JPS6347029B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a film recording device for producing a movie film by recording an image signal such as a television video signal on a 16 mm color film or the like.
This is designed to improve the image quality when recording using a laser beam.

Conventionally, when recording using a laser beam in this type of film recording device, a 16mm camera similar to that used in so-called kinescope recording was used, but the image projected on a cathode ray tube was projected onto the film. Compared to kinescope recording,
In laser recording, image quality such as definition has been greatly improved due to the significant difference in spot diameter between the laser beam and the electron beam. Because it does not have an afterglow like the body,
It has become clear that defects in photographic cameras, such as film shake, which were not a problem with conventional kinescope recording, considerably impair the image quality of laser recording.

In conventional kinescope recording, when recording an image projected on a cathode ray tube onto film, the shutter of the camera is opened for one frame while the film remains stationary, and the image signal for one frame is recorded. I try to record on one frame of film. For example, a television video signal has a frame rate of 30 frames per second, compared to 24 frames per second for a movie film, so the period during which the film should stand still during film scraping is approximately 2 1/2 field periods. Usually, the timing of every other film scraping is made to coincide with the timing of the vertical synchronization signal of the television video signal to be recorded. Therefore, the above-mentioned recording of one frame is alternately started almost at the same time as the film is scraped off, or started after 1/2 field period has elapsed since the film is scraped off. However, if you start recording almost at the same time as the film is scraped off, recording will start immediately after the film is scraped off and the film has not yet come to a complete standstill, so naturally there will be slight image blurring. However, in conventional kinescope recording, as mentioned above, the spot diameter of the electron beam is relatively large, and the phosphor has an afterglow property, so the jitter of the film is reduced. Since the image blur due to this was smoothed out, the recorded image quality did not deteriorate much.

On the other hand, in laser recording, as mentioned above, the intensity of a small diameter laser beam spot that does not have afterglow is increased, and each pixel is instantaneously recorded on a film with extremely low sensitivity but high resolution. Therefore, while it is possible to record extremely high image quality with excellent definition, the image blur due to the above-mentioned film jitter is also reproduced extremely faithfully.
This will significantly degrade the long-awaited high image quality, and will seriously reduce the overall image quality.

The manner in which image blur occurs due to film jitter is explained in detail with reference to the timing chart of each part of the kinescope recording device shown in FIG.
Timing waveform TAG in the figure shows the timing of the film scraping pulse of a camera for shooting motion picture film at 24 frames per second, and timing waveform 11 shows the timing of the vertical synchronization signal in a television video signal of 30 frames per second and 60 fields, that is, each frame. It shows the timing. However,
A fast-pull-down camera is used, in which the film scraping is completed within the vertical blanking period of the television video signal, and recording of one frame can be started almost simultaneously with the film scraping. When recording, the recording timing is as shown in timing waveform 10. Recording for one frame is started immediately after the film is scraped, and the recording timing is as shown in timing waveform 10.
Frame A is used for recording F2), (F6, F7), etc., and recording for one frame is started after 1/2 field period has passed after the end of film scraping, and two field periods each (F4, F5) are recorded. ) (F9, F10), etc. Two types of frame recording are performed alternately with the B frame recording.

However, since the above-mentioned B frame starts recording after 1/2 field period has elapsed after the film is scraped off and the film is sufficiently stable, the above-mentioned image cannot be produced even with laser recording. There is no risk of image quality deterioration due to blurring, but since the A-frame described above starts recording immediately after the film is scraped off, the film is not yet stable enough and is vibrating slightly. When recording, the scanning lines formed by the laser spots become unevenly arranged, resulting in uneven brightness in the recorded image, which significantly impairs the image quality.

In addition, in a type of conventional film recording device that uses a so-called Paloma camera, it takes about 4 milliseconds to scrape off the camera's film, so vertical blanking of the image signal is performed as in the case described above. Since the film scraping is not completed within the period, recording for one frame is started after 1/2 field period has elapsed from the film scraping for each frame, as shown in timing waveform 9 in FIG. Start recording from the center of the screen and press 2 each
Field period (1/2F1, F2, 1/2F3), (1/2F6,
Frame A' records F7, 1/2F8), ..., and starts recording from the beginning of the screen to record each complete 2-field period (F4, F5), (F9, F10), ...
Two types of frame recording are performed alternately with B' frame,
Even in this type of film recording, the A' frame is
Since a discontinuous portion of brightness, which is a so-called shutter bar, occurs in the center of the screen, the recorded image quality deteriorates as described above, and this method cannot be particularly applied to laser recording.

