JPH0134459Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a film recording device that uses a laser beam to convert time-series television video signals into two-dimensional film images. , an attempt is made to produce motion picture film with less image blur by combining a continuously running film camera and a video signal storage device that can read out video signals at arbitrary timing.

Conventionally, one example of a method for recording television video signals on film is to display the television signal on a picture tube.
A method called kinescope recording is used in which the image displayed on the picture tube is re-captured with a special film camera. In this method, the film travel of the film camera is intermittent,
The film is kept stationary during exposure, and a shutter is used to block light while the film is moving. The movement of the film of a film camera used in kinescope recording is completed within the vertical retrace period of the television signal, but because intermittent high-speed movement and rapid stopping are required, the film There are problems with the accuracy and stability of the stopping position, which has a major effect on the blurring of recorded images, so improvements are desired. Especially when trying to apply film recording to movie production,
The biggest challenge was to improve the precision and stability of film feeding. One of these problems arises from the need for the film to stop moving rapidly, so as a countermeasure, it is possible to continuously run the film with a number of frames equal to the number of fields or frames of the video signal. There is a method of sequentially recording one field or one frame of a television signal for each frame in sequence. In this case, the vertical direction of the recorded image is due to the movement of the film, while the horizontal direction is scanned having the content of a television signal and having the cycle and timing of horizontal scanning of the television signal. By running the film continuously, accuracy and stability can be much improved compared to intermittent motion.
The vertical positional accuracy of the recorded image depends entirely on the accuracy and stability of mechanical film running, and is insufficient for image recording with higher positional accuracy.

Therefore, in view of the above points, the purpose of this invention is to
The object of the present invention is to provide a laser recording device that achieves high precision and stability in film feeding.

To this end, the present invention provides a continuous film running section with an average number of running frames equal to the number of fields or frames of the video signal, a variable delay device that provides an arbitrary delay time to the video signal, and an output video signal of the variable delay device. a recording signal section having an optical modulator that modulates a laser beam and an optical deflector that deflects the laser beam modulated by the optical modulator in a direction substantially perpendicular to the film running direction in synchronization with the horizontal scanning of the video signal; a detection unit that detects perforation in the vicinity of the film position at which recording of the video signal should be started; and a timing difference by comparing the output of the detection unit and the field or frame synchronization timing of the video signal. a control section that forms a control signal according to the control section, and the control signal from the control section is applied to the recording signal section to control at least the delay time of the variable delay device. be.

In other words, as mentioned above, the present invention controls the recorded image position (on the film) using the film perforation position as a reference and controls it on the recording video signal side, so that even if there is jitter in the film travel, the correct position on the film can be maintained. This allows images to be recorded.

The present invention will be described below with reference to the drawings.

FIG. 1 is a diagram for explaining an example of the basic configuration of the present invention. In FIG. 1, a laser beam from a laser light source 1 is intensity-modulated by an optical modulator 2 according to the output signal of a memory 6 of a video signal 11, and is modulated in intensity by a sawtooth wave generator 9 in synchronization with a horizontal drive signal 12. The memory output of the created sawtooth wave is horizontally deflected by an optical deflector 3 and focused onto the film of a film camera 4. The film camera 4 is of a continuous running type, and is configured so that film is continuously supplied and wound in synchronization with a vertical drive signal VD associated with a video signal. The running direction of the film is perpendicular to the horizontal deflection direction, and since the film running functions as a vertical deflection, the film has a two-dimensional raster structure in combination with the horizontal deflection by the optical deflector 3. The image is recorded. The perforation detector 5 is for detecting the running state of the film in the film camera, especially its jitter, and the output signal of the perflation detector is applied to the phase comparator 8, where it is combined with the above-mentioned vertical drive signal. By comparing the phases of , a signal relating to the timing relationship between the video signal to be recorded and the perforation of the film at the mounting position of the detector 5 (therefore, the correct frame position to be recorded) is obtained. Therefore, the output signal of the phase comparator 8 is
This corresponds to the timing of the video signal to be recorded relative to the correct frame position of the film to be recorded. Therefore, based on this output signal, a timing pulse generator 10 generates a timing pulse 18 that controls the readout timing of the sawtooth wave memory 7 that drives the video signal memory and the horizontal deflector. This sawtooth wave memory 7 is a sawtooth wave generator 9
provides and stores a sawtooth generator output signal 14 from the timing pulse generator 10 described above.
Readout is controlled at the timing of timing pulse 15 from .

