JP2565222B2 - How to play magnetic tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A Industrial field B Outline of invention C Conventional technology D Problems to be solved by the invention E Means for solving problems (Fig. 1) F Action G Example G ₁ Circuit configuration (Fig. 1) ) G ₂ main body structure (Fig. 2) G ₃ display details (Fig. 3) G ₄ music scan related operation (Figs. 4 and 5) H Effect of the invention A Industrial field of application The present invention relates to a magnetic tape reproducing method suitable for use in a tape deck, a disc player, and the like.

B Outline of the Invention In the present invention, when a specific operation button is pressed during the operation of reproducing only the beginning of the music from the first music one after another (hereinafter referred to as music scan), the reproduction mode is set as it is. During the search for the song, the operability is simplified by entering the playback mode from the beginning of the song that has just been played.

C Conventional Technology A rotary head is known as a digital tape recorder for recording an audio signal on a tape as a PCM signal.

This is called R-DAT and has a diameter of 3
The tape is wound around a small drum of about 0 mm by 90 °, and two rotary heads having different azimuths arranged at 180 ° are rotated at, for example, 2000 rpm, and these two rotary heads are alternately rotated 90 ° on the tape. Intermittent scanning is performed for each lap.

On the other hand, when the audio signal
Sampling at kHz, each sample value is linearly quantized by 16 bits to generate a PCM audio signal, which is time-compressed to 90 ° wrap angle every 1/2 rotation time of the rotating head, Is recorded as one diagonal track. At the time of reproduction, the PCM signals from the two rotary heads are decoded, expanded on the original time axis, and then restored to analog audio signals.

In this case, not only the PCM data but also the tracking servo signal during playback, as well as the subcodes such as the time code and the program number inserted at the beginning of the song, etc., are recorded on each track in an area different from the PCM data. You.

FIG. 6 shows the tape format of the R-DAT, in which the PCM audio signal is recorded on each track T within a 90 ° angle range.
Is recorded in an area PCM of a little less than 60 ゜, and two areas ATF on both sides of this area PCM (about 2.3
In ゜), a pilot signal for tracking servo is recorded. Further, a subcode is recorded in two areas SUB (each about 5 °) on both sides on the outside.

The pilot signal area ATF and the sub-code area SUB for the tracking servo thus have two upper and lower tracks.
The reason for this is to cope with dropouts and to make it possible to pick up sub-codes as much as possible during high-speed search.

Note that a guard area is formed between the areas PCM, ATF and SUB, and a head area and an end area of each track are a margin area.

The program number among the subcodes is recorded at the beginning of each song for several seconds, for example, as follows.

That is, at the time of recording, when recording is started from the stop state or the pause state, the start ID signal is recorded for the first 9 seconds, for example. During recording, the start ID signal is recorded at the beginning of the next song when a non-signal section between the songs lasts for more than 2 seconds, for example.
It is recorded in seconds. In addition, recording is performed at an arbitrary position (for example, at a position considered to be the beginning of a song) by a user's button operation during recording. The recording of the start ID signal by the manual operation by the user can be performed even during reproduction.

Thus, at the beginning of the song, the tape on which the start signal was recorded as part of the subcode in the area SUB was rewound,
In the program number recording mode, the device searches for the start ID signal from the beginning of the tape,
An operation of sequentially rewriting signals to program numbers is performed. Therefore, when a start ID signal is recorded at the beginning of each song, a serial number is written in the subcode area SUB as a program number for each song from the beginning of the tape.

In this case, eight subcode blocks are written in each subcode area SUB, but subcodes having the same contents are written in the upper and lower areas of one track.

FIG. 7 shows the format of a subcode block, and one block of the subcode block is composed of 288 bits like the PCM data block.

