JP3314528B2 - Magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a magnetic recording / reproducing apparatus having linearity determination, head clogging detection, and automatic tracking function.

[0002]

2. Description of the Related Art In recent years, with the increase of high value-added products, VTRs equipped with many functions are increasing. However, in order to realize the multi-function, there are many signals having different input / output conditions, so that several microprocessors or an input expansion system are required, so that the system configuration is complicated and the system is expensive.

A conventional auto-tracking function for automatically controlling a tracking condition so that a level detection signal is maximized, and a track recorded on a tape using a maximum value and a minimum value of the level detection signal are described below. The system operation of the linearity determination function that determines linearity and the clogging detection function that detects that the head is clogged when the level detection signal falls below the reference level for a certain period of time in the conventional system and the level detection signal A system in which an automatic tracking function for automatically executing auto-tracking again after a certain change is added will be described.

FIG. 3 is a block diagram showing a conventional auto-tracking and linearity discrimination system, FIG. 4 is a flowchart showing the processing inside a microprocessor of the conventional auto-tracking and linearity discrimination system, and FIG. It is a block diagram which shows the addition system at the time of adding tracking. Table 1 shows a comparison of sampling and input filter constants required for auto tracking, linearity determination, clogging detection, and automatic tracking.

[0005]

[Table 1]

In FIG. 3, 101 is a cylinder, 10
Reference numeral 2 denotes a rotating head mounted on a cylinder for reproducing a video signal, 103 denotes a reproducing head amplifier, 104 denotes a reproducing envelope detector, 119 denotes a sampling a setting unit, 106 denotes a filter constant A / B switching control unit, and 120 denotes a microprocessor. 108 is a level detection voltage A / D converter composed of hardware inside the microprocessor 120, and 109, 111, 112, and 121 are processes composed of software inside the microprocessor 120.
09 is an A / D converter control processing unit, 111 is an auto tracking processing unit, 112 is a linearity determination processing unit,
Reference numeral 121 denotes a filter constant control processing unit, where S1a to S1d, S1f to S1i, and S1k indicate signals or data handled by software in the microprocessor 120, S1a is a reproduction head output signal, S1b is a reproduction envelope signal, and S1c. Is a level detection signal, S1
d is a sampling a signal, S1f is a filter constant A passing signal, S1g is a filter constant B passing signal, S1h is a level detection signal A / D conversion data, S1i is A / D conversion control data, and S1k is a filter constant A / B switching. This is a control signal.

In FIG. 5, reference numeral 122 denotes a filter constant A setting unit, 123 denotes a sampling b setting unit, 124 denotes a filter constant B setting unit, 120 denotes a microprocessor, and 108 denotes hardware inside the microprocessor 120. With a level detection voltage A / D converter,
Reference numerals 125, 113, and 114 denote processes constituted by software in the microprocessor 120, and 125 denotes an A / D
A converter control processing unit, 114 is a clogging detection processing unit;
Reference numeral 113 denotes an automatic tracking processing unit, and S1c to S1i represent signals or data handled by software in the microprocessor 120, S1d represents a sampling a signal, S1f represents a filter constant A passing signal, S1c represents a level detection signal, and S1e. Is a sampling b signal, S1g is a filter constant B passing signal, S1h is a level detection signal A /
D conversion data, S1i is A / D conversion control data.

Next, the operation of the automatic tracking and linearity determination system will be described with reference to FIGS.

First, the cylinder 101 rotates so as to reproduce the tape, and the reproduction head output signal (S1a) obtained from the rotary head 102 is amplified by the reproduction head amplifier 103 and reproduced by the reproduction envelope detector 104. The amplitude of the signal (S1b) is detected, A / D converted, and output as a level detection signal (S1c). This level detection signal (S1c) is supplied to the sampling a setting unit 1
19 becomes a sampling a signal (S1d). This sampling a signal (S1d) is used as an auto-tracking end determination process (Process 2) in the microprocessor 120.
01), if the auto-tracking is not completed, the filter constant A is set by the filter constant control processing unit 121 (processing 203), and the filter constant A is selected by the filter constant A / B switching control unit 106, and the filter constant A is set. The passing signal (S1f) is input to the microprocessor 120, and is converted into the level detection signal A / D conversion data (S1h) by the level detection voltage A / D converter 108, and the auto tracking processing unit 111
, An auto tracking process (process 204) is executed. Also, if auto tracking has been completed,
By setting the filter constant B in the filter constant control processing unit 121 (processing 207), the filter constant A /
The filter constant B is selected by the B switching control unit 106, the filter constant B passing signal (S1g) is input to the microprocessor 120, and the level detection voltage A / D converter 108 converts the signal into the level detection detection signal A / D conversion data (S1h). Converted linearity determination processing unit 112
Then, the linearity determination process (process 208) is executed.

Next, a system in which clogging detection and automatic tracking are added will be described with reference to FIG.

