JPS60247801A - Reproducing device - Google Patents

Abstract

PURPOSE:To prevent erasion of recorded important information resulting from malfunctions in a magnetic recorder, by constituting the circuit in such a way that the erasion becomes possible only when the content of recorded information of a recording carrier is confirmed under the reproducing condition. CONSTITUTION:The output of a reproducing operation commanding circuit 13 is boosted from the low level L to the high level H at the 1st turning on of a reproducing switch 14 and returned to L at the 2nd turning on. When an erase switch 20 is turned on under the reproducing condition, a timer 16 is actuated and a magnetic head 3 is connected with a recording amplifier 23 and at the same time, an erase signal generating circuit 21 generates an erase signal. Then video signals are recorded on the track of a magnetic disk 1 through the magnetic head 3 under a superposed condition and already recorded video signals are erased. When the reproducing condition is not set, no erasing operations are performed even when the erase switch 20 is turned on, because the reproducing operation commanding circuit 13 outputs the L signal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a reproducing device, and more particularly to a reproducing device equipped with erasing means for erasing recorded information from a record carrier.

[Prior art]

For example, in a magnetic disk playback device that uses a rotating magnetic disk as a record carrier and plays back information such as a video signal recorded on its annular recording tracks, the information recorded on each annular recording track is It is beneficial to be able to erase them individually. .

In this case, for example, with one operation of the erase switch, the
It would be extremely convenient if it was configured so that information on one drug could be deleted.

On the other hand, with such a configuration, if the erase switch is operated by mistake, the recorded information on one track on the magnetic disk that the erase head is in contact with may be partially damaged. Or it could be completely erased, causing you to lose important records that you don't want erased.

〔the purpose〕

This invention was developed in view of the above circumstances, by making it possible to erase the information recorded on the record carrier only when the content is confirmed.

It is an object of the present invention to provide a reproducing device capable of erasing information, which can eliminate the undesirable situation of loss of important recorded information due to erroneous operation.

[Example of real sister]

The present invention will be explained below based on the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention.

In the figure, reference numeral 1 denotes a magnetic disk as a record carrier, on which one field of video signals is recorded as information on each concentric track. 2 is controlled by a motor control circuit (not shown) at a speed that is 5 times higher than the field frequency of the standard television system (for example, in the case of the NTSC system &i,
A motor rotating at a speed of 3.60 Orpm rotates the mJ magnetic disk 1 in the direction of the arrow. 3 is a magnetic head provided so as to be in contact with the magnetic disk 1;
This magnetic head 3 is moved in the radial direction of the magnetic disk 1 as shown by the double-headed arrow by a head moving mechanism 4,
It is now possible to change the opposing track. 5 is a head movement control circuit which moves the magnetic head 3 one track pitch to the right (toward the center of the magnetic disk 1) when the forward switch 6A is turned on;
When the day is ONL, the magnetic head 3 is moved one track.
The head moving mechanism 4 is controlled to move the head by a pitch to the left (toward the outer circumference of the magnetic disk 1). Reference numeral 7 denotes a reproduction processing circuit, which inputs the signal from the magnetic head 3 via the first gate circuit B and the reproduction amplifier 9, and performs reproduction processing.

The magnetic head 3, the reproduction processing circuit 7, the first gate circuit 8. The reproduction amplifier 9 constitutes reproduction means for reproducing recorded information.

Reference numeral 10 denotes a display device which inputs the signal subjected to rQ raw processing in the reproduction processing circuit 7 and the video signal from the video signal input 11 via a second switching circuit 12, and displays the input signal as a visible image 1. Reference numeral 13 denotes a regeneration operation command circuit, the output of which changes from low level (L) to high level (H) when the town student switch 14 is turned on for the first time, and returns to L when it is turned on for the second time. There is. 115
is an AND gate, which inputs a signal from a timer 16 for setting an erasing period via an OR gate 17 and an inverter 18, and also inputs a signal from the reproduction operation command circuit 13, and its output signal controls the first gate. circuit 8
and controls the second switching circuit 12. The timer 16 is set to a time sufficient to erase one track's worth of signals on the magnetic disk 1. , 19 are AND gates which input signals from the erase switch 20 and the reproduction operation command circuit 13, and control the operation of the tie 716 by the output signals thereof.