Then, as shown in FIG. 7 A, 1 8-bit at the beginning of the block, the block synchronizing signal SYNC, data W ₁ are sub-code ID in the next 8 bits, the sub-code ID data W ₂ for the next 8 bits an address signal of the block, the parity P of 8 bits following for error correction that is generated for the data W ₁ and W _2, (consisting of 32 symbols so to form one symbol in 8 bits) the remaining 256 bits are sub Code data and error correction parity generated for the code data.

The 8-bit data W ₁ and W ₂ are described in more detail in FIG. 7B.
It is supposed to be as shown in.

That, MSB data W ₂ are used for that block to identify whether the sub-code block or a PCM data block, this is when the subcode block is "1" as shown in FIG. The lower 4 bits of data W ₂ is a block address, the LSB contents of the subcode ID are different "0" or "1". When the block address LSB is "0", data W ₁ consists of 4 bits of the control ID and a 4-bit data ID, the upper 3 bits of the block address of the data W ₂ is the format ID.

The start ID signal described above is recorded as one bit of the control ID. When the start ID signal is "1", the start of the music is set.

Data W ₁ when LSB of block address is “1”
And the upper three bits of the data W ₂ indicates the program number. In this case, the program number is represented by BCD code 3 digits, the top three of the block address of the data W ₂
Bit PNO-1 is the most significant digit, the data W ₁ upper 4 bits P
NO-2 represents the middle digit, the lower 4 bits PNO-3 represents the least significant digit, and the program number is [00
It is represented from 1] to [799]. [000] indicates that no program number is recorded, and [0AA]
Indicates that the program number is invalid.

The subcode block whose LSB of the block address is "0" and the subcode block whose value is "1" are alternately recorded by 4 out of 8 blocks in each subcode area SUB.

Because writing the program number on the basis of the above-mentioned start ID signal, a start ID signal in a control ID of W ₁ is a sub-code ID is detected whether the "1" and "1"
, The program number is written to the subcode block whose LSB of the block address is “1” ([0A
A) is sequentially rewritten for each song).

D Problem to be Solved by the Invention By the way, in such an R-DAT, a so-called music scan function can be considered. In other words, when you don't know what kind of song is recorded on the tape, you can use this music scan to find the desired song. It is necessary to enter the normal reproduction operation from the scan operation. However, in the past, the music scan operation had to be stopped by the stop button, and the song had to be played back after the beginning of the song as a REW (rewind) search, which made the operability complicated.

The present invention has been made in view of the above circumstances, and an object thereof is to propose a magnetic tape reproducing method capable of simplifying the operability when shifting from the information signal search state to the normal reproduction mode.

E Means for Solving Problems The present invention reproduces a magnetic tape on which a plurality of information signals and a start ID signal indicating the start position of each information signal are recorded, based on the start ID signal. In the reproducing method of the magnetic tape, the information signal recorded on the magnetic tape is searched based on the start ID signal recorded on the magnetic tape, and the searched information signal is recorded on the part where the start ID signal is recorded. When the play button is operated during the search for the information signal recorded on the magnetic tape based on the start ID signal, the search operation based on the start ID signal is canceled. When the play button is operated while the information signal searched based on the start ID signal is being reproduced for a predetermined time, the searched information is A reproducing method of a magnetic tape is characterized in that a reproducing mode for reproducing a signal is switched.

According to the present invention, the information signal recorded on the magnetic tape is searched based on the start ID signal recorded on the magnetic tape, and the searched information signal is recorded as the start ID signal. When the play button is operated while the information signal recorded on the magnetic tape is searched based on the start ID signal, the search operation based on the start ID signal is canceled. , When the play button is operated while reproducing the information signal searched for based on the start ID signal for a predetermined time, the reproduction mode for reproducing the searched information signal is switched to.

G Embodiment Hereinafter, an embodiment in which one embodiment of the present invention is applied to an R-DAT will be described in detail with reference to FIGS. 1 to 5.