As shown in (Table 1), the input conditions necessary for each function are the same as the combination of sampling and filter constant for auto-tracking and auto-tracking, but linearity discrimination and clogging detection are different from each other. In order to realize each function, it is necessary to create necessary input signals for each and input them to the microprocessor.
Since clogging detection and automatic tracking are performed after the end of the auto tracking, the conventional filter constant A / B switching control unit 106 is set to the filter constant B after the end of the auto tracking. Filter constant B passing signal (S
1g), a sampling b setting unit 123 and a filter constant B setting unit 124 are required for detecting clogging, and a conventional sampling a setting unit 119 is used for automatic tracking.
And an A / D converter control processing unit 125 for controlling the A / D conversion of each input.

Therefore, functions can be realized by adding these systems.

[0013]

However, if a plurality of functions (auto-tracking, linearity discrimination, clogging detection, and auto-tracking) with different input conditions of the level detection signal (S1c) can be realized, the conventional system will
Multiple input terminals are used to obtain the required input signal for each function.
There is a problem of need .

[0014]

According to the present invention, a mechanism for controlling a filter constant and sampling during execution of auto tracking, linearity discrimination, clogging detection and automatic tracking is added, and input conditions are controlled by a microprocessor. Each function is realized by performing time division processing.

[0015]

With this configuration, when a plurality of functions (auto tracking, linearity discrimination, clogging detection, and automatic tracking) having different input conditions of the level detection signal can be realized,
By controlling the input conditions on the microprocessor, it is possible to be realized all functions in one input pin. In addition, linearity determination, clogging detection, and automatic tracking can be realized by a single microprocessor by performing time-division processing after the end of auto-tracking, so that an inexpensive system configuration is possible.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the magnetic recording / reproducing apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a magnetic recording and reproducing apparatus according to the present invention.
Block diagram showing a clogging detection and automatic tracking system,
FIG. 2 is a flowchart of the internal processing of the microprocessor of the automatic tracking, linearity determination, clogging detection and automatic tracking system in one embodiment of the magnetic recording / reproducing apparatus of the present invention.

In FIG. 1, 101 is a cylinder, 10
Reference numeral 2 denotes a rotating head mounted on a cylinder for reproducing a video signal; 103, a reproducing head amplifier; 104, a reproducing envelope detector; 105, a sampling a / b switching controller;
6 is a filter constant A / B switching control unit, 107 is a microprocessor, 108 is a level detection voltage A / D converter configured by hardware inside the microprocessor 107, and 109 to 118 are microprocessors 1
Reference numeral 109 denotes an A / D converter control processing unit, 110 denotes a time division control processing unit, 111 denotes an auto tracking processing unit, 112 denotes a linearity determination processing unit, and 113 denotes a clogging detection processing. Department,
114 is an automatic tracking processing unit, 115 is a filter constant A setting processing unit, 116 is a filter constant B setting processing unit, 11
Reference numeral 7 denotes a sampling a setting processing unit, 118 denotes a sampling b setting processing unit, and S1a to S11 denote signals or data handled by software in the microprocessor 107, S1a denotes a reproduction head output signal, and S1b.
Is a reproduction envelope signal, S1c is a level detection signal, S
1d is a sampling a signal, S1e is a sampling b signal, S1f is a filter constant A passing signal, S1g is a filter constant B passing signal, and S1h is a level detection signal A / D.
S1i is A / D conversion control data, S1j is a time-division control signal, S1k is a filter constant control signal,
1l is a sampling control signal, and S1m is auto-tracking end data.

Auto-tracking using FIGS. 1 and 2
The operation of the linearity determination, clogging detection, and automatic tracking system will be described.

Level detection signal (S1c) during reproduction
The control up to creation is the same as in the prior art. First, the cylinder 101 rotates so as to reproduce the tape, and the reproduction head output signal (S1
The signal a) is amplified by the reproducing head amplifier 103, and the amplitude of the reproduced envelope signal (S1b) amplified by the reproducing envelope detector 104 is detected, A / D converted, and output as a level detected signal (S1c). The level detection signal (S1c) is obtained by the time-division control processing unit 1 based on the auto-tracking end data (S1m) set by the auto-tracking processing unit 111 in the microprocessor 107.
Automatic tracking end determination processing at 10 (processing 201)
Is executed. First, the auto tracking end data (S
1m) is not set, the time division control processing unit 11
According to 0, the sampling a setting processing unit 117, the filter constant A setting processing unit 115 and the auto tracking processing unit 111 are selected, and the sampling a and the filter constant A
(Processing 202 and 203), the sampling a / b switching control unit 105 and the filter constant A /
In the B switching control unit 106, the sampling a signal (S1
d) The filter constant A passing signal (S1f) is selected. The signal that has passed through the sampling and filter is input to the microprocessor 107, and the level detection voltage A /
The A / D converted data (S1h) is converted into a level detection signal by the D converter 108.
In step 1, an auto tracking process (process 204) is executed.

