JPH02146169A - Rotary head type pcm signal recording/reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce character information by determining a recording format on a pack with attributing an item for the character information, a character code and ancillary information as a sub-code. CONSTITUTION:The two retrieving and normally reproducing pack items of the character information are used. The normally reproducing pack item is set at '1000,' the retrieving pack item is set at '1001,' and for the character code and the ancillary information of the character code, an address at four bits, character contents at three bits, a character type at four bits, and a pit indicating the pair of the character codes at one bit are allocated, and they are recorded. By the sub-code of the character information determined in such a way, the character information can be recorded and reproduced by a digital audio tape recorder, and a music name, a singer's name and a text can be displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to, for example, a subcode format of an apparatus for recording an audio signal as PCM or reproducing a PCM recording.

[Conventional technology]

As a digital audio chip recorder, audio signals are converted into PCM (Pulse Code Modula)
tion) signals, which are recorded on a magnetic tape using a rotating head. This is DAT (Di
Gi tal Audi.

This is called a tape recorder, in which a tape is wound 90 degrees around a small drum with a diameter of about 30 fm, and two rotary heads with different azimuths placed 180 degrees apart are connected to a drum with a rotation speed of 201 rpm, for example.
It is rotated by m. The two rotary heads alternately scan the tape and record the PCM signal intermittently every 90° wrap angle of the drum.

, the audio signal has a sampling frequency of 48) G
(Sampled with z, and quantizes each sample value with 16 bits to generate a PCM audio signal.

This PCM audio signal is time-compressed during the rotation of the drum by the 90° wrap angle every 1/2 rotation time of the rotary head, and is recorded as one diagonal track on the tape by the rotary head. . Also, during playback, the PCM audio signals from the two rotating heads are decoded and expanded to the original time axis, and then
It performs digital-to-analog conversion to return the signal to an analog audio signal. In this case, each track contains not only a PCM audio signal, but also a tracking servo signal during playback, and subcodes such as a time code and a program number inserted at the beginning of a song, which are separate from the PCM audio signal. recorded in the area. Based on this subcode, the longitudinal position of the tape can be known during playback, and the beginning of the tape can be found using the search mode.

For example, when recording music using DAT, it is recorded according to the track format and block format shown in FIGS. 3 and 4. In this case, a subcode including a program number, position information such as a time code, and other necessary auxiliary data may be recorded at the same time.

As shown in Fig. 3, one track consists of 196 blocks, with the PCM audio data recording section at the center, an ATF period on both sides in which a pilot signal for tracking is recorded, and an auxiliary data outside the ATF period. A subcode period is provided for recording. P
A PLL period for synchronization is provided in each of the CM period and the subcode period, and a gap is provided between the PCM period and the subcode period, and the timing of recording, playback, and playback modes is determined in this gap. By combining the PCM audio signal or subcode signal, it is possible to record the PCM audio signal or subcode signal independently. Note that the numbers shown in FIG. 3 indicate the number of blocks in each period.

FIG. 4 shows the format of a subcode block, and one subcode block is composed of 288 bits like a PCM data block.

As shown in the figure, the first 8 bits of one block are the block synchronization signal 5YNC, the next 8 bits of data W are the subcode ID, and the next 8 bits of data are the subcode ID and the address of the block. The next 8 bits are the error correction parity P generated for the data w1 and W, and the remaining 256 bits (consisting of 32 symbols as 8 bits form one symbol) are the subcode data. This is the error correction parity generated for it.

The 8-bit data W1 and W are as shown in FIG. 4 in more detail.

That is, the MSB of the data block is used to determine whether the block is a subcode block or a PCM data block, and if it is a subcode block, it becomes "1" as shown in the figure. Further, the lower 4 bits of data W8 are a block address, and the contents of the subcode ID differ depending on whether the LSB is "0" or "1". Block address LS
When B is r(l, data W1 consists of a 4-bit control ID and a 4-bit data ID, and the upper 3 bits of the block address of the data town are the format ID.
It is said that

The above-mentioned start signal is recorded as one bit of the control ID, and when it is "1" it indicates the beginning of the song, and when it is "0" it indicates the middle of the song.