The A N , D gate 19 and erase switch 20 constitute erase control means.

Reference numeral 21 denotes an erasing signal generating circuit as an erasing means for erasing recorded information, which is ON-Oh"F controlled based on the signal level from the timer 16.

22 is a first switching circuit, which connects the erasure signal generation circuit 21 and the recording amplifier 23 when the signal level from the timer 16 is H, and connects the recording processing circuit 24 and the recording amplifier 23 when the signal level is L; The recording processing circuit 24 is adapted to process the video signal from the video signal source 11 for recording. 25 is a second gate circuit, which is ON-OFF controlled based on the level of the output signal of the gate 17, and connects and separates the magnetic head 3 and the recording amplifier 23. 26 is a synchronization signal separation circuit. , the video signal is separated into vertical and horizontal synchronization signals. 27 is a gate control circuit.

Immediately after the recording switch 28 is turned on, one field period H (number i) including the vertical synchronizing signal from the synchronizing signal separation circuit 26 is output. Note that the output of this gate control circuit 27 is , and is also sent to the head movement control circuit 5 as a control Will signal for head movement.

Next, the operation will be explained based on the above configuration.

First, the recording operation will be explained.

In the recording mode, the playback switch 14 is set to 01”F,
The reproduction operation command circuit 13 outputs L (i). Therefore, the output of the A N I gate 19 is L, and the timer 16 is maintained in an inactive state. Therefore,
The timer 16 outputs L(i), and this L signal is input to the first switching circuit 22 and the OR gate 17.The first switching circuit 22 then connects the recording processing circuit 24 and the recording amplifier 23. Connecting.

While projecting the signal from the video signal source 11 on the displayer 10, turn on the recording switch 28 at a desired timing.
When N, the gate control circuit 27 is connected to the synchronization signal separation circuit 26.
An H signal is output for one field period including the vertical synchronization signal immediately after the recording switch 28 is turned on in synchronization with the vertical synchronization signal from the recording switch 28, and this H signal is input to the gate 17 (01).

Then, the gate 1''r inputs this H signal to the second gate circuit 25 to connect the recording amplifier 23 and the magnetic head 3.

At this time, the H signal from the OR gate 17 is input to the inverter 18, inverted to an L signal, and then input to the AND gate 15. Here, in the recording mode, the endogenous operation command circuit 13 That's the output! 7A
The ND gate 15 outputs an L signal, so the H signal from the gate control circuit 27 has no effect. Incidentally, when the output of the AND gate 15 is L, the first gate circuit 8 becomes OFF' F, and the magnetic head 3 and the reproduction amplifier 9 are separated, while the second switching circuit 12
, the video signal source 11 and the displayer 10 are connected. Therefore, the video signal from the video signal source 11 is displayed as a visible image on the display area 10 in a manner similar to a series of images.

As described above, when the second gate circuit 25 is turned on with the first switching circuit 22 connecting the recording processing circuit 24 and the recording amplifier 23, the input signal from the video signal source 11 to the recording processing circuit 24 is turned on. One field of the video signal processed here is input to the magnetic head 3, and recorded by the magnetic head 3 while forming an annular track on the magnetic disk 1.

Then, at the same time as the recording of one field's worth of video signals is completed, the level of the output signal of the gate control circuit 2T changes from H to L, and in response to this fall, the head movement control circuit 5 operates the head movement mechanism 4. and moves the head 3 by one track pitch.

Next, the reproduction operation will be explained. In the reproduction mode, the recording switch 28 is OFF and the output of the gate control circuit 27 is maintained at L. Also, l
If the thick white switch 20 is OFF, it is the A N D gate 1.
The output of 9 is low, which keeps timer 16 inactive. Then, the timer 16 outputs the I'' signal and inputs this L signal to the OR gate 17. Also,
The L signal from the gate open side 1 circuit 27 is input to the OR gate 17, so this 01 (, gate 17 outputs the L signal, this L signal is input to the second gate circuit 25, and the second The magnetic head 3 and the recording amplifier 23 are separated by turning off the 62nd gate circuit 25.
The L signal from gate 1γ is input to inverter 18,
H (inverted to i). Then, this 11 signal is
The signal is input to the D gate 15.

