JPH071530B2 - Recording / playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is a tracking system that considers correction of recording / reproducing signals in tracking control of a device for recording / reproducing information signals such as video and audio on a recording medium. The present invention relates to a recording / reproducing apparatus having control, and more particularly to a recording / reproducing apparatus that obtains a tracking error signal by utilizing a time difference between signals reproduced by at least two heads having different azimuth angles.

(Prior Art) In recent years, tracking control is required to be highly accurate as the recording / reproducing track becomes narrower.

As conventional tracking control, for example, Japanese Patent Application Laid-Open No. 1-
No. 134712 is disclosed.

In the conventional tracking control, the recording / reproducing apparatus using two heads having different azimuth angles as one set
The accuracy of the mounting position of the two heads was mechanical and assembly.

(Problems to be Solved by the Invention) However, in order to mount the head with the accuracy of the standard value for obtaining compatibility in the conventional tracking control, the mechanical accuracy and the mounting accuracy become strict and the device becomes expensive, There has been a problem that a deviation of the mounting position of the head causes an error in the detected tracking error signal, which deteriorates the tracking accuracy.

The device of the present invention is to solve the above-mentioned conventional problems, in which an error peculiar to the recording / reproducing device due to the displacement of the mounting position of the head is measured in advance with a standard tape or the like as a time error,
By recording the value and using the stored value as information unique to the recording / reproducing apparatus, the signal can be accurately recorded on the tape, and at the time of reproduction, the deviation of the signal corresponding to the mounting error of the head can be corrected. Is. Therefore, it is an object of the present invention to provide a recording / reproducing apparatus having tracking control in which compatibility between the apparatuses can be easily realized and tracking accuracy in recording / reproducing is improved.

(Means for Solving the Problem) In order to achieve this object, the recording / reproducing apparatus of the present invention has two heads mounted in a recording / reproducing apparatus of a system using two heads having different azimuth angles as one set. An error peculiar to the recording / reproducing apparatus which is deviated from the specified value of the position is previously stored as a time error, and a tracking control means for correcting the phase of the information signal by using the value at the time of recording / reproducing to perform control is provided. is doing.

(Operation) With the configuration of the present invention, the device of the present invention measures the error, which is peculiar to the recording / reproducing device, of the displacement of the mounting position of the head, using a standard tape or the like in advance as a time error, stores the value, and stores the value. By using as the information unique to the recording / reproducing apparatus, the signal can be accurately recorded on the tape, and the deviation of the signal corresponding to the mounting error of the head at the time of reproducing can be corrected.

(Examples) Hereinafter, the present invention will be described in detail by examples with reference to the accompanying drawings.

FIG. 1 shows two heads with different azimuth angles.
FIG. 2 shows a schematic block diagram of a first embodiment of a recording / reproducing apparatus according to the present invention in a digital video tape recorder (hereinafter abbreviated as DVTR) used as a set, and FIG. 2 shows recording on a tape in the same embodiment. Pattern diagram, Fig. 3, Fig. 4
The figure is a view for explaining the tracking error in the same embodiment. In FIG. 1, 15 and 17 are pair heads A, B, 16 and 18 having different azimuth angles, and pair heads C, D, 10 (a) and 10 (b) having different azimuth angles are used for amplification and equalization. RF circuits for signal processing, 11 (a) and 11 (b) detect SYNC signal from within a block in digital data
SYNC detector, 12 is a phase comparator that compares the phases of the SYNC signals output from SYNC detectors 11 (a) and 11 (b), and detects the phase difference between the two, 13 is detected by the phase comparator 12. Of the reproduced signal, the compensator for compensating for the error caused by the displacement of the mounting position of the reproducing head indicated by the head height, 14 is the signal detected by the phase comparator 12 and the compensator.
It is an adder that adds the 13 output signals and outputs a tracking error signal.

Regarding the recording / reproducing apparatus using the tracking control of the present invention configured as above, the operation will be described below.
A description will be given with reference to the drawings and FIG.

First, digital data is written on the track 19 with the azimuth angle as shown in FIG. 2 by a rotary head having two heads having different azimuth angles as one set.

Next, at the time of reproduction, the digital data reproduced from the A, B, C and D heads in FIG. 1 are processed by the RF circuits 10 (a) and 10 (b). Also, head A, head C, and head B
Since the head D and the head D are mounted on the cylinder at a mounting angle of 180 degrees, they are used while switching each time the cylinder rotates. Therefore, the RF circuits 10 (a), 10
In (b), the reproduced signal that has been switched is processed and output. Therefore, the signals reproduced by the head A and the head B will be described below.

Therefore, the digital data output from the RF circuits 10 (a) and 10 (b) is input to the SYNC detectors 11 (a) and 11 (b) to extract the SYNC signal in the block. Then, as shown in FIG. 3 (a), assuming that the head is just scanning over the track, the A and B heads read the SYNC signal at the same point, and as a result, there is no difference in read time between the two heads. . However, as shown in FIG. 3 (b), if the head is scanning with the track shifted to the left compared to (a), when the SYNC signals of the A head and the B head are read, the point is that of the B head. The head becomes faster, and conversely, the A head becomes slower. As a result, a phase difference is detected in the SYNC signal between the two heads. On the contrary, when scanning is shifted to the right as compared with FIG. 3 (a), as shown in FIG. 3 (c), the head A reads the SYNC signal earlier, and conversely the head B does not. One becomes slower and the phase difference is detected similarly. Therefore, the phase difference signal detected by the phase comparator 12 changes according to the tracking deviation.

