JPH03788Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an apparatus for imaging and recording high-speed phenomena using a television camera and a VTR.

BACKGROUND TECHNOLOGY AND PROBLEMS There is a high-speed film camera as a conventional device for imaging and recording high-speed phenomena, but it has the disadvantage that it cannot be reproduced immediately. In order to compensate for this drawback, a television camera is used to capture images of high-speed phenomena, which are then recorded using a VTR (video tape recorder).
A variety of research and development efforts have been conducted to enable immediate reproduction by recording information such as the following:

As is well known, a typical television camera takes at least 1/60 second to convert one screen to an electrical signal. Therefore, dynamic objects that change faster than this cannot be captured. In order to solve this problem, for example, in Japanese Patent Publication No. 52-26416, the field of view of the image pickup tube is divided into multiple sections, and the entire subject is located in one of the divided sections. A technique has been disclosed that enables imaging of high-speed phenomena by scanning an object image on an image pickup tube for a scanning time of .

In addition, Japanese Patent Publication No. 13631/1983 discloses that an optical image of a subject is sequentially applied to a plurality of image pickup tubes having an accumulation effect for a certain period of time at regular intervals, and the imaging signals from each image pickup tube are recorded in a plurality of recording devices. A technique has been disclosed in which a time image of a high-speed phenomenon is continuously recorded by supplying a high-speed phenomenon.

Furthermore, Japanese Patent Application Laid-Open No. 54-21119 discloses a technique that uses two image sensors and shifts their deflections by 1/2 frame to obtain a high-speed video signal that is twice the frame rate. is disclosed.

However, with the technique described in Japanese Patent Publication No. 52-26416, the field of view is substantially narrowed, so that only images of the periphery of a moving object can be obtained. Furthermore, the movement range of a dynamic object is limited to one divided section, making it unsuitable for general use. Also, Tokko Akira
The technique described in Japanese Patent No. 55-13631 requires a plurality of image pickup elements having a storage effect and a plurality of recording devices, making the configuration complicated and extremely inconvenient for actual use. Furthermore, the above-mentioned Japanese Patent Application Laid-open No. 1983-
The technique disclosed in Japanese Patent Publication No. 21119 also requires a plurality of image pickup elements, and the recording pattern of the magnetic tape is also special, so there is no compatibility between recorded tapes.

Furthermore, it is conceivable to use a VTR to directly record an image signal captured by a television camera at a scanning speed that is multiple (N) times the normal scanning speed, but in that case, the tape guide drum The rotational speed of the rotating drum must be set to N times the standard value, and the tape running speed must be set to N times the standard value, but if this is done, the following problems will occur.

(1) In order to rotate the rotating drum of the tape guide drum at a rotation speed N times the standard rotation speed, both the carrier wave frequency and baseband frequency of FM modulation must be set to N times the standard value. However, in this case, a signal recorded at a speed N times the standard value needs to be played back at the standard speed.
Correspondence between emphasis and de-emphasis,
It is extremely difficult to guarantee the characteristics of the recording and reproducing circuits, such as the frequency stability of the FM modulated signal frequency, and furthermore, recorded tapes are not compatible.

(2) Since the carrier wave frequency of FM modulation is N times the standard value, it is quite difficult to increase the N value when considering the impedance of the rotating magnetic head, the characteristics of the rotary transformer, etc.

(3) If the rotational speed of the rotating drum of the tape guide drum is increased by N times the standard value, the air film may reduce the contact pressure of the rotating magnetic head against the magnetic tape, resulting in a decrease in reproduction sensitivity.

Therefore, the applicant first filed a patent application for a high-speed phenomenon recording device that can easily capture and record high-speed phenomena using a television camera and a VTR.
It was proposed as No. 58-49761.

Such a high-speed phenomenon recording device includes a storage means for storing an imaging signal from an imaging device that scans at a speed faster than the scanning speed of a standard television signal, and a plurality of channels of imaging signals read out in parallel from the storage means are supplied. The apparatus has a plurality of rotating magnetic heads, and is configured to record imaging signals of a plurality of channels sequentially so as to form adjacent inclined tracks using the plurality of rotating magnetic heads.

A specific example of such a high-speed phenomenon recording device will be described below with reference to FIG. This specific example is
This is a case where an imaging device that scans at a scanning speed five times the scanning speed of a standard television signal of the NTSC system is used.

The subcarrier frequency, horizontal frequency, vertical frequency and frame frequency of this imaging signal are respectively ′ _SC ,
′ _H , ′ _V , ′ _FR are expressed as follows.

′ _SC = 910/4′ _H = 17.9 (MHz) ′ _H = 525/2 _{′ V} = 78.75 (KHz) ′ _V = 300 (Hz) ′ _FR = 1/2′ _V = 150 (Hz) 1 is the imaging device It includes an image pickup device such as an image pickup tube and a solid-state image pickup device, driving means therefor, a signal processing circuit, etc., and here also includes an encoder for obtaining an NTSC system composite color image pickup signal. However, such an encoder can also be provided in a signal processing circuit system at a stage subsequent to the imaging device 1 (for example, at a stage subsequent to a D/A converter described below).

The composite color imaging signal from the imaging device 1 is A/D
It is supplied to a converter 2 and digitized. 3
is a synchronization separation circuit that receives an imaging signal from the imaging device 1 and separates various synchronization signals. A color framing signal from the imaging device 1 and horizontal and vertical synchronization signals from the synchronization separation circuit 3 are supplied to a clock signal generation/system control circuit 4. The frequency ′ _W-CK from this circuit 4 is, for example, 4′ _SC {=71.6 (
M
Hz)} clock signal is supplied to the A/D converter 2. A control signal from the circuit 4 is also supplied via an amplifier 5 to a fixed magnetic head 6 for recording on the side edge of a magnetic tape (not shown).

