JPH03225661A - Traveling state detector - Google Patents

Abstract

PURPOSE:To easily and speedily judge the traveling state of a magnetic tape by providing plural averaging circuits, forming tracks on this magnetic tape with high accuracy and reproducing the magnetic tape. CONSTITUTION:A magnetic head 8 is fitted to a rotary cylinder part 2 so as to scan the tracks and to reproduce the signals of a magnetic tape 28. A detection circuit 3 performs envelope detection to pilot signals out of the reproducing signals of the tracks under scanning, and a detection circuit 4 detects the pilot signal of a certain track adjacent to the track under scanning. For the detection output of the circuit 3, the level is averaged by an averaging circuit 5, and the output of the circuit 4 is averaged by an averaging circuit 6 while using the plural tracks. When the level of the output signal from the circuit 6 is fixed, the output signal of the circuit 5 is defined as the detection signal for the traveling state of the track. Therefore, only by forming the tracks on the tape 28 with high accuracy in advance and reproducing this tape 28, the traveling state of the tape 28 can be taken out. Thus, the traveling state of the tape 28 can be easily and speedily judged.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a running state detection device, and in particular to a magnetic tape device for recording information on a magnetic tape or reproducing information on a magnetic tape using a rotating cylinder. The present invention relates to a running state detection device for detecting the running state of a vehicle.

Conventional technology A device that uses a rotating cylinder to record information on a magnetic tape or reproduce information recorded on a magnetic tape, such as a digital audio recorder (DA
Tracks are formed diagonally on a magnetic tape in devices such as T) and video tape recorders (VTR). In such devices, the linearity of the tracks is measured and the running system of the magnetic tape is adjusted in order to ensure compatibility of tracks formed by devices of the same format.

Conventionally, such track linearity has been measured by developing a magnetic tape using a chemical or the like, and measuring the track pattern on the developed magnetic tape using an optical microscope, as shown in FIG. ,X+,...
The XTI was measured, the difference from the theoretical value was determined, and the track pattern was graphed as shown in FIG. 10 based on the measurement results, the curved shape of the track, etc. was determined, and the tape running system was adjusted.

Problems to be Solved by the Invention However, in the conventional method, after adjusting the running system once,
It was necessary to record the track pattern on the magnetic tape, then take the magnetic tape out of the cassette, go through the development process, measure the dimensions with an optical microscope, and then run the measurement results on a computer, so the development and optical microscope work was necessary. In addition, it requires expensive equipment such as an optical microscope or a combination camera, and there are other problems such as it takes about 20 minutes to obtain the results.

The present invention has been made in view of the above two points, and it is an object of the present invention to provide a running state detection device that can quickly measure track patterns on a magnetic tape.

Means for Solving the Problems The present invention provides an apparatus for reproducing a magnetic tape on which a track is recorded with a pilot signal for detecting a relative position with a magnetic head, the magnetic head being attached to the magnetic tape, and the track being scanned. a rotating cylinder section for reproducing signals on the magnetic tape; a detection circuit for envelope-detecting the pilot signal of the track being scanned by the magnetic head from among the reproduced signals reproduced by the rotating cylinder section; a detection circuit for detecting the pilot signal of a track adjacent to the track being scanned by the magnetic head from among reproduced signals of the track being scanned by the magnetic head; and an output envelope detection signal of the detection circuit; and a second averaging circuit that averages the output detection signals of the detection circuit.

The active rotating cylinder section reproduces the magnetic arp, which has been previously tracked with high precision. The detection circuit detects a pilot signal of a track adjacent to the track being scanned by the magnetic head from among the reproduced signals.

Since the output detection signal of the detection circuit is a signal that corresponds to the relative position between the magnetic head and the track, the running state of the magnetic tape can be determined from this signal. The output is averaged by the averaging circuit and used as judgment data. In addition, when using the detection signal as judgment data, the area where the pilot signal of the track being scanned by the magnetic head is uniform,
In other words, the magnetic head must scan the entire track. For this reason, the pilot signal of the scanning track is obtained by the envelope detection circuit, and this is averaged by the first averaging circuit, thereby providing data for determining whether or not the output detection signal of the detection circuit can be used as determination data. It can be used as

The running state of the magnetic tape can be easily determined simply by reproducing the magnetic tape on which tracks are formed with such high precision using the apparatus of the present invention.

Example FIG. 1 shows a 70 block diagram of one embodiment of the present invention.

1 shows a running state detection device according to the present invention. The running state detection device 1 includes a rotating cylinder section 2. Envelope detection circuit 3
．． Detection circuit 4. It consists of a first averaging circuit 5 and a second averaging circuit 6.

The rotating cylinder portion 2 has a magnetic head 7.8. Rotary transformer9. It consists of a radio frequency (RF) amplifier 10. The magnetic head 7.8 has a different azimuth angle, and the rotating cylinder has 1
It is mounted at an 80° angle. magnetic head 7.8
is connected to a rotary transformer 9, and the D-tary transformer 9 is connected to an RF amplifier 10.

The envelope detection circuit 3 is connected to the output of the RF amplifier 10. The envelope detection circuit 3 is connected to the magnetic head 7 or 8.
Envelope detection is performed on the reproduced signal. The output of the envelope detection circuit 3 is connected to a first averaging circuit 5.

The first averaging circuit 5 averages the input signal as shown in the following equation and outputs it.

((N 1)/N)XV+Vo=V'((N-1)/
N) xV' +V. =■"((N-1)/N) The output of 5 is connected to the measurement terminal 11.

The detection circuit 4 includes a buffer circuit 12. Bandpass filter 1
3. Gain control circuit 14. Envelope detection circuit 15. Sample and hold circuit 16.17. Synchronous signal detection circuit 18. Timing generation circuit 19. Differential amplifier 20
It becomes more.

The buffer 7 circuit 12 is an RF
It is connected to the output of the amplifier 10, and the output of the buffer circuit 12 is input to a gain control circuit 14 via a bandpass filter 13 for detecting pilot signals of adjacent tracks.

The output of the gain control circuit 14 is input to an envelope detection circuit 15, and the output of the envelope detection circuit 15 is input to a sample hold circuit 16 and a differential amplifier 20. The differential amplifier 20 includes a sample hold circuit 16 in addition to the output of the envelope detection circuit 15.
The output of is input, and the difference signal is output.

The output of the differential amplifier 20 is input to the sample hold circuit 17. The sample and hold circuits 16 and 17 sample and hold the signal based on the timing signal from the timing generation circuit 19. A synchronization signal is inputted to the timing generation circuit 19 from the synchronization signal detection circuit 18, and the timing generation circuit 19 generates a timing signal based on the synchronization signal from the synchronization signal detection circuit 18.

The synchronization signal detection circuit 18 is connected to the R
It is connected to the output of the F amplifier 10, and the RF amplifier 10
Detects and outputs a synchronizing signal from the output signal.

The output of the sample and hold circuit 17 becomes the output of the detection circuit 4, and the output of the sample and hold circuit 17 is connected to the second averaging circuit 6 and also to the differential amplifier 21. The second averaging circuit 6 averages the input signal based on the following equation and outputs the averaged signal.

((N-1)/N)XV+Vo =V'((N-1)
/N ) XV'+V(1=V"((N-1)/N
)xV' +Vo =V"'However, the number of averaging Vo is the reading voltage v, v', v", ■"'... is the output voltage.The output of the averaging circuit 6 of the tube 1 is connected to the terminal 22. The terminals 11.22 are connected to an oscilloscope 23, and the oscilloscope 23 performs display based on the output signal of the terminals 11.22.

In addition to the output of the sample and hold circuit 17, the differential amplifier 121 receives the output of a frequency generator (FG) 26 that detects 250 revolutions of the capstan motor.
) is input via the conversion circuit 27. F-V conversion circuit 2
7 outputs a signal with a frequency corresponding to the rotation speed of the capstan motor 250 of the FG 26. The F-v conversion circuit 27
A voltage corresponding to the frequency of the output signal of G26 is output and inputted to the differential amplifier 21. The differential amplifier 21 outputs a difference signal between the outputs of the sample hold circuit 17 and the l-V conversion circuit 27, The motor drive circuit 24 is connected to the capstan motor 25 and controls the signal supplied to the capstan motor 25 according to the output of the differential amplifier 21 to drive the capstan motor 2.
Rotate 5 by 11JW.

A track 29 consisting of a pilot signal, a synchronizing signal, etc. as shown in FIG. 2 is formed on the magnetic chip 128, and adjacent tracks are recorded at different azimuth angles. The magnetic head 7 has a +azimuth angle and scans the +azimuth track 29a, and the magnetic head 8 has a +7 azimuth angle and scans the one azimuth track 29b. The width of the magnetic head 7.8 is set wider than the track width, and can read signals from the scanning track and the track adjacent to the scanning track.

Next, the operation of the device will be explained. The magnetic head 728 is moved, the magnetic head 7.8 is rotated, and the magnetic head 728 is rotated.
The upper tracks 29a and 29b are scanned.

Since the magnetic head 7.8 is wider than the tracks 29a and 29b, the magnetic head 7.8 is wider than the scanning track 29a while the magnetic head 7 or 8 is scanning.
Or, in addition to 29b, the byte signal and synchronization signal on the tracks at both ends thereof are detected.

The signal detected by the magnetic head 7 or 8 is output via the 0-Tari transformer 9 and the RF amplifier 10. The output signal of the RF amplifier 10 is subjected to envelope detection by the envelope detection circuit 3, and a detected output having a waveform as shown in FIG. 3(A) is obtained. The detection output of the envelope detection circuit 3 is averaged in level by a first averaging circuit 5, and outputted from a terminal 11. The terminal 11 is connected to an oscilloscope 23, and the averaged signal waveform is displayed on the oscilloscope 23.

The reproduced signal from the magnetic head 7 or 8 is also supplied to the detection path 4. The detection circuit 4 is a circuit for detecting a pilot signal of a track adjacent to the scanning track of the magnetic head 7 or 8 from the reproduced signal.

The reproduced signal from the magnetic head 7 or 8 is sent to a buffer circuit 12.
The signal is supplied to the bandpass filter 13 via the bandpass filter 13. The bandpass filter 13 is the frequency of the pilot signal ~1
Only 30KHz signals are allowed to pass. The Byot signal that has passed through the bandpass filter 13 is transferred to the Gainhund D-
The signal is supplied to the envelope detection circuit 15 via the loop circuit 14. The envelope detection circuit 15 performs envelope detection on the input pilot signal to obtain a signal waveform as shown in FIG. 4(A). Since the output signal of the envelope detection circuit 15 includes not only the necessary byte signals at both ends of the scanning track but also the pilot signal of the scanning track, it is necessary to separate these signals.

A synchronizing signal is recorded in the pilot signal recording portions of the tracks on both sides of the scanning track, and the synchronizing signal of this scanning track is detected by the synchronizing signal detection circuit 18.
The timing signal shown in FIG. 4 (8) and (C) is obtained by the timing generation circuit 19, and the sample and hold circuit 16. Differential amplifier 20. A sample and hold circuit 17 obtains a pilot signal component of a track adjacent to the scanning track. For example, a signal with a waveform as shown in FIG. 5 is obtained.

As shown in FIG. 5, the detected pilot signal components on both sides have characteristics as shown in FIG. 8 depending on the deviation from the scanning track of the magnetic head 7 or 8, and the waveform shown in FIG. The running state of the tape can be measured by looking at the signal, but as it stands, the DC bias level and waveform state will change slightly each time each track pattern runs, and the width of the change is shown by the broken line in Figure 5. It is so large that it cannot be used to judge the tape running state.

Therefore, by averaging the output of the detection circuit 4 using a plurality of tracks as shown in FIG. 6 by the second averaging circuit 6, fluctuations can be eliminated as shown in FIG. It is possible to obtain a small and regular measurement signal.

This waveform is supplied to an oscilloscope 23 via a terminal 22, and the oscilloscope 23 displays this waveform. By looking at the waveform displayed on the oscilloscope 23, the relative position between the track and the magnetic head 7 or 8 can be detected.

At this time, only when the waveform of the output signal of the terminal 11 is flat, the information shown in FIG. 8 is obtained, so that the display of the output signal waveform can be viewed at the same time and used to judge the tape running state. You can judge whether it is data or not.

Since the tape running state can be known while observing the oscilloscope 23 in this way, it is possible to accurately and quickly adjust the tape running system.

Note that the track pattern of the magnetic tape is not limited to that of this embodiment, and other track patterns may be used. However, in this case, it is necessary to make the rotating cylinder section 2 suitable for the track pattern.

Effects of the Invention As described above, according to the present invention, tracks are formed in advance on a magnetic tape with high precision, and the running state of the magnetic tape can be extracted as an electrical signal simply by reproducing the magnetic tape with the apparatus of the present invention. Therefore, the tape running state can be easily and quickly judged, and therefore, the adjustment work of the tape running system can be carried out efficiently.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a diagram for explaining the track pattern of a magnetic tape, and FIGS. 3 to 8 are diagrams for explaining the operation of an embodiment of the present invention. , FIG. 9, and FIG. 10 are diagrams for explaining the conventional measurement method. 1... Running state detection device, 2... Rotating cylinder section,
3... Envelope detection circuit, 4... Detection circuit, 5
...first averaging circuit, 6...second averaging circuit,
7゜8...-Magnetic head, 28...Magnetic tape, 29
a. 29b...Truck. Figure Figure 6 Figure Figure Track Figure Figure Input 0 Figure 0

Claims (1)

[Scope of Claims] A device for reproducing a magnetic tape on which a track is recorded with a pilot signal for detecting a relative position with respect to a magnetic head, wherein the magnetic head is attached, the track is scanned, and the magnetic tape is a rotating cylinder section that reproduces a signal on a tape; a detection circuit that performs envelope detection of the pilot signal from a reproduced signal of a track being scanned by the magnetic head of the rotating cylinder section; a detection circuit that detects a pilot signal of a track adjacent to the track being scanned by the magnetic head from inside; a first averaging circuit that averages the output envelope detection signal of the detection circuit; and output detection of the detection circuit. a second averaging circuit that averages signals, and when the output signal of the second averaging circuit is at a constant level, the output signal of the first averaging circuit is used to detect the running state of the truck. A driving state detection device characterized in that it is a signal.