G ₁ Circuit Configuration FIG. 1 shows the circuit configuration of the present embodiment. First, the signal system will be described. At the time of recording, the input analog audio signal is band-limited by the low-pass filter (1). Thereafter, the digital signal is supplied to an A / D / D / A converter circuit (2) and converted into a digital signal. The digital signal is supplied to an encoder section of an error correction encoder and decoder circuit (3) and converted into a PCM signal for each block. At the same time, addition of an interleave process, parity for error correction, a block synchronization signal, a block address signal, insertion of a subcode, and the like are performed.

During this recording, the switch circuits (4) and (8) are switched to the recording REC by a switching signal from the circuit (3) in synchronization with the switching of the circuit (3) to the encoder. And
From the circuit (3), a half-rotation signal of the audio signal HA or HB is PCM audio signal that is time-compressed to 90 ° with the parity added.
This is obtained in the tape contact section of A and HB, which is supplied to the rotary heads HA and HB via the switch circuit (4), the recording amplifier (5), the switch circuit (8) and the head changeover switch circuit (9). The tapes are supplied alternately and sequentially recorded on the tape (10) as one diagonal track.

The head changeover switch circuit (9) uses the head changeover signal from the circuit (3) to supply a PCM signal time-compressed by 90 ° rotation to the head in contact with the tape (10). The mode is alternately switched between the A side and the B side every two rotations.

Next, at the time of reproduction, the switch circuits (4) and (8) are switched to the PB side by a switching signal from the circuit (3), and the head changeover switch (9) is set to one of the rotary heads HA and HB similarly to recording. It is alternately switched to the side that comes into contact with the tape (10). The PCM signal reproduced from the tape (10) by the heads HA and HB is supplied to a reproduction process circuit (7) via a reproduction amplifier (6), where a reproduction equalizer process is performed and bit synchronization is performed, and digital reproduction is performed. The data is shaped into data, and the recovered clock is obtained by the PLL circuit.

The PCM data from the reproduction process circuit (7) is supplied to the error correction encoder and decoder circuit (3). At the time of this reproduction, the circuit (3) functions as a decoder, and the PCM signal is decoded after error correction and the like.

The decoded signal is converted back into an analog signal in the D / A converter section of the A / D, D / A converter (2), and an audio signal is reproduced through a low pass filter.

Next, a description will be given of a head drum and a tape running control system. (11) shows a drum, and two rotary heads HA and HB are separated from each other by 180 ° from the peripheral surface of the drum (11). Attached in a slightly protruding state,
The drum motor M ₁ typically is rotated in a predetermined direction at 2000rpm of rotating speed.

(12) the frequency signal proportional to the drum rotation speed than that in the rotation detector of the drum motor M ₁ (head speed)
D _FG and a signal D _PG indicating the head rotation phase are obtained.

(10) is a magnetic tape, which is taken out from a supply reel (13), is wrapped obliquely within a 90-degree angle range of the peripheral surface of the drum (11), and is then moved to a capstan (14) and a pinch roller (1).
5) It is taken up by the take-up reel (16).

Capstan (14) is rotated by a capstan driving motor M _2, the tape feeding.

(17) in the rotation detecting means of the motor M _2, which from the frequency signal C _FG proportional to the rotational speed can be obtained.

M ₃ and M ₄ are each reel motor for driving the reel (13) and (16), each rotation detecting means (18) and (19), the rotational speed of the motor M ₃ and M ₄ are detected,
As a result, frequency signals T _S and T _T proportional to the rotation speed are obtained.

Also, (20) is a system controller (hereinafter abbreviated as syscon), (21) is a capstan and drum servo circuit, (22) is a reel drive control circuit, (23) is an arithmetic unit for reel drive control, 24) is a search control circuit, and (25) is a brake means.

Further, (26) is an input device equipped with various operation buttons,
(27) is a display for displaying the tape running direction, recording / playback display, program number and the like.