The digitized image signal from the A/D converter 2 is supplied to the field memories M (M- ₁ to M-10) via on/off switches S1 to _S10 , respectively, at a data rate of the writing frequency ' _W-CK. It is written with . Field memory M-1, M-6; M-
2, M-7: M-3, M-8: M-4, M-9;
M-5; Read frequency _R-CK (1/5
_{' W-CK} ) The digitized image signals read out at a data _rate of The signals are supplied to the circuits DA-1 to DA-5, and are subjected to D/A conversion using a clock signal having a read frequency _R-CK . D/A converter DA-1
~Analog imaging signal VID obtained from DA-5-
1 to VID-5 are supplied to FM modulators MD-1 to MD-5 for FM modulation, and the obtained FM modulated imaging signals are sent to five rotating magnetic fields via amplifiers _A1 to _A5 , respectively. The magnetic tape is supplied to heads H _A to H _E and recorded on the magnetic tape so as to form successive adjacent inclined tracks.

In addition, FM modulators MD-1 to MD-5 have video level, carrier frequency (frequency 5 times the standard value),
It has means for adjusting deviation, DC, DP, frequency characteristics, etc., and thereby makes it possible to match the characteristics of each channel.

In addition, such a high-speed phenomenon recording device is composed of a television camera and a helical scan type VTR, but in this example, the imaging device 1 to D/A converters DA-1 to DA-5 are connected to the television camera side. Assume that the FM modulators MD-1 to MD-5 to the rotating magnetic heads H _A to H _E , the amplifier 5 and the fixed magnetic head 6 are on the VTR side, but the boundaries are not limited to this.

Next, the operation of the apparatus shown in FIG. 1 will be explained with reference to FIG. 2 as well. In FIG. 2, T ₁ , T ₂ , T ₃ . . . indicate field periods, each having a time width T (=1/′ _V ).

Now, during the period _T1 , only the switch _S1 is made, and the digitized image signal is written into the memory M-1. Next, in field period T ₂ ,
Only switch _S2 is made, and the image signal is written into memory M-2. Below, each memory M
Imaging signals are sequentially written in -3 to M-10.

Then, in the field period _T6 , the switch _S11 is set to the fixed setting a side, and the image pickup signal written in the memory M- ₁ in the field period T1 is
W _1N begins to be read. Since _R-CK = 1/5' _W-CK , in order to read out the imaging signal W _1N and obtain its readout signal R _1N , it takes 5 field periods T ₆ to
Requires _T10 .

Similarly, in field period _T7 , memory M
-2 imaging signal written in field period T ₂
W _2N begins to be read. Similarly, five field periods T ₇ to _{T 11} are required to read the imaging signal W _2N and obtain the read signal R _2N . Thereafter, proceed in the same manner, and switch S ₁₁ in field period T ₁₁ .
is made to the fixed contact b side and starts reading out the image signal W _6N from the memory M-6 to obtain a read signal R _6N . Therefore, the written digital image signal
When W _1N , W _2N . . . are controlled to be one field from the beginning of each field, the read image signals R _1N , R _2N . . . are read from the beginning of each field, D/A converter DA-1 to DA-
Analog imaging signals VID-1 to VID-5 from 5 are given a phase interval of 1/' _V = 1/51/ _V .
The phase imaging signal will be output.

Also, focusing on the image pickup signal VID-1, this consists of image pickup signals R _1N →R _6N →R _1(N+1) →... which are read out sequentially. Now, if W _1N is the first field imaging signal of the NTSC system, W _2N is the second field imaging signal, ... W _4N is the fourth field imaging signal,
W _5N is the first field imaging signal, W _6N is the second field imaging signal, and so on. Therefore, the imaging signal VID-1 is the sequential imaging signal R _1N (first field) → R _6N (second field) → R _1(N+1) (third field) → R _6(N+1) (4th field) R _1(N+2) (1st field) Consists of..., apparently continuous,
In other words, it is an NTSC image signal with color framing. Similarly, the imaging signal VID-2...VID-
5 is also a continuous VTSC imaging signal. in the end,
Five-phase STSC imaging signals are output from each D/A converter.

Figure 3 shows each rotating magnetic head (recording head) H _A
~H Shows the arrangement of _E. That is, the five rotating magnetic heads H _A to H _E are the rotating drum of the tape guide drum GD.
They are placed at 72° intervals in the RD and rotate clockwise once every 1/ _V , or at 60Hz. Note that SD is a fixed drum. Also, the tape to be recorded is at point P ₂
Counterclockwise along the outer circumference of drum GD from point P ₁
The winding angle is approximately 344°. Further, the tape running speed is five times the standard value v _t for steady running.

A tape recorded under the above conditions must satisfy all dimensions specified by the standards. That is, in FIG. 4, the recording track pattern vector QP ₁ on the tape is the vector sum of the tape running vector QP ₂ and the drum rotation vector P ₂ P ₁ , as shown in the following equation.

QP ₁ =QP ₂ +P ₂ P _{1 1} cos _{θ C} − _{2 1} cos _{θ H} = 5v _{t 1} sin θ _C = _{2 1} sin θ _H = h where θ _C and θ _H are the track angle and the helix angle, respectively.

From these two equations, _{2 1} and θ _H are determined. h, v _t ,
OP ₁ is, for example, h = 18.4, v _t = 4.07, ₁ =
It is 410.764.

θ _H = sin ^-1 h/P ₂ P _{1 2 1} , θ _H are 390.4357 and 2.70117°, respectively (=2°42′0
Four")
It is. Therefore _{2 1} is 344/36 of the outer circumference of drum DG
0, and θ _H should be set to be the inclination angle of the tape and the drum.

Next, in order to form an inclined track on the tape so that the relative speed of the rotating head and the tape matches when the tape is played back on a SMPTE type C VTR, the outer diameter of the tape guide drum was
It is necessary to make it smaller by a certain amount than that of a Type C VTR. This will be explained below with reference to FIG.