FIG. 2 shows the phase relationships among video signals, synchronization signals, timing pulses, etc. The video signal handled here is a progressive scanning signal, and for the sake of simplicity, the number of frames per second is assumed to be the same for television and film systems. In FIG. 2, 11 is an input video signal, and 12 is a horizontal drive signal. 1
As mentioned above, reference numeral 5 is a readout timing pulse of the memory 7 obtained by detecting perforation of the film camera, which indicates the phase at the reference position of perforation. Therefore, the timing pulse moves back and forth based on the phase of VD13. When the video signal memory 6 is read out at the timing of the timing pulse 15, the video signal 1
6 is applied to the optical modulator 2, and when the sawtooth wave memory 7 is read out at the same timing, the read out sawtooth wave 17 is applied to the optical deflector 3, and an image is recorded at the reference timing.

Next, when the film is fed quickly and the timing pulse 15 at the perforation reference position,
When the timing pulse 18 whose phase is advanced is generated, the optical modulator 2 and the optical deflector 3 are activated in response.
The waveforms added to are waveforms 19 and 20, and images are recorded at earlier timings. As a result, the positional relationship with the perflation is as follows: timing pulse 1 at the perflation reference position
The same image as that recorded using 5 is recorded. Similarly, when the film is fed slowly and a timing pulse such as timing pulse 21 lags timing pulse 15, waveforms with phases such as waveforms 22 and 23 are applied to the optical modulator 2 and the optical deflector 3, resulting in Images without displacement, that is, without image blur, are always recorded. The memory storage time for the video signal and sawtooth wave must be set somewhat longer than the P-P value of the film's jitter.

The above concept can be applied when using a fast-response optical deflector, such as an acousto-optic optical deflector, but it cannot be applied when using a slow-response optical deflector, such as a rotating polygon mirror with large inertia. It is difficult to

When using an optical deflector with a slow response, the horizontal deflector is always synchronized with the horizontal drive signal and driven at a constant timing and cycle, and the video signal to be applied to the optical modulator is supplied via a delay line. , a method is adopted in which the delay amount of the delay line is switched in units of one horizontal scanning time (1H) according to the amount of film running jitter.

FIG. 3 shows an embodiment of the invention according to this method. In FIG. 3, a laser light source 1, an optical modulator 2, an optical deflector 3, a film camera 4, a perforation detector 5, a phase comparator 8, a sawtooth wave generator 9, a timing pulse generator 10, a video signal 1
1, horizontal drive signal 12 and vertical drive signal 13
The operation is exactly the same as that described above, but here, a magnitude discriminator 25 for determining the error in the perforation position of the film and a delay line 24 for the video signal are newly added. The magnitude discriminator 25 discriminates how much the error in the perforation position is compared to the period H of the horizontal synchronizing signal, and generates a timing pulse for switching the delay amount of the delay line 24 in units of 1/2H. In other words, when the error is 0 to ±1/2H, the standard delay amount is given, and when the error is between ±1/2H and ±11/2H, it is 1H.
Increase or decrease the amount of delay by Furthermore, a delay amount is added as necessary. With this method, image blur can be compensated to less than ±1/2H and recorded. Furthermore, to improve the accuracy of image blur reduction,
An effective method is to record using multiple laser booms.

FIG. 4 shows still another example of the present invention in which two laser light sources and a light modulator are used to further improve image blurring. In FIG. 4, the operation is exactly the same as described above except for the newly added laser light source 26, optical modulator 27, and combining optical system 28. The laser light source 26 and the optical modulator 27 may also be considered to be completely equivalent to the laser light source 1 and the optical modulator 2. The synthetic optical system 28 is
When the two output laser beams of the optical modulators 2 and 27 are combined, and the raster of the video signal recorded on the film of the film camera is concerned, the rasters created by the two beams do not overlap, and are just 1/1
This is for adjusting the scanning so that it is shifted by a position in the vertical direction corresponding to 2H. The selection of one of these two scanning beams is controlled by a shutter signal that is applied to each optical modulator along with the video signal, and one is selected depending on the magnitude of the perforation position error signal. By recording, image blur can be suppressed to less than ±1/4H. According to this method, image blur can be further improved by increasing the number of scanning light beams used.