A signal D _FG indicating the number of rotations of the rotary heads HA, HB from the rotation detecting means (12) and a signal D _PG indicating the rotation phase, and a signal C indicating the rotation speed of the capstan (14) from the rotation detecting means (17). _FG is a capstan and drum servo circuit (21)
Is supplied to. Then, the feed tape to the motor M ₂ together with the servo circuit (21) is the system controller (20) when the signal receiving and recording from and normal reproduction generates a signal for controlling the rotational speed and the rotational phase of the motor M ₁ Generates a signal that keeps the speed constant.

G ₂ Main body structure Fig. 2 shows the structure of the main body of the R-DAT.
Is a main body, (31) is a power switch, and (32) is a cassette tray. The cassette tray (32) is inserted with the cassette tape window facing upward with the erroneous erasure prevention tab facing forward. (33) to (36) are start ID buttons, (33) is an auto button, (34) is a manual button, (35) is an erase button, and (36) is a renumber button.

In the case of the auto button (33), the start ID signal is automatically recorded during recording when the auto indicator is lit.
If the auto display is not lit, press this auto button (33). When the sync signal is sent, such as at the beginning of a song, or when the recording level rises again after the recording level has fallen below a certain level for 3 seconds or more, the start ID signal will be 9 each time.
Recorded for a second.

Manual button (34) starts when recording
Press to record the ID signal at any location (manual display lit). The start ID signal is recorded for 9 seconds from the point where the button is pressed.

For the erase button (35), press to erase the start ID signal. If the start ID signal and program number are recorded, both are erased.

For the renumber button (36), enter the program number 1
Press to repeat from the beginning. When only the start ID signal is recorded, the program number can be sequentially changed from 1 by this method.

(37) to (39) are counter buttons used for switching the counter display, resetting the counter, and storing the reset point. (37) is a mode button,
(38) is a reset button, and (39) is a memory button.

In the case of the mode button, the mode is switched each time the counter display (tape running time, music playing elapsed time, remaining time) in the display window is pressed. For the reset button (38) When the counter is displayed on the display, press it to reset the counter to 0m00 _S. For the memory button (39), press it when the counter is displayed to store the 0 _M 00 _S position. When you press the rewind button to rewind, the tape stops at 0m00 _S. Press the rewind button and press the play button to rewind to 0m00 _S , and playback will start automatically from there.

(40) and (41) are skip ID buttons used for recording and erasing skip ID signals. (40) is a write button and (41) is an erase button.

When using the light button (40), press it where you want to skip it when you listen later during recording or playback. It lights up momentarily when pressed, and the skip ID signal is recorded for 1 second. In the case of the erase button (41), this button is pressed to delete the previous skip ID signal. The button display flashes while the tape is being rewound and lights up while the skip ID signal is being erased.

(42) is a numeral (0-9) button, that is, a numeric keypad. When a desired number is pressed before recording is started (recording is paused), a song number is automatically assigned from that number.
When playing, select the song number of the song you want to hear with this button. When you press the start button, playback starts from the beginning of the song.

(43) is a recording level adjustment knob, which adjusts the recording level while watching the peak level meter. The outside is for the L channel and the inside is for the R channel, and both channels can be turned at the same time.

(44) is a timer switch, which is normally turned off and is switched when recording or reproducing at a desired time using a timer provided separately.

(45) is a headphone jack, (46) is a remote control light receiving section, and (47) is a cassette tray open / close button.

(48) to (54) are tape operation buttons,
Is a stop button, (49) is a play button, (50) is AM
Reverse direction with S button Press to move to the beginning of the song, and Press to find the beginning of a song with. (51) is fast forward / cue And rewind / review When the button is pressed in the play state, it becomes a cue or a review, and when it is pressed in the stop state, it becomes fast forward or rewind.
(52) is a recording button, (53) is a pause button, and this pause button (53) is automatically released when paused for about 10 minutes, and the deck is stopped. (54) is a recording muting button.

