JPS629561Y2 - - Google Patents

Description

[Detailed description of the invention] The invention relates to a magnetic recording and reproducing device such as a VTR.
In particular, when a cassette changer is mounted on this magnetic recording and reproducing device so that recording can be performed almost continuously on the magnetic tapes of multiple cassettes, the magnetic recording and reproducing device has a tape end detection mechanism and a cassette changer. The present invention relates to a magnetic tape in which continuous recording is performed on the magnetic tape by prohibiting the operation of the auto-rewind mechanism when the magnetic tape has a rewind mechanism that operates in conjunction with the auto-rewind mechanism.

In general, a cassette VTR records recording signals on almost the entire surface of the magnetic tape inside the cassette.
It is designed to be driven in one direction at a constant speed, and it is not possible to record another signal from the end of the magnetic tape. Therefore, when recording on the magnetic tape ends, an auto-rewind mechanism that automatically rewinds the magnetic tape to the initial winding start position and an auto-shut-off mechanism that detects the start of winding and stops the running mode are provided. There are many.
However, in recent years, in order to extend the recording time, a system called a cassette changer has been proposed, which automatically attaches two or more tape cassettes one after another to predetermined locations within a magnetic recording/reproducing device, allowing continuous recording. This allows it to be easily attached to a magnetic recording/reproducing device during use. However, even when such a cassette changer is used, detecting the end of the magnetic tape and performing the auto-rewind operation and auto-shut-off operation as described above is not enough to perform the auto-rewind operation. However, there is an inconvenience in that continuous recording on the next magnetic tape by the cassette changer is temporarily interrupted, which is a practical problem. That is, in a magnetic recording/reproducing device, an auto changer that operates to eject a tape cassette and load a new tape cassette when the auto rewind operation is completed automatically records on the magnetic tape in a new tape cassette. Since the rewind operation is not performed during the rewind operation time, the desired continuous image information etc. cannot be obtained.

The present invention has been made to improve such conventional drawbacks, and in particular, after detecting the end of automatic rewinding of a magnetic tape, an automatic changer associated with a magnetic recording/reproducing device is used to automatically rewind a tape cassette. In the case where the exchange of
The auto changer detects that it is attached to the magnetic recording/playback device, prohibits the auto rewide operation when the end of the magnetic tape is detected, and automatically changes the tape cassette exchange and constant speed running mode of the magnetic tape. It is an object of the present invention to provide a novel magnetic recording/reproducing device formed as shown in FIG.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 shows a block circuit of the main part of the magnetic recording and reproducing apparatus according to the present invention. 1 is an end sensor that detects the end of the magnetic tape in the tape cassette, and detects the end of the magnetic tape in the tape cassette. Various mechanical means for detection are used, to which is connected a tape end detection circuit 2 equipped with an amplifier for amplifying the detected signal. Further, a stop plunger 4 is connected to the detection circuit 2 via a driver circuit 3 to establish a stop mode of the magnetic recording/reproducing apparatus. Further, a switch 5 is connected to the detection circuit 2, which prohibits the magnetic recording/reproducing device from entering the auto-rewind mode.
A driver circuit 7 is connected to this via a mono-multivibrator 6, and the operation of this circuit energizes a rewind plunger 8 for setting the magnetic recording/reproducing apparatus in an auto-rewind mode. Furthermore, a flip-flop circuit 9 having a set input terminal 9a and a reset input terminal 9b is connected to the detection circuit 2, and a transistor _Tr1, a resistor R, and a capacitor C are connected to the output side of the flip-flop circuit 9.
Another charging/discharging circuit 10 is connected, and a Schmitt circuit 1 for clip level detection is connected to the output side of the charging/discharging circuit 10.
A hold circuit 12 for a timer signal is connected via 1. The hold circuit 12 operates to hold the timer signal set by the timer 13 for a certain period of time, and when the set signal is input, it energizes the relay 14 on the collector side of the transistor Tr ₂ connected to it. , the power supply for the VCR will be cut off. Reference numeral 15 denotes a power switch whose opening and closing are controlled by the relay 14 described above.