In this case, it is possible to use one laser light source and to divide the beam into a plurality of beams and apply them to the optical modulator.

Further, the modulated laser beam is placed between the optical modulator 2 and the optical deflector 3 at 1/n of the horizontal scanning time (n=2,
3,...) is provided, and this means is controlled by the output from the timing pulse generator 10.
Thereby, the laser light source 26, the optical modulator 27, and the combining optical system 28 may be omitted. In this case, image blur can be reduced to within ±1/2 nH with a simple configuration.

As is clear from the above, according to the present invention, raster recording of television can be performed on a film that is continuously running with a high precision that is difficult to obtain with intermittent running.

In the first embodiment of the present invention, since a fast-response optical deflector is used, film advance errors can be continuously corrected, and almost perfect image blur correction is possible.

In the second embodiment of the present invention, an optical deflector with a slow response is used, so there is a residual error due to delay line switching in units of 1H, but there is a possibility that sufficient accuracy can be obtained for practical use. There is.

The video signal handled in this invention is a progressive scanning signal that corresponds to the continuous running of the film, but the timing of image blur correction is determined at the start of recording, and this principle is similar to the interlaced scanning signal of an intermittent feed film camera. It can also be applied to recording.

In order to apply this invention to general television signals, it is necessary to convert the number of frames per second of the television and the number of frames per second of the film standard, but this can be processed as a format conversion in the signal memory. .

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a basic configuration example of the present invention, Fig. 2 is a signal waveform diagram for explaining the phase relationship of signals handled by the present invention, and Figs. FIG. 3 is a block diagram showing two examples of FIG. 1... Laser light source, 2... Optical modulator, 3...
Optical deflector, 4... film camera, 5... perforation detector, 6... video signal memory,
7...Sawtooth wave memory, 8...Phase comparator, 9
... Sawtooth wave generator, 10 ... Timing pulse generator, 11 ... Video signal, 12 ... Horizontal drive signal, 13 ... Vertical drive signal, 14 ... Sawtooth wave generator output signal, 15 ... timing pulse, 16
...Memory read waveform, 17...Horizontal deflection waveform, 18...Timing pulse, 19...Memory read waveform, 20...Horizontal deflection waveform, 21...
...Timing pulse, 22...Memory readout waveform, 23...Horizontal deflection waveform, 24...Video signal delay line, 25...Error signal magnitude discriminator, 26...
Laser light source, 27... optical modulator, 28... synthetic optical system.

Claims (1)

[Claims for Utility Model Registration] 1. A continuous film running section with an average number of running frames equal to the number of fields or frames of a video signal, a variable delay device that provides an arbitrary delay time to the video signal, and an output image of the variable delay device. a recording signal section having an optical modulator that modulates a laser beam with a signal; and an optical deflector that deflects the laser beam modulated by the optical modulator in a direction substantially perpendicular to the film running direction in synchronization with the horizontal scanning of the video signal; a detection unit that detects perforation in the vicinity of the film position at which recording of the video signal should be started; and a detection unit that compares the output of the detection unit with the field or frame synchronization timing of the video signal. and a control section that forms a control signal according to a timing difference, and the control signal from the control is applied to the recording signal section to control at least the delay time of the variable delay device. A laser recording device featuring: 2 Utility Model Registration The laser recording device according to claim 1, wherein the optical deflector performs a deflection operation in synchronization with the output video signal from the delay device. 3 Utility Model Registration Scope of Claim 1 The laser recording apparatus according to claim 1, characterized in that the delay time of the variable delay device is changed in units of one horizontal scanning time in accordance with the control signal. Device. 4 Utility Model Registration In the laser recording device according to claim 3, a deflected laser beam from the optical deflector is applied to the recording signal section by 1/n (n=2, 3, . . . ) of the horizontal scanning time. 1. A laser recording apparatus characterized in that a means for setting a position in a film running direction corresponding to , is provided, and the position is set in accordance with the control signal.