(55) is a clear button, and when the track number is mistakenly pressed, if the button is pressed before the start button is pressed, the track number disappears. Reference numeral (56) denotes a skip switch, which is turned on when it is desired to listen to the next start ID signal from the point at which the skip ID signal is recorded during reproduction, and turned off when it is desired to listen to the entire signal without skipping. (57) is an input selector switch, which is the input source AN for recording
Switches between ALOG (when recording from a device connected to the LINE IN jack) and DIGITAL (when recording from a device connected to the DIGITAL IN terminal). (58) is a start button, and when you press the number button (42) to select the song number of the song you want to hear and then press this button, the song starts playing immediately. When pressed during stop or playback, each song will be played for about 8 seconds at the beginning and sent to the next (music scan).

G ₃ Display details Figure 3 shows the details of the display (27).
(60) is a counter display section, which indicates that the counter is displaying the approximate tape running time. Reference numeral (61) denotes a remaining (REMAINING) display portion, which indicates that the remaining time until the end of the tape is being displayed on the counter. Reference numeral (62) denotes a memory display portion, which indicates that the memory button 0 m00 _S is stored. (63) is a program time (PMG TIME) display section, and indicates that the elapsed time of the current song is being displayed on the counter.

(64) is an EMPHASIS display section,
When you play a tape with emphasis, de-emphasis is automatically applied and the emphasis display lights. The display also lights when recording a source with emphasis on DIGITAL IN. Lights when recording with LINE IN. (65) is a PGM (song number) display section, which displays the current song number when a program number is recorded. Reference numeral (66) denotes an AMS (track start) display section, which indicates, when the button (50) is depressed, how many songs, including the song currently being listened to, to go back or to go forward. When the number button (42) is pressed, the number (song number) is displayed while searching for a desired song.

Reference numeral (67) is a digital copy prohibition display portion, which blinks when a digital copy prohibition code is present during digital dubbing. In this case, you cannot record. (68) is a caution (CAUTION) display unit. When water drops due to dew condensation while the deck is operating, this display flashes and the operation stops.

Reference numeral (69) denotes a search display section, which lights up when the button (50) is pressed or when a direct song selection is performed by designating a song number, or during a skip operation. Reference numeral (70) denotes a start ID display section, which blinks while the start ID signal is being recorded (for about 9 seconds) or during erasure, and lights up while the portion where the start ID signal is recorded is being reproduced. Reference numeral (71) denotes a skip ID display section, which is recording a skip ID signal (about 1 second) or erasing a skip ID signal.
Also, during playback, it lights up momentarily when it reaches the part where the skip ID signal is recorded.

(72) is a sampling frequency display section that lights up in correspondence with the sampling frequency of the digital program source (32 kHz: DBS (direct satellite broadcasting), 44.1 kHz: recorded DAT soft tape, 48 kHz: DBS, DAT recording Re)). (7
3) is a peak level meter, which indicates the peak value of the recorded signal level during recording and the peak value of the recorded signal level during playback. (74) is a counter which displays the running time of the tape, the elapsed time of the current song, and the remaining time until the end of the tape. Each time the mode button (37) of the counter is pressed, the displayed content switches.

G ₄ Music Scan-Related Operations Next, operations related to the music scan will be described with reference to FIGS. 4 and 5. First, the basic operation of the present invention will be described with reference to FIG. In FIG. 4, the start ID signal is recorded for about 9 seconds at the beginning of each song. If the play button (49) is pressed during the music scan operation, that is, during the playback of the beginning of the song for which the start ID signal is recorded for about 8 seconds (while the play button (49) flashes during this time) The music scan operation is stopped and the playback mode is directly entered (operation 1). The display of the play button (49) lights up when the playback mode is entered.

In addition, during the music scan operation, that is, during the search after about 8 minutes of the beginning of the song, in other words, when the play button (49) stops blinking and the next song is searched for, the play button ( When (49) is pressed, the music scan operation is stopped, the REW search mode is immediately entered, the start ID signal is found, the playback of the played song is performed, and the playback mode is entered from the beginning of the song (Operation 2). .

