JPH0687327B2 - Playback device - Google Patents

Description

The present invention relates to a reproducing apparatus for reproducing a cassette tape on which an audio signal or the like is recorded, and more particularly to sequence control.

[Conventional technology]

The digital audio tape recorder (DTA) has a fixed head system (S-DAT) and a rotary head system (R-DAT). S-DAT is a method of recording signals on a number of tracks parallel to the longitudinal direction of the tape by using a multi-track fixed head, and R-DAT is a helical scan using a rotating head for the longitudinal direction of the tape. This is a method of recording signals on diagonal tracks. When recording a music signal or other information by DAT, a PCM music signal is recorded and a subcode including position information such as a program number and time code and other necessary auxiliary data is recorded. Based on this subcode, the position of the tape can be known at the time of reproduction, and the tape can be cued in the search mode. For example, when recording music with R-DAT, it is recorded according to the track format and block format as shown in FIGS.
In this case, the subcode including the position information such as the program number and the time code and other necessary auxiliary data may be recorded at the same time. As shown in Fig. 4, one track is composed of 196 blocks, and the ATF period in which the pilot signal for tracking is recorded is on both sides of the PCM audio data recording section, and the auxiliary data is further outside of it. There is a subcode period for recording the. A PLL period for synchronization is provided in each of the PCM period and the sub-code period, and a gear is provided between the PCM period and the sub-code period, and the timing of recording / playback mode switching is adjusted to this gear. As a result, the PCM audio signal or subcode signal can be recorded independently. The fourth
The numbers shown in the figure indicate the number of blocks in each period. Fig. 5A
As shown in, one block consists of 288 bits,
An 8-bit identity eye code (ID code) and a block address code are provided, an 8-bit parity code is provided, and 256-bit data (PCM data or sub-code data) follows. . As shown in FIG. 5B, the MSB of the block address code is "0" in the PCM block and "1" in the sub code block. Use of voice, emphasis characteristic, quantization characteristic by ID code in PCM area,
The sampling frequency, channel number, etc. are displayed. In the subcode area, a program start signal indicating the beginning of the recorded program, a program number, etc. are displayed. At the beginning of each program, the program start signal and the program number are recorded and used for 9 seconds.

Next, the sequence of shifting from the reproducing operation to the next operation such as the fast-forward operation when there is no conventional main signal will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing the basic principle. FIG. 6 (A) shows a normal recordable tape having program numbers “1” and “2” and a main signal from point b. When the tape is not played back, as shown in FIG. 6 (b), when it is played back from the point a, the fast feed mode is set within a few seconds, for example, about 3 seconds from the point b where the main signal does not enter, and the EOT (tape end) is set. The rewind mode is detected and the playback mode is set again at the BOT (tape end). As a matter of course, when reaching the point b in this reproduction state, the operation described above is repeated. Next, FIG. 6 (c) shows the case of a cleaning tape for cleaning the head for reading the main signal, and naturally the main signal is present when reproduced from the point c as shown in FIG. 6 (D). Since it does not exist, the fast-forward mode is set after 3 seconds, the EOT is detected and the rewinding mode is set, and the playback mode is set again at the BOT. However, after 3 seconds, the fast-forward mode is set again and the same operation is repeated. The reason for this operation is to move the tape to a position where sound can be produced as quickly as possible while avoiding the silent part, and set the playback mode.

FIG. 7 is a diagram showing the operation flow chart of the main part thereof. The presence or absence of the main signal is detected in step (71), and if not, it is judged in step (72) whether 3 seconds have elapsed. In either case, if there is a main signal, the process returns to the same step (71), and if 3 seconds have not elapsed, the process returns to step (71). When 3 seconds have passed in step (72), the fast-forward mode is set in step (73). The subsequent operation flow chart is not shown
When EOT is detected, the rewind mode is entered, and when BOT is detected, the replay mode is entered again.

[Problems to be solved by the invention]

Since the conventional playback device is configured as described above, when trying to clean the head by playing the cleaning tape, it usually needs to maintain the playback state for about 30 seconds, but the playback is started. Then, the fast-forward mode is set. Therefore, in order to solve such a problem, there is a problem that it is necessary to provide a switch for not automatically shifting to the fast-forward mode.

