JPH01128255A - Traveling state detecting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a digital audio tape recorder (DAT).
This device relates to a running state detection device used to adjust the magnetic tape running system of devices that record and playback by forming diagonal tracks on a magnetic tape, such as video tape recorders (called VTRs) and video tape recorders (called VTRs). It is.

Conventional Technology When producing devices such as DATs and VTRs that record and reproduce signals by forming diagonal tracks on a magnetic tape, the linearity of the tracks must be maintained to ensure compatibility of the tracks formed. Generally, the traveling mechanism is adjusted so that the recording position falls within a predetermined value range.

The conventional trunk linearity measurement method is known to develop the track recording pattern and calculate the deviation from the pattern's original position (for example, "Introduction to Home VTR", Corona Published by the company, written by Katsuya Yokoyama,
p120).

An example is shown in FIG. In FIG. 6, tracks 2 are formed on the magnetic tape 1 and developed. Check the tape end 27 while looking at a microscope.
The intersection of each trunk with the perpendicular line 24 and the tape end 27
Measured as a distance of 25 from

By taking the difference between the distance 25 and the ideal value, the linearity of the formed track, the deviation of the pattern, etc. can be accurately measured.

Problems to be Solved by the Invention In the above method, it is necessary to adjust the traveling mechanism once, record it on a magnetic tape, develop it, and measure the deviation of the 1-rack pattern. The problem is that it takes time and effort to confirm the information.

In view of the above-mentioned problems, the present invention has been developed so that when adjusting the traveling mechanism, the deviation of the playback trace locus of the head from the standard track can be visually and immediately seen using an oscilloscope in real time. It is an object of the present invention to provide a running state detection device that can quickly make adjustments.

Means for Solving the Problems In order to solve the above problems, the running state detection device of the present invention forms diagonal tracks on a magnetic tape, and uses crosstalk between each track of the magnetic tape to detect the head and track. Using a tape on which a tracking detection signal consisting of two parts, a pilot signal for detecting the relative position of the head and a synchronization signal for detecting the pilot signal, is recorded in a plurality of places, the rotating cylinder to which the head is attached is used. , a synchronization signal detection circuit that detects the synchronization signal of track-F and outputs a pulse; a counter that counts output pulses of the synchronization signal detection circuit to count the order of the synchronization signals from the start of the track; and the pilot. a pilot amplitude detection circuit that detects the amplitude of the signal; a tracking circuit whose number is equal to the number of tracking detection signals recorded; and a tracking circuit that detects tracking information from the output of the viroft amplitude detection circuit; and a tracking circuit that detects the synchronization signal from the output of the counter. a distributor that distributes the output of the detection circuit to the plurality of tracking circuits to facilitate tracking detection; a plurality of smoothing circuits that smooth the output signals of each of the plurality of tracking circuits; and a plurality of smoothing circuits that smooth the output signals of the plurality of tracking circuits respectively; an output switching circuit for switching the output; and tape drive means for controlling tape running using only one of the outputs of the plurality of tracking circuits, the output of the output switching circuit being used as a trunk running status output. It is configured to do this.

Function: If playback is performed using the above-mentioned running state detection device and a mechanism that adjusts the running, the magnetic tape can be stably run controlled by one word of tracking detection at only one location, and at the same time, multiple tracks recorded on the magnetic tape can be controlled stably. The relative position of the head and the I rank at each position can be detected as an electrical signal by the tracking detection signal. By creating a magnetic tape with high recording accuracy in advance and observing this output electrical signal with an oscilloscope, for example, you can immediately determine the head relative to track tracing state on the spot while adjusting the running of the mechanism, that is, the desired head head. Any deviation from the running position can be observed, making it possible to quickly adjust the running mechanism.

Embodiment Hereinafter, a driving state detection device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a running state detection device according to an embodiment of the present invention, and FIGS. 2 (al to (e)) and 3 are operational waveform diagrams thereof.

