JPH0297185A - Recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent the degradation of picture quality at the time of continuous reproducing and to shorten an erase time by alternatively moving a third head, which has operatable width over track width and can be independently move to a pair of in-line heads, and a first or second in-line head between the tracks. CONSTITUTION:At the time of the continuous reproducing, the reproducing of (n)XV time is executed by a head 2 for the same track and after that, the track to be next reproduced is reproduced for the same time by a head 1. Then, the above-mentioned operation is repeated. At the time of erasing, switches 11 and 14 are changed over by a control circuit 8 and the torque of a stepping motor 9 is given to the head 2. Then, the center of the head 2 is positioned in the center of the recorded track and a signal for erasing is impressed from an oscillating circuit 12 through an amplifier 13 to the head 2. Then, the erasing is executed. Thus, at the time of the continuous reproducing, the complete envelop of no level change can be obtained and at the time of the erasing, the erasing can be executed only by once rotating a disk. Then, the erase time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording and reproducing apparatus for still video and the like that performs continuous reproduction while keeping one of two heads always in the reproducing state.

[Prior Art] Conventionally, when performing continuous playback in a still video device, one of the two heads (CHI, CH2) is always in the playback state, and when playing a track and moving from one track to the next track, one of the two heads (CHI, CH2) is always in the playback state. Regardless of the format, the reproduced envelope signal of the head is configured to be outputted as a video through the same processing as during normal reproduction.

Figure 5 shows the head trajectory during conventional continuous playback of a still video device; however, the disk is assumed to be in a stationary state.)
, FIG. 6 shows the envelope output level characteristics in FIG.

As shown in Figure 5, the head passes from the video track ■, through the guard punt ■, to the video track ■, and then from the video track ■ through the guard band ■ to the video track link ■, where continuous playback begins. It will be done. At this time, the envelope output becomes the minimum when passing through the guard band as shown in FIG.

Note that when erasing a recorded track, since both the recording head and the erasing head are used, by fixing the head position, both ends of the recording track may be left unerased. That is, considering compatibility as well, there may be cases where the width of the erasing head is smaller than the recording track due to variations, or the recording track may be slightly eccentric, so that unerased data is likely to occur.

For this reason, a configuration is adopted in which the head position is moved several times and the data is erased repeatedly. For example, as shown in FIG. 7, erasing is performed by shifting the position three times for one track A and rotating the recording medium (disc) three times (B is the head movement direction).

[Problems to be Solved by the Invention] However, in the conventional recording and reproducing apparatus as described above, when the head crosses the gart band (approximately 401) during continuous reproduction, the output level of the envelope decreases, and as a result, the video screen There were areas where noise and S/N deterioration occurred, making the video screen difficult to view.

Further, when erasing, it is necessary to repeat the erasing operation by moving the head to several points as shown in FIG. 7, resulting in problems such as complicated control and increased erasing time.

The present invention has been made to solve these problems, and it is an object of the present invention to provide a recording and reproducing apparatus that can prevent image quality deterioration during continuous reproduction and shorten erasing time.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides recording, reproducing,
1st for erasing. In a recording/reproducing apparatus equipped with a second in-line head, a third bed having a movable width exceeding a track width and movable independently with respect to the pair of in-line heads; Alternatively, the control means is provided to alternately move the second in-line head between tracks, and to switch and output video signals from these in a vertical blanking section for continuous reproduction.

Further, in order to erase data without leaving anything unerased, it is preferable to use the third head, which can have an erasing width wider than the track width, for erasing.

Further, in order to perform video signal switching in the vertical blanking section without damaging horizontal continuity, the distance between the pair of in-line heads and the third head is preferably set to an integral multiple of the horizontal section.

[Function] With the above configuration, one of the pair of inline heads and the third head alternately move between tracks, and the video signal is continuously played back avoiding the guard band, so the envelope output No level drop occurs and no noise or the like is generated on the screen.

Further, the third head, which can have an erasing width wider than the track width, erases the entire width of one track in one erasing operation. Therefore, it is no longer necessary to repeat erasing while moving the head at several points as in the conventional method.

Furthermore, since the pair of inline heads and the third head are arranged at integral multiples of the horizontal section, the horizontal section is continuous, which is advantageous against skew.

[Example] FIG. 1 is a block diagram as an embodiment of the present invention.

In FIG. 1, 1 is one of the in-line heads conventionally provided for reproduction, 2 is a reproduction and erasing head provided in addition to the conventional in-line head, and 3 and 4 are heads 2. 5 is a switch that selects the output of high gain amplifiers 3 and 4, 6 is a video signal processing circuit that demodulates the output signal of switch 5, and 7 is a video signal processing circuit. This is a V synchronization separation circuit that extracts V (vertical) information of a reproduced video signal from 6. 8 is a control circuit for controlling the system during continuous playback and erasing, etc.; 9 is a stepping motor that is controlled by the control circuit 8 to move the head l or 2; and 10 and 11 are control circuits that control the rotational torque from the stepping motor 9. This is a switch for transmitting information to head 1 or head 2.

