JPS5916467B2 - Continuous running film scanning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television screen projection device that scans a moving motion picture film to extract a television signal, and more particularly, a continuous motion picture film that controls the vertical deflection of a flying spot scanning light according to the film speed. The present invention relates to a traveling film scanning device.

The device that projects the television screen from the movie film is
Mainly used by television broadcasting stations.

Recently, a small home television screen projection device has been developed so that 8 mm film can be viewed on a television screen. However, the number of frames for movie film is usually 24 frames per second (8mm film has 24 frames, 16 frames, and even 18 frames per second), while television has 30 frames per second. When projecting a television screen from film, it is necessary to convert the number of images every second. For this reason, in the conventional television screen projection device, the movie film is
At 4 frames per second, the so-called 2-3 pulldown method, in which each piece is scanned alternately by 2 and 3 fields, is used to move the pieces intermittently at different intervals, and move the stationary pieces to a flying spot scanner. (FSS) and an image pickup tube.

This intermittent forwarding method has the disadvantage that the device is complicated, operations such as fast forwarding and rewinding are inconvenient, and the upper screen shakes and flickers. In order to solve these drawbacks, a continuous running type device has been proposed in which images are taken while the motion picture film is running.

One of the devices of this type uses a precision speed detector such as a rotary encoder to detect the moving position of the film, and controls the vertical deflection of the flying spot scanning light according to this moving position, and also controls the frame switching. There is a method in which the passage of a perforation is detected, one perforation drilled next to each piece (Japanese Patent Laid-Open No. 52-36416). This scanning method has the advantage that even if many types of motion picture films having different numbers of frames per second are used, even if the transport of the film changes, it is possible to carry out follow-up scanning correctly. There are two methods for switching the pieces: one is to switch the pieces immediately when the perforation is detected even in the middle of the field, and the other is to delay the switching until the scanning of the field is completed.

The former method poses a problem of screen discontinuity because one field becomes a composite of the upper and lower halves of two frames due to frame switching. The latter method does not cause this discontinuity, but since the switching of the pieces is delayed by half a field, the next piece to be scanned moves from the reference line during that time. Therefore, when switching the pieces, a difficult problem arises in that the moved position must be detected and the raster movement must be performed. SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, it is an object of the present invention to provide a continuous-travel type film scanning device which is capable of changing frames when changing fields using a simple device.

The device of the present invention is provided with two counting means in order to know the moving position of a piece, one counting means counts the moving amount of the piece from the reference line during scanning, and the moving amount of the next piece is counted by another counting means. This is characterized in that two counting means are used alternately for each piece.

That is, one counting means counts the amount of movement of the frame being scanned from the reference line, this counted value is converted to an analog signal by a D-A converting means, and this is mixed with a standard vertical deflection signal by a mixing means. This mixed signal controls the vertical deflection of a flying spot scanner or image pickup tube. When the next perflation signal is received, the other counting means starts counting, and the reference line of the frame to be scanned next (the field start position when scanning a motion picture film that is stationary) is set. count the amount of movement from the line). The counting means that was counting the frames being scanned is reset by the first vertical synchronizing signal (vertical synchronizing pulse) after this perforation signal, and is stopped until counting of the next frame. Therefore, since the counting means counts the amount of movement from the reference line, the raster is correctly moved to the moved position when changing the pieces.

Since each counting means counts each consecutive piece, at the same time as the pieces are switched, the counting means responsible for counting the pieces to be scanned is selected, and the contents are read out and sent to the mixing means. Means are provided. D
Two -A conversion means are provided so as to convert the signals of each of the two counting means, and these are connected between each counting means and the selection means.

It is also possible to use one D/A conversion means and insert it between the selection means and the mixing means to convert the contents of the selected counting means into a signal. As a variation of the method described above, a main counting means for counting the amount of movement of the pieces to be scanned during the period from one frame conversion to the next, and a main counting means for counting the amount of movement of the pieces to be scanned during the period from the perflation signal to the vertical synchronization signal. There is a method in which a correction counting means for counting only the distance is provided, the main counting means is reset at the same time as the frame is switched, and the contents of the correction counting means are transferred to this.