In Fig. 5, the relative speed v between the rotating magnetic head and the tape is expressed as the tape running speed 5v _t (v _t
is the vector sum of the standard velocity of the SMPTE type C VTR tape during steady running) and the linear velocity v _h of the rotating magnetic head.

v=v _h +5v _tAlso , if the length of the inclined track (track length) formed on the magnetic tape by the rotating magnetic head during still playback of an SMPTE type C VTR is lc, then this is expressed as the following equation. is expressed in

lc=πDc・(Φc/360) Here, Dc is the tape of the SMPTE type C VTR.
The outer diameter of the tape guide drum, Φc, is its tape winding angle (=344°).

Also, when the tape is running at five times the standard speed, the track length l is expressed by the following equation.

l=πD·(Φc/360) Here, D is the outer diameter of the tape guide drum of such a VTR.

Thus, lc ² and l ² are respectively expressed as in the following equations.

lc ² = h ² + (Lcosθc−vt) ² l ² = h ² + (Lcosθc−5vt) ^2Here , h is the length of the track on the tape in the width direction, and L is the standard speed of the tape. Tape C of a SMPTE Type C VCR when running at 5 times the speed of
This is the track length on a VTR tape.

Thus, Dc/D is expressed as the following equation.

Dc/D={h ² + (Lcosθc−vt) ² } ^1/2 × {h ² +
(Lcosθc−5vt) ² } ^1/2 Thus, the outer diameter D of the tape guide drum (<Dc)
is selected.

The tape pattern of the tape recorded by the tape guide drum, rotating magnetic head, tape running system, etc. determined as described above is the SMPTE type C tape pattern.
This will satisfy the VTR standards.

Figure 6 shows the tape pattern that meets the SMPTE Type C VTR standard and each rotating magnetic head H _A ~
The arrangement relationship of each inclined track corresponding to H _E is shown.
In Figure 6, TP indicates magnetic tape, and T _A ~
T _E indicates a tilt track corresponding to the rotating magnetic heads H _A to H _E , respectively. Note that T _CTL indicates a control signal track.

The tape recorded in the above manner is converted to SMPTE
By playing normally on a VTR that meets the Type C standard, high-speed phenomena can be played back in slow motion.

Next, with reference to FIG. 7, another specific example of the previously proposed high-speed phenomenon recording device will be described. Switches S ₁ to S ₁₀ , memory M, and switches S ₁₁ to S 10 in FIG.
_S16 and D/A converters DA-1 to DA-5 are collectively considered as one memory M'.
The following modifications can be considered for M′. That is, if a serial memory such as a CCD or a shift register is used, the memory M' can be composed of six field memories, a switch, a D/A converter, etc.

The operation of memory M' in this case will be explained with reference to FIG. It is assumed that the memory M' has the above-mentioned six field memories M-1 to M-6.
Now, in field period _T1 , the digitized imaging signal is written and stored. Next, in field period _T2 , the imaging signal is transferred to the memory M.
-2 is written. Similarly, each memory M-3
Imaging signals are sequentially written into M-6. Then, in the field period _T2 , the image pickup signal _W1N written in the memory M- ₁ during the field period T1 starts to be read out. Since f _R-CK = 1/5f' _W-CK , five field periods T ₂ to T ₆ are required to read out the imaging signal W _1N and obtain the read signal R _1N .

Similarly, in field period _T3 , memory M
-2 imaging signal written in field period T ₂
W _2N begins to be read. Similarly, five field periods T ₃ to _{T 7} are required to read out the imaging signal W _2N and obtain the readout signal R _2N . Thereafter, in the same manner, during the advance field period _T7 , the switch _S11 is made to the fixed contact b side, and reading of the image pickup signal _W6N from the memory M-6 is started to obtain a readout signal _R6N .
Thus written digital image signals W _1N , W _2N
... is controlled so that it is one field from the beginning of each field, the read image signal
R _1N , R _2N ... can be read from the beginning of each field, and the analog imaging signals VID-1 to VID-5 from the D/A converters DA-1 to DA-5 have 1/f'v= Five-phase imaging signals are output with a phase interval of 1/5 1/fv.

Also, if we focus on the imaging signal VID-1, this is the imaging signal R _1N → R _6N → R _1(N+1) →...
Consists of. Now, if W _1N is the imaging signal of the first field of the NTSC system, R _2N is the imaging signal of the second field, ... W _4N is the imaging signal of the fourth field, W _5N is the imaging signal of the first field, W _6N is the imaging signal of the second field... Therefore,
The imaging signal VID-1 is a sequential imaging signal R _1N (first
field) → R _6N (2nd field) → R _1(N+1)
(3rd field) → R _6(N+1) (4th field)
R _1(N+2) (1st field) Consists of..., and is apparently continuous, that is, with color framing.
This is an NTSC image signal. Similarly, the imaging signal
VID-2...VID-5 are also continuous NTSC imaging signals. In the end, each D/A converter outputs 5 phases.
An NTSC imaging signal will be output.

In the memory M' of FIG. 7, when RAM is used, writing and reading can be performed in a time-division manner, so only five field memories are required.

In addition, in FIG. 1, the synchronization signal is separated from the composite imaging signal from the imaging signal 1 and is supplied to the clock signal generation/system control circuit 4.
As shown in the figure, a synchronization signal may be generated from the clock signal generation/system control circuit 4 itself and supplied to the image pickup signal 1.

By the way, the recorded tape obtained by the above-mentioned high-speed phenomenon recording device is
In order to play back on a VTR, the rotary magnetic head and playback circuit of this VTR are one channel, so
The inclined tracks formed on the magnetic tape by the five rotating magnetic heads H _A to H _E must be recorded with the same characteristics.

To do this, each inclined track recorded on the magnetic tape by each of the rotating magnetic heads H _A - _{H E} is reproduced and checked, and each recorded track for the rotating magnetic heads H _A - _{H E} is checked accordingly. A device is required to adjust and align the characteristics of the system.