Next, the auto tracking end data (S1
If m) is set, first the time division control processing unit 11
According to 0, the sampling a setting processing unit 117, the filter constant B setting processing unit 116, and the linearity determination processing unit 112 are selected, and the sampling a setting processing (processing 20) is performed.
6) The sampling a / b switching control unit 105 is executed by executing the filter constant B setting process (process 207).
Further, the sampling a signal (S1d) and the filter constant B passing signal (S1g) are selected by the filter constant A / B switching control unit 106. The filter constant B passing signal (S1g) is input to the microprocessor 107, and becomes the level detection signal A / D conversion data (S1h) by the level detection voltage A / D converter 108, and the linearity determination processing unit 112 performs the linearity determination processing (processing 2).
08) is executed for one second from the end of the auto tracking.

Next, the sampling b setting processing section 118, the filter constant B setting processing section 116 and the clogging detection processing section 113 are selected by the time division control processing section 110, and the sampling b setting processing (processing 210) and the filter constant B setting are performed. By executing the processing (processing 211), the sampling a / b switching control unit 105 and the filter constant A
/ B switching control section 106 performs sampling b signal (S1
e) The filter constant B passing signal (S1g) is selected. The filter constant B passing signal (S1g) is input to the microprocessor 107, and becomes a level detection signal A / D conversion data (S1h) by the level detection voltage A / D converter 108, and the clogging detection processing unit 113 performs clogging detection processing (processing). 212) is executed for one second, and then the sampling a setting processing unit 1 is
17, the sampling a / b switching control unit 1 is selected by selecting the filter constant A setting processing unit 115 and the automatic tracking processing unit 114 and executing the sampling a setting process (process 214) and the filter constant A setting process (process 215).
The sampling a signal (S1d) and the filter constant A passing signal (S1f) are selected by the control unit 05 and the filter constant A / B switching control unit 106. The filter constant A passing signal (S1f) is input to the microprocessor 107, and becomes the level detection signal A / D conversion data (S1h) by the level detection voltage A / D converter 108, and the automatic tracking processing unit 114 performs the automatic tracking processing (processing 216). Is executed for one second. Thereafter, the linearity determination described above is executed again for one second. As described above, in the embodiment, the linearity determination processing (processing 208), the clogging detection processing (processing 212), and the automatic tracking processing (processing 216) are performed at one-second intervals.
Are sequentially executed, but the time interval is not particularly limited to one second.

When the present invention further adds functions having different filter constants and sampling conditions for level detection signals, the functions can be realized only by adding software inside the microprocessor.

[0024]

As described above, the present invention provides a microprocessor
The sampling switch control unit and the filter
The level detection signal is input to the
Of the microprocessor to one input terminal of the microprocessor.
With this, auto tracking, linearity discrimination,
Inexpensive system for head clogging detection and automatic tracking
It can be realized with a system configuration .

[Brief description of the drawings]

FIG. 1 is a block diagram showing an automatic tracking, linearity determination, clogging detection, and automatic tracking system in an embodiment of a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 is a flowchart of the processing inside the microprocessor of the automatic tracking, linearity determination, clogging detection and automatic tracking processing system in the same embodiment.

FIG. 3 is a block diagram showing a conventional auto tracking and linearity discrimination system.

FIG. 4 is a flowchart of the internal processing of a microprocessor in a conventional auto tracking and linearity discrimination system.

FIG. 5 is a block diagram showing an additional system in which clogging detection and automatic tracking are added to the conventional system.

[Explanation of symbols]

 104 Reproduction envelope detector 105 Sampling a / b switching controller 106 Filter constant A / B switching controller 107 Microprocessor 108 Level detection voltage A / D converter 109 A / D converter control processing unit 110 Time division control processing unit 111 Auto tracking Processing unit 112 Linearity determination processing unit 113 Clogging detection processing unit 114 Automatic tracking processing unit 115 Filter constant A setting processing unit 116 Filter constant B setting processing unit 117 Sampling a setting processing unit 118 Sampling b setting processing unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 15/467 G11B 5/455

Claims (1)

(57) [Claims] 1. A reproduction envelope detector for amplifying a signal reproduced from a rotary head for reproducing a video signal recorded on a tape and detecting an amplitude level thereof, and a sampling of an output of the reproduction envelope detector. Switching sampling
A switching control unit and an output of the sampling switching control unit
Filter constant switching control to switch the filter constant
Unit and the output of the filter constant switching control unit.
Has one input terminal of that microprocessor, said first input
And auto-tracking function of the signal from the terminal to automatically control the tracking condition to maximize the 1 input
And linearity determination function to determine the linearity of the tracks recorded on the tape using the maximum and minimum values of the signal from the force terminal, below a reference level predetermined time or more with a signal from the first input terminal a clogging detecting function for detecting that the head clogging state when said first input
It has an automatic tracking function that automatically executes auto tracking again when the signal from the terminal changes over a certain amount ,
The signal from the one input terminal is turned on at a certain time interval.
Auto tracking function or linearity judgment function
Or for the clogging detection function or the automatic tracking function
Sampling switching system so that necessary input conditions are satisfied
Time to control the control unit and the filter constant switching control unit
A magnetic recording / reproducing apparatus comprising a split control unit .