KR960015998B1 - Video tape recording with a video printing controller - Google Patents

Abstract

None.

Description

Magnetic recording and playback device

1 is a pattern of tracks showing marker signal positions in the magnetic recording and reproducing apparatus of the present invention.

2 is an explanatory diagram of a track pattern when the marker region is enlarged.

3 is a code pattern illustrating an example of a coded marker signal.

4 is a block diagram showing an embodiment for designating a marker region of the present invention.

5 is an explanatory diagram of waveforms for forming a gate signal.

6 is a plan view of a rotating drum of 8 mm VTR.

7 shows a track pattern of a tape of 8 mm VTR.

Fig. 8 is a diagram showing signal arrangement of recording tracks in 8 mm video.

* Explanation of symbols for main parts of the drawings

26: gate circuit 27: demodulation circuit

29: control unit 30: system controller

31: counter 32: pulse generator

M: Marker signal

The present invention relates to a magnetic recording and reproducing apparatus capable of recording and reproducing a video signal on a track in a tape inclined direction by a rotating magnetic head, and in particular, adds a marker signal to a desired track to record a video signal recorded on the track. The present invention relates to a magnetic recording and reproducing apparatus suitable for finding the head by cue search.

According to the present invention, in a helical scan type VTR for recording a video signal by means of a rotating magnetic head, a track in which the video signal is recorded when printing out, for example, a video signal recorded on a track in the inclined direction of a tape, is recorded. The marker signal is recorded over a number of fields by a rotating head in an area outside of the recording area, and after searching the marker signal, the video signal designated by the marker signal can be printed out.

The method of recording / reproducing a video signal and an audio signal with a helical scan method for an 8 mm video tape is standardized in so-called 8 mm video and already commercialized.

FIG. 6 shows an example of such an 8mm video rotating head device, and FIG. 7 is its tape format.

In these figures, H _A and H _B represent the rotating heads for recording and reproduction, (1) is a rotating drum, and (2) is wound around the rotating drum 1 in the range of 180 ° + α. Magnetic tape running in the direction of 3T.

The two rotating heads H _A and H _B are configured to have different azimuth angles of the magnetic gaps, and are attached to project slightly from the rotating drum 1 at intervals of 180 ° from each other.

The frame frequency (30 Hz) of the video signal is rotated in the direction of arrow 3H.

Therefore, the recording tracks of the magnetic tape 2 formed by such a rotating head device are alternately formed in the inclined direction of the magnetic tape 2 with tracks 4A and 4B having different orientations as shown in FIG. do.

In the area AV corresponding to the 180 ° angle of the tracks 4A and 4B, a video signal is normally recorded. The area AP of the α angle (≒ 36 °) shortens the audio signal along the time axis, and generates a PCM (Pulse Code Modulation). The normalized signal can be recorded sequentially for each field.

In 8 mm video, the audio signal is not limited to the above-mentioned area AP, but the frequency of the voice signal can be modulated and supplied to the rotating heads H _A and H _B , and the audio signal can be superimposed on the area AV of the video signal.

In this manner, in the 8 mm video recording and reproducing method, a function of recording and reproducing the audio signal by the rotation heads H _A and H _B is added, so that the recording and reproduction of a very high quality audio signal can be performed.

However, the track format of the 8 mm video as described above will be described in more detail as shown in FIG.

That is, in one recording track, the inclined portion 11 at the head angle is five degrees from the area where the rotating head is in contact with the tape 2, and 2.06 degrees in the second half of the indented portion 11 (at 3H minutes of the video signal). In the equivalent period, the preamble section 12 serving as a part of the clock line synchronized with the PCM data is provided.

Following this preamble section 12, a PCM data section 13 for converting and recording the time-base compressed speech signal into PCM data is provided over 26.32 degrees. The period of 2.06 degrees (3H) subsequent to the PCM data portion 13 is the postamble portion 14, and the subsequent 2.62 degrees is the VP guard portion 15 indicating the boundary between the video signal and the PCM data portion. .

The recording area 16 of the video signal is formed next to the VP guard unit 15. As described above, a video signal for one field is recorded over 180 degrees, and at the same time, a pilot signal for tracking is placed in this part. Overlaps.

Finally, the separation part 17 for about 5 degrees is formed.

The PCM data is a binary signal. For example, it is recommended that the portion of the logic " 1 " be FM-modulated into a signal of frequency 5.8 MHz and the portion of the logic " 0 " Data "1" is input to the preamble section 12 and the postamble section 14.

However, according to the invention proposed by the present applicant, for example, in the track format, for example, the postamble unit (1) in the track format can be searched so that the predetermined recording track can be searched first during the normal playback mode or multi-PCM mode playback of such 8 mm video. A method of detecting a desired track by recording an index signal in 14) and reading the index signal has been proposed (Japanese Patent Application No. 60 (1985) -64554).