Note that image blur due to film jitter in the conventional kinescope recording described above did not pose much of a problem, partly because the resolution and graininess of the film used were relatively low, but in laser recording, As described above, the occurrence of image blur due to film jitter has become a significant drawback since other conditions can significantly improve the recorded image quality.

An object of the present invention is to eliminate the above-mentioned drawbacks of the conventional technology, and to record one complete frame of each frame with the film stationary after a certain period of time has elapsed since the film is scraped off. To provide a film recording device capable of obtaining good image quality without image blurring even when the image is blurred.

That is, the film recording apparatus of the present invention can record television images at 30 frames per second, for example, at 24 frames per second.
When recording frames on movie film, each frame is recorded using the same timing adjustment as when the 6-frame period, which corresponds to the difference between the number of frames per second and the number of frames per second, is evenly distributed over the period of each film scraping pulse interval. For each film scraping pulse interval, one complete frame is recorded with a delay of approximately 1/2 field period from the film scraping pulse, and the input image signal is delayed by the time τ. an image delay means for forming a delayed image signal; a camera driving means for forming a film scraping timing pulse synchronized with an input vertical drive signal synchronized with a vertical synchronization signal of the input image signal; an image switching means for switching between the input vertical drive signal and a delayed vertical drive signal synchronized with a vertical synchronization signal of the delayed image signal; vertical deflection drive means for forming a vertical deflection drive signal for an image projection means for projecting an image formed by a switching output image signal of the image switching means onto a film under control by a drive signal; The driving switching means are operated in synchronization with each other, and the switching means is alternately delayed by the time τ and the time τ subtracted from one field period of the input image signal from the film scraping timing pulse, one frame period at a time. It is characterized in that the image projection means is activated.

The invention will be explained in detail below by way of example embodiments with reference to the drawings.

First, a timing chart similar to that shown in FIG. 1 for conventional kinescope recording is shown in FIG. 2 to explain the recording mode in the film recording apparatus of the present invention.

The timing waveform TAG in the timing chart shown in FIG. 2 shows the timing of film scraping exactly the same as in the timing chart shown in FIG. 1, and the vertical synchronization signal of the input image signal, Therefore, the film scraping timing pulse is generated at a timing that is synchronized with the vertical retrace period and in phase with the point C in FIG. 2. The timing waveforms 11 and 12 also indicate sequential frame periods of an input image signal, for example, an NTSC television video signal, and a predetermined period of time τ, for example, an NTSC television video signal.
It shows the timing of successive frame periods of a delayed image signal obtained by delaying the system television video signal by approximately 1/2 field period,
Delay time τ in timing waveforms 11 and 12
The same field symbols F1, F2, . Therefore, in the frame period F(1) of the timing waveform 12, an image signal having the same content as the frame period F1 of the timing waveform 11 appears with a delay of time τ. Note that the boundaries of each frame period correspond to the vertical synchronization signal or vertical blanking period in each image signal, and the sequential film scraping timing pulses in the timing waveform TAG correspond to the boundaries of the frame periods in timing waveforms 11 and 12. As shown in the figure, these events occur at alternately coincident timings every 2 1/2 frame periods. Therefore, the timing waveform
For each period of the sequential film scraping timing pulse interval shown in TAG, one frame of the input image signal shown in timing waveform 11, that is, an image signal for a complete two field period, and a delayed image signal shown in timing waveform 12 1 frame inside,
That is, by alternately recording the image signals of two complete field periods, for example, the timing waveform 13
As shown in , each two-field period [F(1), F
(2)], [F4, F5], [F(6), F(7)], [F9, F10],
…
If the image signals of are sequentially recorded for each period of the film scraping timing pulse interval,
To extremely easily and reliably achieve the object of the present invention, which is to record a complete image signal for one frame on each frame of a film while the film remains sufficiently stable after a certain period of time has elapsed since the film is scraped off. Therefore, film recording of good image quality without image blur can be performed by laser recording.

Next, FIG. 3 shows an example of the configuration of the essential parts of the film recording apparatus of the present invention, which is adapted to perform film recording in the manner described above. In the illustrated configuration, the input image signal 11 corresponds to the timing waveform 11 shown in FIG. A delayed image signal 12 corresponding to the illustrated timing waveform 12 is formed, and the input image signal 11 and delayed image signal 12 are supplied to the image signal converter 2.

