JPS6383904A - Still picture recording and reproducing device - Google Patents

Abstract

PURPOSE:To obtain a still picture recording and reproducing device having an erasing function which is free from a sense of insecurity and has a good operability, by constituting the titled device so that a fact that an erasing operation has been started and a fact that a recording signal has been erased can be confirmed directly and visually. CONSTITUTION:The titled device is controlled so that muting is applied to an output video signal in the course of an erasing operation, the muting is released at the time point when the erasion has been ended, and also, the recording and reproducing system always becomes a reproducing state once. That is, since muting is applied to a reproducing signal a processing circuit 14 in the course of erasion, a viewer can confirm a fact that the erasing operation has been started. Also, at the time point when the eration has been ended, the system becomes a reproducing state immediately, and also, the muting is released, therefore, the no-signal noise is reproduced on a monitor screen of a display device 15. In this way, the viewer not only can confirm a fact that the erasing operation has been ended, but also can confirm directly and visually whether the recorded signal has been erased exactly or not, and a sense of insecurity for an operation in the erasing operation is not generated.

Description

[Detailed description of the invention] [Field of professional use] The present invention records video signals using a rotating recording medium.

The present invention relates to an FE filter for reproduction, and particularly to a still image recording and reproducing apparatus having a signal erasing function.

[Conventional technology]

Recently, a large number of still image video signals are recorded on concentric tracks using, for example, a small rotating magnetic disk as a recording medium.
A so-called electronic camera system has been developed that easily reproduces video footage on a video monitor. Generally speaking, in these recording/playback devices, when the playback head moves to an unrecorded track in the playback state, or when a magnetic disk with no signals recorded on it is inserted into the playback state, the video monitor device In this case, so-called no-signal noise containing speckled noise is output, which causes discomfort to the viewer. An example of a device in which this number has been changed is shown in Japanese Patent Laid-Open No. 85269/1983. This device detects the level of the signal read by the playback head, and if it is determined that the level is below the basic level, it overshadows the video signal circuit or causes an EE condition in the video signal circuit. The monitor is configured to prevent no-signal noise from being output to the video monitor.

[Problem that the invention seeks to solve]

However, although conventional devices are easy to use during normal playback, they do not take into consideration the case of track erasing. In other words, the above-mentioned recording/reproducing device uses a high coercive force (high Hc
) If you are using a recording medium and want to rewrite the recorded signal, overlapping recording will cause the recorded image quality to deteriorate due to unerased areas. Therefore, in order to re-record a nice image, it is necessary to once completely erase the recorded signal and then re-record it, and a track erasing means is required. However, when the above-mentioned conventional technique is applied to a recording/reproducing apparatus equipped with this track erasing means, problems arise. That is,
Since the track with seven squares erased is equivalent to an unrecorded track, when the playback mode is set to confirm the erasure after erasing, it is automatically controlled to be in the Mieto or EE system. However, since these control states can occur even when the device is stopped or in other cases, the viewer may mistake it for a malfunction, or the viewer cannot directly confirm that it has been erased. There was a problem that there was still some uneasiness during operation.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to realize a still image recording/reproducing device having an erasing function with good operability.

[Means for solving problems]

The above purpose is to provide a control means that mutes the output video signal at least during the erasure operation, and a control means that releases the mute at the erased track position at the end of the erasure and always puts the recording/playback system into the playback state. This is achieved by providing a control hand R'lt.

[Effect]

In the above configuration, muting is applied during erasing, so that the viewer can confirm that the erasing operation has started. Further, as soon as erasing is completed, the reproduction state is entered and the mute is released, so that no-signal noise is reproduced on the monitor screen on the display. This allows the viewer to confirm that the erasing operation has been completed, and also allows the viewer to directly visually confirm whether or not the recorded signal has been securely erased. There is no.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the apparatus of this embodiment shown in FIG. 1, a magnetic disk 1 as a rotating magnetic recording medium is removably mounted on a rotating shaft 5 of a DC motor 2. The magnetic disk 1 is made of a magnetic sheet coated with a matrix recording material and has a diameter of about 5 Qmm, and a plurality of recording tracks, for example 50 recording tracks, are concentrically recorded on its recording surface.

The signal recorded on the recording track is a video signal, for example, an old color video signal in which a luminance signal and a skin sequential color difference signal are FM modulated and frequency multiplexed (one field of video signal is recorded to one track). be done.

