JPH0249245A - Magnetic tape reproducing device - Google Patents

Abstract

PURPOSE:To reduce the interruption of reproducing sound at the time of rewinding a tape by executing a state to reproduce only odd-th or even-th program information in an ascending order and a state to reproduce it in a descending order setting the odd-th information oppositely alternately. CONSTITUTION:Digital information recorded on a magnetic tape 1 is read out with a head 2, and is inputted to a signal processing circuit 4 via a reproduction circuit 3, and is stored in a RAM 5. An analog signal reproduced at the circuit 4 via a D/A conversion circuit 6 is outputted to an output terminal. The operating control of a system is performed by a switch 10 via a system control part 11. The state to reproduce only the odd-th or the even-th program information in the ascending order and the state to reproduce it in the descending order setting the odd-th information oppositely are executed alternately, and also, reproducing information before and behind transition when it is transited are located being neighbored or adjacently on the tape, therefore, a time required for movement to the next program position can be shortened, and the rewinding quantity of the tape can be performed distributedly, thereby, the interruption of the reproducing sound can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic tape reproducing apparatus for reproducing digital data recorded on a magnetic tape.

2. Description of the Related Art In recent years, a digital audio tape recorder (hereinafter abbreviated as DAT) has become known as a device that converts audio signals into PCM signals and records and reproduces them. This DAT
is a helical scan method using a rotating head.
This is a device that records and reproduces signals on tracks diagonal to the longitudinal direction of a magnetic tape.

FIG. 5 shows a DAT tape format, and an example of the specifications shown in the figure is shown below.

Tape width A = 3.81 effective recording @ W = 2.61 / #1 Tape speed a V t = 8.15 y / S Track length L = 23.5 Dark track pitch p
-13.6 μm Track angle θ = 6° 22' Azimuth angle α = ±20° Corresponding to this format of tape, the diameter and rotation speed of the drum of the rotating head are, for example, 30 ru.
t, 2000rr) 11, and the relative velocity of the head and tape (Vh in FIG. 5) is 3.13 m/s.

Further, the angle of the tape winding is 90°.

When an audio signal is converted into a PCM signal and recorded using DAT, it is recorded in a track format or a block format as shown in FIGS. 6 and 7'2. In this case, sub-codes containing position information such as program number, track number, time code (a code that displays the time from the start point of the program, such as 090 seconds), and other necessary auxiliary data are recorded at the same time. There is also. As shown in FIG. 6, one track consists of 196 blocks, with a 128-block PCM audio data recording section at the center, and 8-block subcode sections for recording auxiliary data on both sides. As shown in Figure 7, one block consists of 288 bits, each block consists of an 8-bit block synchronization code, followed by an 8-bit block synchronization code.
A bit identification code (hereinafter abbreviated as ID code), a block address code, and an 8-bit bassoti code are provided, followed by 256-bit data (PCM data or subcode data). Note that M2S (most significant bit) of the block address code is set to "0" in a PCM block, and set to 1 in a subcode block.

Use of voice by ID code in PCM area,
Emphasis characteristics, sampling frequency, number of channels, etc. are displayed. In addition, in the subcode area,
TOC-, which indicates the presence or absence of subcode data, respectively.
10. 5-1 indicating the recording start point of the recorded program
0, a shortening IO indicating the start point of skipping the program during playback is allocated.

At the beginning of each program, the ID code 5-ID
is set to "1" for 9 seconds and is used as a program start signal.

In conventional magnetic tape reproducing apparatuses, when a magnetic tape on which a plurality of program information is recorded is "repeatedly reproduced", one of the following system controls is performed.

One of them is to detect that the magnetic tape has been reproduced to the end, rewind the tape at high speed to the beginning, and then play again from the beginning. The other method is to play the program information sequentially, play the Nth program information, that is, the last program information on the magnetic tape, then rewind at high speed to the beginning of the magnetic tape, and then start playing again from the beginning. It is something to do.

Problems to be Solved by the Invention In such a conventional configuration, when the same tape is "repeatedly played", the magnetic tape is rewound from the end to the beginning, which takes a long time. had the problem that the reproduced sound was interrupted, giving the user a strange feeling.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic tape playback device that can reduce interruptions in playback sound caused by rewinding the magnetic tape during "repeated playback."

Means for Solving the Problems The magnetic tape reproducing apparatus of the present invention is an apparatus for reproducing a magnetic tape on which a plurality of program information and program start signal information of these programs are sequentially recorded. Or, it has a first state in which only even-numbered programs are played back in ascending order, and a second state in which only even-numbered or odd-numbered programs are played back in descending order, with odd-even being the opposite of the first state. The present invention is characterized in that it includes a system control section that alternately executes the first state and the second state when executing the playback mode.

Effect: According to this configuration, at the time of transition from the first state to the second state, since the program information to be reproduced before and after the transition is adjacent or close to each other on the magnetic tape, it is difficult to rewind to the beginning of the next program. Even if it is implemented, the time will be short, and the silent period will be dispersed to eliminate the strange feeling.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 4.

