JPS63257948A - Monitoring device for rotary drum - Google Patents

Abstract

PURPOSE:To improve the accuracy in the rotation of a DAT drum and the productivity by displaying the rotation of a DAT drum on a TV display, etc. and monitoring the rotary state by an inspection. CONSTITUTION:The means generating the rotation frequency 1 becoming of the reference of a drum rotation frequency from a reference oscillator, the means 15 changing over the PG (phase generation) signal 2 from a drum and a rotation frequency 1, the means generating a vertical synchronizing pulse signal 4 from the output signal of the changing means 15, the means generating a horizontal synchronizing pulse signal 6 from the reference oscillator, the means generating a blanking signal 7 from the vertical and horizontal synchronizing pulse signals and the means 10 mixing the blanking signal with the signal obtd. by detecting a reproduction output signal with its envelope are provided. The rotation state can thus be grasped by inspection by displaying the output showing the rotary state of the drum of a rotary head type digital audio tape recorder (R-DAT) on a TV scope.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention relates to 1. A monitoring device for a rotating drum, particularly for a rotary head type digital audio tape recorder (hereinafter abbreviated as R-DAT in this specification). Regarding.

B4 Summary of the Invention By generating a vertical synchronization signal and a horizontal synchronization signal based on the rotational frequency and blackout frequency of the drum of the R-DAT, and further multiplying and lowering the frequency,
Assuming the pull-in range of normal TV monitor synchronization, R-DA
The PG or FG output indicating the rotational state of the T drum is displayed on the television screen so that the rotational state can be grasped by inspection. Further, the amplitude of the envelope of the reproduced output signal is displayed in the horizontal direction of the television screen. moreover,
The rotation status of the drum and the envelope of the playback output of the head are displayed on the screen at the same time.

The C0 prior art R-DAT generally has a diameter of 3 mm, as shown in FIG.
0+am drum D at 2000 revolutions per minute (33,3
3rps), and for winding, two heads A and B are used intermittently (each 90° of one revolution) to record digital signals on a tape T with a 90" square, and the winding is performed at a constant rotation speed during playback. The signal is read out by tracing the recording pattern with the drum head.In other words, in R-DAT,
Maintaining a uniform rotational speed of the drum is a necessary condition in both recording mode and playback mode.

To control the rotation of the drum, 24 magnetic signals are recorded during one rotation of the drum, and the reproduced signal 80011z is used as a reference (FG) for the rotational frequency of the drum. Furthermore, one reproduction signal is used for one rotation of the drum as a reference for matching the temporal positions of the recording/reproducing patterns with the heads A and B. The latter is PG (phase generation)
It is called. The rotational frequency of the drum is obtained by frequency downgrading based on the frequency 9.408Mllz of the reference oscillator built in the DAT.8001 (controlled by z, and one rotational phase is generated in one rotation of the drum.PG It is controlled by comparing it with the phase of 33.3311z obtained by stepping down from the double signal fc.

Conventionally, such an important rotational state of the drum was not particularly monitored. It is necessary to monitor the rotational state of the drum when the drum rotation system is assembled or when the entire DAT functions as a device.

D9 Problems to be Solved by the Invention The purpose of the present invention is to display the rotation of the DAT drum on a television display or the like so that the state of one rotation can be monitored by inspection, thereby improving the rotation accuracy of the DAT drum and increasing productivity. It is an object of the present invention to provide a rotating drum monitoring device that can contribute to improvement.

Means for Solving the E0 Problem In order to achieve the above object, the rotating drum monitoring device according to the first invention of the present application includes means for generating a rotation frequency serving as a reference for the drum rotation frequency from a reference oscillator; means for switching the rotational frequency of the PG multiplied signal from the drum;
means for generating a vertical synchronizing pulse signal from the output signal of the switching means; means for generating a horizontal synchronizing pulse signal from the reference oscillator; and means for generating a blanking signal from the vertical synchronizing pulse signal and the horizontal synchronizing pulse signal. and means for mixing the blanking signal with a signal obtained by envelope detection of the reproduced output signal.

A rotating drum monitoring device according to a second aspect of the present application includes means for generating a rotation frequency serving as a reference for a drum rotation frequency from a reference oscillator, and means for switching the rotation frequency with an FG multiplied signal from the drum.

means for generating a vertical synchronizing pulse signal from the output signal of the switching means; means for generating a horizontal synchronizing pulse signal from the reference oscillator; and means for generating a blanking signal from the vertical synchronizing pulse signal and the horizontal synchronizing pulse signal. ,
and means for mixing the blanking signal into a monitor signal formed from a difference in the FG double signal sawtooth voltage.