This method is convenient because a small and inexpensive correction counting means can be used. Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, a motion picture film 1 has one perforation 2 formed in the center next to each frame.

The motion picture film 1 is supported by a pair of capstans 3 and 4, and is continuously run in the direction of the arrow from a supply reel to a take-up reel while being held between pinch rollers (not shown). One capstan 3 is driven by a motor 5. This motor 5 is designed to be driven at a speed corresponding to the number of frames per second of the motion picture film being used.
It is controlled by a speed control circuit 6. This capstan 3
A sprocket may be used instead. A disk 7 having fine pitch cuts on its outer periphery is connected to one of the capstans 4.

This disc 7 is irradiated with a spot light source 8, and the reflected light is received by a photoelectric element 9, whereby a pulse train signal corresponding to the running speed of the motion picture film 1 is obtained. Note that the light transmitted through the disk 7 can also be received. Therefore, by counting this pulse train signal, the traveling position of the motion picture film 1 can be known. A spot light source 10 and a photoelectric element 11 are disposed facing each other on the perforation path 2 of the motion picture film 1 with the motion picture film 1 in between, and generate a perforation signal for frame switching. Note that each piece may be marked and this may be detected. The flying spot scanning light from the Flying Spot Scanner (FSS) 12 is
The frames of the movie film 1 are irradiated via the lens 13.

In addition to this flying spot scanner, there is also an image pickup tube,
A flying spot scanning method using laser light or the like can also be used. In this flying spot scanner 12, horizontal and vertical deflection signals are supplied to a deflection coil 14, and a raster of flying spot scanning light is drawn. For horizontal deflection, a horizontal synchronizing signal (horizontal synchronizing pulse) HD of standard television is applied to the horizontal deflection signal generating circuit 15 to generate a sawtooth horizontal deflection signal phase-synchronized with this, and deflection is performed using this signal. On the other hand, for vertical deflection, a vertical synchronization signal (vertical synchronization pulse) VD with a period TO (1/60 seconds) is supplied to the standard vertical deflection signal generation circuit 16 to generate a sawtooth standard vertical deflection signal, which is then sent to the mixing circuit. At step 17, a vertical deflection signal is synthesized by mixing with a film shift signal corresponding to the running position of the motion picture film 1, and deflection is performed using this signal. That is, for horizontal deflection, a sawtooth wave having the same period and amplitude as the standard television system is used.
The vertical deflection has an amplitude and a period modified according to the film speed, and is deflected by a sawtooth wave that is shifted in the film running direction for each field period according to the film speed, and each of the motion picture film 1 Pieces are scanned. Released from the Flying Spot Scanner I-12, movie film 1
The flying spot scanning light transmitted through the dichroic mirror 18,
The color is separated into three color lights by 19, and electron multiplier tubes (photo multipliers) 20, 21 for red, blue, and green are used.
, 22, each of which is converted into a video signal. The video signal of this three primary color image is sent to the processor 2 via the encoder 23.
4, is completed into a standard color television signal, and is taken out from an output terminal 25. Next, the device for forming the vertical deflection signal will be explained. The perforation signal from the photoelectric element 11 is input to the processing circuit 26, where it is correctly binarized even if the signal is out of shape or the level has changed. Ru. This waveform-shaped perforation signal is a horizontal synchronizing signal HDl and a vertical synchronizing signal D.
At the same time, it is input to the switching pulse generation circuit 27. The switching pulse generation circuit 27 uses these signals to control the first and second counters 28, 29 and the first and second counters 28, 29.
Controls the operation of first and second gate circuits 32 and 33 connected to DA conversion circuits 30 and 31, respectively. On the other hand, the pulse train signal of the photoelectric element 9 for detecting the amount of movement of the motion picture film 1 is multiplied by a multiplier circuit 34 in order to increase the detection accuracy of the amount of film movement, and then input to the first and second counters 28 and 29. The amount of movement is counted.