FIG. 1 shows a magnetic tape reproducing apparatus of the present invention.

Digital information recorded on the magnetic tape 1 based on the DAT format shown in FIGS. 5, 6, and 7 is read by the head 2, and compensates for the frequency characteristics of the preamplifier and the head 2. The signal is input to the signal processing circuit 4 through a compensation amplifier, an integrating circuit for compensating for the head having a differential reproduction characteristic (such as a coil header), and a digital information reproduction circuit.
Stored in M5. The signal processing circuit 4 performs digital demodulation,
After deinterleaving and error detection and correction processing, the reproduced signal is input to the D/A conversion circuit 6.

The D/A conversion circuit 6 converts the digital signal into analog and outputs it to the output terminal 7.

In addition to the above configuration, the magnetic tape playback device of this embodiment has the following features:
It inputs and outputs the above-mentioned subcodes to and from the signal processing circuit 4, and outputs signals for changing the mechanism 8 to the playback state, fast forward, rewind state, stop state, etc. to the mechanism drive circuit 9, You can count the time, count the start D code in the subcodes mentioned above, or count the DA
The system is equipped with a system control section 11 that controls the operation of the system using a switch 10 on the operation panel of the T. The switch 10 includes at least a play mode switch for switching between a normal play mode and a repeat play mode, a direction switch for controlling state transitions, and the like.

FIG. 2 shows a flowchart of the main parts of the system control section 11. When the play mode switch of the switch 10 is in the repeat play mode, when the playback of the magnetic tape 1 is started, the following operation is performed. Here, magnetic tape 1 has N
-When 2m program information is recorded and N-
(Consider two cases in which 2m-1> programs are recorded.

First, an example of an operation when N=2m pieces of program information are recorded as shown in FIG. 3(a) will be described. When an even number of 12 m of program information is recorded on the magnetic tape, the first program information is reproduced as the first state of the reproduction operation [step 102]. In FIG. 3(b), the reproduction is being indicated by a thick arrow. When the start ID that is the start point of the second program information is detected during playback (step 105), the second program information is fast-forwarded as fast as the device can read the start ID (step 106), and the third program information is started. When the start 10 representing the point is detected [step 108
), the third program information is played (step 109), and so on, the odd numbered program information is played back in ascending order, and the odd numbered program information is played back in ascending order (step 109).
) When the start ID representing the start point of program information No. 2m is detected [Step 10
5], fast forward the 2mth program information [step 106], continue fast forwarding until the start ID representing the (2m+1)th program information start point is detected,
If the end of the tape is detected without detection (step 10)
7, 108), performs loopback [step 110], detects the start 10 of the 2mth program information [step 111], and reproduces the 2mth program information [steps 112, 113].

The above operation is a transition operation from the first state to the second state during reproduction. If start 10 cannot be detected during the transition from the first state to the second state, the tape is fast-forwarded to the end of the tape, but if the start ID cannot be detected even after a predetermined time during fast-forwarding, fast-forwarding is stopped. , the rewinding operation may be started.

Next, the reproduction operation in the second state will be explained. While the 2mth program information is being played back, the start ID representing the (2m+1)th program information start point is monitored, but here we are considering the case where N=2m pieces of program information are recorded. (2m+1)th start ID
could not be detected, and the unrecorded part was detected [
Step 114), when detected, performs a rewinding operation [
Step 115], detect the start ID representing the (2m-2)th program information start point, and
The program information of the (2m-2)th program is played back, but it takes 2m until the start IO of the (2m-2)th program information is detected.
Since the start ID of the program information number and (2m-1) is detected during rewinding, the start ID
Detect [step 116] and count (step 1
17) L: When the third start ID is counted, rewinding is stopped and the (2m-2)th program information is reproduced (steps 119 and 120). If the start ID of the (2m-1)th program information is detected during playback, it starts rewinding (step 121), and when the start ID is detected three times, it stops rewinding and starts rewinding (2m-1). -4) When reproducing even numbered program information, such as reproducing program information numbered,
Playback is performed in descending order from number 2m to number 2. After playing the second program information, if the start ID representing the start point of the third program information is detected, rewinding is performed, and when in repeat mode, the start end of the tape is detected. [not shown in FIG. 2] will stop rewinding and start playing the smallest odd numbered program information again [not shown in FIG. 2] from the second state. The reproduction operation transitions to the first state. In this way, the first state and the second state are alternately changed for repeated reproduction.