F1 action The principle of the present invention is shown in FIG. Basically, if the rotational frequency of the drum is fv, then fv''33°331(z), and this is the vertical synchronization frequency of the display system.On the other hand, the horizontal synchronization frequency of one display system is equal to the clock frequency fC, and fH= For example, fc = 44.1
Let kllz = fu.

If N horizontal and vertical sync pulses are applied to a television monitor, the raster will appear as shown in FIG.

2N, the solid line is the scanning of the display, the broken line shows the scanning of the retrace period, and there is no display in the broken line period, Fig. 2 (b) is,
The signal 1 associated with the rotation of the drum, for example, the phase of 800 Hz (
This is an example in which θ) is plotted on the horizontal axis, and shows how the phase changes with one rotation. Furthermore, if the outputs of the A and B channels, which are the outputs of the drums, are displayed, they are displayed in a band shape on the screen as shown in FIG. 2(C). Both (b) and (c) are obtained by adding horizontal and vertical blanking signals.

G. EXAMPLES The present invention will be explained in more detail using examples below with reference to nine drawings, but these are merely illustrative and various modifications and improvements can be made without going beyond the scope of the present invention. Of course it is possible.

FIG. 1 is a block diagram showing the configuration of a rotating drum monitoring device according to the present invention. In FIG. 1, 1 is a DAT drum PG signal f.
v ” 33.33 Hz, 2 is fo =44.
fV generated from 1 kHz = 33°33m, 3 is fs+ = 44.1 kHz, 4 is the vertical synchronization pulse generation circuit, 5 is the frequency down-down circuit fv ” f
u/1323 (f-n = 44.1 k)lz
).

6 is a horizontal synchronizing pulse generation circuit, 7 is a blanking (blanking) signal generation circuit, 8 is a monitor signal, 9 is a signal processing system, 10 is a blanking mixing circuit, 11 is an image monitor (TV monitor), 12 is a Vertical sync input, 13 is horizontal sync input.

14 represents a video signal input, 15 represents a synchronization changeover switch, fH3 from a clock oscillator passes through a frequency down-down circuit 5, and is set to 33.33 Hz 2 , DAT
drum f formed from PG double signal 1 and f□
v2 are connected to the a and b terminals of switch 15, respectively. The output of the switch 15 causes the vertical synchronizing pulse generation circuit 4 to generate a vertical synchronizing pulse. switch
When switch 15 is set to a, it matches the PG signal of the drum, and when switch 15 is set to b, the vertical synchronization frequency is 33.33 Hz based on the clock oscillator. f
H3 is made into a pulse of fH frequency by the horizontal synchronization pulse generation circuit 6, and the outputs of the vertical synchronization pulse generation circuit 4 and the horizontal synchronization pulse generation circuit 6 are made into a synchronization signal for the television monitor. On the other hand, from the vertical and horizontal synchronizing pulses of the vertical synchronizing pulse generating circuit 4 and the horizontal synchronizing pulse generating circuit 6, the retrace signal generating circuit 7 generates a signal that turns off the video signal only during the retrace period of the monitor.
blanking is added to the monitor signal 8 that has passed through the signal processing system 9, and the video input 1 of the television monitor 11 is
Add to 4. For example, if the outputs of the A and B channels of the drum are input to the monitor signal 8, and the processing in the signal processing system 9 is envelope detection processing, the TV monitor 11 will display the following signals as shown in FIG. 2(c). A and B
Areas with channel signals are displayed in white.

The device shown in FIG. 1 is extremely basic.

A normal television monitor has 60 fV.

f) Since it is 15.73 kHz in I, 33-33 Hz in fV shown in Fig. 1 44.1 kHz in t fu
Even if the synchronization system of the television monitor is set to 33.33 Hz in fV and 44.1 in fu, flicker will be noticeable at 33.33 Hz in fV.

Therefore, f is close to the synchronous frequency of the current television system.
Changed to use 66.66 Hz in V and 14.7 kHz in fH. Figure 3 shows a system diagram for using a TV monitor. In Figure 3, 16 is a frequency multiplier (x 2
)66.66 Image generation (the hanging part is the frequency multiplier 16
33.33 of the output of synchronous changeover switch 15
Multiply - by 2 times and change fV to 66.667, f
It is also possible to generate the normal television horizontal frequency fH = 15.73 kHz from the DAT reference oscillator's 9.8 MHl, by reducing 44.1 to 7 H to 1/3 using the frequency down-converter 17, but f++ =14.7kHz is easier to generate.

Figure 4 shows the image on the monitor 11 and the drum on the human power 14.
A block diagram showing the configuration when looking at fluctuations in FG is shown. In this case, the vertical synchronization is the changeover switch in Figure 3.
When using drum PG with a,
Changeover switch that steps down from the clock frequency 15
The former is synchronized with the rotation of the drum and monitors the 800 Hz phase change of the FG for each revolution, and the latter is based on the PG of the drum.
Phase fluctuations in Hz will be monitored.

