JPS607648A - Device for generating video signal - Google Patents

Abstract

PURPOSE:To extract a signal of one CH at a normal scanning speed by executing one scanning every N fields of a TV having a speed of N times and returning the obtained high speed video signal to a normal speed signal through a D/A converter, an A/D converter, etc. CONSTITUTION:When signals obtained from output terminals 61-63 are to be recorded by a VTR, these signals are delayed by every 1/3 field period. If these delayed signals are reproduced by a normal VTR, these signals are successively reproduced for every field in the 1st-3rd CHs. Similarly to the case of so- called slow motion against the normal speed, a high-speed phenomenon can be reproduced as a visible picture. Thus, a signal of one CH can be obtained at the the normal scanning speed without changing the scanning speed of the high- speed scanning TV camera and reducing its sensitivity.

Description

[Detailed description of the invention] Industrial field of application This invention images high-speed phenomena using a television camera,
In a high-speed video system that makes it possible to reproduce heavy-speed phenomena at a speed that can be visually captured by recording the video signal, which is the imaging output, on a VTR, for example, the video signal recorded on the VTR is The present invention relates to a video signal generation device that obtains a suitable one.

BACKGROUND ART AND PROBLEMS Conventionally, high-speed film cameras have been used as devices for capturing and recording high-speed phenomena, but they have the drawback of not being able to reproduce images instantly. In order to compensate for this drawback, we used a television camera to image the (0) velocity phenomenon and transferred it to a VTR.
1%F of various researches to enable immediate reproduction by recording etc.
One shot has been fired.

For example, it is well known that a television camera with a frequency of tπ that obtains an NTSC signal takes 1!; 1/60 seconds to convert one screen (one field) into an electrical signal.

Therefore, words cannot capture dynamic objects that change faster than this.

In order to solve this problem, for example,
In Publication No. 6, the field of view of the image pickup tube is divided into a plurality of sections, the entire subject is located in each of the divided sections, and the object image on the image pickup tube is scanned for a scanning time corresponding to each section. Techniques are disclosed that enable imaging of high velocity phenomena by scanning.

In addition, in Japanese Patent Publication No. 55-13631, there are multiple 111
Optical images of the subject are sequentially applied to image pickup tubes with a storage effect for a certain period of time at regular intervals, and the imaging signals from each image pickup tube are supplied to a plurality of recording devices, respectively, to create a time image of a high-speed phenomenon. A technique for continuous recording has been disclosed.

However, with the technique described in Japanese Patent Publication No. 52-26416, the field of view is substantially narrowed, so that only a 6J image of the periphery of a moving object can be obtained. Furthermore, the moving range of the moving object is limited to one divided section, making it unsuitable for general use. In addition, the technique described in Japanese Patent Publication No. 55-13631 requires a plurality of image pickup elements with storage effects and a plurality of recording devices, making the configuration complicated and extremely inconvenient for actual use. Become.

A different technology from the above-mentioned technology is the one in which images are captured at a scanning speed of N (N is an integer of 2 or more) (t'i) when obtaining a normal, that is, standard, television signal with a television camera. It is also possible to record the captured image signal as is using a VTR.However, in this case, the high-speed video signal obtained by capturing the image at a speed of 11]J, which is N times the normal speed, is recorded as is. Since recording is performed at the same speed, N times the recording bandwidth is required.

For this reason, if the number of rotations of the rotary head is increased by N times the normal case, and the Utt transmission frequency of the FM variable string d for the video signal is also made N times the normal case, the baseband processing will also be N times as much as 4). It must be a characteristic of

Furthermore, in order to ensure compatibility by adjusting the inclination angle of the recording trunk to the normal recording pattern, the tape running speed must also be set to N4 (17).

By playing back the signal recorded at N times the speed on a VTR at the normal rotating head rotation speed and tape running speed, the high-speed phenomenon can be visually captured. It becomes extremely difficult to maintain the characteristics of the recording/reproducing circuit, such as the correspondence between de-emphasis and the frequency stability of the FM modulated signal during playback. When playing back a band-processed signal, it is very difficult to maintain the original characteristics even if the signal is processed with an odd "C" signal. Furthermore, if the carrier wave frequency of the FM modulation of the recording signal becomes N times that of a normal VTR, the impedance of the rotary head, the characteristics of the rotary transformer, etc. become problematic, and a system with a large value of N becomes practically impossible.

