JPH03154256A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To guarantee the consecutive recording by detecting a control signal changed in its duty ratio, controlling a capstan motor in order to make a new recording part recorded from the end of the previous recording part and controlling the recording position on a tape. CONSTITUTION:When the tape is rewound into a cassette, a control signal control circuit 8 is controlled by a system control circuit 1, and the duty ratio at the end part of the tape is changed. That is, the change is made for the control signal in such a way that + time(t1 t3) and - time(t2 t4). At the time of reproducing, the capstan motor is controlled by timing for rising + signal in an output of a control signal waveform shaping circuit 10. At this time, when the tape is wound to come under the recording standby state again, the timing for rising one side control signal changed in the duty ratio is detected by the circuit 1 to control a capstan motor control circuit 11, and then the tape is stopped to be under the recording standby state. By this method, the occurrence of a nonrecording part between the previous recording part and the new recording part is prevented.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention involves winding and running a magnetic deso around a rotating cylinder to which a magnetic head is attached, so that the magnetic head and magnetic tape come into sliding contact with each other. The present invention relates to a magnetic recording and reproducing device such as a video tape recorder that records and reproduces predetermined information signals.

(Conventional Technique #I) FIG. 4 is a plan view of a magnetic recording/reproducing apparatus, and FIG. 5 shows a splicing circuit of the conventional magnetic recording/reproducing apparatus. In FIG. 4, 5■ is a rotary cylinder, 52 is a cassette, 53 is a supply reel in the cassette, 54 is a take-up reel in the cassette, 55 is a tape loading means (1), and 56
is a tape loading means (2), 57 is a magnetic tape,
58 is gear (5), 59 is loading gear (1), 6
0 is loading gear (2), 61 is gear (3), 6
2 is a gear (4), 63 is a control head, 64 is a running post (1), 65 is a running post (2), 66 is a worm gear, and 67 is a loading motor.

In FIG. 5, 1 is a system control circuit, 2 is a loading motor, 4 is a power switch, 5 is a cassette eject switch, 6 is a recording standby switch, and 7
8 is a control signal control circuit; 9 is a control head; 10 is a control signal waveform shaping circuit; 11 is a capstan motor control circuit;
12 is a head switching pulse detection circuit, and 13 is a rotating cylinder magnetic head switching pulse detection head.

Next, the operation of the above conventional example will be explained with reference to FIGS. 4 and 5. In FIG. 5, the system control circuit 1 drives the loading motor 2 in response to a signal from the recording/reproduction changeover switch 7. Next, explanation will be given using FIG. 4. Fourth
In the figure, when the loading motor 67 is driven,
By rotating the worm gear 66, the loading motor 67 drives the loading gear (1) 59 in the b direction by the tape loading means (1)' 55-2 connected to the loading gear (1) 59.
The magnetic tape 57-2 is wound around the rotating cylinder 51 from the cassette 52. Similarly, the loading gear (2) 60 is driven by the tape loading means (2) '56-2 which is connected to the loading gear (2) 60 by driving the gear (3) 61°, the gear (4) 62 and the gear (5) 58. magnetic tape 5
7-2 is wound around the cylinder 51. In this state, the recording standby state is entered.

Next, explanation will be given with reference to FIG. 5. In FIG. 5, a recording state is entered from a recording standby state in response to a signal from a recording standby switch 6. At this time, system control circuit 1
controls the control signal control circuit 8 to output a control signal recording current to the control head 9 to record the control signal on the magnetic tape. The control signal recording current generates N and S poles in the control head 9 (see Figure 2). During reproduction, the reproduction voltage of the control head 9 is shaped in the control signal waveform shaping circuit 10. Normally, the control signal is The output of the magnetic head switching pulse detection head 13 of the 0-rotation cylinder that controls the capstan motor at the rising timing of the + or - signal of the output of the waveform shaping circuit 10 is input to the head switching pulse detection circuit 12, and the control The outputs of the signal waveform shaping circuit IO and the head switching pulse detection circuit 12 are input to the capstan motor control circuit 11 to control the capstan motor.

(Problems to be Solved by the Invention) However, suppose now that the magnetic tape is rewound into the cassette by the power switch 4 or the cassette eject switch 5 in the recording state and standby state. At this time, in FIG. 4, the tape loading means (1) 55
-1 and tape loading means (2) 55-2 move into the cassette 52. At this time, in order to prevent the tape from sagging, the cassette supply reel 53 winds the tape while rotating in the C direction for a certain period of time. However, since the winding diameter of the supply portion 53 in the cassette is not constant, when the magnetic tape is wound around the rotating cylinder 51 again to enter the recording standby state, the end of the recording section of the magnetic tape is not fixed to the rotating cylinder 51. It is uncertain where it is located. Therefore, if recording is started again from this state, there is a problem in that either no recording is made between the previous recording section and the new recording section, or a part of the end of the previous recording section is erased.