When the LSB of the block address is 1-1, data W! and data W! The upper three bits indicate the program number. In this case, the program number is represented by a 3-digit BCD code, and the upper 3 bits of the block address of data W2, PNO-1, are the most significant digit, and the upper 4 bits of data W, No-2 are the middle digit. , the lower 4 bits PNO-3 represent the lowest digit, and the program number is from [001] to (799,1
is expressed up to. Note that (neo) indicates that the program number is not recorded, and [OAA] indicates that the program number is invalid.

Four subcode blocks of which the LSB of the block address is "0" and four subcode blocks of which the LSB is "1" are alternately recorded out of the eight blocks of each subcode area SUB.

Writing the program number based on the start signal mentioned above means that if the start signal in the control ID of Wl, which is subcodes I and D, is "1" or not, it is detected that it is "1". A program number is written in a subcode block with the LSB of the block address being "1" ([ooo] is rarely used, but it is sequentially rewritten for each song).

FIG. 5 shows the pack format, which is composed of 64 bits obtained by dividing 256 bits of subcode data into four units. Broadly dividing the inside, there are 4-bit packed items, 52-bit packed data, and 8-bit packed parity. The back item is used to determine what the pack data means, and currently the back item '0001' is used as the program time that indicates the elapsed time within the program song.
100101 is the total recorded time of the program.
011" is a running time indicating an arbitrary time,
The TOC (Table of Control) shows the total number of programs in which "0100" is recorded on the tape and the start position of each program in absolute time.
ents) As information, '01fl! 'As a back item such as a date indicating the date it was recorded'
0001' to "0111" are determined. Also, back item '1111' is scheduled to be used for a pre-recorded tape in the future.

[Problem to be solved by the invention]

However, there was a problem in that the DAT could not record or reproduce text information because no text information item was assigned to the pack in the subcode of the DAT, and the recording format for the text information was also not determined.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a device that can record and reproduce single-character information, as well as search using character information.

[Means to solve the problem]

The recording and reproducing apparatus according to the present invention is configured to reproduce character information by determining an item and a recording format for character information in a pack as a subcode.

C Effect] The subcode of character information in this invention is controlled by the system controller and recorded and reproduced.

[Embodiments of the invention]

First, the recording format of character information will be explained.

Two text information pack items are used: one for normal playback and one for search. FIG. 2(4) shows the back format of character information for normal reproduction. Items in the pack are PCI
'1000' shown in B7 to B4 of B3 to 4 of BO
Bits are used as address information. Character codes are recorded from PO2 to PO7, and from B3 of PO2 to 4 of BO
The bit means the character type, and indicates whether the character code is recorded as an ASCII code or a Kanji code. B4 of PO2 is character code 1
Used when the data is represented by 16 bits. In other words, if one of the character codes is completed with 8 bits like ASCII code, it can be handled with 8 bits each from PO2 to PO7, but if one of the character codes is 16 bits like Kanji etc., PC3~ Any of the PC7s will be used in two pairs.

In this pair, for example, B4 of PO2 is 101, and PO2 and P
Consists of O4, PO5, PO6, PO7 and the next character information pack PCB, B4 of PO2 is 111 and PO4 and P
O5, PO6 and PC? , PO2 and the previous character information pack PC? Consists of. The 3 bits B7 to B5 of PO2 represent the character content, and are made to indicate whether the character code represents the title of the song or the genre of the song. If one of the character codes is represented by 8 bits, one pack contains five characters, and if one of the character codes is represented by 16 bits, two packs contain five characters. In addition, the address information can continue the character code by repeating ``1111'' from ``oooo'', and thereby there is no limit to the maximum number of characters that can be recorded.

@Figure 2 (b) is the back format of character information for search. The pack items are "1001" shown in PCI B7-B4, PCI B3-BO and PC2 B
The contents of 7 to BO are the same as for the pack item "xono@.The character code of the pack in this mode is recorded from PC3 to PC7, and the same content is recorded for about 300 frames, for example. The content of the character code is, for example, if the pack item is '100'.
0' and address information 'oooo'.