The present invention has been made in order to solve the above-mentioned problems of the conventional ones, and it is a case of reproducing a tape without a main signal such as a cleaning tape and a case of reproducing a tape with a main signal. It is an object of the present invention to obtain a reproducing apparatus capable of changing the time from the reproduction mode to the operation mode other than the next reproduction mode.

[Means for Solving Problems] A reproducing apparatus according to the present invention is a reproducing apparatus for reproducing a recording medium such as a magnetic tape in which an audio signal, a video signal or a composite signal thereof is recorded as a main signal. Main signal presence / absence detection means for detecting the presence / absence of the main signal recorded in, and holding means for retaining the signal as main signal presence information when the main signal presence / absence detection means detects the presence of the main signal Releasing means for releasing the information with main signal in the holding means by reattaching the recording medium to the reproducing device; and reproducing the recording medium with the information with main signal held in the holding means. If the main signal is not detected during the first predetermined period, the operation mode of the device is switched to an operation mode other than the reproduction mode. In the case where the recording medium is being reproduced in a state where the main signal presence information is not held in the control means and the holding means, then the second predetermined signal is longer than the first predetermined period. The second control means switches the operation mode of the apparatus to an operation mode other than the reproduction mode when no detection is made during the period.

[Operation] In the present invention, since the apparatus is configured as described above, the main signal presence information indicating that the main signal can be detected is always held during the mounting of the magnetic tape, and the main signal is recorded. The recording medium that has been recorded and a completely blank recording medium such as a cleaning tape are identified, and it takes a long time to switch to the next operation mode for the cleaning tape and so on, and for the recording medium that contains the main signal, The time is designed to be short. Therefore,
When playing a cleaning tape, etc., it is possible to prevent problems that occur because the time from switching from the playing state to the next state such as fast-forwarding is short, and conversely when playing the tape containing the main signal, It is possible to shorten the time required to switch from the reproduction state to the next state such as fast-forward, and the quick response is not impaired.

Example of Invention

An embodiment of the present invention will be described below in detail with reference to FIGS. 1, 2, and 3. First, the basic principle of the present invention will be described with reference to FIG. FIG. 2 (A) shows the case of a normal recordable tape having program numbers “1” and “2” and no main signal from point e. As shown in B), when there is a main signal when it is played back from point g, the main signal is memorized, and in a few seconds, for example, 3 seconds from the point e where the main signal does not enter, the fast-forward mode is set, EOT is detected, and the rewind mode is set. Then it becomes the playback mode again. When the point e is reached in this reproduction state, the above-described operation is repeated. Also, as shown in FIG. 2 (C),
If the part where the cassette tape is inserted and played back starts from the f point, it has not been known that the main signal has existed even once, so it takes several minutes from the f point, for example, about 1 minute to enter the fast-forward mode and set the BOT. The rewind mode is detected and the playback mode is set again at the BOT. In this reproduction state, it is stored that there is a main signal, and for a few seconds from point e where the main signal does not enter, for example, 3
The fast-forward mode is set in about a second, and the operation described above is repeated thereafter. Next, FIG. 2 (D) shows the case of a cleaning tape for cleaning the head for reading the main signal.
As shown in Fig. (E), when the signal is reproduced from the point h, the main signal is not input, so one minute later, that is, fast-forward at a time longer than the time when the main signal is present (3 seconds in this case). The mode is entered, and the operation described above is repeated thereafter.