On the other hand, an input vertical drive signal is generated by supplying the input image signal 11 to a synchronization regenerator (not shown) or the like and generating it in synchronization with the vertical synchronization signal of the input image signal 11.
VD is supplied to the camera drive circuit 4, and a film scraping timing pulse train TAG corresponding to the timing waveform TAG shown in FIG. 2 is generated at a timing coinciding with the input vertical drive signal VD. For example, a camera (not shown) loaded with a 16 mm color film is controlled to scrape off the film at the timing shown in the timing waveform TAG shown in the second diagram.

Furthermore, the above-mentioned delayed image signal 12 is supplied to a synchronization regenerator (not shown), or the input vertical drive signal VD is supplied to a delay line (not shown), so that the vertical synchronization signal of the delayed image signal 12 is A delayed vertical drive signal (VD) generated in a manner that is synchronized and delayed by a predetermined time τ from the input vertical drive signal VD and the above-mentioned input vertical drive signal VD are supplied to the vertical drive switch 3. and input vertical drive signal VD
and film scraping timing pulse train
Supply TAG to film scraping timing pulse, input image signal 11 and delayed image signal 12
The image signal switch 2 and the vertical drive switch 3 are operated under the control of a timing detection circuit 5 which detects the timing at which the vertical synchronization signals of
The switching operations are performed in synchronization with the switching devices 2 and 3, so that both switching devices 2 and 3 are switched every period of the film scraping timing pulse interval.
Therefore, the switching output vertical drive signal of the vertical drive switch 3 is supplied to the sawtooth wave generation circuit 6 to control the generation timing of the sawtooth waveform signal generated for deflecting a laser beam for recording, for example, to generate a vertical deflection drive waveform. When the signal 14 is formed, the timing waveform is as shown in the timing chart of FIG.
During the pulse interval period following the film scraping timing pulse shown at each point C in TAG, the vertical drive switch 3 is switched to output a delayed vertical drive signal (VD), and the timing waveform TAG is During the pulse interval period following the film scraping timing pulse shown at each point D, the vertical drive switch 3 changes the input vertical drive signal.
Since the switching is made to output VD, the vertical deflection drive waveform signal from the sawtooth wave generation circuit 6 becomes a delayed and non-delayed sawtooth waveform alternately with a 2 1/2 field period, as shown in the timing waveform 14. . On the other hand, the image signal switch 2, which switches in synchronization with the switching operation of the vertical drive switch 3, generates a timing waveform as shown in a timing waveform 13.
During the pulse interval period following point C, where the timing of the film scraping timing pulse during TAG and the input vertical drive signal VD coincide, the delayed image signal 12 is delayed by 1/2 field period from the film scraping timing pulse. The image signals of complete two field periods [F(1), F(2)], [F(6), F(7)], ... are output, and the timing waveform TAG
During the pulse interval period following point D, where the input vertical drive signal VD is delayed by 1/2 field period with respect to the film scraping timing pulse in the middle, the input vertical drive signal VD is delayed by 1/2 field period from the film scraping timing pulse. Complete two field periods of the input image signal 11 [F4, F5], [F9, F10],
The image signals of... are outputted to form a recording signal 13 used for intensity modulation of a recording laser beam, for example.

Therefore, the switching output image signal of the image signal switching device 2, that is, the recording signal 13, is the same as the input image signal 11, as shown in the timing waveform 13 of FIG.
and the delayed image signal 12 appear alternately every 2.5 field periods, and the vertical deflection drive waveform signal 14 from the sawtooth wave generation circuit 6 is as follows.
As shown in timing waveform 14 of FIG.
The waveform for 1/2 field is interpolated into the complete deflection waveform for the field.

The recording signal 13 and vertical deflection drive waveform signal 14 formed as described above have half-field information interpolated every two field periods, so they can be directly transmitted to an image display device such as a cathode ray tube. Although it cannot be displayed, when recording on film, as shown in timing waveform 15 in Figure 2, a period of 1/120 seconds, or 8.3 milliseconds, corresponds to the odd information of the 1/2 field period. If you use the camera's electronic shutter to block the incident light from the film and at the same time scrape off the film within that period, you can scrape off the film with sufficient margin, and the film remains stable enough. In this state, a complete one frame image of two complete field periods is recorded, and high-quality recording without image blur or brightness unevenness can be achieved even by laser recording.