The detection and adjustment device will be described below with reference to FIGS. 9 and 10. First, as shown in FIG. 9, the rotary magnetic heads H _A to FIG. 3 described above are attached to the rotating drum RD of the tape guide drum GD.
In addition to H _E , there is also a rotating magnetic head H _M for monitor playback.
will be established. In FIG. 9, for example, the rotating magnetic head H _C ,
A rotating magnetic head _HM is provided approximately in the middle of _HD .
Incidentally, the angle θ _D between the heads H _C and H _M is approximately 36°.
In addition, indicates the difference in level between head H _M and heads H _A to _{H E.}

Then, as shown in FIG. 10, the output terminal of the rotating magnetic head H _M for monitor reproduction is connected to the input terminal of the reproduction equalizer 9 via the amplifier _AM , and the output terminal is fixed to the changeover switch S ₂₂ . Connect to contact a.
On the other hand, each output terminal of the FM modulator MD-1 to MD-5 for each rotating magnetic head H _A to H _E is connected to each fixed contact a to e of a changeover switch S ₂₁ , and the movable contact f is connected to the white reference. Mixing circuit 7 for mixing signals
Connect to the input end of The output end of this mixing circuit 7 is connected to the movable contact c of the changeover switch _S22 to the input end of the FM demodulator 8.

Next, the operation of such a detection/adjustment device will be explained. First, switch the movable contact c of the changeover switch S ₂₂ to the fixed contact a side, and select the SMPTE type C.
A standard tape recorded on a VTR is run at five times the standard speed, played back by a rotating magnetic head _HM , and the playback system is adjusted so that its characteristics meet the standards. After that, each FM modulator
A test signal (for example, a white signal) is supplied to MD-1 to MD-5. Then, the movable contact c of the changeover switch _S22 is switched to the fixed contact b side. Mixing circuit 7
Now, a reference signal having a white signal frequency is inserted into the vertical synchronization signal section of the modulated test signal from each FM modulator MD-1 to MD-5. Then, by switching the changeover switch _S21 , the level of the demodulated signal of each channel obtained from the FM demodulator 8 is compared with the level of the reference signal, and the gain of the recording system of each channel is adjusted so that they are the same. Adjust.

Thereafter, the movable contact c of the changeover switch _S22 is switched to the fixed contact a side. And each FM modulator
A test pattern signal is supplied to MD-1 to MD-5, and the modulated test pattern signals from each are sequentially recorded on the magnetic tape by rotating magnetic heads H _A to H _E so as to form an inclined track. At this time, by displacing the rotating magnetic head H _M for monitor playback (which can be displaced in a direction substantially perpendicular to the scanning direction), a specific magnetic field of the tilt track produced by each magnetic head H _A to _{H E} is detected. The video level, clamp level, pre-emphasis frequency characteristics, DG,
Adjust the various characteristics of the recording system for each channel so that the DP, waveform characteristics, etc. match the test pattern signal from standard tape playback. In this way, the characteristics of each recording system of each rotating magnetic head H _A to H _E will be uniform.

Next, referring to FIG. 11, a displacement drive circuit for the rotating magnetic head H _M for monitor reproduction will be described. The rotating magnetic head H _M for monitor reproduction connects to the rotating drum of the tape guide drum GD shown in FIG. 9 via the bimorph 10 as an electro-mechanical conversion element.
Mounted on RD. This bimorph 10 has
A strain gauge 11, which is a mechanical-electric conversion element, is attached to detect the displacement.

In the dynamic tracking servo circuit 24, the displacement detection output from the strain gauge 11 is transferred to the well-known dynamic tracking control circuit 13 used in SMPTE type C VTRs, etc.
supplied to A control signal from the control circuit 13 is supplied to the bimorph 10 as a displacement drive signal via an on/off switch _S32 , a combiner (adder) 14, and a dynamic tracking drive circuit 15.

Furthermore, the displacement detection signal from the amplifier 12 is passed through the low pass filter 16 - amplifier 17 - on/off switch.
It is supplied to the hold capacitor 18 via _S31 . The terminal voltage of the capacitor 18 is supplied via an amplifier 19 to a combiner (subtractor) 20 and subtracted from the output of the amplifier 17. The output of the combiner 20 is supplied to another combiner (subtractor) 21, and the movable contact f of the changeover switch _S35 of the DC voltage generation means 25
The DC voltage from E is subtracted from ₀ . Synthesizer 21
The output from the dynamic tracking control circuit 13 is supplied to the combiner 14 via the amplifier 22 and the on/off switch _S33 , and added to the output from the dynamic tracking control circuit 13.
_DC voltages Ea (>0), Eb (>0), Ec (=0), Ed (<
0) and Ee (<0) are given.

23 is a cancellation signal generation circuit, which generates a damped vibration cancellation signal that converges to 0V, and outputs an on/off switch S ₃₄
It is supplied to the combiner 14 via.

Next, the operation of the circuit shown in FIG. 11 will be explained with reference to FIG. 12 as well. Figure 12 shows a certain moment during recording.
That is, it shows, for example, the moment when head H _C has finished scanning one track. T _A to T _E are heads respectively.
The scanning tracks of H _A to H _E are shown. M is the neutral position of the reproducing movable head H _M when the bimorph 10 is not biased. The straight line shows the line of movement of the movable head H _M. M is the head of the movable head H _M
H _A is on the scanned track T _A and the movable head
If H _M moves two track pitches in the positive direction along the movement line, it will be on track T _D , if it moves one pitch, it will be on track T _E , if it moves one pitch in the negative direction, it will be on track T _B , and if it moves two pitches, it will be on track T C. You can move up and play each track.

Actually, on the track where M is located, move the movable head so that N is located between tracks T _D and T _C.
Determine the position of H _M. Here, if N is chosen as the midpoint of tracks T _D and T _C , then becomes 2.5 track pitch. Generally, ≒2p+ CN tan(θ _H −θ _C ). Furthermore, p is the track pitch and C is the head.
The position of H _C , θ _H is the helix angle, and θ _C is the track angle. In the above equation, p=0.18, tan (θ _H −θ _C )
If = 0.5p, then becomes 0.45.