Figure 2 shows VTR 16 and cassette changer 17.
1 is a schematic perspective view showing the relationship between the VTR and the
The prohibition switch 5 is provided on the top surface of the cassette 16. The prohibition switch 5 can be manually operated to be turned on or off regardless of the presence or absence of the cassette changer 17. Alternatively, the prohibition switch 5 can be manually operated to be turned on or off regardless of the presence or absence of the cassette changer 17.
The cassette changer 17 is mounted so that when it is placed on the top panel of the VTR 6, a protrusion protruding from the cassette changer 17 will push in and operate the switch 5 inside the VTR. Therefore, when the cassette changer 17 is not installed, the switch 5 is closed. It is also possible to make the switch 5 unable to be operated by hand from the outside.

Next, the operation of such a magnetic recording/reproducing device will be described.

First, store a tape cassette in the cassette holder of the VTR 16, set the VTR 16 to record mode, and set the absent recording timer 13 for two tape cassettes (this depends on the type of cassette changer and recording mode). (depending on the length of time). Then the above
A cassette changer 17 with one tape cassette to be replaced is placed on the VTR 16. At this time, the prohibition switch 5 is opened as described above. When the time set by the timer 13 is reached, the VTR 16 starts the recording operation, and the recording mode is established at _T1 as shown in FIGS. 3a and 3b, and the timer is turned on. That is, the transistor _Tr1 is turned on by the signal from the reset input terminal 9b of the flip-flop circuit shown in FIG. Therefore, the hold circuit 12 is not energized at all. Therefore, the relay 14 is not energized, the power switch 15 is kept on, and the recording operation continues in this state. When the magnetic tape reaches the end, it is detected by the end sensor 1 described above, and the detection signal is supplied to the driver circuit 3 and the set input terminal 9a of the flip-flop circuit 9 through the detection circuit 2. be done. As a result, the driver circuit 3 is driven, the stop plunger 4 is energized, and the VTR is placed in the stop mode. Meanwhile, the flip-flop circuit 9 inverts the operation of the transistor Tr ₁ according to its set input. , this transistor
The collector potential of Tr ₁ will rise. Therefore, the potential across the capacitor C (at the point A) rises as shown in FIG. 3c. When the rise reaches a certain level, the Schmitt circuit 11
The hold circuit 12 is energized by the signal obtained by driving the hold signal, and holding of the hold signal is prohibited. However, the cassette changer 17
If the tape cassette is replaced quickly,
A new recording mode by the cassette changer 17 is immediately established. That is, if the tape cassette exchange time Tc is shorter than the time for the potential at the point A to reach the operating level of the Schmitt circuit 11, a signal is obtained at the reset input terminal 9b of the flip-flop circuit 9, and the transistor _Tr1
is turned on, the potential at point A is lowered, and the energization of the hold circuit 12 by the Schmitt circuit 11 is also stopped. In this way, recording on the magnetic tape of the tape cassette to be replaced for the second time continues after a short time Tc. When the second recording is completed and the end of the magnetic tape is detected, the stop plunger 4 is energized as described above to establish the stop mode, and a tape end signal is sent to the set input terminal. is supplied, the state of the flip-flop circuit 9 is inverted again, and the transistor
The operation of Tr ₁ is turned off, and the potential at the point A increases. At this time, if there is no tape cassette to be replaced in the cassette changer 17 and the tape cassette is not replaced, the VTR 16 will not be able to enter the recording mode again. At a predetermined input level at a time Ts exceeding , the Schmitt circuit 11 is activated, energizes the hold circuit 12 to release the hold, and turns on the transistor _Tr2 . This energizes the relay 14 and opens the power switch 15, stopping all modes of operation. That is, when the cassette changer 17 is set on the VTR 16,
Even if the end of the magnetic tape in the tape cassette is detected, the auto-rewind operation is not performed and re-recording continues immediately after replacing the tape cassette, allowing almost continuous recording and playback of long-running television programs. It becomes possible.