The reason for providing two counters in this way is that after the perflation signal, the same frame is scanned continuously until the next vertical synchronization signal, and the count value when switching to the next frame is calculated based on the perflation signal. This is because it is necessary to set the value to a value counted from the signal. This value can also be found by subtracting (zi-up) the count value corresponding to the perflation interval from the previous counter value when switching pieces. This accumulates and eventually causes the reproduced image to be blurred. In this regard, if the perforation signal is counted for each frame as in the present invention, this problem can be prevented and a stable image can always be obtained. As a result, even if the running speed of the film changes slightly or greatly, or even if the film stops or reverses, a television image without image blur can always be obtained.

The contents of the first counter 28 and the second counter 29 are converted into analog signals by first and second DA conversion circuits 30 and 31, respectively. This analog signal
The signals are selectively sent out by the second gate circuits 32 and 33, and combined by the selector 35 to form a film shift signal. This film shift signal is mixed in mixing circuit 17 with the signal from standard vertical deflection signal generating circuit 16 to form a vertical deflection signal, with which flying spot scanner 12 is controlled. Figure 2 shows one D-A conversion circuit.
This shows an embodiment in which only one is provided.

In this embodiment, a DA conversion circuit 36 is connected between the selector 35 and the mixing circuit 17 to simplify the apparatus. FIG. 4 shows waveforms of each circuit forming a vertical deflection signal.

The perforation signal, horizontal synchronization signal HDl, and vertical synchronization signal VD are applied to the switching pulse generation circuit 27.
The perforation signal is normalized by the first horizontal synchronization signal HD after this signal, and the scanning start phases are aligned. A pulse that sets the first and second counters 28 and 29 to alternately count each frame by this normalized perflation signal, and a vertical synchronization signal VD added after the perflation signal. A reset signal for resetting one of the counters counting the frames being scanned and a gate pulse for alternately passing the analog signals of the DA conversion circuits 30 and 31 are generated. Although there are 262 water↑ synchronization signals HD per field, only the necessary horizontal synchronization signals are shown for convenience. The multiplier 34 multiplies the pulse train signal from the photoelectric element 9 constituting the rotary encoder by four and sends it to the first or second counter 28, 29.

A first counter 28 is set by the normalized perforation signal and counts the pulse train signal to count the amount of movement of the first frame to be scanned next from the reference line. The contents of the first counter 28 are converted into an analog signal by a DA converter circuit 30 to form a film shift signal with fine steps. The first gate circuit 3 receives the first vertical synchronization signal after the perforation signal.
2 is opened, and the signal from the D-A conversion circuit 30 is sent to the selector 3.
5 is input.

The output signal of the selector 35 corresponds to the amount of film movement. When the motion picture film 1 is advanced by one frame and the next perforation signal is generated, the second counter 29 is set and starts counting the amount of movement of the second frame. Then, when the next vertical synchronizing signal VD comes, the frame to be scanned is switched from the first frame to the second frame, and at the same time, the first gate circuit 32 is closed and the second gate circuit 33 is switched.
will be held. The counter read in this way is switched from the first counter 28 to the second counter 29. Since this switched second counter counts the amount of film movement from the reference line, it is possible to accurately know the film start position of the second frame. The selector 35 alternately reads the contents of the first counter 28 and the second counter 29 to form a sawtooth film shift signal.

This film shift signal is sent to a mixing circuit 17 and mixed with a standard vertical deflection signal to form a vertical deflection signal that follows the film running speed. In the case of the embodiment shown in FIG. 2, one D-A converter circuit 36 is used, and from this D-A converter circuit 36, the same film shift signal as the output signal of the selector 1 shown in FIG. A signal is output.

FIG. 3 shows an embodiment in which a main counter 40 and a correction counter 41 are used in place of the counters 28 and 29, and FIG. 4A is a waveform diagram thereof.

This main counter 40 continuously counts the pulse train signal sent from the multiplier circuit 34 and is reset at the first vertical synchronization signal following the perflation signal. Therefore, counting is performed from zero for each perforation, and the amount of movement of the film from the time of frame switching to the next frame switching can be known. However, in this case, the amount of movement of the film from the reference line is not counted, and the field starts from the middle of the frame. Therefore, a correction counter 41 is provided to count the amount of film movement from this reference line to the time of frame switching. This correction counter 41 is
It is set by the normalized perflation signal, and stops counting at the next vertical synchronization signal, and at the same time transfers its contents to the main counter 40 and adds it to the count value of the main counter. There is. Main counter 4
The content of 0 is converted into an analog signal by the DA conversion circuit 42. In this device, since the number of counts of the correction counter 41 is small, a small and inexpensive counting device such as a register can be used. Note that the switching pulses necessary for the above circuit operation are supplied from the switching pulse generation circuit 27. Fifth
The figure is a waveform diagram showing the vertical deflection of a motion picture film at 24 frames per second, with the horizontal axis representing time and the vertical axis representing the scanning position of the film surface.