Furthermore, if the rotational speed of the rotary head is changed between recording and reproduction, the thickness of the air film layer interposed between the rotary head drum and the tape changes, and the scanning state of the head of tape E differs. The contact pressure of the head against the tape also changes, and there is a possibility that the reproduction sensitivity will decrease.

On the other hand, a method is also known in which an equivalent high-speed video signal is obtained each time the output of a television camera whose scanning speed is a standard scanning speed is shifted by a predetermined timing. However, this has the disadvantage of increasing the number of video devices operating at normal speeds and requiring complex mechanisms.

Therefore, it is possible to make the signal from a television camera whose scanning speed is higher than normal one similar to the output signal from a television camera whose scanning speed is AWs, without causing the above-mentioned drawbacks. The applicant has previously proposed a device that allows for processing.

FIG. 1 shows a system diagram of an example of the basic configuration of this device. In the figure, C(1) is a Kelehi camera which operates at a scanning speed N times the normal scanning speed. In this example, the scanning speed is, for example, tripled. Therefore, this TV camera flll
The output video signal has a frequency band three times that of a normal scanning speed television camera. The video signal band of a normal television camera is about 6M112, so the output video signal of this television camera (1) is 18M.
It has a band of Hz or more. Further, since the scanning speed of the output video signal of this television camera (1) is 3 times the speed, the period of one field of the standard television signal is FS.

In other words, in the case of an NTSC color video signal, 3
A field worth of video signals will be obtained.

The output video signal of the television camera +ti passes through a low-pass filter (2) and is supplied to a ζA/D conversion circuit (3). The low-pass filter (2) is for limiting the signal band, and in this example has a characteristic that allows signals of 20 MIIZ or less to pass. Also, A/D conversion circuit (3)
In this case, the sampler is sampled at three times the speed when sampling the output video signal from a television camera at a normal scanning speed. The sampling rate of a normal television signal is approximately 6MIIz, so color printing is 1u.
For example, 14.3MII considering the ll transmission frequency rsc.
z (4[sc)] or about 13.5M1lz is usually used. In the above example, the sampling rate in the A/D conversion circuit (3) is three times that, so it is 42.9MI.
Iz or about 40.5 MIIz will be selected.

In this example, the sampling rate is 40.5MIIz, and this 40.5MHz clock signal CKH is
The signal is supplied to the /D conversion circuit (3) and converted into, for example, an 8-bit digital signal per sample.

The output digital signal of this A/D conversion circuit (3) is converted into a three-times speed signal into a normal scanning speed signal in a speed conversion circuit (4) having a memory.

Figure 4 shows an example of the specific configuration of this speed conversion circuit (4).
3 field memories (1, 11) (112) (
113) is provided, and the high-speed digital video signal from the A/D conversion circuit (3) is sent to these field memories (lh).
, (112), (113). Then, write address signals ΔDW+, 8DW2 . Eight D-3 are the respective field memories (lh), (li2), (11
3) as well as the read address signal from the read address setting circuit (13).
R2 and 8DR3 are each field memory (lh)
, (112), (113).

40.5M for the advantageous address signal setting circuit (12)
A clock signal (JN) at three times the normal speed of 11z is supplied, thereby forming a write address signal ^0~^3 which changes at three times the normal speed of 1π.On the other hand, the read address setting Circuit (13) 13.5Ml1z
A clock signal CKO at a normal speed is supplied, and address signals ^DFt1 to ADR3 that change at a normal speed are formed. These field memories (l11), (112
), (113) are such that writing and reading are performed in a time-division manner, and it appears that writing and reading can be performed simultaneously. That is, as shown in FIG. 5, a high-speed digital video signal DV (
FIG. 5A) is set to the field memory (111) by the write signal from the write address setting circuit (12).
(112) and (113), but as is clear from Figure 5B and C5D, the timing of the writing is in the 10 period of 1 field period 1''S of the normal speed television signal. Every minute you're late.

For example, the memory (ib) (112
) (113), and in the input address setting circuit (12), each -4 period F
This happens every time the same address is repeatedly set in 1, F2, and F3. Therefore, the address signal ﾆﾆﾆ1. Since Heko 2 and ADWq are the same, they may be common.