In FIG. 11, initially, during the recording mode, the switch S ₃₂ was turned off once to release the dynamic tracking loop, and then the switch S ₃₄ was turned on to send an erase signal to the bimorph 10 of the head _HM . This returns the position of the bimorph 10 to the neutral position. At this time, the head H _M
It should be scanning over T _A. In this state, close the dynamic tracking loop once. At this time, the head _HM completely scans the track _TA by tracking it. At this time, the output of the low-pass filter 16 is held in the capacitor 18 by turning off the switch _S33 and making the switch _S31 . Next, turn off Switchi S ₃₁ , make Switchi S ₃₃ , and then switch to Switchi S ₃₅ .
When the movable contact f is connected to the fixed contact a, a voltage Ea corresponding to two pitches of the output of the strain gauge 11 is amplified by the amplifier 22, and the voltage Ea is amplified by the amplifier 22.
Therefore, the output of the strain gauge 11 is made to substantially match the voltage Ea. In this way,
Head _HM is moved two pitches to scan that track.

Thereafter, the movable contact f of the switch _S35 is sequentially switched to the fixed contacts b...e, so that the head H _M scans each of the tracks T _A to T _E.

Another specific example of the previously proposed high-speed phenomenon recording device will be described below with reference to FIG. 13, but parts corresponding to those in FIG. 1 will be designated by the same reference numerals and redundant explanation will be omitted. This embodiment is a case where an imaging device that scans at a scanning speed three times the scanning speed of a standard television signal of the NTSC system is used.

The subcarrier frequency, horizontal frequency, vertical frequency and frame frequency of this imaging signal are respectively `` <sub>SC''</sub> ,
Assuming `` _H ,'' `` _V ,'' _FR , these are expressed as follows.

″ _SC = 910/4″ _H = 10.7 (MHz) ″ _H = 525/2″ _V = 47.25 (KHz) ″ _V = 180 (Hz) ″ _FR = 1/2″ _V = 90 (Hz) A/D conversion The digitized image signals from the device 2 are supplied to the field memories M (M- ₁ to M-6) via on/off switches S1 to _S6 , respectively, and are written at a data rate of the write frequency ' _W-CK. It can be done.
Field memory M-1, M-4; M-2, M-
5; Read frequency _R-CK from M-3 and M-6 (=1/
The digitized image signals read out at a data rate of 3° _W-CK ) are transferred to respective changeover switches (each having fixed contacts a, b and movable contacts c) S11 _~
D/A converters DA-1 to DA-3 respectively via _S13
and is D/A converted using a clock signal of read frequency _R-CK . D/A converter DA
Analog imaging signals obtained from -1 to DA-3
VID-1 to VID-3 are supplied to FM modulators (carrier frequency is 3 times the standard value) MD-1 to MD-3 for FM modulation, and the obtained FM modulated image signals VID-1 to VID, respectively. -3 are connected to three rotating magnetic heads H A to _{H C} at 120° intervals via amplifiers A ₁ to A ₃ respectively.
are supplied to the magnetic tape and recorded so as to form successive adjacent inclined tracks on the magnetic tape.

Next, the operation of the apparatus shown in FIG. 13 will be explained. 1st
In FIG. 4, T ₁ , T ₂ , T ₃ . . . indicate field periods, each having a time width T (=1/ _V ).

Now, during the period _T1 , only the switch _S1 is made, and the digitized image signal is written into the memory M-1. Next, in the field period _T2 , only the switch _S2 is made, and the imaging signal is written into the memory M-2. Thereafter, similarly, imaging signals are sequentially written into each of the memories M-3 to M-6.

Then, during the field period _T4 , the switch _S11 is made to the fixed contact a side, and the image pickup signal written in the memory M- ₁ during the field period T1 is
W _1N begins to be read. Since _R-CK = 1/3′ _W-CK , read out the imaging signal W _1N and use the readout signal
Three field periods T ₄ to _{T 6} are required to obtain R _1N .

Similarly, in field period _T5 , memory M
-2 imaging signal written in field period T ₂
W _2N begins to be read. Similarly, three field periods _T5 to _T7 are required to read out the imaging signal _W2N and obtain the readout signal _R2N . Thereafter, proceed in the same manner, and switch S ₁₁ in field period T ₁₁ .
is made to the fixed contact b side and starts reading the image signal W _4N from the memory M-4 to obtain the read signal R _4N . Therefore, the written digital image signal
When W _1N , W _2N ... are controlled to be one field from the beginning of each field, the read image signals R _1N , R _2N ... are read from the beginning of each field. D/A converter DA-1~
Analog imaging signal VID-1 to VID from DA-3
-3, three-phase imaging signals are output with a phase interval of 1/'' _V = 1/31/ _V .

Also, if we focus on the imaging signal VID-1, this is the imaging signal R _1N → R _4N → R _1(N+1) →...
Now, if W _1N is the imaging signal of the first field in the NTSC system, W _2N is the imaging signal of the second field, ... W _4N is the imaging signal of the fourth field, and W _5N is the imaging signal of the first field. The signal W _6N is the imaging signal of the second field. Therefore,
Imaging signal VID-1 is imaging signal R _1N (first field) → R _4N (fourth field) → R _1(N+1) (third field) → R _4(N+1) (second field) →R _1(N+2)
(1st field)..., and the color framing is broken. Therefore, when performing NTSC color encoding after the D/A converter, the imaging signals R _4N (4th field), R _4(N+1) (2nd field)... are the phase of the carrier color signal. must be reversed. The same applies to the imaging signals VID-2 to VID-3. Therefore, in this case, if the NTSC color encoder in the imaging device 1 is installed after the D/A converter, the NTSC
By providing means for inverting the phase of the carrier color signal in each color encoder for obtaining composite color imaging signals of the system, the imaging signals VID-1 to
A signal with apparently distorted color framing is generated as VID-3.

