JPS6043984A - Video tape recorder - Google Patents

Abstract

PURPOSE:To obtain the minimum amplitude of a piezoelectric element by loading plural heads on a piezoelectric driving element, selecting an opposed head having the same azimuth angle when an integer part of a tape speed is an even number, and selecting that which has a different azimuth angle. CONSTITUTION:A piezoelectric driving element 13 is bent by applying an electric field, and heads 14, 14' or 15, 15' of the tip are displaced. When an integer part of a tape speed is even number times of positive and negative containing stillness, a field is reproduced, and at the time of an odd number, a frame is reproduced, by which a voltage applied to the piezoelectric driving element becomes small by a portion corresponding to one track pitch in comparison with other case. That is to say, at the time of an even number, a head whose azimuth is the same is selected, and at the time of even number times, a head whose azimuth is different is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a helical scan type video tape recorder (hereinafter abbreviated as VTR).

Conventional configuration and its problems: The Rikarsny-Yang VTR has 17 Lenos and 2 magnetic heads with different azimuth angles of 711.
I record it on a book track. Therefore, the video detective dU
The second recording was synchronized with the same amount of vertical copy, and was recorded on magnetic tape (-t7
(At the same time as one control per frame, one field is recorded in one track,
1: By synchronizing with a control signal and tracing the recording track with a head of the same azimuth as the head at the time of internal reproduction, a reproduced one-plane image without renoise is obtained.

However, the angle of the running trajectory of /shi\ato is the same as the angle 1W of the recording track. As a result, the head moves over the recording track and displays the screen (
t(l noise -) appears. Fig. 1 shows the traveling locus of the head when it runs on the tape at a magnification of 3 times.

Recently, piezoelectric ceramics have been used to compose the driving end of a bonded type pressure sensor, and a magnetic head is mounted on the piezoelectric element, and during special N generation, an electric field is applied to the pressure element to move the head. The driving trajectory of the helmet! There are 11 VTRs on the market that will cause damage to the track during playback. In Figure 1, 1f is the head traveling trajectory when the tape speed is three times the normal one stroke, the head is moved by the arrow 3fi by the piezoelectric element, and the head traveling trajectory is completely traced over the recording track as shown in 2. I'm making 2.

This system provides a clear, noise-free screen during normal and special engineering operations. However, as shown in Figure 2, the pressure? Two heads are mounted on one wrist dynamic element.

In the figure, there are four rotors/linders, 5.5' is a piezoelectric drive element, 6 and 6' are heads with the same azimuth, and 7 is a mounting tool for the piezoelectric drive element. The reason why the heads 6 and 6' have the same azimuth is to prevent images from shifting even on fast-moving screens during static IF playback. In such a system, the condition is to always perform frame playback.

In Figure 3, i, /f, J--if! -It is a ftc thing, and the trajectory of the head is like 8 (1', this IL is j lower' iL Otsu, and the driving and auxiliary elements are like 9, Shuyama [-1, it is. The trajectory of the head will be like 1mu/i1o, so you don't have to do +lut trace modification 11-, but to the next 71・11υ1,
Trace (T, Jllll, trace another track B in the same figure and stop.Here, the azimuth of both heads is IL:)
-C, so it is necessary to correct one track for one track on the trajectory η・11㎞j:trajectory 1o. U when replaying the song several times
: There needs to be a quotient difference of 1 track between the two heads, and even if this is divided by jJi-l'-, the electric itching of 0.6 tracks will be 11', 1. Opening force [
1 (not rJ)

This 22 is 1-j] electromotive element, j, life-threatening; λ
To struggle (/(There are no two, Motoko's maximum width is determined.
1゜Invention 10j which means narrower 1\Takumei +i/(determined 1 [reverse speed A'11 匝1!1]) υWide and high The purpose of this invention is to provide a highly reliable noiseless VTR.

Composition of Departure J In order to solve the above problems (l Then, when the integer part of the tape speed is an even number, the azimuth angle of the opposing heads is the same, and when it is an odd number, the azimuth angle of the opposite heads is selected depending on the difference between the heads, so that the minimum piezoelectric By making the amplitude of the drive element suffice, we provide fFiM1 (1U low noiseless VTR) which has a longer lifespan than the piezoelectric drive element.