The DC motor 2 is rotated by a motor drive circuit 4, and is servo-controlled by a speed control circuit 5 to rotate at a constant speed of a predetermined rotation speed, for example, 3600 rotations/minute.

A magnetic head 6, which is integrally formed with a recording/reproducing head 6α and an erasing head 6b arranged on the same track, is in sliding contact with the recording surface of the magnetic disk 1. This magnetic head 6 moves the head! [7] is configured to be movable in the radial direction of the magnetic disk 1 in response to the signal TEACK output from the control circuit 8, from the outermost circumference 1 @ to the innermost circumference 5
It is configured so that any track on the recording surface up to address 8 can be selected.

The recording/reproducing head 6α is connected to a recording amplifier 1o and a reproducing amplifier 11 via a cutoff switch circuit 9t. During recording, the video signal input to the input terminal 12 undergoes signal processing such as FM modulation by the recording signal processing circuit 13, and then is transferred to the magnetic disk 1 by the recording/reproducing head 6α via the recording amplifier 10 and the changeover switch circuit 9. recorded. Here, the recording signal processing circuit 15 receives the signal G from the control circuit 8.
The ATE outputs a signal only during one rotation period of the magnetic disk 1, so that one field of video signal is recorded on one track. During video playback, the video signal read by the recording/playback head 6α passes through the switch circuit 9, is amplified by the playback amplifier 11, undergoes signal processing such as demodulation by the playback signal processing circuit 14, and is displayed on the screen of the display device 15. will be played.

The reproduced signal processing circuit 14 further receives the signal MUTE-Jk from the control circuit 8, sets the horizontal scanning period of the video signal as a blank signal, and performs a miniting operation.

The erasing head 6b is disposed integrally with the recording/reproducing head 6a at a position tracing the same track as the recording/reproducing head 6α, and its erasing track width is set to be slightly wider than the track width of the recording/reproducing head 6tL. It is.

This is to erase a wide range of recording signals with respect to the track width, taking into account head positioning errors, misalignment of the 8-air disk 1, or track deviations due to eccentricity caused by expansion and contraction due to changes in thermal anonymity. When erasing,
In response to the signal ERASE output from the control circuit 8, a high frequency erase signal is output from the erase signal circuit 16, and an erase 'rIt current is applied to the erase head 6b via the erase amplifier 17, thereby erasing the recorded signal. Here, the erasing signal is a high frequency signal outside the recording band of the video signal, but it is not limited to this, and other erasing signals such as an FM carrier signal whose amplitude gradually decreases may be used, and the erasing signal of the erasing head 6b may be It is sufficient if the recording signal is an erasing signal that can be sufficiently erased in accordance with the erasing ability.

The aforementioned control circuit 8 is a control circuit advantageously constructed by a microprocessor system, and is connected to various keys for controlling the device according to operations by an operator. In the embodiment, a playback key PBCF indicating the playback mode of the device is used.
II' or RV), a forward key FW that moves the magnetic head 6 in the forward direction (for example, from an outer track to an inner track), and a backward key RV% device that moves the magnetic head 6 in the opposite direction. Stop key 5rp1 to start the device and instruct recording standby -R, S, recording key REC to instruct recording in the recording standby state, and erase key REC to instruct signal erasure -? -Equipped with ER.

Next, the operation in the erase mode of this embodiment will be explained with reference to the flowchart of FIG.

First, to erase the signal, operate either the FW or RV of the playback key PB to put the device into the playback mode c 100 ), and then press the track advance operation key FW'
Or display the reproduced image or track address f to the track position to be erased by operating the RV appropriately.
Track movement (1
o1). When a predetermined track is selected and the erase key ER is operated (102), the erase mode is selected and the erase operation is started. Note that the erase key ER is systemized within the control circuit 8 so that it becomes effective only when the previous state is the reproduction mode. By operating the erase key ER, the signal NUT E is first turned on from the control circuit 8.
Output to the status. In response to this, the reproduction signal processing circuit 1
4 mutes the output video signal so that the distorted video during the erasing operation is not displayed on the video monitor screen of the display device ftJm15. This allows the operator to visually confirm that the erasing operation has started. At the same time, the control signal circuit 8 outputs the signal ERASE in an ON state (104), an erase signal is output from the erase signal circuit 16, and an erase current is applied to the erase head 6b via the erase signal amplifier 17. In order to sufficiently erase a signal, applying the erasing current only once (one rotation) may not be sufficient, and erasing must be performed multiple times to sufficiently erase the signal.