On the other hand, the cassette engine 1 is attached to the VTR 16 above.
If you do not want to equip 7, use the prohibition switch 5 above.
is closed. As described above, when the recording operation is started with the operation of the timer 13,
The recording signal and the timer output are as shown in the time charts of FIGS. 4a and 4b. At this time, a reset signal is input to the reset input terminal 9b, and the flip-flop circuit 9 enters the reset state. Therefore, the transistor _Tr1 is on, the Schmitt circuit 11 does not operate, the timer signal is kept in a hold state, and the power switch 15 is also closed. However, when recording is completed and a tape end signal is input to the end sensor 1, the stop plunger 4 is energized and a stop mode is established, and the driver circuit 7 is activated after the operating time TA of the mono multivibrator 6. Through this, the rewind plunger 8 is energized as shown in FIG. 4c, and the VTR 16 enters the rewind mode to rewind the magnetic tape. Incidentally, at this time, the potential at point A is as shown in FIG. 4d. When the magnetic tape is returned to the starting position by this rewinding operation and time Ts has elapsed, this is detected by the tape sensor 1 and the stop plunger 4 is activated via the driver circuit 3. energized,
Since the VTR 16 enters the stop mode and a set signal is input to the set input terminal 9a of the flip-flop circuit 9, the potential at the point A rises and drives the Schmitt circuit 11 at a certain level. Due to this, hold circuit 1
2 is energized, the transistor Tr ₂ becomes conductive, the relay 14 is energized, the power switch 15 is opened, and all modes are stopped.

Furthermore, Fig. 5 is a time chart of the signal when forming the fast forward or rewind mode by manual operation from the record mode or playback mode. By operating the read mode switch, at the end of the recording or playback mode of FIG. 5a, a pulse as shown in FIG. A word plunger (not shown) is energized to operate the VTR in this mode, and when rewinding or winding of the magnetic tape is completed, an end sensor detects the end or beginning of the magnetic tape (the first 5c), by immediately energizing the hold circuit 12, the hold signal of the timer 13 is stopped as shown in FIG. 5d, the power switch 15 is opened, and all modes are stopped. It can be carried out.

As explained in detail above, according to the present invention, the magnetic tape end detecting means detects the end of the magnetic tape in the tape cassette, and the detection signal from the detecting means is supplied to the tape rewinding means drive circuit. In the magnetic recording and reproducing apparatus equipped with an auto-rewind mechanism for rewinding the magnetic tape, a switching means is provided between the magnetic tape end detection means and the tape rewinding means driving circuit, and the switching means When the operating section of the magnetic recording/reproducing apparatus is configured to face an opening provided in the outer casing of the main body of the magnetic recording and reproducing apparatus, and when a cassette automatic changer is installed, the switch operating means provided on the cassette automatic changer is configured to face the opening provided in the outer casing of the main body of the magnetic recording/reproducing apparatus. By switching the cassette changer, the auto-rewind mechanism is deactivated and the tape cassette can operate in conjunction with the tape cassette. When the cassette changer is in use, the auto-rewind operation of the magnetic recording/reproducing device is regulated and smooth operation is achieved. It is possible to exchange tape cassettes and perform continuous recording with short non-recording times over a long period of time.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG.
A block circuit diagram of a VTR. Fig. 2 is a schematic perspective view of a VTR equipped with a cassette changer. Figs. 3 and 4 are time charts showing the operation of the circuit shown in Fig. 1. Fig. 5 is also a VTR. This is a time chart showing the operation in another usage method. 1...End sensor, 4...Stop plunger, 5...Auto rewind operation release means, 8
...Auto rewind plunger, 16...Main body of magnetic recording and reproducing device, 17...Cassette changer.

Claims (1)

[Scope of utility model registration request] An auto-rewind mechanism that detects the end of a magnetic tape in a tape cassette by a magnetic tape end detection means, supplies a detection signal from the detection means to a tape rewinding means drive circuit, and rewinds the magnetic tape. In a magnetic recording and reproducing device equipped with
A switching means is provided between the magnetic tape end detection means and the tape rewinding means driving circuit, and the operating section of the switching means is configured to face an opening provided in the outer casing of the main body of the magnetic recording and reproducing apparatus, When the cassette autochanger is installed, the switch operating means provided on the cassette autochanger operates the operating section of the switching means to cancel the operation of the auto rewind mechanism and to control the interlocking operation of the tape cassette. A magnetic recording/reproducing device characterized in that it enables.