JPH0448427A - Signal recording and regenerating device - Google Patents

Abstract

PURPOSE:To reduce a maximum voltage which is impressed to a movable element at the time of normal reproduction and simultaneous reproduction, and to enlarge the variable range of the height of a reproduction head by setting the height of a reproduction head when the voltage is not impressed to the variable element, to almost midway between the height at the time of the normal reproduction and that at the time of the simultaneous reproduction.H CONSTITUTION:Reproduction heads 61(B) and 62(B ') are set at the heights of B0 and B0' indicated by a diagram when the voltage is not impressed to the variable element, against the positions of recording heads 41(A) and 42(A'). At the time of the simultaneous reproduction, the reproduction heads 61(B) and 62(B') are set at the heights of B1 and B' after the voltage is impressed to the variable element. At the time of the normal reproduction, the reproduction heads 61(B) and 62(B') are set at the heights of B2 and B2' after the voltage is impressed to the variable element. Thus, it is possible to reduce the maximum voltage which is impressed to the variable element at the time of the normal reproduction and the simultaneous reproduction, and to enlarge the movable range of the height of the reproduction head.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a video and audio signal recording and reproducing apparatus such as a VTR.

2. Description of the Related Art In recent years, video/audio signal recording and reproducing devices such as VTRs have been designed to achieve higher image quality and higher sound quality, and are transitioning from conventional analog recording to digital recording. In a digital VTR that digitally records video and audio signals, after converting an input analog signal to digital, the data is shuffled within a certain period of time and an error correction code is added before recording. During playback, errors are corrected based on the error correction code, the scattered data is returned to its original state (deshuffling), and then converted into an analog signal and output. In this way, since processing is performed in units of a certain period,
Processing time is required during recording and playback.

This processing is performed, for example, in units of ⅓ field or 1 field of the video signal. On the other hand, in a VTR, in addition to digital signals, analog audio signals (cue signals) and time codes are simultaneously recorded in the longitudinal direction of the tape.

There is no time delay like digital signals when recording and playing back these cue signals and time codes, so if digital signals are recorded and played back using the same head, the digitally recorded signals will lag behind the cue signals and time codes. The problem arises. To solve this problem, there is a method for reproducing digital signals using a reproducing head that precedes the recording head.

Furthermore, in order to check the recording state during recording, VTRs for broadcasting, etc., are required to have a simultaneous playback function that allows recording and playback at the same time.

An example of a recording/reproducing apparatus having such a function is shown in FIG. In FIG. 3, a signal input to a signal input terminal 1 is guided to a recording signal processing circuit 2, where it is subjected to processing necessary for recording, and then to a recording amplifier 3. The information is recorded on the tape 5 through the recording head 4. The reproducing head 6 is a movable element (not shown)
Its height is controlled by the output signal of the movable element drive circuit 11 controlled by the mode switching signal 10, and during normal recording, it is placed at a height that lags behind the recording head 4, and immediately after recording. signals at the same time.

The reproduced signal is led to the reproduced signal processing circuit 8 through the reproduced amplifier 7, and after being subjected to reproduction processing, is outputted from the output terminal 9, and the recording state is confirmed.

During normal playback, the playback head 6 is placed at a height that is ahead of the recording head 4 by a time corresponding to the total processing time for recording and playing back signals to be digitally recorded and played back, by the operation of the movable element. Ru.

The signal reproduced by the reproduction head 6 is reproduced in the same manner as in the case of simultaneous reproduction, and a signal whose timing matches the cue signal and time hood is obtained at the output terminal 9.

As the movable element, one constructed of a piezo element and controlled by applying a voltage is often used. When no voltage is applied, they are placed at the height of normal reproduction or simultaneous reproduction.

Problems to be Solved by the Invention In the configuration shown in FIG. 3, when no voltage is applied to the movable element, for example, if the position of the reproducing head 6 is set at the height for normal reproduction, then when a voltage is applied during simultaneous reproduction, the high It is necessary to change the height, and the amount of change in height increases as the unit of shuffling becomes longer, that is, as the recording/reproduction signal processing time becomes longer.
The wider the track pitch, the larger it becomes. Therefore, in order to realize both normal playback and simultaneous playback with this configuration, there are restrictions on the signal processing method (units of error correction and Yafling) and track pitch.

It is an object of the present invention to provide a device that can solve these problems and alleviate the above-mentioned limitations.

Means for Solving the Problems In order to achieve the above object, the signal recording and reproducing device of the present invention includes a pair of recording heads attached to a rotating surface at the same height,
A first rotating surface that is located above the movable element and has a height that precedes the recording head that is positioned during normal reproduction when no voltage is applied to the movable element, and a first rotating surface that is higher than the recording head that is positioned during simultaneous recording and reproduction. and a reproducing head mounted approximately midway between the second rotating surface and the trailing second rotating surface.

Further, during normal recording, the signal recording/reproducing device of the present invention sets the reproducing head at a height behind the recording head by applying a voltage to the movable element, and the signal processed by the recording signal processing unit is While recording with the recording head, a signal reproduced by the reproduction head is processed by a reproduction signal processing unit to obtain an output, and during normal reproduction, by applying a voltage to the movable element, the reproduction head is The apparatus includes means for obtaining an output obtained by processing a signal reproduced by the reproduction head by the reproduction signal processing section, which is set at a height preceding the head.