In FIG. 1, 1 is a magnetic tape, 11 is a head, and 12 is a magnetic tape.
1 is a rotating cylinder to which the head 11 is attached; 13 is a synchronization signal detection circuit for detecting a synchronization signal on the tape 1 from the playback signal of the head 11; 141 is a band-pass filter;
42 is a rectifier circuit, 14 is a band pass filter 141.
A pilot amplitude detection circuit includes a rectifier circuit 142 and detects the amplitude of a pilot signal on the magnetic tape 1, 151 is a delay circuit, 152 is a frequency divider, and 15 is a delay circuit fl 15
L is a counter consisting of a frequency divider 152, 16 is a divider that distributes the pulse output from the synchronization signal detection circuit 13 using the output of the counter 15, 1.01 L is a sample hold circuit, and 1013 is a subtracter. , 1.01 is a sample hold circuit 1.011.1012. Subtractor 10
13, a tracking circuit detects the position of the head relative to the track using the output pulse of the distributor 16 from the output of the pilot amplitude detection circuit; 102 to 119 have the same configuration as the tracking circuit 101, and each has a different distribution output pulse of the distributor 16; a tracking circuit that operates in response to
201 is a resistor 2011. A smoothing circuit consisting of capacitors 2.12, 202 to 219 have the same configuration as the smoothing circuit 201, and are connected to the outputs of the tracking circuits 102 to 119, respectively; 17 is a smoothing circuit to which the outputs of the smoothing circuits 201 to 219 are connected; an output switching circuit 18 that switches the outputs of 201 to 219 according to the output of the counter 15;
04 is a capstan motor that runs the magnetic tape 1;
1801 is an FG that outputs a frequency signal proportional to the rotation speed of the capstan motor 1804, 1802 is an FC], 8
1803 is an adder that adds the output of the speed control circuit 1802 and the output of the tracking circuit 119; 18 is the capstan motor 1804; F
The tape drive means includes a G1801, a speed control circuit 1802, and an adder 1803.

Next, the magnetic tape used in the running state detection device of the present invention will be explained.

FIG. 4 is a diagram showing the recording state of tracking detection signals on the trunk, and FIG. 5 is a diagram showing an example of the recording pattern of each tracking detection signal.

In FIG. 4, 2 is a track on the magnetic tape 1, 8a
8s is an area on track 2 where the l-racking detection signal is recorded. In this example, there are 19 areas where tracking detection signals are recorded. Of course, 1
It may be a number other than 9.

FIG. 5 is a diagram showing a specific recording example of these 8a to 8s, and in particular only the portion 8a is shown.

In FIG. 5, 3 and 6 are pilot signals 4a and 7 recorded at different azimuths for detecting the relative position of the head and trunk by cross-steering.
4b and 7b are synchronization signals for detecting pilot signals recorded at different azimuths; 4b and 7b are pilot signals 4a and 7a having different recorded lengths but the same recording start position; 4a and 7a, respectively. 9 is a head moving in the direction of arrow 10. Pilot signal 3. Synchronization signals 4a and 4b have the same azimuth head, and pilot-to-signal 6 and synchronization signal 7a
, 7b are recorded with heads of the same azimuth. or,
The same signal of the same azimuth is recorded in the same shaded area. The tracking detection signal recorded is the fifth
The recording pattern of the four trunks shown in the figure is repeatedly recorded every four tracks.

Next, the operation when a magnetic tape recorded as shown in FIGS. 4 and 5 is reproduced using the embodiment shown in FIG. 1 will be described.

When the head 9 moves in the direction of the arrow 10 in FIG. 5, the pilot signal is transmitted by the diagonal line 6 in FIG. The signals are reproduced by the head 9 in the order indicated by the diagonal line 3, and a signal having the waveform shown in FIG. 2(a) is outputted from the bandpass filter 141 in the pilot amplitude detection circuit shown in FIG.

The rectifier port 8142 rectifies the output of the bite bus filter 141 and outputs a signal as shown in FIG. 2(C). At the same time, the synchronization signal 7a reproduced by the head is temporally shown in FIG.
111, and the synchronization signal detection circuit 13 detects this signal and outputs two pulses shown in FIG. 2(d) and (el). It can be configured with a level detection circuit, etc. Of course, other methods may also be used.