The present invention is intended to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a magnetic recording/reproducing device that does not create a blank area or erase a part of the recorded information.

(Means for Solving Problem i) In order to achieve the above object, the present invention provides a magnetic recording and reproducing device that includes a rotating cylinder having a magnetic head, a power switch, a cassette eject switch, a recording and reproducing changeover switch, a recording standby switch; a system control circuit that controls the system by inputting the outputs of the power switch, the cassette eject switch, the recording/playback changeover switch, and the recording standby switch; and a control signal inputting the output of the system control circuit. a control signal control circuit for controlling a duty ratio of a control signal; a control head; a control signal waveform shaping circuit for shaping a control signal output from the control head; and a magnetic head switching pulse detection head for the rotating cylinder. and a head switching pulse detection circuit that detects the output of the magnetic head switching pulse detection head, and a capstan motor control circuit that receives the outputs of the control signal waveform shaping circuit and the head switching pulse detection circuit as input signals. It is something.

(Function) Therefore, according to the present invention, before the tape is rewound into the cassette by the cassette eject switch and the power switch, the system control circuit is configured to record a control signal with a changed duty ratio at the end of the magnetic tape. controls the control signal control circuit.

After that, when the magnetic tape is wound around the cylinder and put into the recording standby state again, the system control circuit detects the control signal that changes the duty ratio, and the new recording section is recorded from the end of the previous recording section. The capstan motor control circuit is controlled to control the recording position of the magnetic tape, so that even after the tape is rewound into the cassette, there will be no recording area between the previous recording area and the new recording area, or It has the function of ensuring continuous shooting so that a part of the end of the previous recording section is not erased.

(Embodiment) FIG. 1 shows a guarantee circuit for continuous shooting via eject of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 show timings of control signals, and FIG. FIG. 4 is a plan view of the magnetic recording/reproducing device. 1st
In the figure, the same symbols as in FIG. 5 are the same as in the conventional one, and 3 is a control signal duty ratio control circuit.

Next, the operation of the above embodiment will be explained. In the embodiment described above, the system control circuit 1 drives the loading motor 2 based on the signal from the recording/reproduction changeover switch 7. This will be explained below using FIG. When the loading motor 67 is driven.

Rotate the worm gear 66 and load gear (2) 6
0, the magnetic tape 57-2 is wound from the cassette 52 onto the rotary cylinder 51 by the tape loading means (1)' 55-2 connected to the loading gear (2) 60. Similarly, loading gear (2
) 60 drives the gear (5) 5g, the gear (4) 62, and the gear (3) 61 to load the magnetic tape 57- by the tape loading means (2)' 56-2 connected to the loading gear (1) 59. 2 is wound around the rotating cylinder 51. In this state, recording standby is established.

Next, explanation will be given using FIG. In FIG. 1, a recording standby switch 6 causes a recording state to be entered from a recording standby state. At this time, the system control circuit 1
Controls the control signal control circuit 8, controls the duty ratio of the control signal via the control signal duty ratio control circuit 3, outputs a control signal recording current to the control head 9, and records the control signal on the magnetic tape. . Normally, as shown in FIG. 2, an N pole and an S pole are generated in the control head 9 by the control signal recording current. During reproduction, the reproduction voltage of the control head 9 is shaped by the control signal waveform shaping circuit 10. Normally, the capstan motor is controlled at the rising timing of ten signals among the outputs of the control signal waveform shaping circuit 10. The output of the magnetic head switching pulse detection head 13 of the rotating cylinder is inputted to the head switching pulse detection circuit 12, and the output of the control signal waveform shaping circuit 10 and head switching pulse detection circuit 12 is inputted to the capstan motor control circuit 11. Controls the stun motor.

When the tape is rewound into the cassette by the cassette eject switch 5 and the power switch 4, the system control circuit 1 controls the control signal control circuit 8 to record a control signal with a changed duty ratio at the end of the magnetic tape. do.

In order to record a control signal with a changed duty ratio at the end of the magnetic tape, the time t of the ten control signals shown in FIG. 3 is changed to t3, and the control time t2 is changed to t4.

During reproduction, the reproduction voltage of the control head 9 is shaped by the control signal waveform shaping circuit 10.