Thus, a color imaging signal having a scanning speed N times the standard value of the NTSC system is obtained from the imaging device as a component signal, written to a memory having a storage capacity of N fields or more, and the standard scanning speed is read from the memory. By obtaining N-channel component signals and color-encoding each into an NTSC signal, a color imaging signal is obtained, which is supplied to each of N rotating magnetic heads, and the N-channel color imaging signals are sequentially phased. In a high-speed phenomenon recording device that records on a magnetic tape so as to form adjacent inclined tracks, N is
4n+1 or 4n-1 (however, n=1, 2, 3,...
), the configuration of the color encoder differs accordingly. That is, in the case of N=4n+1, the color encoder may be a normal NTSC encoder. However, in the case of N=4n-1, in order to obtain a color imaging signal with good color framing while being recorded on tape, the phase of the carried color signal of each channel is reversed at each field position. As such, it is necessary to make changes to the NTSC color encoder.

In addition, in such a high-speed phenomenon recording device, regarding the color encoder, when handling color imaging signals of the SECAM system, a color framing operation similar to that when handling color imaging signals of the NTSC system is required.

Furthermore, when handling PAL color imaging signals, N=8n+1 (if N=4n+1 and n is an even number)
When (n=1, 2, 3, ...), the color encoder can be a normal PAL encoder,
N=8n-3 (if N=4n+1 and n is an odd number) (n
= 1, 2, 3...), it is necessary to make changes to the PAL color encoder at the downstream stage of the D/A converter so that a color imaging signal with color framing can be obtained on the tape.

Therefore, when N is an odd number of 3 or more, the configuration of the color encoder becomes simple. However, if this point is not taken into account, N may be an even number.

According to the above-described high-speed phenomenon recording device, high-speed phenomena can be easily imaged and recorded using a television camera and a VTR. The tape recorded with such a high-speed phenomenon recording device is a standard method.
It can be played back on a VCR, thus providing a compatible pre-recorded tape.

When N=4n±1 (n=1, 2, 3, . . . ), the configuration of the color encoder becomes simple in each television system.

By the way, in the above-mentioned high-speed phenomenon recording device,
In order to record the inclined tracks of the SMPTE Type C VTF format on the magnetic tape, the outer diameter of the tape guide drum is adjusted to the SMPTE Type C VTF.
It was designed to be a predetermined amount smaller than that of the VTR.

However, it is undesirable from a standard and manufacturing standpoint to make the outer diameter of the tape guide drum different from the standard outer diameter, so instead, the outer diameter of the tape guide drum is the same as that of the SMPTE Type C VTR format. By making the winding angle of the magnetic tape around the tape guide drum different from that of a SMPTE type C VTR, the inclination angle of the inclined track on the magnetic tape is different from that of an SMPTE type C VTR, even though the tape running speed is faster than the standard speed. (Therefore, it is necessary to use a bimorph head as a single rotating magnetic reproduction head to perform tracking.) In addition, the time axis of the imaging signal from the imaging device must be After compression, the length of the inclined track is
The idea was to make it the same format as the SMPTE Type C VTR.

In this way, when compressing the time axis of an imaging signal, if the frequency characteristics of the pre-emphasis circuit remain the same as when no time axis compression is performed, there is a risk that the S/N of the reproduced imaging signal will deteriorate. be.

Purpose of the invention In view of the above, the present invention provides an imaging signal from an imaging device that scans at a surface and line scanning speed that is N times (a natural number of 2 or more) times the surface and line scanning speed Ssn and Sln of the standard television signal. N pre-emphasis circuits to which the N channels of imaging signals read out in parallel from the storage means are respectively supplied, and N pre-emphasis circuits to which the outputs of the N pre-emphasis circuits are supplied. FM modulators, the modulated imaging signals from the N FM modulators are supplied to N rotating magnetic heads that rotate at a standard rotational speed, and at a speed N times the standard speed. In a high-speed phenomenon recording device that records data so as to form an inclined track on a running magnetic tape, when the time axis of the imaging signal obtained from the imaging device is compressed,
The present invention attempts to propose a high-speed phenomenon recording device that is free from the risk of deterioration of the S/N of reproduced image signals.

Summary of the invention The present invention is designed to record images by being supplied with imaging signals from an imaging device that scans at a surface and line scanning speed that is N (a natural number of 2 or more) times the surface and line scanning speeds of standard television signals Ssn and Sln, respectively. N pre-emphasis circuits to which the N-channel imaging signals read out in parallel from the storage means are respectively supplied, and N FM modulators to which the outputs of the N pre-emphasis circuits are supplied. and supplies the FM modulated imaging signals from the N FM modulators to the N rotating magnetic heads, each rotating at a standard rotation speed, and running at a speed N times the standard speed. In a high-speed phenomenon recording device that records data so as to form a tilted track, a time-base compression circuit is provided to compress the time-base of the imaging signal obtained from the imaging device, and the frequency characteristics of the N pre-emphasis circuits are compressed on the time-base. It is set according to the compression ratio of the compression circuit.

According to the present invention, it is possible to obtain a high-speed phenomenon recording device that is free from the risk of deterioration of the S/N of the reproduced image signal when the image signal obtained from the image pickup device is time-base compressed.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 15 to 20. FIG. 15 shows the apparatus according to the present invention as a whole, and parts in FIG. 15 that correspond to those in FIGS. 1 and 13 are given the same reference numerals, and some redundant explanations will be omitted. This example is
This is a case where an imaging device that scans at a scanning speed three times the scanning speed of a standard television signal of the NTSC system is used.

The subcarrier frequency, horizontal frequency, vertical frequency and frame frequency of this imaging signal are respectively `` <sub>SC''</sub> ,
Assuming `` _H ,'' `` _V ,'' _FR , these are expressed as follows.

