JP2563610B2 - Magnetic recording / reproducing device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking shift function,
The present invention relates to a magnetic recording / reproducing apparatus having an automatic tracking function or a manual tracking function.

Prior Art FIG. 4 shows a magnetic tape pattern in the VHS format. The X value (distance from the CH-2 video track 180 ° exit to the control signal pulse on the tape pattern) in Fig. 4 is specified, and normally the control signal (hereinafter CTL (Abbreviated as signal) is recorded. And at the time of playback, it was recorded
By changing the phase between the CTL signal and the rotary head signal (hereinafter abbreviated as HSW signal), it is necessary to control the rotary head locus to trace the recording track pattern accurately (optimum tracking state). . During playback
Hereinafter, changing the phases of the HSW signal and the CTL signal is referred to as a tracking shift operation.

In normal self-recording playback, HSW signal and CTL during playback
The optimum tracking state is achieved by controlling the signal phase to be the same as the recording phase. However, in the case of compatible reproduction, there are variations in the mechanism or the operating environment (temperature,
If the phases of the HSW and CTL signals are controlled to be the same as during self-recording / playback due to factors such as humidity conditions) or expansion / contraction of the tape temperature, the optimum tracking conditions may not be achieved, and noise may appear on the screen. Therefore, HSW during self-recording playback
The tracking shift operation is performed on the basis of the phases of the signal and the CTL signal so that the optimum tracking condition can be obtained.

Next, a conventional example in the tracking shift operation will be described. FIG. 5 is a block diagram of a conventional example, and FIG. 6 is a timing chart of the conventional example. In FIG. 5, the servo control IC 200 performs the generation of reference signals f to j and the error detection by the input signals a to e and the clock signal K, and the calculation result is passed through the D / A conversion unit 201 to the motor drive circuit.
It outputs to 202 and 203, and controls the rotation of each motor 204 and 205.

Since the control of the motor is the same as the conventional one, the details are omitted and only the tracking shift operation will be described here. In the phase control of the rotary head, the cylinder phase reference signal generation block 206 of FIG. 5 detects the phase error between the cylinder phase reference signal f and the HSW signal b generated at every constant period T in the cylinder phase control block 210. Then, the phase difference between the signal f and the signal b is controlled to become T ₁ in FIG. On the other hand, the capstan phase reference signal g
First, the first delay signal generation block 207 generates a signal h obtained by delaying the signal f by T ₂ shown in FIG. 6, and further the second delay signal generation block 208 generates the signal h by the tracking mono-multi circuit 209. The tracking mono-multi signal (hereinafter abbreviated as TRMM signal) e obtained is delayed by the time (T _{3 in} FIG. 6). And CT
The phase control of the L signal d is performed by the capstan phase control block 2
At 11, the phase error between the signal g and the signal d is detected and controlled so that the phase difference between the signal g and the signal d becomes T ₄ in FIG. Here, VR1 of the tracking mono-multi circuit
Is a volume for adjusting the time of the signal e so as to be T ₃ in order to obtain the optimum tracking state at the time of self-recording reproduction with the VR 2 set at the center. This state is called tracking fix. Also, VR2 is an external volume that can be used by the user and can be varied around the center and on both sides, and is for performing a tracking shift operation.

Next, the operation when changing VR2 will be described. FIG. 6 shows the case where the VR2 is set to the center, the case where the VR2 is changed to the side, and the case where the VR2 is changed to the side. VR2
Assuming that the time change amount of the signal e due to the change of Δ is ΔT, the timing of the signal g is Δ when compared with ΔT.
T is advanced and the signal d is also advanced by ΔT, and as a result, the phase difference between the signal b and the signal d is controlled to be shortened by ΔT. On the other hand, when it is changed to the side, it is controlled so that ΔT becomes longer. By changing VR2 in this way, the tracking shift operation becomes possible.

Problems to be Solved by the Invention In the above configuration, since the tracking mono-multi signal that determines the tracking shift amount is analog mono-multi as in the device 209 of FIG. 5, even if VR2 is varied, the tracking mono-multi signal time is changed. Since 0 cannot be set to 0, the tracking shift operation can be performed only within the range of T _{D3 in} the direction and T _{D4 in} the direction with respect to the entire range T of the tracking shift in FIG. It is impossible. However, due to the variation of the mechanism or the variation of the tape, the X value is considerably deviated, and there is a tape having the optimum tracking condition in the section 1 or the section 2, and the noise on the screen is cut off even if the tracking shift operation is performed during reproduction. There is a case where there is no.

Means for Solving the Problems A magnetic recording / reproducing apparatus of the present invention for solving the above problems uses a microprocessor capable of handling a tracking mono-multi signal in a digital amount, and performs a tracking shift operation by a function realizing means combined with software. A means for scrolling in the entire tracking shift range is provided.

Action The present invention, by expanding the tracking shift possible range to the entire range by the above-mentioned configuration, makes it possible to obtain the optimum tracking condition for tapes having any X value deviation, and also the phase control of the CTL signal. Can also be performed stably.

Examples Examples of the present invention will be described below.

FIG. 1 is a block diagram, FIG. 2 is a timing chart, and FIG. 3 is a flowchart.

First, the block diagram of FIG. 1 will be described. In the microprocessor unit 100, the time base counter 101 is a free-run down counter that always keeps counting by the input clock signal K ′, and its count value can be read arbitrarily. Reference numeral 102 denotes a register that latches the generation of a flag indicating the arrival of each input signal and the count value of the time base counter 101 (hereinafter abbreviated as TBC) in the conventional case, and latches the data as the arrival time. It Reference numeral 103 denotes a tracking shift key block that can be used by the user during the tracking shift operation, and is input to the microprocessor unit 100 by serial signal communication. And 1
04 is a software department, which is a time base collector 101,
Each error is detected using the information of the register 102 and the tracking shift key block 103, and the calculation result is
Outputs through the / A converter 105 to control the motor.
Reference numeral 106 is a random access memory.

