JPH057818Y2 - - Google Patents

Description

[Detailed explanation of the invention] Industrial field of application This invention can be used, for example, when recording something taken with a TV camera on a VTR, the seam between one cut and the next can be viewed on the playback monitor screen. The present invention relates to a video signal recording system suitable for use when special effects such as changes in screen development when viewed are required.

BACKGROUND TECHNOLOGY AND THEIR PROBLEMS When recording images taken with a TV camera on a VTR, popular TV cameras and
When using a VTR, the only conventional methods used to create the seam between one cut and the next are a splicing method to prevent the image from being distorted at the seam, or a screen expansion using a fader.

However, with professional TV camera equipment,
Techniques such as wiping are used in which an editing machine is used to connect one cut to the next in various patterns. However, in the case of this professional equipment, the multiple signals to be spliced are so-called genlocked to the external synchronization signal, and the phase of the synchronization signal and burst signal is managed, and it is necessary to manage the phase of the synchronization signal and burst signal. However, it is difficult to apply this to popular television cameras and VTRs.

Therefore, when editing with a popular camera or VTR to create a special effect, seams are sometimes processed to create the special effect when dubbing from the master tape to the slave tape. However, since it was based on dubbing, there was an undeniable drawback that the image quality deteriorated.

Purpose of the invention In view of the above points, this invention is simple, yet
The present invention aims to provide a device that allows special effects to be obtained without performing tabbing or the like.

Summary of the invention This invention is designed to switch between a video signal and signals that do not need to have a synchronous relationship with the video signal, such as a monochromatic signal or a character signal, in synchronization with a horizontal synchronization signal and a vertical synchronization signal. The switching period is gradually changed from a predetermined point so that the image based on the video signal gradually becomes smaller or larger on the monitor screen, and the remaining part of the image that is not the image based on the video signal can be displayed in a single color or with text. in,
Special effects in the mesh can be easily obtained.

Embodiment FIG. 1 shows an example of this inventive device, and is an example in which what is photographed with a television camera is recorded on a VTR.

That is, in the figure, 10 is a television camera, 20
is a VTR. In this case, the control signal CS obtained in response to the operation of a start/stop switch (not shown) provided on the television camera 10 causes the VTR 20 to start recording, pause or stop in synchronization with the start and stop of recording by the television camera 10. is now under control.

In this example, the color video signal SV (FIG. 2A) obtained by imaging with the television camera 10 is transmitted to the VTR 2 through one input terminal of the switch circuit 31.
0. Further, in this example, the color subcarrier frequency signal SC from the television camera 10 is supplied to the phase shift circuit 32 and extracted as a blue phase signal, for example, which is supplied to the other input terminal of the switch circuit 31. ing.

Furthermore, a horizontal synchronization signal from the television camera 10
HD (FIG. 2B) is supplied to the sawtooth wave generation circuit 33. In this sawtooth wave generation circuit 33, a rectangular wave signal MM (FIG. 2C) with a duty ratio of approximately 50% is formed from the horizontal synchronizing signal, and this signal
A sawtooth signal HSA (FIG. 2D) is formed from the MM. This sawtooth signal HSA is then supplied to one input terminal of the level comparison circuit 35.
On the other hand, a wipe signal WIPE (see FIG. 2D), which will be described later and is obtained in conjunction with the operation of the start/stop switch of the television camera 10, is supplied to the other input terminal of this comparison circuit 35, and the levels of the two are compared. Ru. Then, during a period in which the signal HSA is at a higher level than the signal WIPE, a signal HSW (FIG. 2E) which is at a higher level is obtained from this comparison circuit 35.

When the start/stop switch is pressed to stop the start/stop switch as shown in FIG. This is a signal that gradually rises from 0V at a constant slope from when the button is pressed to turn on the stop, and returns to 0V again when the VTR enters the pause (or stop) state. When you press the switch to turn on the start, the VTR 20 will also start recording, but from the start on, the voltage will immediately rise to a certain level, and a predetermined period of time, e.g. 1 to 2 seconds, will elapse from that constant voltage. This is a signal whose level gradually decreases at a constant slope until

Therefore, when the start/stop switch is pressed to turn on the stop, the signal HSW becomes a signal whose high level period gradually narrows as shown in FIG. 2E. In other words, the signal HSA is a signal with a horizontal period, and the peak value of the sawtooth wave is approximately at the center of the horizontal scanning period, so the signal
The high level period of HSW becomes a signal that gradually narrows toward the center of the horizontal scanning period.
Of course, during the period before and after pressing the start/stop switch, the signal WIPE is always at 0V, so the output HSW of the comparator circuit 35 is always at a high level.

When the start/stop switch is pressed again to turn on the start, the level of the signal WIPE is gradually lowered, so the width of the period in which the output of the comparator circuit 35 gradually becomes high level increases from the center of the horizontal scanning period to both sides thereof. The signal becomes wider towards the other direction. Then, after a predetermined period of time, the signal WIPE goes to 0V.
When this happens, the signal HSW is always at a high level again.

Similarly, the vertical synchronization signal VD from the television camera 10 is supplied to the sawtooth wave forming circuit 34, which forms a sawtooth wave signal VSA with a vertical period similar to the sawtooth wave formed based on the horizontal synchronization signal. One input terminal of the comparison circuit 36 is supplied, and a wipe signal WIPE is supplied to the other input terminal of the comparison circuit 36. Therefore, from this comparator circuit 36, the period in which it is at a high level in the vertical period is the period from when the start/stop switch is pressed to turn on the stop until the camera and VTR are completely stopped, and the period in which the level is gradually increased to a high level. A signal is obtained in which the signal becomes narrower towards the center of the vertical scanning period, while when the start/stop switch is pressed to turn on the start, the high level period gradually becomes wider from the center of the vertical scanning period. It becomes a signal.