Description of examples The present invention will be described in detail below with reference to the drawings.

Fig. 4 is a diagram of a rotating cylinder (14) with 4 stems. In the same figure, 12 is a rotating cylinder, 130;
Laminated piezoelectric drive element, 14 and 14' are unmassed %1
ノN fx 7:r IB Kihet R, L', 15
, 15'rr Another magnetic heno l with different anomalous angle
-' L, R', and 16 are interrogators. The piezoelectric actuator 13 is bent by applying a '1u field, displacing the tips of the tip helenoids 14, 14' and 15'.

FIG. 6 is a block diagram of a 3-head/stem rotary cylinder, where 17 is a 1n1 rotary cylinder, 18 is a laminated piezoelectric 4.
IJg II! JJ elementary-γ, 191d 1IFi-\
Nol', 20.20'IJ A/To the magnetic field of one string with different mass angles, Do, 21 (r:j is a corner tool. By applying a voltage to the pressure 1 driving element... te, i4 figure Noshi 11
Similarly, 19,20°20'-\)h' f 24
It is changed to f\n.

Figure 6 A9 shows the field + 4 life saving - l,, lc J 烏合(B), 1\dd change 1Nn Ikaf to realize noiseless with the same unmas head. 0
In the same figure, this 1
1 for the word? '6 Jtl] The head is switched on with L. Also, the solid line d- is -\7 on one side, and the dotted line is +J+ centered on the opposite head. The figure shows an operation in the range of 2 to 4 times as much.

Figure 7 A 2 mouth il'J'e = frame r'l' No. 1. Change of the head for the noiseless condition of L fc J combination (h> is not shown. Similar to FIG. 6, operation in the range of 12 to 4 times the tape speed is shown,
If a fast image of one assistant is reproduced near a stationary position, the regenerated image will be blurred, so field +4 must be generated.

No. 6121. As can be seen from Fig. 7, even under the same noiseless condition, when the forward and reverse directions including rest are 1 times higher, even under the r space condition, when the forward and reverse times including rest are 1 times higher + 1 gj, (rl)r ~
When the tape speed is odd times, Kti7 frame μ is played back.
If f is generated, the voltage applied to the piezoelectric drive element (・'() will be smaller by the amount of force that is applied to the piezoelectric drive element (・') compared to when it is not the case. d. Select a head with different azimuth.

Next, pattern generation for driving the head 1 will be described.

As can be seen from Figures 6 and 7, the tape speed is J,
-) - The above pattern changes. 'First of all, switch the throat switch 1 to No. H3W and turn on the FG of the capstan motor.
Count pulses. The number d of FG pulses during 14 cycles of H3VV is proportional to the absolute value of the tape speed. Therefore, by determining whether it is forward or backward, 1. L (FG during 1/2 period of SW
Calculate the tape speed V from the number of pulses.

v-1=n14H2 (where nl: integer part n2: decimal part (05 (n2 < 0.5), 1. Determine nl and n2, L1 is j', head 1 is necessary as a bar movement pattern. Noris N - (n, 1- n 3)
When n2-○, &Tin3=O, and when n2\O, n3-2.

Therefore, )(1/2 circumference of SW]υ] n 1F 7 ,
The moss amplitude is 1
1. /i is a composite drum shape with the sawtooth ρ of the track pitch, and h'I or N4-
3] Two sea urchins, N l-di.

A head driving pattern that returns 5 degrees Q is generated within the opening.The moving pattern of the head jJl is obtained when the 1° 81st loop is 2.3 times faster than the 81st loop. (Sutake (/koyori n1=1.n2=0.3 -Crb 6 i'ry C), 1 of H3W Id Sea 3
/2 laps] 11-ranokubi with υI, chimin/'Kokenojatsu 1
1jlj sawtooth drum and 0.3 track F pitch I
I, +'i mushroom wave 1. The waveform is repeated with a thread width of 2 threads so that the combination with 2θ does not exceed the equivalent of (n 1 + 2) l rack pitch. , a voltage pattern to be applied to the piezoelectric drive element for driving. In the same figure, the solid line corresponds to the number of 2 points to the number of S by 1.