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is an overall block diagram of an example of a recording and reproducing apparatus to which the present invention is applied. First, the signal system will be explained. During recording, the input analog audio signal is filtered through a low-pass filter (
After being band-limited in step 2), it is supplied to A/D and D/A converter circuit 4 and converted into a digital signal, which is then supplied to the encoder section of error correction encoder and decoder circuit 4 and converted into a PCM signal for each block. While being converted, interleaving processing, parity for error correction, addition of block synchronization signals, block address signals, and insertion of subcodes are performed. In recording subcodes of character information, the system controller C (hereinafter referred to as system controller) in (b) inputs character information in advance from the input device Oη equipped with various character keys and various operation buttons, and corrects errors as appropriate during recording. Supplied to the encoder section of the encoder and decoder circuit (a).

At the time of recording, the switch circuits (1) and 4 are switched to the recording side REC by a switching signal from the circuit (5) in synchronization with the switching of the circuit (2) to the encoder. Then, from the circuit bone, the PCM audio signal, which is a half-rotation signal of the audio signal head HA or HB, is time-compressed into 90' rotations with parity etc. This is obtained in the contact section, and this is the switch circuit (goods), the recording amplifier (2),
The signal is alternately supplied to the rotary heads HA and HB via the switch circuit (to) and the head changeover switch circuit, and is sequentially recorded as diagonal tracks on the tape (3).

The head changeover switch circuit (to) is set to 1/2 so that a PCM signal compressed in time for 90° rotation is supplied to the head that contacts the tape (3) in response to the head changeover signal from the circuit (2). It is alternately switched to side A and side B every two rotations.

Next, at the time of playback, the switch circuits (goods) and (to) are switched to the PB side by a switching signal from the circuit bone, and the head changeover switch holder is switched to the rotating head HA as in the case of recording.
and HB are alternately switched to the B side that contacts the tape (3). Then, the PCM signal reproduced from the tape (3) by the heads HA and HB is supplied to the reproduction process circuit (Incorporated) via the reproduction amplifier Sakaki, where it is subjected to reproduction equalization processing and bit synchronization, and converted into digital data. The signal is shaped and a reproduced clock is obtained by a PLL circuit.

The PCM data from this reproduction process circuit (2) is supplied to an error correction encoder and decoder circuit (4). During this playback, the circuit works as a decoder, and the PC
The M signal is subjected to error correction and the like and then decoded.

The decoded PCM signal is returned to an analog signal in the D/A converter section of the A/D and D/A converter (A), and the audio signal is reproduced through a low-pass filter.

Further, subcode information such as character information is extracted by the system controller aυ. That is, the pack item is °10(1
Character information of 0' and °1001' can be obtained.

Next, to explain the head drum, tape running control system, etc., (1) shows a drum, and this drum (1) has two rotating heads HA and HB separated by 180 degrees.
), and the drum motor M normally has a speed of 200 (lrpm).
It is rotated in a constant direction at a rotation speed of .

(2) is a rotation detecting means of the drum motor (1), from which a frequency signal DFG proportional to the drum rotation number (head rotation speed) and a signal Dpc indicating the head rotation phase are obtained.

(3) is a magnetic tape, which is unwound from a supply reel (4) and is wound diagonally around a 90° angle range of the surface of the drum (1).
) and is wound onto the take-up reel (5).

Capstan (6 is the capstan drive motor M.

It is rotated and the tape is fed.

(8) is a rotation detecting means of this motor M, from which a frequency signal CFG proportional to the rotation speed of the motor M can be obtained.

M3 and M4 are reel motors that drive reels (4) and (5), respectively, and the rotational speeds of these motors M3 and M4 are detected by rotation detection means (9) and Q(1), and from this, the rotational speed is determined. Frequency signals TS and TT proportional to are obtained.