Therefore, for example, in this embodiment, the erasing current is applied for a period of five rotations. The number of erase rotations is counted inside the control circuit 8, and when it is determined that the rotation has been completed a predetermined number of times (to5), the signal ERASE is turned off (1o
d), and signal erasure is completed. At the same time signal MUTE
is also in the OFF state (107). Here, since the recording and reproducing system is in the reproducing mode at step 100, the recording and reproducing head traces the erased track and reproduces the no-signal noise on the monitor screen of the display device 15. It is possible to directly visually confirm that the signal cancellation has been completed. Furthermore, by displaying random no-signal noise on the monitor screen, you can also confirm that the signal has been definitely erased. The reproduction state of this old issue noise only needs to be maintained for a short period of time (at least for the operator to recognize the completion of erasing, for example, in this embodiment, it is about 2 seconds. This time is counted by the control circuit 8, When it is determined that a predetermined period of time (2 seconds in the embodiment) has elapsed (108), the device is brought to a halt state (109) and the erasing mode is terminated.

Here, the stop mode was set in step 109, but the magnetic head 6 is returned to another mode, such as a recording standby mode, or to the previous track! +Main mode may be set, and furthermore, the reproduction state of the no-signal noise may be cut off until a button operation instructing the primary operation is performed without limiting the predetermined time.

Next, other embodiments of the present invention will be described.

In the above embodiment, an example was shown in which an erasing head was provided exclusively, but it is also possible to use the erasing head also as a recording/reproducing head, and an example of this is shown in FIG.

In FIG. 3, parts designated by the same reference numerals as those in FIG. 1 are the same as those already described.

In the figure, 20 is a magnetic head for recording/reproducing and erasing, and 21 is a recording/erasing switch circuit, which is switched to terminal d in response to the signal ERASE from the control circuit 8, and outputs the output from the erase signal circuit 16 to the recording term width. Lead to vessel 10. The speed control circuit 5 receives the signal LOWVC output from the control port TM18.
In response, the rotation speed of motor 2 is set at a constant speed (S600 rpm)
It operates to reduce the speed to about 3.

Further, 21 is a character display circuit, which receives a signal CHARA output from the control circuit 8 and displays characters, symbols, etc. on the display device. With such a configuration, when erasing a signal, the operation is performed as shown in the chart a-f +- in FIG. Steps 20 to 202 are the same as in the previous embodiment, and erasing is started by operating the erasing key ER (202). Then, the signal MUTE is ON state B (2
05) Mining is applied to the output video signal, but the signal CHARA is output at the same timing as the signal MUTE, and the track number being erased and characters indicating that the erasing operation is in progress are displayed on the minited screen. Is displayed. This allows the operator to be more sure that the erasing operation has started than in the previous embodiment. Next, the changeover switch circuit 9 receives the signal REC and is connected to the recording side terminal ff1 (2o4), and furthermore, the signal ERASE switches the switch circuit 21 to tL9111 (20
5) An erase signal is applied to the magnetic head 20. In step 206, the signal LO1F' is output from the control circuit 8 to the ON state, and the number of revolutions of the magnetic disk 10 is decelerated to about 3.

This is because, in this embodiment, an AC signal that allows the magnetic head to operate efficiently is used as the erase signal, and the frequency is approximately the same as that of the recorded video signal. For this reason, if the signal is erased at a constant speed, the erased signal will remain as it is.
This will have a negative impact on recording. Therefore, magnetic disk 1
The rotational speed of the signal is reduced, effectively achieving the same effect as canceling the signal using a high-frequency signal outside the band. In addition, since the erasing head also serves as a recording/reproducing head, the recording track width and the erasing track width are the same, and if the recording track is eccentric due to expansion or contraction of the magnetic disk 1, the track will be misaligned during erasing, resulting in unerased portions. Occur. In order to prevent this, in this embodiment, the recording track is erased five times each at positions where the magnetic head is shifted by 2 degrees toward the outer circumference and toward the inner circumference for about 4 equivalents of the track width W. . These operations are performed in steps 207 to 210, and when the recorded signal is completely erased, the application of the erase signal to the magnetic head 20 is stopped (211), and the magnetic head 20 returns to the center position of the recording track (212). ) The erase operation is complete. After that, the signal PB from the control circuit 8 returns to the playback mode (215).
, the miniing and character display are canceled (214), and no-signal noise is reproduced on the screen of the display device 15. This allows the operator to confirm that erasing has been completed.