As is clear from the above description, according to the present invention, when an image signal such as an NTSC television video signal is recorded on a movie film, after approximately 1/2 field period has elapsed after the film is scraped off, Since recording starts one frame at a time with the film in a sufficiently stable and stationary state, there is no risk of being affected by film jitter that occurs immediately after the film is scraped off. Even though recording is performed one frame at a time after the 1/2 field period has elapsed, recording is always started from the beginning of the screen, so there is no possibility that a so-called shutter bar will appear within the frame.

Furthermore, since 1/2 field period, for example, 8.3 milliseconds, is allocated as the film scraping time, the expensive fast-pull-down method used in conventional photography is required to complete film scraping within the vertical blanking period. There is no need to use a camera, and it is possible to make high-quality recordings without shutter bars being mixed in. In particular, since fast-pull-down cameras are not in practical use for 35mm film cameras, high-quality recordings can be made with 35mm film. The film recording apparatus of the present invention is essential for recording.

Further, the film recording device of the present invention includes, for example,
When converting 30 frames per second of an NTSC television video signal to 24 frames per second of motion picture film and recording, the non-recording time corresponding to the difference in the number of frames per second of 6 frames is equivalent to 24 frames of film. The delay time τ of the input image signal, which corresponds to the equally allocated film scraping time, is 1/1/2 of the horizontal scanning period H in the NTSC television video signal. 2 fields = 131.25H = 8.3ms. If the delay time τ of this value is 131.0H, which is approximated to 131.25H mentioned above, the time allocated to scraping the film is
Although 131.0H and 131.5H are alternately unbalanced, the continuity of horizontal synchronization in the switching output image signal 13 is maintained, so there is no possibility of an adverse effect on the horizontal deflection circuit or the like. Also, this delay time τ
If is set to an even multiple of the horizontal scanning period H, which approximates the 1/2 field period, that is, 2nH, where n is an integer, for example, 130H, 132H, etc., not only the continuity of the horizontal synchronization described above is maintained, but also , the continuity of the phase of the color subcarrier in the switching output image signal 13, that is, the recording signal is also maintained, and a special effect can be obtained in that the carrier color signal of the color image signal performed during recording can be easily decoded.

[Brief explanation of the drawing]

FIG. 1 is a timing chart showing the recording mode in a conventional film recording device, FIG. 2 is a timing chart showing an example of the recording mode in the film recording device of the present invention, and FIG. 3 is a timing chart showing an example of the recording mode in the film recording device of the present invention. FIG. 3 is a block diagram showing an example. 1... Delay line, 2... Image signal switch, 3...
Vertical drive switch, 4...Camera drive circuit, 5...
Timing detection circuit, 6...Sawtooth wave generation circuit, 11...Input image signal, 12...Delayed image signal, 13...Switching output image signal, 14...Vertical deflection drive waveform signal, TAG...Film scraping timing Pulse, VD...input vertical drive signal,
(VD)...Delayed vertical drive signal.

Claims (1)

[Scope of Claims] 1. An image delay means for forming a delayed image signal by delaying an input image signal by a time τ, and a film scratching unit whose timing is aligned with an input vertical drive signal synchronized with a vertical synchronization signal of the input image signal. camera driving means for forming a drop timing pulse; image switching means for switching between the input image signal and the delayed image signal; and a delayed vertical drive signal synchronized with a vertical synchronization signal of the input vertical drive signal and the delayed image signal. and a vertical deflection drive signal of an image projection means that is controlled by a switching output vertical drive signal of the vertical drive switching means to project an image formed by the switching output image signal of the image switching means onto the film. the image switching means and the vertical drive switching means are operated in synchronization with each other, and from the time τ and from one field period of the input image signal by the film scraping timing pulse. Alternately delayed by the time τ subtracted by 1
A film recording apparatus characterized in that the image projection means is operated for each frame period. 2. The film recording apparatus according to claim 1, wherein the input image signal is an NTSC television video signal, and the time τ is approximately equal to 1/2 of the field period. Recording device. 3. In the film recording apparatus according to claim 2, the time τ is an even multiple of the horizontal scanning period, so that the horizontal synchronization and color subcarrier phase between successive frames in the switching output image signal are continuous. A film recording device characterized by: