JPH0363913A - Fixed head inclination angle measuring instrument for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To exactly adjust the inclination angle of a fixed head by measuring the time width of a gate circuit signal as the amplified output of a signal, which is outputted from the fixed head, by counting clock signals. CONSTITUTION:An amplifier circuit 2 amplifies a reproducing signal 11 from a head 1 for signal reproducing and a gate circuit 3 operates a counter circuit only when a signal more than a fixed voltage is inputted. A counter 5 is provided to count the clock signals from a clock oscillation circuit while the gate is opened. A magnetic recording tape, to which pulse signals are recorded, is reproduced by the fixed head in a magnetic recording and reproducing device and the time width of rise and fall is measured by the counter. Then, the inclination angle of the fixed head is adjusted so that the time can be made shortest. Thus, the inclination angle of the fixed head can be exactly adjusted.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a magnetic recording/reproducing device having a fixed head and one or more recording tracks capable of performing recording/reproducing linearly in the longitudinal direction of a magnetic recording tape. The present invention relates to a measuring device that measures the inclination angle of a fixed head in the tape longitudinal direction.

2. Description of the Related Art A conventional fixed head tilt angle measuring device for a magnetic recording/reproducing device will be described below with reference to the drawings.

FIG. 2a is a front view showing the vicinity of the fixed head of the magnetic recording/reproducing device. In the figure, 8 is a magnetic recording tape, 6 is a fixed head, 1 is a recording/reproducing head within the fixed head, and 10 is a recording track. Regarding the magnetic recording/reproducing apparatus configured as described above, a conventional method of adjusting the inclination angle of the fixed head will be explained.

First, a magnetic recording tape 8 having one or more tracks on which signals are recorded linearly in the longitudinal direction is mounted on a magnetic recording/reproducing device, and the tape is run. Next, magnetic recording tape 8
In order to match the gap angle between the track 10 recorded in the fixed head and the playback head 1 in the fixed head, the tilt angle of the fixed head is changed and adjusted so that the output of the playback signal shown in Fig. 2 is maximized. I try to do this.

Problems to be Solved by the Invention However, in the method described above, the signal output changes depending on the relative position between the reproducing head 1 in the fixed head and the recording track 10 on the magnetic recording tape 8. The reproducing head 1 in the fixed head is connected to the magnetic recording tape 8.
If the fixed head is off the recording track by more than 1°, there is a problem in that the inclination angle of the fixed head cannot be adjusted accurately.

In view of the above-mentioned problems, the present invention provides a technology that allows the tilt angle of the fixed head to be accurately adjusted even when the reproducing head in the fixed head is off the track 10 on the magnetic recording tape. This will be a major issue.

Means for Solving the Problems In order to solve the above problems, the present invention provides a magnetic recording and reproducing apparatus that uses a magnetic recording tape on which pulse signals are recorded by a magnetic recording and reproducing apparatus having a fixed head with a definite angle of inclination. A measuring device for measuring the inclination angle of a fixed head, comprising: an amplifier circuit that amplifies a signal output from the fixed head; a gate circuit that discriminates the amplified output of the amplifier circuit at a predetermined threshold level; It is comprised of a clock oscillation circuit that generates a clock signal, and a counter that measures the time width of the gate signal of the gate circuit by counting the clock signal.

According to the above-described structure, the present invention reproduces a magnetic recording tape on which a pulse signal is recorded by a fixed head in a magnetic recording/reproducing device, and adjusts the time width of the rising edge or falling edge of the reproduced pulse. Measure with a counter and adjust the tilt angle of the fixed head to minimize the time. We met,
By setting a threshold value for the reproduction signal output, if the reproduction head in the fixed head deviates significantly from the recording track of the magnetic recording tape and the output decreases, it is not counted, so that adjustments can be made without malfunction.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

Fig. 1 is a block diagram of a fixed head inclination angle measuring device according to the present invention, Fig. 2a is a front view of the vicinity of the fixed head used in a magnetic recording/reproducing device, and Fig. 2 is a magnetic recording tape on which pulse signals are recorded. 3 is a waveform diagram of a signal output from the third
Figures a and b are a front view of the same part and a waveform diagram of the output signal when the inclination angle of the fixed head is changed; Figure 4a,
5.b shows a front view of the same part and a waveform diagram of the output signal when the reproducing head in the fixed head comes off the recording track of the magnetic recording tape, and FIG. 5.6.7 shows the waveform diagram of the output signal, respectively.
3.4 shows the signal states of this embodiment in Figure 3.4.

In FIG. 1, 1 is a signal reproducing head.

Reference numeral 2 denotes a signal amplification circuit, which amplifies the reproduced signal 11 from the signal reproduction head 1. 3 is a gate circuit with a threshold, which is a circuit that operates a counter circuit only when a signal of a certain voltage or higher is input. 4 is a clock oscillation circuit that oscillates clock pulses. 5 is a counter that counts the number of clock pulses while the gate is open, and its counting output is displayed on a display (not shown).

2a to 4a, 6 is a fixed head, 1 is a reproduction head within the fixed head, A is a gap at the tip of the head, 8 is a magnetic recording tape on which a pulse signal of a predetermined period is recorded, 9 is the edge of the pulse on the magnetic recording tape, 10
is the recording track.

Further, in FIGS. 2 to 4, 16 to 18 show signal waveform diagrams in each case. In addition, in FIGS. 5 to 7, 12 is a waveform diagram of the amplified reproduction signal, and 13 is a waveform diagram of the amplified reproduction signal.
14 represents a clock pulse signal, 14 represents a gate signal, and 15 represents a pulse signal counted by a counter.

The operation of the fixed head inclination angle measuring device for a magnetic recording/reproducing apparatus constructed as described above will be explained below.

As shown in FIG. 3, when the fixed head 6 has a certain angle with respect to the magnetic recording tape 8, the gap 7 at the tip of the head and the pulse edge 9 on the magnetic recording tape 8 also have an angle. . Since the gap 7 has the same width as the track width, the time it takes for the pulse to pass through the pulse edge 9 on the magnetic recording tape 8 increases depending on the angle, so the reproduction signal obtained from the reproduction head 1 is as shown in Figure 3. Bring in the time range as shown in . Therefore, as shown in FIG. 6, the rising edge or falling edge signal (in this case, the rising edge) of the signal 12 amplified by the amplifier circuit 2 is sent to the gate circuit 3 to generate an output of a certain potential or higher. The inclination angle of the fixed head 6 can be converted into time by reading the clock pulse 13 emitted from the oscillation circuit 4 during this time using the counter 6. Additionally, as shown in Figures 2 and 5,
By changing the inclination angle of the fixed head 6 so that the number of transmission pulses is minimized during this time, it is possible to have the same fixed head inclination angle as the magnetic recording/reproducing device that recorded the magnetic recording tape 8. .

Furthermore, as shown in FIGS. 4 and 7, when the reproducing head 1 deviates from the recording track 10 section of the magnetic recording tape 8, the time for the gap 7 to pass through the pulse edge section 9 is shortened. Since the playback output is low, the first
In the figure, when the voltage is below the threshold value of the gate circuit 3, no output is made to prevent malfunction.

When adjusting the position of the fixed head 6 using this method, the relative position between the reproducing head 1 in the fixed head and the recording track portion of the magnetic recording tape 8 can be adjusted by checking the output of the reproduction signal. The inclination angle of the fixed head 6 can be adjusted independently by managing the time, that is, the count value of the counter, so it is possible to make adjustments with high precision. .

As described in detail, according to the present invention, a magnetic recording tape on which a pulse signal is recorded is reproduced by a fixed head in a magnetic recording/reproducing device, and the rising edge or rising edge of the reproduced pulse is detected. By measuring the time width of the lower position using a counter and adjusting the inclination angle of the fixed head so that the time width becomes the shortest, it has the effect of allowing accurate adjustment.

In addition, by setting a threshold value for the playback signal output, if the playback head in the fixed head deviates from the recording track of the magnetic recording tape and the output decreases, it will not be counted, so accurate adjustment can be made without malfunction. It has the effect of being able to do it, and its practical effect is a dog.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a fixed head inclination angle measuring device according to the first embodiment of the present invention, FIG. 3 is a waveform diagram of a signal output from a magnetic recording tape on which a pulse signal is recorded, FIG. Waveform diagram, Figure 4a is a front view of the same part when the reproducing head in the fixed head is off the recording track of the magnetic recording tape, Figure 4 is a waveform diagram of the output signal, Figures 5 to 5. FIG. 7 is a waveform diagram showing the signal processing state in the cases of FIGS. 2 to 4, respectively. 1... Playback head within the fixed head, 2...
・Amplification circuit, 3...Gate circuit with threshold, 4...Oscillation circuit, 6...Counter circuit, 6...Fixed head, 7... ... Gap section at the tip of the head, 8 ... Magnetic recording tape,
9...Pulse edge portion, 10...Recording track, 11...Reproduction signal from head, 1
2...Amplified signal, 13...Clock pulse signal, 14...Gate signal, 15...
...Pulse signal to count, 16 to 18...
Playhead output.

Claims (1)

[Claims] A measuring device for measuring the inclination angle of a fixed head of a magnetic recording/reproducing device using a magnetic recording tape on which a pulse signal is recorded by a magnetic recording/reproducing device having a fixed head with a clear inclination angle. an amplifier circuit that amplifies the signal obtained by the signal, a gate circuit that discriminates the amplified output of the amplifier circuit at a predetermined threshold level, a clock oscillator circuit that generates a clock signal of a predetermined period, and a time width of the gate signal of the gate circuit. A fixed head tilt angle measuring device for a magnetic recording/reproducing device, comprising: a counter for measuring the angle of inclination by counting the clock signal.