JPH0531221B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to magnetic recording and reproducing devices such as video tape recorders.

Background Art In recent years, the prevalence of magnetic recording and reproducing devices (hereinafter abbreviated as VTR) has increased, and commercially available soft tapes have become abundant. There is also an increasing number of accidents in which VTRs are damaged during recording or playback.

FIG. 3 is a block diagram of a safety circuit in a conventional VTR. The outline is explained below. First, the rotation command A enters the motor control circuit 6, this control output enters the motor control circuit 7, and the capstan motor 8 is rotated by this drive output. This capstan motor 8 is equipped with a rotational phase generator 10 for motor control, and this output (FG) is returned to the motor control circuit 6.
Controls the rotation of the capstan motor 8.

On the other hand, the rotation of the capstan motor 8 is transmitted to the reel 1 by a transmission device 9 such as a belt, gear, or pulley, and the reel 1 rotates. This reel 1 is equipped with a rotation detection device 2, which generates a pulse synchronized with rotation, and this pulse is F
→ Enter the V (frequency → voltage) conversion circuit 4. If some abnormality occurs here (for example, the capstan motor 8 does not rotate, or the transmission device 9 such as a belt comes off), the reel rotation detection device 2 will no longer generate pulses, and the F→V conversion circuit 3 detects this condition and activates the abnormality detection circuit 4.
and enter it. If the reel is not rotating despite a rotation command, the abnormality detection circuit 4 outputs an abnormality signal to the motor stop command circuit 5. In response to this abnormality signal, a stop command is issued from the motor stop command circuit 5 to the motor control circuit 6, and the capstan motor 8 is stopped.

This safety circuit performs the operations described above, but this circuit has the following drawbacks. That is, if the capstan motor 8 does not rotate, the tape is pulled out to the running position, and then an abnormality is detected and the unloading command circuit 11 is activated.
An unloading command is then issued to the loading motor drive circuit 12, whereby the loading motor 13 unloads. However, since the capstan motor 8 does not rotate, the tape cannot be wound on the reel 1, and the tape remains drawn out into the running system. Next, when you remove the tape, it comes out as a ``crunchy'' mess.

Problems to be Solved by the Invention However, the conventional configuration has a problem in that if the capstan motor does not rotate due to some abnormality, tape damage will inevitably occur.

In view of the above-mentioned problems, the present invention provides a magnetic recording and reproducing apparatus which prevents tape damage even if the capstan motor does not rotate due to some abnormality by devising a safety circuit.

Means for Solving the Problems In order to solve the above problems, the magnetic recording and reproducing device of the present invention prevents the tape from being properly stored inside the cassette due to the reel rotation detection device and the capstan motor rotation detection device. If this occurs, the system is configured to recognize this and prohibit tape ejection.

Effect The present invention has the above-described configuration, so that even when the capstan motor does not rotate normally, the capstan motor's rotation detection device detects this and ejects the tape. ) The prohibition circuit prevents the tape from being ejected, thereby preventing tape damage.

Embodiment An embodiment of the present invention will be described below with reference to FIG.

When the VTR enters the playback mode, the rotation command A enters the motor control circuit 6, its control output enters the motor control circuit 7, and the drive output causes the capstan motor 8 to begin rotating. This capstan motor 8 not only drives the tape, but also rotates the reel 1 via a transmission device 9 (belt, pool, etc.) to wind up the tape. The reel 1 is equipped with a reel rotation detection device 2 on the winding side, and this output pulse is detected by F→
The frequency is converted into voltage by the V conversion circuit 3 and input to the abnormality detection circuit 15.

On the other hand, the capstan motor 8 is equipped with a rotational phase generator 10, and the output FG signal is
It is input to the F→V conversion circuit 14 in parallel with that used to control the rotation of the capstan motor 8. The F→V conversion circuit 14 converts the FG signal into a voltage and inputs it to the abnormality detection circuit 15. This abnormality detection circuit 15 outputs an output signal to the motor stop command circuit 5 to stop the capstan motor 8 when either the reel 1 or the capstan motor 8 does not rotate normally, or when both do not rotate normally. At the same time, an output signal is also sent to the tape ejection prohibition circuit 16, and this circuit sets the front loading drive circuit 17 to a stop mode.
The front loading motor 18 is made inoperable. As a result, especially when the capstan motor 8 does not rotate, it is possible to prevent the occurrence of a situation in which the tape is unloaded while being pulled out into the tape running system, and then ejected, causing the tape to become "crunchy".

When the above-mentioned failure mode occurs, the service department manually takes out the tape without damaging it, and then repairs the failure, thereby making it possible to reliably prevent conventional tape damage.

FIG. 2 shows another embodiment of the present invention, and the only difference from the embodiment shown in FIG. 1 is that the front loading drive circuit 17 and front loading motor 18 are replaced by a loading drive circuit 12 and a loading motor 13. It is. In other words, when an abnormality is detected, the loading motor is prohibited from rotating to the eject position, making it impossible to remove the tape.

Furthermore, the eject position mentioned here is
The state of the mechanism when ejecting the tape (the main brake is disengaged, and the main brake is engaged when stopped). The VTR has
The mechanism has states such as play, review, FF/REW, stop, and eject, and these positions can be moved by rotating the loading motor. In the embodiment shown in Fig. 2, the tape is ejected.
To remove slack from the tape before
After moving to the FF or REW position, the rotation of the capstan motor is detected, and if an abnormality is detected, the loading motor is prohibited from moving to the eject position.

Effects of the Invention As described above, according to the present invention, even if an abnormality occurs in which the cabstan motor does not rotate, this can be detected by detecting the rotational state of the reel and the rotational state of the capstan motor, and the tape can be removed. By prohibiting this, tape damage can be effectively prevented and excellent effects can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a main part of a first embodiment of the present invention, FIG. 2 is a block diagram of a main part of a second embodiment of the invention, and FIG. 3 is a block diagram of a main part of a conventional example. 1... Reel, 2... Reel rotation detection device, 3
...F → V conversion circuit, 5 ... Motor stop command circuit, 6 ... Motor control circuit, 7 ... Motor drive circuit, 8 ... Capstan motor, 9 ... Transmission device, 10 ... Rotation phase generation Device, 12... Loading drive circuit, 13... Loading motor, 14... F→V conversion circuit, 15... Abnormality detection circuit, 16... Tape removal prohibition circuit, 17
...Front loading drive circuit, 18...Front loading motor.

Claims (1)

[Claims] 1. A helical scan type magnetic recording and reproducing device that drives a reel with a capstan motor, including a capstan motor rotation detection device that detects the rotational state of the capstan motor, and a reel that detects the rotational state of the reel. a rotation detection device; an abnormality detection device that detects an abnormality when a signal indicating rotation abnormality is generated from at least one of the reel rotation detection device and the capstan motor rotation detection device; and an abnormality detection device that responds to the output of the abnormality detection device. 1. A magnetic recording and reproducing apparatus comprising a tape ejection inhibiting device for prohibiting ejection of a tape cassette.