Further, as shown in FIG. 4, when the phase difference signal detected by the phase comparator 12 indicates that the mounting position of the reproducing head indicated by the head height of the A head and the B head is displaced,
An error occurs as a tracking error signal. That is, when the head heights of the head A and the head B are the same as shown in FIG. 4B, the phase difference is not detected by the phase comparator 12 in the on-track reproduction state. As shown in (a) and (c), in the case where the head heights of the head A and the head B are different, the phase comparator is in spite of the on-track reproduction state.
At 12 a phase difference is detected.

Therefore, the compensator 13 stores in advance the error generated when the mounting position of the reproducing head, which is indicated by the head height and the like, is deviated, and the correction signal obtained by the compensator 13 and the phase comparator 12 are used. Add the detected phase difference signal
By adding at 14, the phase difference error detected by the phase comparator 12 is corrected, and the output signal of the adder 14 is output as a tracking error signal.

Based on this tracking error signal, the head can be brought into the on-track state by a method of controlling the height of the head mounted on the movable element, a method of correcting the control of the capstan servo, or the like.

In the corrector 13, the standard tape (the tape recorded in the pattern regulated by the regulation value) is reproduced, and the tracking error signal obtained from the adder 14 is the stable point of the control value when the reproduction output becomes maximum. By adjusting so as to give an offset as much as possible, the error generated when the mounting position of the reproducing head is displaced is stored.

Further, since the deviation of the mounting position of the reproducing head is an error peculiar to each recording / reproducing apparatus, it is only necessary to adjust the corrector 13 in advance.

Hereinafter, with respect to the recording unit in the first embodiment of the present invention,
A description will be given with reference to the drawings.

Figure 5 shows two heads with different azimuth angles.
FIG. 6 is a block diagram showing a recording circuit of a recording / reproducing apparatus according to the present invention in a DVTR of a system used as a set, and FIG. 6 is a diagram for explaining a tracking error of the same embodiment. In the recording / reproducing apparatus in the first embodiment of the present invention,
In FIG. 5, reference numeral 56 is an input terminal, 50 is a signal processing circuit such as a modulation circuit and an error correction code adding circuit, 51 is a memory for temporarily storing an input signal and correcting an error in the time axis of a recording signal, Reference numeral 52 is a memory write control circuit, 53 is a memory read control circuit, 54 (a) and 54 (b) are RF circuits such as REC amplifiers, and 55 is a signal indicating an error in the mounting position of the recording head indicated by the head height and the like. Are temporarily stored in the offset storage device 57, 59 are pair heads E, F having different azimuth angles, and 58, 60 are pair heads G, H having different azimuth angles.

The tracking error of the recording / reproducing apparatus of the present invention configured as described above will be described below with reference to FIG.

First, digital data is written on a track at a azimuth angle as shown in FIG. 2 by a rotary head having two heads E and F having different azimuth angles as one set.

However, as shown in FIGS. 6A and 6C, when recording is performed in a state where the mounting positions of the recording heads indicated by the head heights of the head E and the head F are displaced during recording,
The recording pattern is misaligned. Therefore, when reproduction is performed with the recording pattern deviated, as shown in FIG. 6, even when the head heights of the reproducing heads A and B are the same, the phase difference in the phase comparator 12 in FIG. Is detected.

Therefore, according to the present invention, the offset storage device 55 stores in advance the error that occurs when the mounting position of the recording head, which is indicated by the head height or the like, is deviated, and the recording signal is stored in the memory according to the stored value. By controlling the time temporarily stored in 51, the time axis error caused by the deviation of the mounting position of the recording head, which is indicated by the head height or the like, is corrected and recorded.

That is, the offset storage device 55 stores in advance an error that occurs when the mounting position of the recording head indicated by the head height or the like is displaced, and the offset storage device 55
By controlling the memory write control circuit 52 and the memory read control circuit 53 according to the value stored in, the time for temporarily storing the recording signal in the memory 51 is determined, and the error of the time axis is corrected. ing.

Hereinafter, a method for detecting the deviation of the mounting position of the recording head, which is indicated by the head height and the like stored in the offset storage device 55, will be described.

In the corrector 13 in the tracking control apparatus shown in the first embodiment of the present invention, the tracking error signal obtained from the adder 14 is the control value when the standard tape is reproduced and the reproduction output signal becomes maximum. It is adjusted to give an offset as much as possible for a stable point. Therefore, the tracking error signal obtained from the tracking control device of the present invention is a signal obtained by correcting the influence of the displacement of the mounting position of the reproducing head, which is indicated by the head height and the like.
Therefore, the self-recording / reproducing operation is performed next time, and the tracking error signal shown in FIG. 6 at the point where the reproduction output signal becomes maximum indicates the displacement of the mounting position of the recording head.