Then, ζ, as shown in Fig. 5 B, C, and D, at the beginning of the period FS, at F+ between the temples, the field memory (111)
The odd field signal 01 of the commercial television signal is written into the field memory (1
12), and then in the next ten period F3, video number 02 of the next odd field of the high-speed video signal is written into the field memory (113), and this process is repeated sequentially.

Then, at the same time as the high-speed video signal is input, the separately input signal is immediately read out sequentially from each field memory at the same writing speed. Therefore, the read address signals ADRzAl)R2, ADI supplied from the read atlas setting circuit (13) to each field memory (111) (112) (113)
? In the third case, the same address data is sequentially supplied with a shift of ten periods of the period FS. Therefore, as shown in FIG. 5B, C, and D, the field memory (fiz'
), (112), and (113) are obtained in a state shifted by a period of +FS, respectively. The digital video signals of the three channels read out in parallel are then transferred to the D/A conversion circuit (51
)(52)(53) The smell 'ζ is returned to the analog video signal and led out to the output terminals (61)(62)(63).

In this way, the first one field of the three fields of commercial video signals read out in the l field period FS is sent to the output terminal (61) as a signal of the ff1l Qi tunnel, and the second one field of the video signal is obtained as a second channel signal at an output terminal (62), and the third one-field video signal is obtained as a third channel signal at an output terminal (63).

Since the sampling rate of the signal of each channel is set to ten, the signal becomes a normal speed video signal. Therefore, the video signals obtained at the output terminals (61), (62), and (63) have a speed equal to that of a video signal from a television camera having a normal scanning speed. However, in this case, the output terminals (61), (62), (
The signals obtained from each of the TV cameras (1)
The high-speed video signal from every third field, that is, the signal obtained at the output terminal (61), for example, is the first field video signal followed by, for example, the fourth field signal, and then the 7 soil toro, In terms of the field order of the 1U1 speed hidden signal, it is intermittent, such as the 10th field.

In this way, the system shown in Figure 1 shows that, according to the traces, the television signal captured by a television camera with a scanning speed of +[1i speed and obtained by minutes in parallel.

I wanted “ζ, this parallel signal for each channel is
It becomes possible to process signals in the same way as when handling normal speed signals.

For example, the signals of these three channels are the following special V and TR (see Japanese Patent Application No. 58-49761! j6)
For example, the SMP T'E is recorded to form a pattern in the Eve C formant, and this format can be played back on a recording tape using a normal V].
By scrolling through the reproduction in R, you can view the 1-speed phenomenon as a reproduced image in a so-called slow motion mode.

Fig. 2 shows an example of a special VTR rotating head device, in which the number equal to the number of channels, that is, in the case of the above example, three rotating heads H1, R2 and R3 are arranged at equal angular intervals.
That is, in this example, they are attached at 120° angular intervals,
- The tape (8) is wound obliquely in the shape of Ω over a predetermined angle, for example, 344°, on the same track on the guide drum (7), and these three heads H1, R2, and R3 sequentially transmit video signals of three parallel channels. It is possible to record it.

In this example, the VTR with this rotary head device is S
Since it is designed to record an MPTE type C'/A-mantle, the rotational speed of the rotary head is at a rate of one revolution per film i of a standard television signal, and is similar to the normal S M P T The same holds true for VTRs recording in the iE type C format, but the tape speed is tripled in this case.

And each time the tape speed is tripled, SMPTE
The angle of inclination of the trunk with respect to the longitudinal direction of the tape is different from that of the Type C format.

If you do this, wrap the tape (8) diagonally around the drum (7).
By adjusting the angle when lifting (so-called still angle), it can be made to match that of sMpr++ Quip C Formats 1-.

If you do this, the head +-11 as shown in Figure 3.
Yo-J-C every third (7) I-rack'r11, T
12, T , .
'r22, T23... are formed, and the remaining every three tracks T31, T32, 'r33 are formed by the head H3.
... is formed.

In this case, since the tape speed is 3x the tape speed, the tape is SMPT[!] from when head H+ starts scanning until head H2 starts scanning. Each time the type C format is shifted by one track. In other words, even if there is a pinch in the recording track, SMPT[! It is identical to that of the Type C format and completely matches the SMPTE Type C format.