To control the capstan motor at the rising timing of ten signals among the outputs of the control signal waveform shaping circuit 10, when winding the magnetic tape around the cylinder and returning to the recording standby state, the system control circuit 1 operates as described above. The rise timing of the unidirectional control signal with a changed duty ratio is detected, the capstan motor control circuit 11 is controlled, the magnetic tape is stopped, and the recording standby state is entered. Thereafter, when the recording state is entered by releasing the recording standby switch 7, a new recording section is recorded from the end of the previous recording section. After the magnetic tape is rewound into the cassette,
Even if you start recording again, there will be a blank section between the previous recording section and the new recording section, or a part of the end of the previous recording section will be erased even in the spliced section between the previous recording section and the new recording section. The shots are taken in succession to ensure that nothing happens.

(Effects of the Invention) As is clear from the above embodiments of the present invention, a rotating cylinder having a magnetic head, a power switch, a cassette eject switch, a recording/reproduction changeover switch,
With recording standby switch.

a system control circuit that controls the system by using the outputs of the power switch, the cassette eject switch, the recording/playback changeover switch, and the recording standby switch as input; and a duty ratio of a control signal using the output of the system control circuit as an input control signal. a control signal control circuit for controlling a control signal, a control head, a control signal waveform shaping circuit for waveform-shaping a control signal output from the control head, a magnetic head switching pulse detection head for the rotating cylinder, and a magnetic head switching pulse for the rotating cylinder. By including a head switching pulse detection circuit that detects the output of the detection head, and a capstan motor control circuit that uses the outputs of the control signal waveform shaping circuit and the head switching pulse detection circuit as input signals, as a result, the cassette After operating the eject switch and power switch, the system control circuit controls the control signal control circuit to record a control signal with a changed duty ratio at the end of the magnetic tape before rewinding the magnetic tape into the cassette. do. After that, when the magnetic tape is wound around the cylinder and put into the recording standby state again, the system control circuit detects the control signal that changes the duty ratio, and the new recording section is recorded from the end of the previous recording section. The capstan motor control circuit is controlled so that even after the tape is rewound into the cassette, there will be no recording between the previous recording section and the new recording section, or a part of the end of the previous recording section will be removed. This has the effect of guaranteeing continuous shooting so that it will not be erased.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a guarantee circuit for continuous shooting via eject of a magnetic recording/reproducing apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are timing diagrams of control signals according to an embodiment of the present invention. Figure 4 is a plan view of the magnetic recording and reproducing device.
FIG. 5 is a block diagram of a continuous shooting circuit of a conventional magnetic recording/reproducing apparatus. 1...System control circuit, 2...Loading motor, 3...Control signal duty ratio control circuit, 4...Power switch,
5...Cassette eject switch, 6...
・Recording standby switch, 7... Recording/playback selector switch, 8... Control signal control circuit,
9... Control head. 10... Control signal waveform shaping circuit, 11...
Capstan motor control circuit, 12... Head switching pulse detection circuit, 13... Magnetic head switching pulse detection head of rotating cylinder, 51... Rotating cylinder 52... Cassette, 53... Supply reel in cassette, 54... Reel for winding inside the cassette, 55-1...
Tape loading means (1), 55-2...Tape loading means (1)'. 56-1...Tape loading means (2), 56-
2...Tape loading means (2)', 57-1.
57-2... Magnetic tape, 58... Gear (5),
59... Loading gear (1), 60... Loading gear (2), 61... Gear (3), 62...
・Gear (4), 63...Control head, 6
4... Traveling post (1), 65... Traveling post (2)
)1.66... Worm gear, 67... Loading motor.

Claims (1)

[Claims] A rotating cylinder having a magnetic head, a power switch, a cassette eject switch, a recording standby switch, a recording/playback changeover switch, and outputs of the power switch, the cassette eject switch, the recording/playback changeover switch, and the recording standby switch. a system control circuit that controls the system as an input; a control signal control circuit that uses the output of the system control circuit as an input control signal to control the control signal; and a control signal control circuit that uses the output of the control signal control circuit as an input and controls the duty ratio of the control signal. a control signal duty ratio control circuit for controlling the control signal, a control head, a control signal waveform shaping circuit for shaping the control signal output from the control head, a magnetic head switching pulse detection head for the rotating cylinder, and the magnetic head. The head switching pulse detection circuit detects the output of the switching pulse detection head, and a capstan motor control circuit whose input signals are the outputs of the control signal waveform shaping circuit and the head switching pulse detection circuit. Magnetic recording and reproducing device.