Further, @ is a capstan and drum servo circuit, 口 is a reel drive control circuit, Q41 is an arithmetic unit for reel drive control, 4 is a search control circuit, and aQ is a brake means.

Further, (7) is a display that displays the tape running direction, recording/playback display, program number, character information, etc.

The signal DyG indicating the rotation speed of the rotating heads HA and HB from the rotation detection circuit (2), the signal DPC indicating the rotation phase, and the signal Cpc indicating the rotation speed of the capstan (63) from the rotation detection circuit (8). This servo circuit (b) receives the signal from the system controller East and generates a signal to control the rotational speed and rotational phase of the motor M1 during recording and normal playback. A signal is generated to the motor M to keep the tape feeding speed constant.

Input device Q for high-speed search? This is done by comparing the target character information set in ) with the character information whose back item is '1001' in the subcode extracted from the reproduced signal.

During high-speed search, the envelope detection output of the reproduced RF (high frequency) signal from the reproduction amplifier (to) is supplied to the search control circuit (to), and the reproduced clock signal from the reproduction process circuit (to) is supplied to the search control circuit (to). b). The playback RF signal is the PCM audio signal on the tape (3)
In the no-signal part, the subcode output supplied from the error correction encoder and decoder circuit to the system controller αη is ignored. The reproduced clock signal is used as a reference for keeping the frequency constant when performing servo to keep the relative speed of the head and tape constant. When the tape is fed, for example, at a speed of 200 times, a signal from the system controller (b) is supplied to the reel drive control circuit port and also to the arithmetic unit a4.

On the other hand, the rotation detection circuit (9) and the rotation detection circuit (A) are connected to the arithmetic unit A barrel for the reel motor and the reel motor M.
Frequency signal Ts and frequency signal T proportional to the rotation speed of 4
t is supplied. The arithmetic circuit unit compares the frequency reference value at 200x speed with the frequency signal 'rs and one frequency signal, and based on the comparison output, the reel drive control circuit Q controls the reel to feed the tape at a constant tape speed. A drive signal is supplied to the motor M and the reel motor M. At this time, the capstan (6) and the pinch roller (7) are separated, and the tape is fed at high speed only by the reel (4) and reel (5). At this time, the capstan drum servo circuit 4 uses signals from the system controller (6) and signals from the search control circuit to keep the reproduced clock frequency constant, that is, to keep the relative speed between the head and the tape constant. The drum rotation speed is controlled so that

In addition, in the above example, the item of the pack is heated to 11000°.
``1001'' was used, but other items with no use may be used.

〔Effect of the invention〕

As described above, according to the present invention, by determining the text information items and recording format in the subcode pack, text information can be recorded and played back, and song titles, singers, etc.
It has the effect of displaying lyrics.

[Brief explanation of the drawing]

FIG. 1 shows a rotary head 2 PCM according to an embodiment of the present invention.
An overall block diagram of the signal recording and reproducing device, Figure 2 is a back format diagram of character information for normal reproduction of this invention,
The second drawing is a back format diagram of character information for searching according to the present invention, the third diagram is a track format diagram of a rotary head type PCM signal recording and reproducing device, and the fourth diagram is a diagram of a rotary head type PCM signal recording/reproducing device.
FIG. 5 is a diagram showing the format of the subcode block of the CM signal recording and reproducing apparatus. FIG. 5 is a diagram showing the back format of the rotary head type PCM signal recording and reproducing apparatus. In the figure, East is a system controller, C is an input device, (7) is a display, and Q is an error correction encoder and decoder circuit. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] A rotary head type PCM signal recording and reproducing device that uses an audio signal as a main signal and records on or reproduces from a recording medium a program number of the audio signal and subcode information such as a program start signal indicating a start position of the audio signal. In addition, two pack items are provided that indicate character information in the contents of the pack in the subcode information, and each includes a 4-bit address, 3-bit character content, and 4-bit address as a character code and additional information of the character code. A rotary head type PCM signal recording and reproducing device characterized in that it is possible to record by allocating character types and bits indicating pairs of 1-bit character codes.