Set the starting point of the above drive waveform to 0, then U-1 so7t1so;l
Since the DC component of the waveform of ``1'' is (n1/2)) equal to the rack pitch and one track pitch, the acid value at the starting point of this value is set to -J-.

Effects of the Invention 1 - As mentioned above, the present invention distinguishes between no-yield TJFF playback and frame playback depending on the tape speed, so that the minimum applied voltage base piezoelectric drive for each playback mode can be achieved. In addition to the element, :', <element sf becomes long. The fact that the 16-current drive voltage is small also contributes to this, so it is possible to provide a VTR capable of efficient 4+ and Q noiseless special playback.

[Brief Description of the Drawings] Figure 1 is a diagram showing the head trajectory during playback at a tape speed three times that of recording and the head trajectory corrected by the piezoelectric drive element.
Figure 2 shows the rotation of two heads using a piezoelectric drive element/Lindai 1171: Cause, Figure 3 shows stationary and 1x rotation, rA4
/ &II; Figure 4 is a diagram showing the trajectory of the '+' point.
History / Ko4'\ Configuration diagram of the rotating 7 cylinder of the Noto system,
Fig. 5C is a configuration diagram of a rotary cylinder of a 3 to 7 stem I combination which is another embodiment of the VTR of the present invention. A diagram of the head drive pattern for frame playback with 4 copies per field at 2 to 4 times the tape speed.
1. It is a drive pattern diagram. 1.2 ・---＼Grot trajectory, 3...Head trajectory correction, 4-・Rotating cylinder, 5, 6'...Laminated piezoelectric 1 history movement element, 6, 6'...・1hj azimuth head, 7...++yi・] tool, 8, 9, 10.11・
...Head trajectory, 12... Rotation/linda, 13,
13'... Bonded type 1-dot drive element, 14,
14'... Different azimuth head, 16.16'... Different azimuth head, 16... Take/N shell, 17-... Rotation/linda, 18, 18'... Bonded piezoelectric Drive element, 19...head, 20.20'...different azimuth head.

Claims (5)

[Claims] (1) Attach a pasting type piezoelectric drive element to a rotating cylinder, and attach a 1.0mm azimuth angle to one displacing tip of the piezoelectric drive element. It is equipped with two magnetic heads, VC'4+5, and 9i! ,! At least one magnetic head with an azimuth angle equal to the force of the two magnetic heads is mounted on the chair of the above two magnetic heads (11), and the azimuth is selected according to the reproduction speed, and one A video tape recorder whose defect is caused by applying a voltage to the 7H port and +1 terminal to cause the magnetic head to change its position so as to trace the recorded track on the magnetic tape. . (2) The tape speed is divided into an integer part and a decimal part based on the normal tape speed at noon. 1)
It is characterized by selecting magnetic heads with the same anomalous angle on the back side of the a/ζ magnetic heads, and selecting magnetic heads with different azimuth angles when the above-mentioned ′ fraction part is a G number times the positive and negative number. A video tape recorder according to claim 1. (3) Set the decimal part to be within the range of -0.6 to 0.6, and superimpose the drive voltage waveform corresponding to the integer part and the drive voltage waveform corresponding to the decimal part to drive the piezoelectric drive element. Claim 11! The video tape recorder according to item 2 of subsection (n). (4) When the decimal part is ○, write 1 as the value subtracted by 1 from the integer part!
Apply the voltage that displaces the head by +- rack.
Output in 4 cycles of switch signal, 1 when decimal part is not O
d. The video tape recorder according to claim 3, characterized in that a waveform whose slope is equal to the value of the decimal part is added to the drive voltage waveform and applied to the piezoelectric element. (5) The video tape recorder according to claim 3, wherein the DC acid component of the drive voltage of the piezoelectric drive element is set to O.