However, in the 8 mm video and recording method as described above, in the mode of recording the audio signal as the PCM data simultaneously with the video signal, the index signal is input to the part of the postamble unit 14 as described above. Although cue search and head search can be done, the simple 8mm VTR does not have a PCM recording function as a commodity, and the simple 8mm VTR does not have a fixed head. Since the head search of the recorded video signal cannot be performed, there is a problem that the time required for searching for the predetermined video signal becomes long even when the video printer prints out the predetermined video signal.

The present invention has been made in view of the above problems, and for example, a counting circuit that counts a clock signal based on a vertical synchronization signal, for example, a portion corresponding to a VP guard of an image track formed in an oblique direction, for example. It is possible to detect and record a marker portion of a predetermined format over several tracks in a portion corresponding to the VP guard.

Even in the case of the simple 8 mm VTR, the angle at which the magnetic tape is wound around the rotating drum is set to be slightly larger than 180 °, and the VP guard portion 15 of the track of the 8 mm recording format formed in the oblique direction is formed. A part becomes head inrush and this part can be used as a recording area.

Thus, by inputting a predetermined marker signal from the rotating head when the rotating head passes through the recording area at the time of recording, a mark for identifying a desired recorded image track can be added and the video signal marked in the search mode can be added. You can do a head search.

FIG. 1 shows a recording format on an 8 mm tape showing an embodiment of the present invention. In the magnetic tape 10, a plurality of tracks T are sequentially formed in the oblique direction by two rotating magnetic heads, as described above. The track area of about 30 ° in the first half becomes the PCM signal area, and a video signal area (video) is formed in the portion of about 180 ° in the second half through the VP guard for about 3.8H.

In the magnetic recording and reproducing apparatus of the present invention, the marker signal M is recorded and read out for a predetermined track in the area of the V-P guard.

FIG. 2 is an enlarged view of this portion, and the inrush portion 11 of the head, the preamble portion 12 of the PCM signal 12, the PCM data portion 13, and the VP guard portion 15 behind the postamble portion 14 are shown. A marker area 15A for about 0.5H is formed in the area, and a marker signal M of, for example, 2.95MH is recorded in this marker area 15A to search for this recording track.

This marker signal M is recorded from track T ₀ of the head search shown in FIG. 1 to subsequent track T _N for t (about 10) seconds.

The VP guard portion l5, which separates the PCM data portion 13 and the recording area 16 of the video signal, corresponds to the head inrush in an 8 mm VTR having no PCM recording function. In the case where the 0.5H marker area 15A is formed at a position of about 0.8H from the front end of the c), if the tape path is adjusted within the standard range, the signal can be recorded or sufficiently reproduced in this area by the circuit head. .

In the case of an 8 mm VTR having a PCM recording function, it is of course possible to record and reproduce a signal in this marker region 15A.

Therefore, if the marker signal M is recorded over several tracks at the position as described above, the marker signal M can be detected in the cue search mode as described below. After the marker signal M is confirmed, the tape rewinding operation is performed. the track T was slightly pass through _zero, in the position of the mark by the track T _0, when a normal reproduction state can be switched to the normal reproducing operation, which is if necessary connected to the playback picture of the track T _0, the VTR printer You can print out by transferring it to the memory of.

As the marker signal M, for example, an alternating number of 2.95 MH is recorded over several tracks in the 0.5H period of the VP guard unit 15. For example, as shown in FIG. 1, any track in the mark period t is shown. If the marker signal M ₂ of 2.95 / 2 MHz is recorded in T ₄ , the head search can be performed for the track in the mark period t by detecting the head and then detecting the marker signal M ₂ again.

It is also possible to code the marker signal M with a digital signal.

3 is a waveform diagram showing an example of coding the marker signal M. In the marker signal area 15A in the 0.5H period, the start bit signal D _S is first placed, followed by the mode bit. The signal D _M is excreted. This mode bit signal D _M is perceived as being representative of the kind of the code signal of the four-word which follows the data D ₀ -D _3, 8-bit configuration code signal D ₀ -D _3, the time code if the address code, and print out Identifies the number.

D _C is an error correction code and D _E is an end bit signal.

When the signal coded as the marker signal M is recorded in this manner, the marker signal can be used for various purposes as an index signal, similar to 8 mm VTR capable of PCM recording.

Next, an embodiment for reproducing (recording) the above-described marker signal will be described with reference to the block diagram of FIG.

Reference numeral 20 denotes a rotating drum having two rotary magnetic heads H _A and H _B , 21 a recording / reproducing switch, 22A and 22B an amplifier for outputting a reproduction signal, and 22C. (22D) represents an amplifier for supplying a recording signal to the rotating magnetic heads H _A and H _B , and 23 represents a switching circuit for switching the rotating heads H _A and H _B by a switching pulse, for example, PCM. In a model capable of recording, the reproduced PCM signal is switched to be input to the audio signal processing circuit 24 as indicated by the dotted line.