FIG. 1 is a circuit block diagram of the R-DAT. In the figure, the rotary heads (11A) and (11B) obtain reproduction output from the magnetic tape (14) wound between the reels (12) and (13) and are supplied to the amplifiers (15A) and (15B). , This amplifier (15
The outputs of A) and (15B) are supplied to the switch circuit (16). The switch circuit (16) is a timing signal generation circuit (1
The half rotation period including the tape contact period of (11A) and the half rotation period including the tape contact period of the head (11B) are alternately switched by the switching signal of 33,3 Hz from 0).
The output signal switched by the switch circuit (16) passes through an equalizer (17), a comparator (18) and a PLL circuit (19) that constitute an electromagnetic conversion system, and an error correction circuit (20).
, Where error correction is performed as necessary.
Then, it is further supplied to a digital-analog converter (21) where it is converted from a digital signal to an analog signal and then taken out to an output terminal (23) as an original analog signal through a low-pass filter (22). In addition, if you want to directly retrieve the digital data, the error correction circuit (2
It can be derived from the terminal (24) on the output side of 0).
In addition, a system controller (26) that functions as an interface is provided on the output side of the error correction circuit (20), where sub-code information including a program start signal, time code, etc. is extracted and, if necessary, a display unit ( 27)
And a signal indicating the presence or absence of the main signal is also given. In addition, the system controller (26) is provided with a cassette presence / absence switch (25) and a plurality of keys (not shown) necessary for operation to control the entire system. The cassette presence / absence switch (25) is, for example, ON to have a cassette tape, and OFF to have no cassette tape. Reference numeral (30) is a drum servo circuit controlled by the system controller (26), and a drum (not shown) to which the rotary heads (11A) and (11B) are attached by the drum servo circuit (30). To control the rotating drum motor (31). Reel (12), (1
3) is provided with a reel drive circuit (32), and a drive signal from the reel drive circuit (32) is supplied to the reel motor (3
It is supplied to the reels (12) and (13) via 3) and (34), respectively. The reel drive circuit (32) receives a reel motor (3) in response to a mode switching signal from the system controller (26).
3) Change the level of the drive signal applied to (34). A capstan servo circuit (35) is controlled by a system controller (26). The capstan servo circuit (35) controls a capstan motor (37) that rotationally drives the capstan (36). It Also,
The capstan (36) is provided with a pinch roller (not shown) and a plunger circuit for controlling the pinch roller against the elastic force. The loading drive circuit (38) controls the cassette loading motor (39) or the tape loading motor (40) according to a command from the system controller (26), and acts as a cassette suction, discharge, or tape loading / unloading.

For example, in playback mode, the system controller (26)
If the cassette presence / absence switch (25) is detected and the loading is not completed, the loading drive circuit (38) is controlled to load the cassette and tape, then the capstan servo circuit (35) and reel servo drive. By controlling the circuit (32) and the drum servo circuit (30), the magnetic tape (14) is fed at a constant speed by the rotation of the capstan motor to enter the reproduction mode. In the fast-forward and rewind modes, the magnetic tape (1) is increased by increasing the drive level applied from the reel drive circuit (32) to the reel motors (33) and (34).
4) can be sent at high speed.

FIG. 3 is a diagram showing the operation flow chart of the main part. If the presence or absence of the main signal is detected in step (80), the main signal flag is set to "1" in step (81). If there is no main signal, the main signal flag is determined in step (82). If the main signal is recorded somewhere on this cassette tape, if there is no main signal, for example, if there is no main signal for 3 seconds, step (85) Enter fast-forward mode. On the other hand, if the main signal flag "0" is reset at step (82), the process proceeds to step (84), where it is determined that the main signal is not recorded on this cassette tape, and at step (84),
For example, when there is no main signal for 1 minute, step (85) is set to the fast-forward mode. That is, by changing the time of the next operation mode depending on whether there is a main signal even once before, if there is a main signal, a quick response is obtained, and the main operation of a cleaning tape or the like is improved. With a cassette tape without a signal, a sufficient reproduction time can be obtained. Further, when the cassette tape is taken out once, the main signal flag is reset to "0" (not shown),
Next, when the cassette tape is inserted, provide it.

As described above, according to the above-described embodiment, it is determined whether or not the main signal is recorded on the magnetic tape on which the audio signal is digitally recorded in the R-DAT format. Is stored as the information with the main signal,
When it is detected that the main signal has disappeared while the main signal present information is held, the reproduction state is maintained for 3 seconds and then the operation mode other than the reproduction such as fast-forwarding is entered, and the main signal present information does not exist. In this case, if it is detected that the main signal has disappeared, the playback state is maintained for 1 minute, then the operation mode other than playback such as fast-forwarding is entered, and the cassette containing the magnetic tape is reattached to this playback device. Since the information with the main signal is canceled, when playing back a cleaning tape, it is possible to prevent troubles due to the short transition time from the playback state to the next state such as fast-forwarding. However, with regard to the recorded recording medium, the control of the system controller is slightly changed so that the quick response when moving to the next operation is not impaired. And it can be achieved by, not causing increase in cost even though with improved function most, there is an effect that can be inexpensively configured the device.