The value of this tracking error signal is stored in advance in the offset storage device 55 shown in FIG. 5, and the correction value on the time axis is determined according to the value of the tracking error signal.
The time axis error of the video signal is corrected and recorded. By doing so, the tracking error signal detected by the tracking control device of the present invention does not include an error, and more accurate tracking control can be performed.

Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 7 shows patterns and waveforms on the tape of the system for recording the control signal in the tracking control in the second embodiment of the recording / reproducing apparatus according to the present invention.

In FIG. 7, 71 is a tape, 72 is a control head, 73 is a control track on the tape on which control signals are recorded, and 74 is a video track on the tape on which video signals are recorded. .

Generally, the distance from the writing end portion of the track of the signal recorded by the rotary head to the control signal portion is defined by a standard value and is called an X value.
Since the tracking controller controls the rotation phase of the rotary head so that the X value is always constant,
When the mounting position of the head for recording / reproducing the control signal deviates from the specified value, the X value varies depending on each recording / reproducing device, and when performing compatible reproduction, the tracking accuracy deteriorates. When the deviation of the mounting position of the head for recording / reproducing the control signal from the specified value is Δx, when a standard tape or the like is reproduced, it can be measured as a time difference dtx from the reference signal when the reproduction control signal is at the reference position.

These dtx are stored in a non-volatile memory such as a ROM for each DVTR, and are used when the phase is adjusted so as to correct their errors at the time of recording / reproducing a signal.

Therefore, in the tracking control device of the second embodiment of the present invention, an error peculiar to the recording / reproducing device, which is a deviation from the specified value of the mounting position of the head for recording / reproducing the control signal, is stored in advance as a time error and recorded. The tracking accuracy is improved by correcting the phase of the signal using the value during reproduction and performing tracking control.

Although the effects of the present invention in the digital VTR have been described in the above embodiments, it is needless to say that the present invention can also provide effective effects in an analog VTR that records by using frequency modulation or the like.

Although some embodiments of the device of the present invention have been described above, it is obvious that the present invention is not limited to this and various modifications and changes can be made without departing from the gist of the present invention. .

(Effects of the Invention) As described in detail above, according to the apparatus of the present invention, due to the above-described configuration, the error peculiar to the recording / reproducing apparatus of the mounting position of the rotary head is stored in advance, and thereby the recording signal or the reproduction is performed. Since the signal phase is corrected, the tracking accuracy is improved, the head can be easily attached and the compatibility is improved, and the practical effect is great.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing the configuration of a first embodiment of a recording / reproducing apparatus according to the present invention, FIG. 2 is a recording pattern diagram on a tape in the same embodiment, FIG. 3, and FIG. FIG. 5 is a block diagram showing the recording circuit of the recording / reproducing apparatus according to the present invention, and FIG. 6 is a diagram for explaining the tracking error of the same embodiment. FIG. 7 and FIG. 7 show a pattern and a waveform diagram on the tape of the method of recording the control signal in the tracking control in the second embodiment of the recording / reproducing apparatus according to the present invention. 10 (a), (b) ... RF circuit 11 (a), (b) ... SYNC detector 12 ... Phase comparator 13 ... Compensator 14 ... Adder 15, 16, 17, 18 ... Playback head 19 ... Track 50 ... signal processing circuit 51 ... memory 52 ... memory write control circuit 53 ... memory read control circuit 54 (a), (b) ... RF circuit 55 ... offset storage device 56 ... input terminal 57, 58, 59, 60 ... head 71 … Tape 72… Control head 73… Control track 74… Video track

Front Page Continuation (72) Inventor Nobuo Hosokawa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Motoki Fujiwara, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Shigekazu Togashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Reference JP-A 63-244351 (JP, A) JP-B 1-27497 (JP, B2)

Claims (2)

[Claims] 1. A recording / reproducing apparatus using two reproducing heads having different azimuth angles and two recording heads having different azimuth angles, and mounting the two reproducing heads on the apparatus. A first storage unit that stores in advance an error peculiar to the recording / reproducing apparatus, which is a deviation from the specified value of the position, as a time error;
Phase difference detecting means for extracting respective sync signals from respective signals reproduced by the one reproducing head and detecting a phase difference between them, and the detected phase difference signals are corrected based on the first storage means. Correction means, a tracking control means for performing tracking control using a signal obtained by the correction as a tracking error signal, and an error peculiar to the recording / reproducing apparatus, which is a deviation from the specified value of the mounting position of the two recording heads, as a time error. And a recording means used for phase correction of the information signal to be recorded, for recording the information signal. Recording / playback device. 2. The standard tape according to claim 1, wherein an error peculiar to the recording / reproducing apparatus, which is a deviation of a mounting position of the two reproducing heads from a specified value, is recorded in a pattern regulated to the specified value. By reproducing, the tracking error signal obtained from the correction means is detected and stored in the first storage means, and the deviation of the mounting positions of the two recording heads from the specified value is detected by the first storage means. After the storage in the storage means is completed, by reproducing the self-recorded / reproduced tape, it is detected as a tracking error signal obtained from the correction means and stored in the second storage means. Recording / playback device.