When the regeneration switch 14 is turned on, the regeneration operation command circuit 1
3 outputs an H signal and inputs this signal to the AND gate 15. Then, the AND gate 15 outputs the F3 signal, inputs this H signal to the first gate circuit 8 and the second switching circuit 12, turns on the first gate circuit 8, and switches the magnetic head 3 and the reproduction amplifier 9. At the same time, the reproduction processing circuit 7 and the display player 10 can be connected by the second switching circuit 12. The endogenous processing circuit 7 inputs the signal from the magnetic head 3 via the first gate circuit 8 and the reproduction amplifier 9, processes it, and displays it on the display 10 as a visible image. The recording track on the magnetic disk 1 to be reproduced can be changed by operating the switches 6A and 6B and operating the head moving mechanism 4 through the control circuit 5.

Next, the erase operation will be explained.

When the erase switch 20 is turned on in the above reproduction state and the H signal is input from the erase switch 20 to the A N l) gate 19, the AND gate 19 inputs the 14 signal to the timer 16 to activate the timer 16. When the timer 16 starts operating, the timer 16 outputs an H signal at the same time.
This H signal is transmitted to the erase signal generating circuit 21. It is input to the first switching circuit 22, OR, and gate 17. Then, the 01-4 gate 17 outputs an H signal, which is input to the second gate circuit 25 to connect the second gate circuit 25 to ONL, the magnetic head 3, and the recording amplifier 23. The first switching circuit 22 connects the erase signal generating circuit 21 and the recording amplifier 23. Further, the erase signal generation circuit 21 generates an erase signal.

Therefore, this erase signal is transmitted to the first switching circuit 22.
A video signal is recorded via the recording amplifier 23, the second gate circuit 25, and the magnetic head 3 over the already recorded track of the magnetic disk 1, and the already recorded video No. 41 is erased.

When the set time of the timer 16 has elapsed and the timer 16 stops operating, the timer 16 outputs the L4% number and inputs it into the L (OR game with the i number) 17.

Then, the 01t gate 17 outputs an L signal, and this L
(No. 3 is manually input to the second gate circuit 25. Then, this second gate circuit 25 is connected to the OF l”L, magnetic head 3
and the recording amplifier 23 are separated. Also, OR gate 1
The L signal from 7 is input to the inverter 18 and inverted to H (% sign), and this H signal is input to the AND gate 15.1Then, the AND gate 15 outputs the H signal, and this The input signal is input to the first gate circuit 8 and the second switching circuit 11. This turns on the first gate circuit 8, connects the magnetic head 3 and the reproduction amplifier 9, and also causes the second switching circuit 12 to The reproduction processing circuit 7 and the displayer 10 are connected.At this time, since nothing is displayed on the displayer 10, the operator can confirm that the recorded signal has been erased.

Here, if it is not in playback mode, press the erase switch 2.
Even if 0 is turned ON, since the reproduction operation command circuit 13 outputs an L signal, the timer 16 does not operate and the erasing operation is not performed.

In the above embodiment, a case has been explained in which the recording and reproducing bag 1' is used, but as shown in the reproducing apparatus shown in FIG.
switching circuit 22. Gate control circuit 27. Recording switch 25, OR gate 17, video signal source 11, synchronizing signal separation circuit 26, and second switching circuit 1
Even if 2 is deleted, it is of course possible to perform the erasing operation only in the reproduction state as in the above embodiment.

Furthermore, although the above embodiment describes the case where the present invention is applied to a magnetic disk recording/reproducing device, the present invention is not limited to this embodiment.

〔effect〕

As explained above, this invention allows erasure of recorded information on a record carrier only when it is confirmed by its reproduction. It has the effect of alleviating fears.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a block diagram showing another embodiment of the invention. 1...Magnetic disk 3...Magnetic head γ...Reproduction processing circuit 8...(first ) Gate circuit 9...
... Reproduction amplifier 16 ... Timer 19 ... AN, l) Gate 20 ... Erasure switch 21 ... Erasure E number generation circuit 23 ...・Recording amplifier

Claims (1)

[Claims] A reproducing device for reproducing information recorded on a record carrier, comprising: reproducing means for reproducing the recorded information; erasing means for erasing the recorded information; and the reproducing means are set in an operating state. 1. An erasing control means that enables the erasing means to record information only when the information is recorded.