In Figure 4, 18 is a frequency down-conversion circuit that generates 8007 from 44.1k7, 19 is a phase adjustment circuit, and 20
is the FG signal (8007), 21 is the synchronous detection circuit, 22 is the differential amplifier, 23 is the frequency multiplier circuit (29, 4 to 7),
24 is a switch (c: 29.4k) h, d
:14.7 kHz), 25 is a sawtooth wave generator,
26 is a comparison circuit, 27 is a reference voltage E, 28 is a delay line τ, 29 is a differential amplifier, 30 is a positive pulse separation circuit, 31°32 is a flip-flop, and 33 is a multiplication circuit.

34 represents a gate circuit, and 35 represents a switch interlocked with switch 24.

A frequency down-down circuit 18 generates 800 Hz from the output (clock frequency) of f,,3.

Phase adjustment circuit including 90° phase FG output at 19 2
The synchronous detection circuit 21 detects the 0800 ball signal. FIG. 5(a), (b) and (c) are respectively phase 71R.
The outputs of the adjustment circuit 19, the FG signal 20, and the comparison circuit 26 are shown. If the output of the phase adjustment circuit 19 and the phase of the FG signal 20 are completely orthogonal, the synchronous detection circuit 21
The output ΔE of is 0, that is, the synchronous detection circuit 2
The output ΔE of 1 is proportional to the phase change of the FG signal 20.

ΔEC/)Δθ On the other hand, the frequency multiplier circuit 23 generates 2fu=29.4 kHz from the fu=14.7klk of the frequency downgrader 17. When the switch 24 is set to C, the phenomenon is displayed on the left half and right half of the screen every 1/66.66 s by 2fH. switch 24 d
If you set it to 1, there will be one display per screen. A differential amplifier 22 uses the output of the sawtooth wave generator 25 to generate a synchronous detection circuit 21.
Subtract the output of . In FIG. 5, (d) shows a sawtooth wave when the switch 25 is set to C, and (a) shows a sawtooth wave when the switch 25 is set to d. The output of the differential amplifier 22 becomes (f) (
Example when switch 25 is set to C), broken line sawtooth wave (d
) is subtracted from ΔE in (c). The output of the differential amplifier 22 is added to the comparator circuit 26 to obtain an output equal to or higher than the reference voltage E shown by the chain line in (f), which is referred to as (g). This signal is passed through the delay line 28, the differential amplifier 29 and After passing through the positive pulse separation circuit 30, it becomes (h).

On the other hand, the switch 35 is linked to the switch 24,
If the switch 24 is d, the switch 35 is also d, and the output of the 4-gate circuit 34 passes through the blanking mixing circuit 10 and is input to the video input 14 of the television monitor 11.
, and the screen shown in Figure 5 (p) appears, with F in the center of the screen.
G fluctuation is displayed. When the switch 35 is C, the signal of the frequency multiplier 16 shown in (j) and (
When the signal from the frequency multiplier circuit 23 shown in 1) is applied to the flip-flops 31 and 32 (reset by the output fv of the synchronous changeover switch 15), the outputs thereof become (k) and (m), respectively. Tazoshi, (k) and (m
) are the same as those of (j) and (i), respectively. The multiplication circuit 33 outputs (n).
In other words, since it is reset at fV, 1/33°33
The first half of 8 (time for one rotation of the drum) is a solid line (n), which is displayed on the left side of the screen by the gate circuit 34, and the second half is a broken line (n), which is displayed on the right side of the screen. In this case, the output of the gate circuit 34 is (i), and
The screen display will be (o), and the first half of one rotation will be on the left side.
The second half will be on the right side.

Next, an example of monitoring the playback level of the head will be shown.

In FIG. 6, 37 is an undetected reproduced output, and the output of the envelope detection circuit 36 is transferred to the differential amplifier 22 in FIG.
Add to. In this case, if switch 24 is set to C,
The screen display is as shown in Figure 7 (,), with the A channel displayed on the left and the B channel displayed on the right.
When the switch 24 is set to d, the A and B channels are displayed in an overlapping manner as shown in FIG. 7(b).

As described in detail of the H0 invention, according to the present invention, the rotational state of the R-DAT and the playback state of the head (including dropouts) can be displayed on the screen of the television monitor, so that they can be easily determined by inspection. can.

Furthermore, because the horizontal and vertical synchronization frequencies are close to those of regular television, it is economical because it eliminates the need for a monitor with a special scanning standard.