At the same time, the deceleration signal LOW is also turned off (215), and the magnetic disk 1 is returned to constant speed rotation. The following operation steps 216 and 217 are the steps 108 in the first embodiment.
, 109. When a dual-purpose erasing head is used as the erasing head as in this embodiment, there is generally not much margin for erasing ability, and if there is a large variation in H of the recording medium, There is a possibility that the data cannot be completely erased in one erase operation. Even in such a case, according to this embodiment, since the erased state can be checked on the screen, complete erasing is possible by instructing the erase command again, and there is no adverse effect on the re-recorded image. You can also get the effect of not having one.

In the first and second embodiments described above, the erasing operation of a single track has been explained, but the effects of the present invention do not change even when erasing a plurality of recording track signals in succession. . An example thereof will be described next.

The configuration of the device is the same as the first embodiment shown in FIG.
The operation flow is shown in FIG. 5, and the operation during continuous erasing will be explained. In this embodiment, continuous erasure in the forward or backward direction is made possible by simultaneously operating the erase key ER and the forward key FW or backward key RV that instructs track movement.

In FIG. 5, steps up to step 105 are the same as in the first embodiment, but in the next step 500, it is determined within the control circuit 8 whether or not continuous erasure is to be performed. If only the erase key ER is operated, it is determined that a single track is erased and step 1 is performed.
The process advances to step 06 and operates as described in the first embodiment. On the other hand, at the same time as the erase key ER, for example, the forward key F is pressed.
If W is operated, it is determined in step 300 that the erasure is continuous, and the process proceeds to step 301, where the erased track in step 105 is the final track (in this case, the innermost track or the track at the time when the key FF operation is released). ] If not, advance one track (402) L, repeat erasing until the last track. When the head is sent to the last track while erasing, the process advances from step 501 to step 106, and the process is the same as in the first embodiment described above. Mining is canceled (107), no-signal noise is reproduced on the display device 15, and the erasing mode is ended.

This allows the operator to confirm that the series of erasing operations has been completed.

The embodiments of the present invention have been described above, and in each embodiment, the number of rotations of the magnetic disk is counted and determined, which is the number of times of erasure during erasing, but the number of revolutions during erasing is constant. Therefore, it is also possible to use it as time management, and it goes without saying that similar effects can be obtained. Also,
The gist of the present invention is to mute the output video signal during signal erasure so that the input signal or the main signal is not displayed on the display device, and once the erasure is finished, to reproduce the no-signal noise on the display device. It goes without saying that the present invention is not limited to the embodiments and can be implemented with various modifications within the scope of the claims.

〔Effect of the invention〕

As explained above, according to the present invention, when erasing a signal, the operator can directly visually confirm on the monitor screen that the erasing operation has started and that the recorded signal has been certainly erased, and the operator can do so without feeling anxious. , it is possible to realize a still image recording and reproducing device with an easy-to-operate erasing function.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a flow diagram showing an example of an erase operation in the embodiment, FIG. 5 is a block diagram showing another embodiment, and FIG. A flow diagram showing an example of the erasing operation in the second embodiment of the configuration shown in FIG.
5 shows another example of the erase operation in the first embodiment7
Q-diagram dl...Magnetic disk 5...Speed control circuit 6.20...Magnetic head 8...Control circuit 13...Record signal processing circuit 14...Reproduction signal processing circuit 15. ...Display device 16...Elimination signal circuit, r') Agent: Patent attorney Masaru Ogawa
Male figure 1 Closed figure 2 ￥ J5 figure f PU4 figure

Claims (1)

[Claims] 1. A magnetic head is provided, a plurality of recording tracks are provided concentrically on a rotating magnetic recording medium, and a video signal is recorded on each track by the magnetic head, and a video signal is recorded from the recorded track. A still image recording/reproducing device comprising a magnetic signal processing circuit that reads a video signal using a magnetic head and outputs the read video signal as an output video signal, the device comprising an erasing means for erasing the recorded signal track by track, and the video signal processing circuit control means to mute the output signal by controlling the output signal, and the control means controls the video signal processing circuit to mute the output video signal during the recorded signal erasing operation, and after the erasure is completed. A still image recording and reproducing apparatus, characterized in that the video signal processing circuit is controlled to enter a reproduction mode and release muting at a track position erased by the erasing means. 2. The still image recording and reproducing apparatus according to claim 1, wherein the video signal includes at least a luminance signal and a line-sequential color difference signal, and each signal is an FM-modulated and frequency-multiplexed signal.