The signals HSW and VSW thus obtained are supplied to the AND gate 37. Therefore, the period in which the AND gate 37 is at a high level for a predetermined period from when the stop is turned on becomes narrower toward the center of the horizontal and vertical scanning periods.
During a predetermined period from when the signal is turned on, the signal gradually becomes wider from the center of the horizontal and vertical scanning periods.

The output of this AND gate 37 is the OR gate 38
The signal is supplied to the switch circuit 31 through the switch circuit 31. Also, a blanking signal BLK from the television camera 10 is supplied to the switch circuit 31 through this OR gate 38. This blanking signal BLK is a signal that is at a high level only during the horizontal blanking period and the vertical blanking period.

The switch circuit 31 is switched to the state shown in the figure when the switching signal supplied thereto from the OR gate 38 is at a high level, and is switched to the state opposite to the state shown when it is at a low level.

Therefore, when the start/stop switch is not operated and the VTR 20 and camera 10 are operating, the signals HSW and VSW are always at a high level, as described above, so the switch circuit 31 is always at the high level as shown in the figure. state, and the color video signal SV that is the camera output is
It is supplied to the VTR 20 and recorded by a rotating head.

Then, when the start/stop switch is pressed to turn the stop switch on from this state, the signal WIPE gradually rises to a high level from that point until the television camera 10 and VTR 20 come to a complete stop, so that the high level period of the signals HSW and VSW increases. The period during which the switch circuit 31 selects the color video signal SV gradually becomes narrower, and the period during which the switch circuit 31 selects the color subcarrier frequency signal indicating the blue phase from the phase shift circuit 32 becomes gradually shorter. It gradually becomes longer, and the composite signal is sent to the VTR.
20. Actually a blanking signal
The horizontal blanking period and the vertical blanking period are switched to the state shown in the figure by BLK, and the horizontal synchronizing signal and vertical synchronizing signal are recorded on the VTR 20.

When the signals recorded in this way are played back on the screen, as shown in Figure 4 A, B, and C from the time the stop-on is turned on, the image based on the camera's imaging signal will initially appear on the entire screen, and gradually the image based on the imaging signal will appear. becomes smaller toward the center of the screen, and the monochromatic blue area around it becomes larger.

Then press the start/stop switch again and
When the start is turned on, the signal WIPE becomes a signal that gradually decreases from a high level, and the signal
HSW and VSW also become signals whose high level periods gradually become wider, and the switch circuit 31 is switched accordingly, so that the color subcarrier of the blue phase from the color video signal SV and the phase shift circuit 32 A synthesized signal whose synthesis ratio with the frequency signal is changed according to the length of the high level period is obtained from the switch circuit 31 for a predetermined period, and this
It is recorded on the VTR20. After that, signal HSW and
Since VSW is always at a high level as the signal WIPE goes to 0 level, only the color video signal SV is obtained from the camera 10 from the switch circuit 31, and this is recorded on the VTR 20.

Therefore, if the playback signal at the start is played back on the monitor screen, the image based on the signal taken by the camera 10 will initially be very small in the center of the screen, as shown in FIGS. 5A, B, and C. appears, and gradually spreads across the screen, and the blue background around the image gradually disappears.

In the above example, a color subcarrier frequency signal with a predetermined phase is used as a signal that has no synchronization relationship with the video signal to be switched, but this signal can be used instead, for example, as a signal with a predetermined phase. It is also possible to easily switch the character signals etc. from the radiator generator using the switch circuit 31 and display them on the top, bottom, left, right or any appropriate location of the screen.

Effects of the invention As described above, according to this invention, a signal that does not need to be synchronized with a video signal is synthesized using a switching pulse formed based on a horizontal synchronization signal and a vertical synchronization signal. Moreover, by gradually changing the compositing ratio, the image generated by the video signal gradually becomes smaller or larger on the screen, and it is easy to create special effects such as a single color or text as the background. can be obtained.

In the case of this invention, there is no need for a synchronization relationship between the video signal and the signal that switches it, so if the device of this invention is attached to popular cameras and VTRs, especially the device of this invention can be attached to cameras. In this way, the photographer can easily obtain the above-mentioned special effects at the seam between one cut and the next.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of one embodiment of this devised device, Figs. 2 and 3 are waveform diagrams for explanation, and Fig. 4
5 and 5 are diagrams for explaining the effects of this invented device. 10 is a television camera, 20 is a VTR, 31 is a switch circuit, and 35 and 36 are comparison circuits for forming a switching pulse whose pulse width is gradually changed from a predetermined point on the basis of a horizontal synchronizing signal and a vertical synchronizing signal.

Claims (1)

[Claims for Utility Model Registration] A television camera, a signal generation circuit that generates a single-phase color signal, and a synchronization signal separation circuit that separates a horizontal synchronization signal and a vertical synchronization signal from the output video signal of the television camera. , a switching pulse forming circuit that forms switching pulses based on the horizontal synchronizing signal and vertical synchronizing signal from the synchronizing signal separation circuit; and a video signal into which the output signal of the television camera or the output signal of the signal generation circuit is input. It has a recording device and a start/stop switch for controlling start or stop of the video signal recording device, and outputs a composite color video signal by switching between the signal from the signal generation circuit and the input video signal using the switching pulse. In the video signal recording system, the pulse width of the switching pulse is gradually changed from the time when the start/stop switch is pressed, so that the combination ratio of the two signals is changed.