″ _SC 〕910/4″ _H = 10.7 (MHz) ″ _H = 525/2″ _V = 47.25 (MHz) ″ _V = 180 (Hz) ″ _FR = 1/2″ _V = 90 (Hz) A/D conversion The digitized image signals from the device 2 are sent to the field memories M (M-1 to M-6) via the time axis compression circuit 30 and on/off switches _S1 to _S6 , respectively.
The input and output frequencies are written at a data rate of _K-CK . Field memory M-
1, M-4; M-2, M-5; Digitized image signals read out from M-3, M-6 at a data rate of read frequency _R-CK (=1/3' _W-CK ) but,
A clock signal with a read frequency _R-CK is supplied to the D/A converters DA-1 to DA-3 through respective changeover switches _S11 to _S13 (each having fixed contacts a and b and a movable contact c). D/A conversion is performed. The analog image signals obtained from the D/A converters DA-1 to DA-3 are sent to variable gain amplifiers 31-, respectively.
1 to 31-3, the FM modulator (carrier frequency is 3 times the standard value) including the de-emphasis circuit 3
2-1, 32-3 and is FM modulated.
The obtained FM modulated imaging signals are sent to the amplifier _A1.
~A ₃ through 3 rotating magnetic heads spaced 120° apart
The signals are supplied to H _A to H _C and recorded on the magnetic tape so as to form successive adjacent inclined tracks.

In this case, in order to record the inclined track of the SMPTE type C VTR format on the magnetic tape, unlike the above, in this embodiment,
The outer diameter of the tape guide drum is SMPTE type C.
The format should be the same as that of the VTR, and the winding angle of the magnetic tape on the tape guide drum should be the same as that of the VTR.
It is different from that of SMPTE type C VTR,
Even though the tape running speed is faster than the standard speed, the inclination angle of the inclined track on the magnetic tape is
The format should be the same as that of an SMPTE type C VTR (therefore, it is necessary to use a bimorph head as a single rotating magnetic reproduction head to perform tracking), and
The time axis of the imaging signal obtained from the imaging device is compressed so that the length of the slope track becomes the same as that of the SMPTE type C VTR format.

The time base compression circuit for this purpose can be installed in either a digital signal system or an analog signal system, but
In this example, as described above, it is provided at the next stage of the A/D converter 2.

By the way, the relative velocity between the rotating magnetic head and the magnetic tape is the sum of their linear velocities when their respective moving directions are opposite as shown in FIG. For SMPTE Type C VTRs, the standard tape running speed is about 1% of the standard linear speed of the rotating magnetic head. Further, in the case of the NTSC television system, the phase difference between the starting ends of adjacent inclined tracks of an SMPTE type C VTR is 2.5H (H is the horizontal period).

Therefore, when the tape running speed is N times the standard speed, the multiplication ratio corresponding to the time axis compression rate of the image signal to be recorded is 1+2.5(N-1)/262.5. Therefore, the multiplication ratio when N=3 is 1+5/262.5=267.5/262.5=535/525=107/105.

Therefore, as the time axis compression circuit 30, the RAM
Using the ratio of write and read clock frequencies,
It is sufficient to select 105:107.

Therefore, variable gain amplifiers 31-1 to 31-3
Common gain control signal generation circuit GCG and
A common frequency control signal generation circuit FCG is provided for each of the FM modulators 32-1 to 32-3.

Note that the frequency of each part of the image signal frequency-modulated by the FM modulators 32-1 to 32-3 is
As shown in Figure 6, the reference frequency at the pedestal
Fp is, for example, 7.9MHz x (107/105), and the reference level corresponding frequency Fs at the tip of the horizontal synchronization signal is, for example, 7.06M
Hz×(107/105).

First, the frequency control signal generation circuit FCG will be explained. 38 is an AFC loop, 39 is a reference oscillator for controlling the reference frequency, and 40 and 41 are input side and output side switching circuits (gate circuits), respectively. circuit 3
8, 40, and 41 are controlled (gated) by three-phase control pulses from the input terminal 42. These three-phase control pulses are transmitted to the FM modulators 32-1 to 32-3.
These are three-phase pulses with timings corresponding to the back porch or front porch of the pedestal obtained every one or more horizontal periods or every field of each FM modulated imaging signal from 2-3.

The three-phase FM modulated imaging signals from the FM modulators 32-1 to 32-3 are input to the input side switching circuit 40.
The frequency of the back porch or front porch of each pedestal is set to the cold quasi frequency Fp from the reference oscillator 39 obtained via the input side switching circuit 40, Fp=7.9MHz×
(107/105), and the three-phase comparison outputs are supplied to the FM modulators 32-1 to 32-3, respectively, and controlled so that their respective carrier frequencies are the same.

Next, the gain control signal generation circuit GCG will be explained. 33 is an AGC loop, 34 is a reference oscillator for controlling the reference level, and 35 and 36 are input side and output side switching circuits (gate circuits), respectively. circuit 3
3, 35, and 36 are switched and controlled (gated) by three-phase control pulses from an input terminal 37. These three-phase control pulses are transmitted to the FM modulators 32-1 to 32-3.
These are three-phase pulses with timings corresponding to the leading edge of the horizontal synchronization signal obtained every one or more horizontal periods or every field of each FM modulated imaging signal from 2-3.

The three-phase FM modulated imaging signals from the FM modulators 32-1 to 32-3 are sent to the input side switching circuit 35.
is supplied to the AGC loop 33 via the AGC loop 33, and the frequency at the tip of each horizontal synchronization signal is the reference frequency Fs from the reference oscillator 34 obtained via the input side switching circuit 35 = 7.06MHz x (107/105) The three-phase comparison outputs are supplied to variable gain amplifiers 31-1 to 31-3, respectively, and their respective gains are controlled so that the levels of the horizontal synchronizing signals are the same.

Next, refer to Figure 17 and take the same configuration.
A configuration example of the AFC loop 38 and the AGC loop 33 will be explained. The output of the input side switching circuit 40 or 35 is supplied from the input terminal 45 to the FM demodulator 46 and demodulated, and the demodulated output is sent to a pair of sample and hold circuits 48 via the reference frequency signal and detection frequency signal switching circuit 47. , 49. The hold outputs of the reference frequency and detection frequency from the sample and hold circuits 48 and 49 are supplied to a level comparison circuit 50 consisting of a differential amplifier, etc., where they are compared, and the comparison output is outputted to an output terminal 51. Each of the circuits 47 to 50 is switched and controlled by three-phase control pulses from an input terminal 52.