By checking the rotational state of the R-DAT drum and the playback output of the head at the same time every rotation, we can compare the two.
Optimal adjustments in the manufacturing process can be obtained through visual confirmation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a rotating drum monitoring device according to the present invention, FIG. 2 is a diagram explaining the basic display according to the present invention, and FIG. 3 is a diagram showing the rotation according to the present invention when observing fluctuations in PG. FIG. 4 is a block diagram showing the configuration of a rotating drum monitoring device according to the present invention when observing fluctuations in FG, and FIG. 5 shows the operation of the device shown in FIG. 4. 6 is a block diagram of a device for monitoring head output; FIG. 7 is a diagram showing a display when the device of FIG. 6 is used; Figure 8 shows R-DAT
FIG. 3 is a plan view of the rotary head for explaining the operation of the rotary head. 1 ・・・・・・・・・DAT Drum P (3 signal f
v=33.33 Hz, 2:...---fH=4
fv = 33.33 H generated from 4.1 kHz
z, 3...fu =44.1 kH
z, 4... Vertical synchronization pulse generation circuit, 5... Frequency down-down circuit, 6...
...Horizontal synchronization pulse generation circuit, 7...
・Blanking (blanking) signal generation circuit, 8...
...Monitor signal, 9 ......Signal processing system, 10 ...Blanking mixing circuit, 11 ...... Image monitor ( TV monitor), 12 ・・・・・・Vertical synchronization input, 13 ・
......Horizontal synchronization input, 14...
-Video signal input. 15......Synchronization changeover switch, 16 ・
・・・・・・Frequency multiplier (x 2 ) 66.6
6 7 (vertical synchronization), 17... Frequency down converter (÷ 3) 14°7kHz (vertical synchronization), 18.
・・・・・・・・・44.1k) Frequency down-down circuit that generates 8007 from H. 19... Phase adjustment circuit, 20...
...FG double signal 800 Hz), 21...
......Synchronous detection circuit, 22...
Differential amplifier, 23... Frequency multiplier circuit (
29.4 kHz), 24...... Switch (c: 29.4 kHz, d: 14.7 kHz)
z). 25... Sawtooth wave generator, 26...
...Comparison circuit, 27...Reference voltage E, 28 ...Delay line τ, 29...
......Differential amplifier, 30...Positive pulse separation circuit, 31, 32...
Flip-flop, 33...Multiplication circuit, 34...Gate circuit, 35...
...Switch 36 that interlocks with switch 24.
......Envelope detection circuit, 37...
...Undetected playback output. Patent applicant: Clarion Co., Ltd. (c) 2 to 4 base; 4:
(-E!'t! Same voice) 17: Fn Shioshisashimi 11 Sweat (÷3) 14.7 to Hz J' crush (horizontal synchronization) Te V+:
Patnita 0ne IIJ? Hot Kaneko Map Figure 3 18 R17ff, J'! []! (4z, IKHz
p□ et al. 800Hz h, l'j)19, A1 to my friend 1flf8ro20: FG 4 official'y (800Hz)21
Fellow friend yellow concave piece 22: IDjtlIlik # 25 Saw # shape ゛J! Raw signal 26 Single & @ layer 271 rate V ear Er 28° 1 ZhaoPp, τ 31.32° Fuson 2σ20ノ2'' 33° Isan circuit 34 Toughtro 8 4 35 Nuitana 24 linked 3z inch FGψzhv
Helmet, along the way - O lecture AΣunT's block Figure 4 36 Connection 1 Each fault F circuit 37: Chirei! /)r+Kechuohead゛f:Ioshibamo:Squirrelj#j,+,a,fl[φ
Figure 6 (a) (b) Figure 7 (m) UT-m-; i(
〆is, t, i Fig. 5

Claims (2)

[Claims] (1) (a) Means for generating a rotational frequency that serves as a reference for the drum rotational frequency from a reference oscillator; (b) Means for switching between the PG signal from the drum and the rotational frequency; (c) Vertical from the output signal of the switching means. (d) means for generating a horizontal synchronization pulse signal from the reference oscillator; (e) means for generating a blanking signal from the vertical and horizontal synchronization pulse signals; and (f) means for generating a blanking signal from the vertical and horizontal synchronization pulse signals. A rotating drum monitoring device comprising means for mixing the blanking signal with a signal obtained by envelope detection of a reproduced output signal. (2) (a) Means for generating a rotation frequency serving as a reference for the drum rotation frequency from a reference oscillator; (b) Means for switching between the FG signal from the drum and the rotation frequency; (c) Vertical from the output signal of the switching means. (d) means for generating a horizontal synchronization pulse signal from the reference oscillator; (e) means for generating a blanking signal from the vertical and horizontal synchronization pulse signals; and (f) means for generating a blanking signal from the vertical and horizontal synchronization pulse signals. A rotating drum monitoring device comprising means for mixing the blanking signal into a monitor signal formed from the difference between the FG signal and the sawtooth voltage.