Next, the detailed operation will be described with reference to FIG. When the play button (49) is pressed in step (a), this is recognized by the syscon (20), and whether or not the music scan is being performed in step (b), that is, whether the start button (58) is pressed or not. Is checked by the system controller (20), and if music is being scanned, proceed to step (c) to see if it is being played, that is, about 8 at the beginning of the song.
Whether or not the second is being played is determined by the syscon (20),
If reproduction is in progress, the reproduction mode is directly entered in step (2).

If it is not playing in step (c), the syscon (20) determines whether or not it is in search in step (e), that is, whether or not about 8 seconds at the beginning of the song has passed. In (f), find the start ID signal of the replayed song that is being rew searched for one song, and enter the replay mode from the beginning of the song. If the search is not in progress in step (e), the process returns in step (g).

If music scanning is not being performed in step (b), another reproduction process, for example, a normal reproduction mode is started.

As described above, in the present embodiment, the play button is not accepted during the music scan, the play mode is entered as it is during the reproduction, and the REW search is performed only during the search to operate the play button. As a playback operation, playback can be performed from the beginning of the song, and the operation becomes easy.

In the case of accepting the play button only during reproduction, if the timing of pressing the play button is delayed even a little, the search goes to the next song, but this does not occur in the present embodiment.

A music scan operation is required to confirm that the music scan is in the normal playback mode, which can be used by blinking the display of the play button (49) during music scan playback. In other words, the display of the play button (49) blinks during playback by music scan, and when the play button (49) is pressed to enter the playback mode, the display is turned on. This also simplifies the display means.

H Effect of the Invention As described above, according to the present invention, a magnetic tape on which a plurality of information signals and a start ID signal indicating the start position of each information signal are recorded is reproduced based on the start ID signal. In the reproducing method of the magnetic tape, the information signal recorded on the magnetic tape is searched based on the start ID signal recorded on the magnetic tape, and the searched information signal is recorded on the part where the start ID signal is recorded. When the play button is operated during the search for the information signal recorded on the magnetic tape based on the start ID signal, the search operation based on the start ID signal is canceled. When the play button is operated while the information signal searched based on the start ID signal is being reproduced for a predetermined time, the searched information is Since the reproduction mode for reproducing the signal is switched to, it is possible to obtain a reproducing method of the magnetic tape which can simplify the operability when shifting from the search state of the information signal to the normal reproduction mode.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention, FIG. 2 is a perspective view showing the appearance of an R-DAT to which the present invention is applied, FIG. 3 is a diagram showing the display in detail, and FIG. Is a diagram for explaining the basic operation of the present invention, FIG. 5 is a flowchart for explaining the operation of the present invention, FIG. 6 is a diagram showing an example of a tape format used for R-DAT, and FIG. FIG. 6 is a diagram showing an example of a subcode format recorded in a subcode area of a recording track. (10) is a magnetic tape, (13) is a supply reel, (16) is a take-up reel, (20) is a system controller, (21) is a capstan and drum servo circuit, (22) is a reel drive control circuit, ( 23) is an arithmetic unit, (26) is an input device, and (27) is a display.

Claims (1)

(57) [Claims] 1. A magnetic tape reproducing method for reproducing a magnetic tape on which a plurality of information signals and a start ID signal indicating a start position of each of the information signals are recorded, based on the start ID signal. The information signal recorded on the magnetic tape is searched based on the start ID signal recorded on the magnetic tape, and the searched information signal is sequentially reproduced for a predetermined time from the portion where the start ID signal is recorded. However, when the play button is operated while searching for the information signal recorded on the magnetic tape based on the start ID signal, the search operation based on the start ID signal is canceled, When the play button is operated while the information signal searched based on the signal is reproduced for a predetermined time, the searched information is searched. Magnetic tape reproducing method being characterized in that the switched to the playback mode for reproducing the item.