Further, 12 is an oscillation circuit for erasing, 13 is an amplifier for amplifying the oscillation signal from the oscillation circuit 12 and passing current through the head.
14 is a switch for switching between continuous playback mode and erase mode.

Next, the operation of the embodiment with the above configuration will be explained.

First, during continuous reproduction, for example, after the same track is reproduced for nXV time by head 2, the next track to be reproduced is reproduced for the same time by head 1, and then the above operation is repeated.Continuous reproduction will be explained.

In FIG. 2(a), the signal reproduced by the head 2 is transferred to the switch 14. High gain amplifier 3, switch 5
and video signal processing circuit 6 to output video and output it to a CRT.
etc. will be displayed on the display screen. On the other hand, the switch 10 is turned on by a control signal from the control circuit 8, the torque of the stepping motor 9 is applied to the head 1, and the head 1 moves to the next track to be reproduced and stops (FIG. 2(b)).

When the movement of the head l is completed, the switch 10 is turned off.

Next, after the head 2 reproduces the signal for nXV time, the switch 5 is switched within the V blanking section according to the V separation information obtained by the synchronization separation circuit 7, and the signal reproduced by the head 1 in FIG. 2(b) is is applied to the video signal processing circuit 6 and displayed. Next, the head 1 is
), the head 2 is moved as shown in FIG. 2(C) and stopped at the next track to be reproduced. Thereafter, in the same manner, heads 1 and 2 are alternately moved to the tracks to perform continuous reproduction.

When erasing, the control circuit 8 switches the switches 11 and 14 to apply the torque of the stepping motor 9 to the head 2 so that the center of the head 2 is positioned at the center of the recorded track as shown in FIG. And the erasing signal is sent from the oscillation circuit 12 to the head 2 via the amplifier 13.
is applied and erased.

With the above configuration, a complete envelope with no level change can be obtained during continuous playback, so that noise can be eliminated from one screen. Further, when erasing data, the disk can be rotated only once, and the data can be erased without leaving any data unerased, thereby reducing the erasing time.

FIGS. 4(a) to 4(c) are explanatory diagrams of head arrangement showing another embodiment of the present invention. In FIG. 4(a), the front and rear arrangement of the conventional head 1.1' and head 2 is reversed to that of the previous embodiment, and the spacing is nXH (H: horizontal section). b).

In (C), there are two newly installed heads 2, 23 and 2b, and the centers of heads 1 and 23 are aligned, and heads 1' and 2
The centers of b are made to coincide with each other, and the spacing before and after is set to nXH. Note that in FIG. 4(b) and FIG. 4(C), the front-to-back relationship between the head 1 and the head 2 is reversed.

By providing two heads 2 as shown in FIGS. 4(b) and 4(C), frame recording can be erased by only rotating the disk once.

[Effects of the Invention] As explained above, the present invention includes a third head which has a movable width exceeding the track width and is movable independently with respect to a pair of conventional in-line heads, and a pair of in-line heads with which the third head is connected. with inline heads and moving them alternately between tracks.

Since the control means is provided for continuously reproducing the video signals by switching them in the vertical blanking section, it is possible to prevent the generation of noise during continuous reproduction and obtain good image quality.

Furthermore, by erasing using the third head,
Since the entire width can be erased with - times of erasing operations, the erasing time can be shortened.

Further, since the distance between the third head and the other heads is set to an integral multiple of the horizontal section, the signal in the horizontal section becomes continuous, which is advantageous against skew.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIGS. 2(a), (b), and (C) are explanatory diagrams of head feed during continuous playback according to the present invention, and FIG. 3 is an erasure diagram of the present invention. FIG. 4(a) is an explanatory diagram of the head position at the time. (b) and (C) are other explanatory diagrams of head feed during continuous playback of the present invention, FIG. 5 is a head trajectory diagram during conventional continuous playback, and FIG. 6 is an envelope output level characteristic diagram in FIG. 5.
FIG. 7 is an explanatory diagram of the conventional head movement during erasing. In the figure. 1: Head 2: Head 3.4: High gain amplifier 5.14: Switch 6: Video signal processing circuit 7: V synchronization separation circuit 8: Control circuit 9 Chipping motor 10.11: Switch 12: Oscillation circuit 13: Amplifier

Claims (3)

[Claims] (1) In a recording/reproducing device equipped with first and second in-line heads for recording, reproducing, and erasing, a third in-line head has a movable width exceeding the track width and is movable independently with respect to the pair of in-line heads. control means for alternately moving the head, the third head, and the first or second in-line head between tracks, and for continuous reproduction by switching and outputting a video signal from these in a vertical blanking section; A recording/reproducing device comprising: (2) The recording/reproducing apparatus according to claim (1), wherein the third head is used to erase the recorded track. (3) The recording/reproducing apparatus according to claim (1), wherein the third head is disposed at a distance that is an integral multiple of a horizontal interval with respect to the pair of first and second in-line heads.