Of the pulses output by the synchronization signal detection circuit 13, FIG.
) is applied to a dividing period 152 via a delay circuit 151 and is frequency-divided. Further, the divided period 152 is cleared by a signal (for example, a signal synchronized with the rotating cylinder 12) indicating the track start end that is applied to the input terminal 19. That is, the counter 15 counts and outputs the order of pulses output from the synchronization signal detection circuit 13 from the track start end. The output of the counter 15 is applied to the distributor 16 and the synchronization signal detection circuit 1
The pulses output by No. 3 are distributed to tracking circuits 101 to 119 in order from the track start end. When the head reproduces the tracking detection signal area 8a shown in FIG.
6 outputs the pulse output from the synchronization signal detection circuit 13 to the tracking circuit 101. Among the pulses output by the synchronization signal detection circuit 13, the sample and hold circuit 1011 samples and holds the output signal of the pilot amplitude detection circuit 14, which is shown in FIG. 2(d). Next, synchronization signal detection circuit 1
The sample-and-hold circuit 1012 uses a subtracter 1013 to sample the difference between the output signal of the pilot amplitude detection circuit 14 and the output signal of the sample-and-hold circuit 1011. Hold.

There are three amplitudes of the pilot signal shown in Figure 2 (al).From the left, the first one is from area 6 in Figure 5, and the second one is from area 6 in Figure 5. 3 things,
The area shown in FIG. 3 is the area where the pilot signal is recorded on the left track as viewed from the direction of head movement in FIG. The second pilot signal. The third is due to crosstalk from adjacent tracks, the amplitude of which is proportional to the amount of protrusion of the head 9 into the relevant trunk. Therefore, FIG. 2(C) shows the amplitude of FIG. 2(a).
The signal level is also proportional to the amount of protrusion to both adjacent tracks. That is, the voltage sampled and held in the sample and hold circuit 1011 by the pulse shown in FIG. 2(d) is a voltage that is proportional to the amount of protrusion of the head 9 toward the right adjacent track in the direction of movement. Furthermore, in the pulse of FIG. 2(e), the pulse of FIG. 2(c)
), that is, the amount of protrusion of the head toward the trunk on the left in the direction of head movement, and the sample and hold circuit 10.
The sample and hold circuit 101 outputs a voltage proportional to the difference between the output of the head and the amount of protrusion of the head to the adjacent track on the right.
It is held at 2.

Therefore, the sample-and-hold circuit 1012 holds and outputs the difference in the amount of protrusion of the head 90 from the adjacent trunks, that is, the position of the head relative to the track, as a voltage. Tracking circuits 102 to 119 each perform the same operation as tracking circuit 101 in accordance with the order in which tracking detection signals from the track start end are recorded.

Therefore, the tracking circuit 119 outputs, as a voltage signal, the position of the head relative to the track at the position where the last 199th tracking detection signal is recorded, counting from the start of the track.

Further, the magnetic tape 1 is driven by a capstan motor 1804. This capstan motor 1804 is provided with an FG1801 that outputs a signal with a frequency proportional to the number of rotations, and a speed control circuit 1802 is used to keep the frequency of the FG18010 at a constant value, causing the capstan motor 1804 to rotate almost at a constant rate. I am trying to make it so that In the embodiment of FIG. 1, the output of the tracking circuit 119 is added to the output of the speed control circuit 1802 via an adder 1803,
The control system is configured so that the output of the tracking circuit 119 is zero.

Therefore, the capstan motor 1804 runs the magnetic tape 1 so that the head 9 passes through the center of the track 2 at the location where the last tracking detection signal is recorded.

Note that the capstan motor 1804, FC 1801, speed control circuit 1802, and adder 1803 constitute tape drive means.

On the other hand, the outputs of the tracking circuits 101 to 119 output the position of the head relative to the track at the position of each tracking detection signal recorded on the track 2 as a voltage signal. These outputs are smoothed by smoothing circuits 201 to 219 each comprising a resistor and a capacitor, and converted into a DC signal with little temporal fluctuation. Smoothing circuit 201-2
The output of 19 is switched by an output switching circuit 17 using a counter 15 that outputs a signal indicating the order from the start end of track 2, and is temporally switched and output in the order of the areas in which each tracking detection signal is recorded. Ru.

FIG. 3 shows the magnetic tape 1 on which tracking detection signals are recorded at 19 locations on one track shown in FIG.
This figure shows an example of the output of the output switching circuit 17 when playing back in the illustrated embodiment.