In the above embodiment, the presence / absence of the main signal of step (80) is determined only in the reproduction mode, but the same processing may be performed in other fast-forward modes. The 3 seconds of step (83) may be any time within the time of step (84). The time of 1 minute of step (84) may be any time of 20 seconds or more, and further step (80) may be omitted so that the next operation is not carried out without the main signal.
You can go back. Further, although the above-described embodiment has been described only with respect to the reproducing apparatus, it can be applied to the reproducing apparatus section of the recording / reproducing apparatus.

〔The invention's effect〕

As described above, according to the reproducing apparatus of the present invention, in the reproducing apparatus for reproducing the recording medium such as the magnetic tape in which the audio signal or the video signal or the composite signal thereof is recorded as the main signal, the recording is performed on the recording medium. Main signal presence / absence detection means for detecting the presence or absence of the main signal, and holding means for holding the signal as main signal presence information when the main signal presence / absence detection means detects the presence of the main signal, and the holding means. In the case where the recording medium is reproduced in a state in which the main signal present information is held by the holding means holding the main signal present information in the holding device holding the main signal present information in the holding device. Then, when the main signal is not detected during the first predetermined period, the operation mode of the device is switched to an operation mode other than the reproduction mode.
In the case where the recording medium is reproduced in a state where the main signal presence information is not held in the control means and the holding means, the second main signal is longer than the first predetermined period after that. Since the second control means for switching the operation mode of the apparatus to the operation mode other than the reproduction mode is provided when the signal is not detected during the predetermined period, the recording medium on which the main signal is recorded and the cleaning tape or the like are completely removed. Differentiating from blank recording media, if the time to switch from the playback state to the next state such as fast-forward is short, the switching time can be extended for cleaning tapes, etc. Since the time to switch to the next operation can be set short for the medium, it is possible to obtain a playback device with high operability and quick response. A.

[Brief description of drawings]

1 is a circuit block diagram showing an embodiment of the present invention, FIG. 2 is a basic principle diagram for explaining the basic principle of the present invention, and FIG. 3 is a flow chart diagram for explaining the operation of the present invention. 4 and 5 are diagrams showing the R-DAT format, FIG. 6 is a basic principle diagram for explaining the conventional basic principle, and FIG. 7 is a flow chart diagram for explaining the conventional operation. is there. (12), (13) are reels, (14) are magnetic tapes, (20)
Is an error correction circuit, (25) is a switch with or without cassette, (2
6) is a system controller, (30) is a drum servo circuit, (31) is a drum motor, (32) is a reel drive circuit,
(33) and (34) are reel motors, (27) is a display, and (3
8) is a loading drive circuit, (39) is a cassette loading motor, and (40) is a tape loading motor. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A reproducing apparatus for reproducing a recording medium such as a magnetic tape in which an audio signal, a video signal or a composite signal thereof is recorded as a main signal, the presence or absence of the main signal recorded on the recording medium. When the main signal presence / absence detecting means for detecting and the main signal presence / absence detecting means detect that there is a main signal, the holding means for holding the signal as main signal presence information, and the main signal presence information in the holding means In the case where the recording medium is being reproduced in a state where the main signal presence information is held in the holding means, a releasing means for releasing the recording medium by reattaching the recording medium to the reproducing device,
When the main signal is not detected during the first predetermined period, the first control means for switching the operation mode of the apparatus to an operation mode other than the reproduction mode, and the holding means hold the main signal presence information. In the case where the recording medium is being reproduced in the absence state, and thereafter, when the main signal is not detected during the second predetermined period longer than the first predetermined period, the operation mode of the apparatus is set to a mode other than the reproduction mode. And a second control means for switching to the operation mode. 2. A reproducing apparatus according to claim 1, wherein the main signal is a digital signal. 3. The reproducing apparatus according to claim 1, wherein the second predetermined time is set to 20 seconds or more.