an input terminal (21) is converted into a digital signal by an analog / digital (A / D) conversion circuit (22) and then an encoder (23). Then, necessary signal processing such as addition of error correction code, interleaving or compression of time axis is performed. The signal subjected to this signal processing is modulated by the modulator (24) based on a predetermined modulation method, and then when the recording state is forward, for example, the tape area (1B) of the magnetic tape (1) is the tape. When the recording is performed in the traveling direction B, the electric power is supplied to the rotary magnetic head (27) through the contact a side of the switch (25) and the recording amplifier (26).

On the other hand, when the recording state is the return path, for example, when the tape area (1A) of the magnetic tape (1) is recorded in the tape running direction A, the order of blocks in one track generated by the encoder (23) is changed. The time axis is reversed for each block by the reversing means (30) as described below and supplied to the rotary magnetic head (27) via the recording amplifier (26) through the contact point b side of the switch (25). To be done.

The encoder (23) is configured to reverse the order of blocks in one track by changing the order of reading data from the memory in the encoder. That is, the encoder (23) is provided with a memory for temporarily storing the input data in order to perform interleave processing for rearranging the input data in an order different from the input order, and the capacity of this memory is at least one track. It has a capacity to store data (128 blocks per track in this example). Then, when the data is finally read in block units from the memory in the encoder (23), a process of reversing the block order in track units is performed. As the control for reversing in units of one track, the counting order of a counter (this counter repeatedly counts the number of blocks constituting one track) for generating data for determining the block number to be read from the memory, Count up when traveling in the forward direction,
The block numbers are incremented by one so that the first block, the second block, the third block, ... The 128th block, the first block ,. Also, when traveling in the backward direction, count down,
The block number is subtracted by 1 from the maximum value, so that the 128th block, the 127th block, the 126th block,
The first block, the 128th block, and so on are read repeatedly.

The inverting means (30) detects edge information from the output of the modulator (24) (“1” for inversion, “0” for non-inversion), an edge detection circuit (31), and this edge detection circuit (31) Serial output that converts the serial signal from a serial signal to a parallel signal
A parallel (S / P) conversion circuit and a memory (33) into which a parallel signal from this S / P conversion circuit (32) is written and read when necessary, and a write / read address of this memory (33) (however, , An address counter (34) consisting of an up / down counter, a sync signal detection circuit for supplying a sync signal (Sync) as a reset pulse to the address counter (34), and a read mode. A read / write switching circuit (36) for switching between a write mode and a write mode; an exclusive OR circuit (37) for giving the most significant address bit to the memory (33) in response to the output of the switching circuit (36); (33)
A parallel-serial (P / S) conversion circuit (38) that converts the parallel signal read from the
It is provided on the output side of the / S conversion circuit (38) and comprises a toggle circuit (39) which inverts the output when the input is "1" and keeps the output as it is when the input is "0".

Next, the operation of the reversing means (30) will be described with reference to FIGS. 2 and 3.

The number of blocks per track is 128, and one block consists of a sync signal (Sync) (1 word), block address (1 word), flag (1 word), data (16 words).
Word), parity (4 words), CRC (1 word)
It consists of 24 words (1 word is 16 bits). In FIG. 2A, one block is typically represented by a sync signal and data. Then, as shown in FIG. 2B, the data per block is divided into, for example, 48 pieces of data (8 bits per piece). D _{101 to} D ₁₄₈ are 48 pieces of data of the first block, and D _{201 to} D ₂₄₈ are 48 pieces of data of the second block.

The address counter (24) is reset by the reset pulse from the sync signal detection circuit (35) as shown in FIG. 2G, and at the end of one read / write cycle, that is, read / write for one address is completed. Each time the clocks as shown in FIG. 2H generated by the switching circuit (36) are counted, and when the count value is counted 48 in this case, a carry signal as shown in FIG. 2I is generated. Supply to the switching circuit (36). The supply of the carry signal causes the switching circuit (36) to move to the address counter (34).
An up / down switching signal as shown in FIG. 2D is supplied to the up / down switching terminal / D. In FIG. 2D, the low level corresponds to the up mode and the high level corresponds to the down mode.

Further, from the switching circuit (36), the read / write switching terminal R / of the memory (33) is read / written as shown in FIG. 2C.
A switching signal for writing is supplied. In FIG. 2C, the high level corresponds to the read mode and the low level corresponds to the write mode.

The up / down switching signal and the read / write switching signal from the switching circuit (36) are exclusive OR circuit (37).
, And a signal as shown in FIG. 2E is obtained at its output side. "1" and "0" of this signal represent the most significant address bits for the memory (33).

Now, according to the address excluding the most significant bit from the address counter (34), as shown in FIG.
If the 0th address is being accessed, the read / write switching signal is at the low level in the write mode when the most significant bit is "0", and the data D ₁₀₁ is written at the 0th address. Further, as shown in FIG. 2F, when the address 1 of the memory (33) is being accessed, the read / write switching signal is at the low level in the write mode when the most significant bit is "0" at this time. Data D ₁₀₂ is written in the address. The same procedure will be performed for the following addresses 2 to 47. 2
Data D _{103 to} D ₁₄₈ are written in the addresses to 47, respectively.