Next, with reference to the timing chart of FIG. 2 and the flowchart of FIG. 3, the software section 104 of FIG.
The basic configuration of the software in will be described.

First, the generation of the reference time T _CY of the cylinder phase reference signal f is performed by the process B in the software unit 104, and the value of T _CY is the RAM 1 in the random access memory 106.
Stored in. The data of RAM1 is updated in process 150 by determining whether TBC has passed the cylinder phase reference period T based on the current data of RAM1. If the result is true, in process 151 of FIG. This is performed by repeatedly storing the result of subtracting T from the data of RAM1 in _RAM1 as the next T _CY . When T _CY is updated, in process 151, fixed data T _{2 is} updated from the updated T _CY.
Is subtracted and the result is the capstan phase reference signal generation time T
Store as _EN in RAM2.

Next, the generation of the reference time T _CA of the capstan phase reference signal g is performed in the process B in the software unit 104, and the value of T _CA is RA in the random access memory 106.
Stored in M3.

In process 153, it is determined whether TBC has exceeded T _EN , and if the result is true, T _CA is generated. T _CA process 154-1
After determining the condition of tracking shift up to 63, calculate the tracking shift amount T _D , and calculate the second from T _EN .
The TRMM-Fix data T ₃ in the figure is subtracted, and it is obtained by adding or subtracting T _{D according} to the tracking shift condition, and the result is stored in the RAM 3.

Next, in the phase control of the rotary head, in process 169, the phase error is detected from the reference time T _{CY of} the signal f and the arrival time of the signal b latched in the register in the software section 102, and the phase error is detected. The phase difference of the signal b is T ₁ as shown in FIG.

Next, in the phase control of the CTL signal, in the process 170, phase error detection is performed from the reference time T _{CA of} the signal g and the arrival time of the signal d latched in the register in the register 102, and the phase error is detected. The phase difference of the signal d is set to T ₄ as shown in FIG.

Next, a bidirectional scroll method in tracking shift according to the present invention will be described with reference to FIGS. 2 and 3.

In the case of tracking shift or mode in the condition judgment of the processes 154 and 155, the process 157 or the process 159.
At the current value of T _D , ie RA
Subtraction or addition is performed on the value of M4, the data is stored in RAM4, and then the above-mentioned calculation of T _CA is performed. By repeating this series of operations for each cylinder phase reference period T, the tracking shift operation is performed. Further, in the tracking shift Fix mode, since T _D is cleared to 0, tracking is in a state during self-recording and reproduction.

The timing of the above operation is shown in FIG.
And.

Next, the operation when the condition determination result of the process 158 or the process 160 becomes true in the series of operations in the above tracking shift will be described.

First, for the tracking shift direction, the process
In 158, T the value of _D is determined to have exceeded the direction of the limiter value T _D1, T _D value in the direction of the limiter value T of the
_D2 (provided that T _D1 is + T _D2 = T) was changed to, at the time of calculation of T _CA, is subtracted heretofore had by adding the value of T _D at process 165 at this time only the process 166, T _CA Is the second value
As shown in the figure, since the shift is from t ₁ to t ₅ , the tracking shift operation in the direction can be continued and scrolling can be performed.

Similarly, for the tracking shift direction, the process
In 160, the value of T _D is determined to have exceeded the T _D2, and change the value of T _D to T _D1, at the time of calculation of T _CA, heretofore process
This time only process that subtracted the value of T _D at 167 1
It is added at 68, and the value of T _CA is from t ₅ to t as shown in Fig. 2.
_Since it is shifted to ₁ , the tracking shift operation in the direction can be continued and scrolling can be performed. Also,
The change in capstan phase reference time during tracking scroll is one cycle, and
Since the timing of the CTL signal is the same as that before the scrolling, the phase control of the CTL signal can be stably performed.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to perform the tracking shift operation in the entire range of the tracking shift, and it is possible to obtain the optimum tracking condition for the tape having any X value deviation.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a timing chart during the same tracking shift operation, and FIG. 3 is a flow chart of a process for performing calculations necessary for the tracking shift operation of the present embodiment. FIG. 5 is a VHS format magnetic tape pattern diagram, FIG. 5 is a block configuration diagram of a conventional example, and FIG. 6 is a timing chart during a tracking shift operation of the conventional example. 100 …… Microprocessor unit, 101 …… Time base counter, 102 …… Register, 103 …… Tracking shift key block, 105 …… D / A converter, 106 …… Random access memory.

Claims (1)

(57) [Claims] 1. In a tracking shift operation for changing a phase difference between a rotary head and a reproduction control signal when a recorded tape is reproduced, that is, a tracking amount, the tracking amount can be treated as a digital value as a tracking shift operation means. When the system has a microprocessor and changes the tracking amount by adding or subtracting a fixed value for each phase reference period of the rotary head within a fixed range, the tracking amount is added (or subtracted) by the fixed value. When the condition exceeds the maximum value (or minimum value) due to, the operation of directly changing the tracking amount to the minimum value (or maximum value) is defined as tracking scroll, and the range between the maximum and minimum tracking amounts is the rotary head. Set both so that it becomes the phase reference period, and Tracking the amount of change when scrolling the rotary head phase reference period by ring scroll,
A magnetic recording / reproducing apparatus characterized by performing a tracking shift operation in the entire range of a tracking shift and stably performing phase control of a rotary head and a reproduction control signal during tracking scroll.