With such a VTR, output terminals (6D), (62D)
), (63), the FM modulation signal of the video signal obtained at the terminal (Er1) is sent to the head H1, and the FM modulation signal of the video signal obtained at the terminal (62) is FM modulated. The video signal obtained by the head H2 at the terminal (63) is an FM variable NI!
If No. 848 is respectively recorded by the head H3, the video signals for each one minute of each field will be sequentially transmitted to the trunks T1'1- and T211"I"3.
1, TI2\”I'22\T32° °゛.

In this case, when the signals obtained at the output terminals (6U), (62), and (63) are recorded on the VTR, they are shifted by the head angle interval, that is, by 4 periods of 1 field period FS. It will be done like this.

As mentioned above, the tape recorded in this way is
If repopulated by a conventional VTR (using one rotating head) capable of playing back tapes recorded in PTE type C format, the rotating head will move to track T 1'11.
Since scanning is performed sequentially as T 2s + T 31..., the first channel, second channel, and third channel are sequentially converted into lids for each field. This means that the high speed phenomenon can be visually captured as an image in the same manner as in the case of slow motion with respect to the current supply speed.

By the way, at a broadcasting station, it is convenient to use the i-speed video signal generator as one of the multiple television cameras that can be commonly controlled along with the current-speed television camera. In this case, it would be desirable to be able to use this + [li speed system in the same way as a normal television camera.
It is conceivable that one channel of the three parallel channels of video signals obtained in steps 61) to (63) is used as a video output as a television camera at IW speed. In this case, the television camera tl) is scanning at 3 times the speed, so the sensitivity drops to 1/3.

In order to avoid this drawback, the scanning speed of the television camera (1) is switched to N times faster curved speed scanning speed and energized scanning speed so that the sensitivity does not drop when used as a normal scanning speed camera. It is possible that However, switching the scanning speed in this manner has the disadvantage that the television camera must be provided with two systems of timing generators, deflection, and video circuits for the two scanning speeds.

Purpose of the Invention In view of the above-mentioned points, the present invention provides a method for obtaining a single channel signal at a normal scanning speed without changing the scanning speed of a high-speed scanning television camera and without causing a decrease in sensitivity. The purpose is to

SUMMARY OF THE INVENTION The present invention provides a device for obtaining N-channel video signals at a current-carrying speed from a high-speed television camera that has a scanning speed of N times higher than an IV speed as described above; A switching function is provided, and when in the f! review speed mode, the television camera with the scanning speed of N times scans only one field every N fields, and by scanning this one field, the jM high-speed video signal is ”2 writing/A conversion circuit, memory, and A/1
] This is a video signal generator that is converted to normal speed by a conversion circuit and taken out as a specific one-channel output of N channels parallel output, and the scanning speed is not changed and N fields are converted to normal speed. Since it is a field or scanning device, the sensitivity is improved by N times.

Embodiment Now, one embodiment of the present invention will be described with reference to FIG. 6, taking the case of N-3 as an example as described above.

In FIG. 6, (1) shows a television camera, which includes an image pickup tube (IA) with a scanning speed N times that of a normal one, and a video circuit (18) for processing the image output from this image pickup tube (18). I
B). The beam scanning speed of the image pickup tube (IA) remains the same at N times the speed, but the beam scanning period is switched between when capturing a high-speed phenomenon and when using the camera as a normal television camera.

(21) is a beam control circuit for this purpose, and the beam scanning speed and beam scanning period in the image pickup tube (IA) are controlled by the timing signal from the timing signal generation circuit Vj/I (22). A timing signal generation circuit (22) is supplied with a control signal for setting horizontal and vertical scanning timing from a horizontal and vertical scanning timing control circuit (23), so that beam scanning is performed at a high speed of N times. be done. Also, this timing signal generation circuit (
22) High speed mode/through speed mode switching control 11
A switching control signal is supplied from cycle II'8 (24), so that in high-speed mode, ζ beam scanning is performed during all field scanning periods, and in energization speed mode, ζ beam scanning is performed every 3 fields at high speed. 1 field &J beam scanning is performed. That is, for example, in FIG. 5, for every one field period FS at the normal speed, beam scanning is performed during the first high speed one field period F1, and during periods F2 and F
In step 3, beam scanning is paused.