By setting the height of the reproducing head when no voltage is applied to the active movable element to be approximately midway between normal reproduction and simultaneous reproduction, the maximum voltage applied to the movable element during normal reproduction and simultaneous reproduction can be lowered. As a result, the variable range of height can be expanded.

Embodiment FIG. 1 shows a recording tape pattern according to the present invention and the head position thereon, FIG. 2 shows the head arrangement on a rotating cylinder at that time, and FIG. 2(a) is a plan view. Second
Figure (b) is a front view.

In FIGS. 1 and 2, 5 is a tape, 12 is a recording track, 41.42 is a recording head, and 61.degree. 62 is a reproduction head.

Signal recording and reproducing processing is performed in the same manner as in FIG. now,
If signal processing for digital recording is performed in units of one field, it takes one field to process the recording signal and at least one field to process the reproduced signal. In reproduction signal processing, the processing time is set around 1.5 fields because time is added to absorb time axis fluctuations that occur during recording and reproduction and to perform output process processing.

In this case, the mounting position of the head is set as shown in FIGS. 1 and 2 in the present invention. That is, with respect to the positions of the recording heads 41(A) and 42(A'), the reproducing heads 61(B) and 62(B') are at the positions shown in FIGS. 1 and 2 when no voltage is applied to the movable elements. BO shown
, BO'.

During simultaneous playback, playback heads 61 (B), 62 (B')
B1. shown in FIGS. 1 and 2 by applying a voltage to the movable element. The height is set to B1'. At this time, the height difference h1 between the recording heads 41 (A) and 42 (A”)
In this case, both heads are installed at an angle (approximately 90 degrees in the figure) so that the playback heads 61 (B) and 82 (B") trace the locus immediately after recording with the recording heads 41 (A) and 42 (A"). ). The trajectory shown by the broken line in FIG. 1 including the recording head 41(A) is the head trajectory when the cheese is stopped, and represents the rotating surface of the head.

Also, during normal playback, the playback spatula l'61 (B), B
B2.32(B') shown in FIGS. 1 and 2 by applying a voltage to the movable element. It is set to the height of B2'. Recording head 41(A) at this time.

The height difference h2 with 42 (A') is the playback radius 81 (B).

After the time required for recording and reproduction signal processing, the signals reproduced at 62 (B') are sent to the recording head 42 (A'), respectively.
), 41(A). In this way, the timings of the digitally recorded signal and the analog recorded cue signal and time code signal are matched. In a device that requires 1 field for digital recording signal processing and 1.5 fields for playback signal processing, and records 1 field on 3 unit tracks,
As shown in FIG. 1, the lead amount of the reproducing head relative to the recording head is 7.5 unit tracks. When digital signal processing is divided into two channels and recording is performed using a bare head consisting of two heads, one unit track is formed by two tracks.

Note that the position BO of the reproducing heads 81 (B) and 62 (B') when no voltage is applied to the movable elements.

Position B1 during simultaneous playback with respect to BO'. B1' and the position B2.hot during normal playback. Level difference h with B21
02 is set to be approximately the same. In this way, the voltage to be applied to the movable element can be made almost the same on the + side and on the one side, and the total variable range can be increased.

Effects of the Invention As described above, the present invention provides a device that is capable of normal playback and simultaneous playback, can ease restrictions on signal processing units, required time, and track pitch, and has an optimal pattern and recording method. can be realized.

[Brief explanation of drawings]

FIG. 1 is a pattern diagram showing an example of a tape pattern recorded by a recording/reproducing apparatus according to the present invention, FIG. 2 is a diagram showing the arrangement of heads on a rotating cylinder in the same embodiment, and FIG. 3 is an example of signal processing of a digital VTR. FIG. 2... Recording signal processing circuit, 3... Recording amplifier,
4, 41. 42... Recording head, B3. 8
1. 62... Reproduction head, 11... Movable element drive circuit, 12... Recording trajectory. Diagram

Claims (2)

[Claims] (1) A helical scan type signal recording and reproducing device that records and reproduces signals on a magnetic tape, which includes a pair of recording heads mounted on a rotating surface at the same height, and a movable element mounted on the In a state in which no voltage is applied to the movable element, a first rotating surface at a height that precedes the recording head located during normal reproduction, and a second rotating surface at a height subsequent to the recording head located during simultaneous recording and reproduction. A signal recording/reproducing device having a reproducing head attached approximately midway with a rotating surface. (2) During normal recording, the reproducing head is set at a height that follows the recording head by applying a voltage to the movable element, and the signal processed by the recording signal processing section is recorded by the recording head. , an output is obtained by processing the signal reproduced by the reproduction head in a reproduction signal processing section, and during normal reproduction, by applying a voltage to the movable element, the reproduction head is set at a height that precedes the recording head. 2. The signal recording and reproducing apparatus according to claim 1, wherein the signal reproduced by the reproducing head is processed by the reproduced signal processing section to obtain an output.