Next, when writing of one block is completed, a carry signal (I in FIG. 2) is generated from the address counter (34),
In response to this, an up / down switching signal (FIG. 2D) is supplied from the switching circuit (36) to the address counter (34), and the address counter (34) switches from the up mode to the down mode. As a result, the output of the exclusive OR circuit (37) is also inverted as shown in FIG. 2E.

Then, by the address excluding the most significant bit from the address counter (34), as shown in FIG. 2F, the memory (33)
When the address 47 is being accessed, the read / write switching signal is at the high level in the read mode when the most significant bit is “0”, and thus the data D ₁₄₈ written at the address 47 is read. When the most significant bit is "1", the read / write switching signal is at the low level and in the write mode, so that the data _D201 is written at the address 47. When address 48 of the memory (33) is being accessed as shown in FIG. 2F, the read / write switching signal is at high level in the read mode when the most significant bit is "0" at this time. The data that was written in D ₁₄₇
Is read. And when the most significant bit is “1”,
The read / write switching signal is at the low level in the write mode, so that the data D ₂₀₂ is written at the address 46. Less than
The same operation is performed for the addresses 45 to 0, and the data D _{146 to} D _101, which were respectively written to the addresses 45 to 0, are read out, and the data D _{203 to} D ₂₄₈ are written.

FIG. 3 shows the data write / read states corresponding to the address addresses 0 to 47 made as described above. When the most significant bit of the address is "0" and the address counter is in the up mode, the address is 0. No. 47 at data D ₁₀₁ ~
When D ₁₄₈ is written and it is in down mode, it is 0 from address 47
The data D _{148 to} D ₁₀₁ written in the address are read. That is, it can be seen that the time axis is inverted for each block.

In this way, the data read from the memory (33) is converted by the P / S conversion circuit (38) from a parallel signal to a serial signal every 8 bits, and when the input is "1" in the toggle circuit (39). Is inverted, and when the input is "0", it is output as it is. Then, it is supplied to the rotary magnetic head (27) through the contact (b) side of the switch circuit (25) and the amplifier (26).

For reproduction, the configuration opposite to the case of this recording may be considered. For example, although not shown, a rotary magnetic head for reproduction and a reproduction amplifier are provided on the input side of the edge detection circuit (31), and one switch (25 ) Is equipped with a demodulator, a decoder and a D / A converter on the common terminal (output) side, and when the playback state is forward, the switch (25) is connected to the contact a side to directly output the playback signal, and the playback state When is the return path, the switch (25) may be switched to the contact b side and output via the inverting circuit (30).

In the above-mentioned embodiments, the magnetic recording / reproducing apparatus has been described as an example, but the present invention is not limited to this, and is similarly applicable to other systems such as an optical recording / reproducing apparatus.

〔The invention's effect〕

As described above, according to the present invention, since the data to be recorded on the recording medium is time-axis-inverted for each block of a certain length, it is not necessary to invert a large volume of data for one track at high speed, and high speed is achieved. You can make the RAM or shift register smaller. Incidentally, the conventional method in which the time axis is reversed for each track requires a high-speed memory with a large capacity of 384 Kbits as described above, but with the present invention, a small capacity of 1/128 3Kbits can be used.

Also, since the time axis is inverted for each block, a modulation method that can be modulated only before, such as convolutional modulation (for example, M ² , M
3, HDM-1, -2, etc.) can be used, and CRCC
Generation and inspection can be done serially from before as usual.

[Brief description of drawings]

1 is a block diagram showing an embodiment of the present invention, FIGS. 2 and 3 are diagrams for explaining the operation of FIG. 1, and FIGS. 4 and 5 are conventional tape guide drums. 6A and 6B are a plan view and a front view, respectively, FIG. 6 is a pattern diagram showing an example of a recording pattern according to the conventional method, and FIG. 7 is a block diagram showing an example of the conventional method. (1) is a magnetic tape, L is a center line, (1A) and (1B) are both tape areas, T _A and T _B are inclined tracks, (2) is a tape guide drum, (6) is a rotary magnetic head, (30) is a reversing means.

Claims (1)

(57) [Claims] 1. A magnetic tape is obliquely wound around a tape guide drum having a rotary magnetic head, and a plurality of magnetic tapes are sequentially unidirectionally run in one of the two tape areas divided by a substantial center line of the magnetic tape. While forming the inclined track of
In a magnetic recording apparatus, an information signal is recorded so that a plurality of inclined tracks are sequentially formed in a tape running in a direction opposite to the one direction in the other tape area divided into two by the approximate center line. A reversing means for reversing a block order of a predetermined length shorter than a unit signal section recorded on the one inclined track generated by the encoder; and reversing means for reversing the time axis of the output of the reversing means for each block. When recording the information signal on both tape areas of the magnetic tape by the rotating magnetic head, the rotating magnetic head is rotated in the same direction and both tape areas are scanned, and the tape is run in one direction. At the time of recording the information signal on the one tape area, the block order of the information signal is reversed by the reversing means, and then the reverse output is reversed. The time axis is inverted for each block by the means and supplied to the rotary magnetic head, and at the time of recording the information signal in the other tape area by the tape running in the reverse direction, the information signal is not passed through the inversion means. The magnetic recording apparatus is characterized in that the information signal is supplied to the rotary magnetic head and the information signal is sequentially recorded in both the tape areas.