Next, based on FIG. 2 and FIG. 4(a)(b), N=
The operation when (2m-1> program information is recorded) is explained.The reproduction of the (2m-1)th program information, which is the largest number among odd numbers (2m-1), is completed. The operation up to this point is omitted because it is the same as when repeatedly playing back a magnetic tape on which 2m of program information has been written.The playback of the (2m-1)th program information ends, and the 2mth program information starts. When a start ID representing a point is detected (step 105), fast-forward operation is started [step 106], but N=(2
Since we are considering the case where m-1) pieces of program information are recorded, in this case, detecting the unrecorded part [Step 10
3] and tape end detection [step 104],
When a non-recorded portion is detected, a timer is set, and if the start 10 representing the 2m program information start point is not detected within a predetermined time, playback is stopped and rewinding is performed (steps 129, 130, 122). ), 2
Playback is restarted by detecting the start ID of the m-2nd program information [step 123], but the first detected start ID is the start ID of the 2m-1st program information, and the start ID of the 2m-2nd program information is the start ID of the 2m-2nd program information. In order to play back the program information, it is necessary to not only detect the start TD (step 123), but also count the start ID (step 124), rewind until the second start ID is detected, and then repeat the process twice. When counted [
Step 125], rewinding is stopped and the (2m-2)th program information is played back (steps 126, 12).
0). The operation from the time when the (2m-2)th program information is being played back is the same as the action from the time when the (2m-2)th program information is being played back when N=2m pieces of program information are recorded, so it is omitted. do.

Although not explained in the operation example, [Step 129.
The reason why the timer is set in step 130) is to protect when there is an unrecorded portion between the program information.

Although not shown in FIG. 2, during the first state of playback in ascending order, that is, during playback of the odd-numbered program, the direction switch of the switch 10 allows
When a state transition control command is input, if the odd numbered program information being reproduced is the Mth program information, the program information located at the M-1st position (or M+1st position) on the tape is reproduced. Furthermore, when the second state is playing back in descending order, that is, when the even-numbered program is played back, when the state\A transition control command is input by the direction switch, the even-numbered program information being played is the M-th one. , the M+1th (M-1
playback of the program information located in the second position).

Although not shown in the flowchart of FIG. 2,
For example, during playback in ascending order in the first state, that is, during playback of the above-mentioned odd-numbered program information, control information (shortening ID) for moving to the next program start position on the magnetic tape is detected, or switch 10
When a control signal for moving to the next program start position is input by the F-8K IP switch, if the odd numbered program information being played is the Mth, the next odd numbered program information is input. Program information, i.e. (
Move to the M+2)th program information start position. In addition, during the second state of playing back in descending order, that is, when playing the even-numbered program described above, shortening 10 is detected on the magnetic tape 1, or the F-8KIP switch is used to move to the next program start position. When the control is input, if the even numbered program information being reproduced is the Mth program information, the program moves to the next even numbered program information, that is, the (M-2)th program information start position.

As described above, according to the present embodiment, there are provided a means for detecting and counting the start ID recorded on the magnetic tape, a means for detecting a blank area, a means for detecting the end and start end of the tape, and a means for detecting the start ID recorded on the magnetic tape. ! means for detecting D;
By providing a means for inputting state control information using switches on the operation panel and a system control unit that controls system operation using all of the above means, the number of pieces of program information recorded on a magnetic tape can be evenly distributed. It has a first state in which only odd-numbered program information is played in descending order, and a second state in which only even-numbered program information is played in descending order, regardless of whether the program information is in descending order. , repeat reproduction can be performed by alternately switching between the first state and the second state.

In the above embodiment, the first state is a state in which only odd numbered program information is played back in ascending order, and the second state is a state in which only even numbered program information is played back in descending order. The first state may be a state in which only the program information of the numbered number is reproduced in ascending order, and the second state may be a state in which only the odd numbered program information is reproduced in descending order.

Effects of the Invention As described above, according to the present invention, in the repeat reproduction mode, the system control unit reproduces only odd or even program information in ascending order; In order to alternately execute the second state in which even or odd numbered program information is played back in descending order, when repeating playback, when transitioning from the first state to the second state, or during the transition from the first state to the second state, 1st from the condition
At the time of transition to the state, the program information to be reproduced before and after the transition is adjacent or close to each other on the magnetic tape, so that the time required to move to the next program position to be reproduced can be shortened. In other words, in the conventional technology, a long silent period would occur when rewinding from the end of the magnetic tape to the beginning, but with the present invention, the rewinding can be dispersed and the long silent period can be eliminated. can.

Moreover, during one cycle between the first state and the second state, each of the N programs recorded on the magnetic tape is processed without duplication.
Since the program can be played back once at a time, there is no problem of the same program being played back consecutively or at close time intervals. Therefore, especially when used in a car or as background music, continuous playback is often performed, and the effects of the present invention can be brought out significantly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a magnetic tape playback device according to an embodiment of the present invention, FIG. 2 is a flowchart of the main part of the system control section of the device, and FIGS. 3 and 4 are playback states of the device. FIGS. 5 to 7 are explanatory diagrams of the DAT recording format. 1...Magnetic tape, 4...Signal processing circuit, 8...
Mechanism, 9... Mechanism drive circuit, 11...
System control unit. Agent Yoshihiro Morimoto

Claims (1)

[Claims] 1. A device for reproducing a magnetic tape in which a plurality of program information and program start signal information of these programs are sequentially recorded, and a first device for reproducing only odd-numbered or even-numbered programs in ascending order. and a second state in which only even-numbered or odd-numbered programs are played back in descending order with the odd-even being reversed from the first state, and when the repeat playback mode is executed, the first state and the second state are A magnetic tape playback device equipped with a system control unit that alternately executes the following functions.