In the model without the PCM recording function, the playback signals of the rotating magnetic heads H _A and H _B are continuously input to the video signal processing circuit 25, and the FM signal is modulated to the audio signal processing circuit 24. Is entered.

Numeral 26 denotes a gate circuit closed by the pulse generator 32 described later in the period of the marker signal region, numeral 27 denotes a demodulation circuit, numeral 28 denotes a signal detection circuit, and numeral 29 denotes a gate circuit. Control units (CPU) and 30 that output control signals corresponding to various operation modes of 8 mm VTRs represent system controllers.

Numeral 31 denotes a counter that counts the clock signal locked to the horizontal synchronous signal during reproduction or recording, and this counter is reset to zero when the vertical synchronous signal VD is input. When the counter 31 reaches a predetermined count value, the pulse generator circuit 32 outputs a home signal with a pulse width of approximately 0.5H period, and closes the gate circuits 26 and 33.

Reference numeral 34 denotes a marker generator for outputting a marker signal to be recorded.

Reference numeral 35 denotes a switching pulse generating circuit which detects the rotational phase reference signal PG of the rotating drum 20 to form the switching switching pulse of the switch circuit 23.

Next, an operation of detecting a desired marker signal by cue search and searching for a head by the circuit of the embodiment of the present invention described above will be described with reference to FIG.

The magnetic recording and reproducing apparatus of the present invention is characterized in that the marker region 15A of the reproduction signal output from the amplifiers 22A and 22B is introduced into the gate circuit 26 during reproduction.

The gate circuit 26 has a counter value 31 that counts the horizontal synchronous signal PH (the horizontal synchronous signal is a continuous signal by the PLL circuit) of the video signal being reproduced. It is closed for approximately 0.5H period by the output SG of the pulse generator 32 driven by the output at the time.

However, since the counter 31 is also reset to zero by the vertical synchronous signal VD of the video signal and counts the horizontal synchronous signal PH based on this point, the number of horizontal synchronous signals + alpha for each field + α (α is approximately zero). When the gate circuit 26 is closed with the count value N of the head incidence portion 11 of 2 degrees, which is set to the number corresponding to the number of horizontal synchronous signals + 2 of the end period of the postamble portion 14, the marker signal area is immediately appropriate. The regeneration output when the rotating head is scanning 15A passes through the gate circuit 26.

Therefore, when the marker signal M is included in the output signal passed through the gate circuit 26, the demodulation circuit 27 is detected and the digitized signal is input to the controller 29 by the detection circuit 28. .

When the cue search command is input, the control unit 29 stops running of the tape at the time when the marker signal M is detected, switches the 8 mm VTR to the rewind mode, and the marker signal M is input as described above. After passing through the first track T ₀ , the unit enters the normal playback mode and detects the track on which the first marker signal M is recorded.

At this point, for example, a still playback state is performed, and the video signal of the desired track is output.

The track to which the marker signal M is added can be designated as an edit point, and may be output to a printer to obtain a hard copy.

When the marker signal is input during recording, the gate circuit 33 is closed only for the period designated by the counter 31 and the pulse generator 32, and the signal output from the marker signal generator 34 is stored in the marker signal area 15A of the track. Is written on.

In this embodiment, the vertical synchronization signal is used as the counting reference of the counter 31. For example, the marker signal recording area on the tape may be designated using the PG signal of the rotating drum.

In addition, the marker signal recording area 15A is disposed on the track corresponding to the VP guard 15. However, in the 8 mm VTR of the simple type, since the end point of the video signal track in the oblique direction is also free, the head separation part of FIG. The count number of the counter 31 may be set to record the marker signal M ₃ of 0.5H on the corresponding track.

As described above, the magnetic recording and reproducing apparatus of the present invention is configured to add a marker signal on a track in the oblique direction formed by the rotating magnetic head and to reproduce it by adding a marker signal on a track on which no video signal is recorded. It has the effect of detecting the desired video signal in cue search mode and finding the head first. Especially when it is adopted in the simple 8mm VTR, the presence of this marker signal improves the playback function. have.

Claims (2)

A magnetic recording and reproducing apparatus having a rotating magnetic head capable of recording a signal on a track in an inclined direction of a magnetic tape, comprising: means for counting a clock signal on the basis of a predetermined position of a video signal recorded on the track; Means for designating a marker region in which the video signal of the track is not recorded by the counting means, and means for recording a marker signal in the marker region over a plurality of fields; A magnetic recording / reproducing apparatus characterized by detecting and searching for a head of a video signal of a predetermined track. The magnetic recording and reproducing apparatus according to claim 1, wherein the marker signal is recorded by a coated digital signal.

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