Therefore, ζ, when in high speed mode, do the same as above,
Period Fs, F2. During the period C of F3, a high-speed video signal for one field is obtained from the video circuit (IB), and this is passed through the low-pass filter (2) and the A/D conversion circuit (
3) is supplied to the speed converting circuit (4), where the speed is converted, and three channels of normal speed video signals are output in parallel to the output terminals (61), (62, and 63), and each field is obtained. It will be done.

Then, when using "C1 normal speed mode", the video circuit (IB
), one field of high-speed video signal is obtained only in one field period F1 of one speed of each period FS. Then, ζ, this is low)
It is supplied to the speed conversion circuit (4) through the D conversion circuit (3). In this speed conversion circuit (4), G) and period F1
The signal is converted to normal speed and output as a first channel signal. Therefore, the D/A conversion circuit (51
), a normal speed video signal is taken out to the output terminal (61). At this time, during the periods F2 and F3, since there is no imaging output signal power, no output signal G is obtained at the other output terminals (62) and (63).

In addition, when beam scanning is performed only in one field period F2 of the three high-speed fields FS, only at the output terminal (62), and only at Ll)- in one field period F3. When the beam is scanned, output terminal (63)? Only this way, you can get normal speed video output.

In this case, beam scanning is performed only in one field period out of the N field periods of N-times high-speed scanning, so the accumulation time of the optical image is N = 1 field period, and the 'Ch Since the conversion output time is one field period, the sensitivity is increased by l-1 compared to the sensitivity of the imaging section of a normal television camera.

This is because the accumulation time of the optical image, that is, the accumulated charge, is the same as in the case of a normal television camera, but the time t for ejecting this charge Q by beam scanning becomes blue, so the current i = dQ/dt. From the relationship, the current i increases and the sensitivity increases by -l-.

As described above, it is possible to maintain the scanning speed of a television camera at a high speed, without lowering the sensitivity of the imaging section, and even improving the sensitivity, so that it can operate like a normal television camera. A normal speed video signal output for one channel can be obtained. In other words, it is not necessary to provide two systems of timing signal generators, deflection devices, etc. unlike when switching the scanning speed, so the apparatus becomes simpler. Furthermore, the sensitivity of the imaging section is also significantly improved compared to that of a conventional television camera because the beam scan is made to last every N fields.

[Brief explanation of drawings]

Fig. 1 is a system diagram of an example of a high-speed video signal generating device, Figs. 2 and 3 are diagrams for explaining an example of a VTR that records signals obtained by this device, and Fig. 4 is a diagram of this device. FIG. 5 is a diagram for explaining FIG. 4, and FIG. 6 is a system diagram of an example of the apparatus of the present invention. (11 is a high-scanning TV camera, (3) is an A/D
A conversion circuit (4) is a speed conversion circuit having a memory, (5
1) to (53) are D/A conversion circuits, (llr) (112
) (113) is a field memory, (21) is a beam control circuit, (22) is a timing signal generation circuit, (24)
) is a high speed mode/full speed mode switching control circuit. Figure 4 Figure 5

Claims (1)

[Claims] A television camera whose scanning speed is N times the standard scanning speed (N is an integer of 2 or more), an A/D conversion circuit that A/D converts the video signal from this television camera at a high sampling rate, and this A/D conversion circuit. a memory for converting the speed of the output digital signal of the D conversion circuit;
The output digital signal of the A/D conversion circuit is written to the memory at the high sampling rate, and the sampling rate is not changed when reading from the memory. In an apparatus having a high-speed mode in which a digital video signal is obtained from this memory in N channels in parallel, and each channel is configured to obtain a digital video signal in field units, the above-mentioned high-speed mode and normal speed mode are switched. Features provided above! In the seat speed mode, scanning is performed every N fields in the television camera whose scanning speed is N times faster, and the high-speed video signal obtained by scanning this one field is stored in the memory on the D/A conversion circuit. A video signal generating device in which the video signal is converted to a normal speed by an A/D conversion circuit and outputted as the output of one specific channel of N channels of parallel output.