Next, with reference to FIG. 18, the configuration of the output side switching circuit 41 or 36, which has the same configuration, will be explained.
The output of the AFC loop 38 or the AGC loop 33 is supplied from the input terminal 55 to the switching circuit 56, and the three switching outputs are sent to sample and hold circuits 57-1 to 57-5, respectively.
7-3, and its hold output is supplied to FM modulators 32-1 to 32-3 or variable gain amplifier 31-
1 to 31-3.

Next, referring to Figure 9, FM with the same configuration
A configuration example of the modulators 32-1 to 32-3 will be explained.

Variable gain amplifier 31-1, 31-2 or 31-
3 is supplied to an FM modulator 62 through a pre-emphasis circuit 61, and its FM modulated output is obtained at an output terminal 63.

The frequency characteristic of this pre-emphasis circuit 61 is a high frequency enhancement characteristic, but as shown in FIG. 20, in relation to the above-mentioned time axis compression, the frequency characteristic is This results in a characteristic curve 65 shown by a broken line that is parallel-shifted by approximately 2% in the direction of increasing height. Therefore, it goes without saying that the frequency characteristics of the de-emphasis circuit during reproduction are also set in accordance with the pre-emphasis characteristics.

If the two time constants of the pre-emphasis circuit exhibiting the characteristic curve 64 are τ ₁ and τ ₂ , then the two time constants of the pre-emphasis circuit exhibiting the characteristic curve 65 are τ′ ₁ ,
τ′ ₂ becomes τ′ ₁ = τ ₁・(1−2/105)=τ ₁・103/105 τ′ ₂ =τ′ ₂・(1−2/105)=τ ₂・103/105, respectively. . If these formulas are generalized, they can be expressed as follows.

τ′ ₁ =τ ₁・{1−2.5(N−1)/262.5} τ′ ₂ =τ ₂・{1−2.5(N−1)/262.5} According to the present invention described above, the The time constants of the pre-emphasis characteristics of the imaging signal supplied to the FM modulator of each channel are reduced according to the time-base compression applied to the imaging signal obtained from the imaging device. Therefore, the S/N of the reproduced image signal in the reproduction system
deterioration can be avoided.

Furthermore, since the gain control signal generation circuit for the variable gain amplifier of each channel and the frequency control signal generation circuit for the FM converter of each channel are common, the influence of variations in circuit characteristics that would occur if they were provided for each channel is reduced. The level of the imaging signal of each channel and the exposure of each channel
A high-speed phenomenon recording device that can align the frequencies of FM modulated imaging signals with high precision can be obtained.

Effects of the invention According to the invention described above, the imaging signal from the imaging device that scans at the area and line scanning speed N (a natural number of 2 or more) times the area and line scanning speed Ssn, Sln of the standard television signal, respectively. N pre-emphasis circuits to which the N channels of imaging signals read out in parallel from the storage means are respectively supplied; and N pre-emphasis circuits to which the outputs of the N pre-emphasis circuits are supplied. has an FM modulator,
FM modulated imaging signals from the N FM modulators are supplied to N rotating magnetic heads rotating at a standard rotation speed to form a tilted track on a magnetic tape running at a speed N times the standard speed. A high-speed phenomenon recording device configured to record as if the image signal is supplied to an FM modulator, in which there is no risk of deterioration of the S/N of the reproduced image signal when the image signal supplied to the FM modulator is compressed in the time axis. can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a specific example of the high-speed phenomenon recording device proposed earlier, FIG. 2 is a diagram showing the timing of writing and reading from memory to explain the device shown in FIG. 1, and FIG. A and B are respectively a schematic plan view and a side view showing the tape guide drum of the device shown in FIG. 1, FIGS. 4 and 5 are vector diagrams for explaining the device shown in FIG. 1, and FIG. 1 is a pattern diagram showing a recording pattern of a tape used to explain the apparatus shown in FIG. 1, FIG.
The figure is a diagram showing the timing of writing and reading memory to explain the device shown in FIG. 7, and FIGS. 9A and B show the device shown in FIG. 1 or FIG. 7 when a rotating magnetic head for monitor reproduction is provided. FIG. 10 is a block diagram showing an example of the detection/adjustment device of the device shown in FIG. 1 or 2, and FIG. A circuit diagram showing a displacement drive circuit for the rotating magnetic head for monitor playback of the apparatus shown in the figure, and FIG. 12 is a line showing the positional relationship between the track on the tape and the rotating magnetic head for explaining the operation of the displacement drive circuit shown in FIG. 11. Figure, 13th
14 is a block diagram showing still another specific example of the high-speed phenomenon recording device proposed earlier, FIG. 14 is a diagram showing the timing of writing and reading the memory to explain the device of FIG. 13, and FIG. 15 is a block diagram showing an embodiment of the high-speed phenomenon recording device according to the present invention,
FIG. 16 is a waveform diagram for explaining the present invention, and FIG.
19 are block diagrams showing specific configurations of some circuits of the device shown in FIG. 15, and FIG. 20 is a characteristic curve diagram showing pre-emphasis characteristics. 1...imaging device, M is a storage means, 30 is a time base compressor, 32-1 to 32-3 and 62 are FM modulators, H _A to H _C are rotating magnetic heads, and 61 is a pre-emphasis circuit.

Claims (1)

[Scope of utility model registration request] Area and line scan speed of standard television signals
A storage means into which imaging signals from an imaging device that scans at a surface and line scanning speed of N (a natural number of 2 or more) times Ssn and Sln are supplied and written, and N channels are read out in parallel from the storage means. N pre-emphasis circuits, each of which is supplied with an imaging signal of
and N FM modulators to which the outputs of the N pre-emphasis circuits are supplied, and N rotating magnets each rotating the FM modulated imaging signals from the N FM modulators at a standard rotation speed. In a high-speed phenomenon recording device that records data so as to form an inclined track on a magnetic tape running at a speed N times the standard speed, the imaging signal obtained from the imaging device is time-base compressed. A high-speed phenomenon recording device comprising: a time-base compression circuit; and frequency characteristics of the N pre-emphasis circuits are set in accordance with a compression ratio of the time-base compression circuit.