In FIG. 3, an arrow 32 indicates a time course, and a voltage signal 31 changing in a stepwise manner indicates the output of the output switching circuit 17.

Therefore, the output 31 of the output switching circuit 17 becomes almost zero at the tracking detection signal recorded at the end of the track 2 used for tape running control, and at the portion where each other tracking detection signal is recorded, the output 31 of the output switching circuit 17 becomes almost zero. It indicates the position. Moreover, since the accuracy of the recorded tape is high, the output 31 of the output switching circuit 17 indicates the deviation of the current head running from the ideal value.

In addition, a sweep trigger is applied to the oscilloscope with a signal that resets the counter 15, and the output 3 of the output switching circuit 17 is
If 1 is displayed on an oscilloscope, the current trace status of the head track can be visually observed in real time. Moreover, even if the signal indicating the relative position of the head and track in the area where each tracking detection signal is recorded fluctuates unstably, the fluctuation is absorbed by the smoothing circuits 201 to 219 and converted into a stable DC signal. This makes observation with an oscilloscope extremely easy.

While observing with an oscilloscope, if the mechanism is adjusted so that the output 31 of this output switching circuit 17 becomes almost zero at the recorded portion of each tracking detection signal,
The running adjustment of the mechanism is completed.

In this embodiment, the tracking detection signal recorded at the end of track 2 was used as the tracking detection signal for use in tape feed control, but the present invention can be applied regardless of the tracking detection signal recorded in any part of trunk 2. The effect remains the same.

Although the smoothing circuits 201 to 219 are first-order low-pass filters composed of resistors and capacitors in the embodiment, similar effects can be obtained with filters other than those in this embodiment.

Effects of the Invention As described above, according to the present invention, tracks are recorded in advance on a tape with high recording position accuracy, and a plurality of tracking detection signals recorded on each trunk are reproduced. The relative position between the head and the recording track at the recording position of each tracking detection signal of the adjustment mechanism can be detected with a stable electrical signal, which can be output in accordance with the head trace time and observed with an oscilloscope, etc. , it is possible to know the current adjustment status of the mechanism in an extremely easy-to-see state. In other words, since the current state can be checked by looking at the oscilloscope while making adjustments, it is possible to make very quick mechanism adjustments, which is highly useful in terms of production.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a running state detection device according to an embodiment of the present invention, FIGS. 2 and 3 are operational waveform diagrams thereof, and FIG.
5 and 5 are explanatory diagrams showing an example of recording a tracking detection signal on a magnetic tape, and FIG. 6 is an explanatory diagram showing a conventional measuring method of recording track accuracy. 1...magnetic tape, 11...head,
12...Rotating cylinder, 13...Synchronizing signal detection circuit, 14...Pilot amplitude detection circuit, 15...Counter, 16... Distributor, 101-119... Tracking circuit, 2
01-219... Smoothing circuit, 17...
Output switching circuit, 18...Tape drive means. Name of agent: Patent attorney Toshio Nakao (1 person) Figure 5 Figure 6

Claims (1)

[Claims] A diagonal track is formed on a magnetic tape, and each track of the magnetic tape is provided with a pilot signal for detecting the relative position between the head and the track by crosstalk, and a synchronization signal for detecting the pilot signal. A device for reproducing a tape on which tracking detection signals are recorded at a plurality of locations, comprising: a rotary cylinder to which a head is attached; a synchronization signal detection circuit for detecting the synchronization signal on the track and outputting a pulse; a counter that counts output pulses of a synchronization signal detection circuit to count the order of the synchronization signals from a track start end; a pilot amplitude detection circuit that detects the amplitude of the pilot signal; and a recorded number of the tracking detection signals. a tracking circuit that is the same in number and detects tracking information from the output of the pilot amplitude detection circuit; and a distributor that uses the output of the counter to distribute the output of the synchronization signal detection circuit to the plurality of tracking circuits to promote tracking detection; a plurality of smoothing circuits that smooth the output signals of each of the plurality of tracking circuits, and an output switching circuit that switches the output of the smoothing circuit based on the output of the counter;
tape drive means for controlling tape running using only one of the outputs of the plurality of tracking circuits,
A running state detection device characterized in that the output of the output switching circuit is a running state output of a truck.