When motion picture film 1 is at rest, the standard vertical deflection is 1-1.
The deflection length is L. Since scanning is started from the reference line, the scanning waveform is 1-2''5-2'.
-3・″t... It becomes a sawtooth shape.The running direction of the movie film is opposite to the scanning direction, and 1-2-3-4...
drive along. Assuming that the amount of movement of the film at any given time t is s, in this case the film must be shifted by s in the running direction when scanning compared to the case where the film is scanned when it is stationary. That is, the vertical deflection length during running is 1. is compressed and shortened compared to when it is at rest, but this vertical deflection length is 1. The vertical deflection length l at the time t is obtained by subtracting the movement amount s from the distance s. Therefore, the vertical deflection waveform of the first field is 1-. The vertical deflection waveform of the second field becomes 2-3'' in the same way as the first field because the field start point has moved to 2.The first frame is thus completed, but the third field also continues. Then, the first frame is scanned, and its waveform becomes 3-5''. When the first frame moves to the 4-4' position, a perflation signal is sent, but the third field continues to scan the first frame.

Then, when a vertical synchronizing signal is received next, the frame moves to the second frame.
At this time, the second frame is ahead of the reference line by the distance between 5' and D, so the scanning start position of the second frame is 5'', and it is scanned in the same way as the first frame. When the perflation signal arrives and the vertical synchronization signal is subsequently sent, the flying spot scanning light moves to the third frame.Therefore, the film shift waveform is 1-5-5''-
7, and in addition to this, the standard vertical deflection waveform 1-2〃-2'-3
``5-3''... is added to obtain the desired vertical deflection waveform 1.
-2''-2-f-3-5''-6''-6... is obtained by following the moving film and scanning one frame twice or three times.
Scan twice.

FIGS. 6 through 9 show vertical deflection waveforms when a motion picture film is run at a speed different from 24 frames per second.

FIG. 6 shows a waveform for vertically deflecting a motion picture film at 48 frames per second, which is higher than the 30 frames per second of television. In this case, the number of pieces scanned only once is 3 and 2 pieces.
The number of frames scanned twice is 1. Figure 7 shows the case where the number of frames is the same as the number of frames per second on television, and in this case,
Each piece is scanned twice.

When the number of frames reaches 20, each frame is scanned three times. 8th
The figure shows a case where the number of frames is 6, and in this case each frame is scanned 10 times.

Figure 9 shows the case where this is reversed, and since the running direction of the film and the scanning direction are the same, '-s+10' is obtained.
This results in a vertically deflected waveform with an opposite slope.

As explained above, according to the present invention, frames are switched when changing fields at any film speed, so it is possible to freely switch between quick motion, slow motion, reverse motion, and still motion for projection. be able to.

In addition, it is possible to follow even minute changes in film speed, projecting a good screen without image blur or flickering, and since it does not require the precision of a film transport device, it is possible to provide an inexpensive device. . Furthermore, two counting means for counting the amount of film movement are provided, and these counting means are operated alternately for each frame, and the contents are converted into analog to form a film shift signal, which is mixed with a standard deflection signal. Since the vertical deflection of the flying spot scanning light is controlled by the obtained vertical deflection signal, the frame can be switched by moving the raster to a position corresponding to the film speed at the end of one field. Moreover, since two counting means are provided and the counting is performed alternately, the configuration and control are simple.Othermore, one counting means can be used as a correction counting means for counting the amount of film movement from the reference line. If the other counting means is used as the main counting means for counting the amount of film movement after the start of scanning, it is convenient because a small correction counting means is sufficient.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the television screen projection device of the present invention, and FIG.
- A block diagram of the main part showing an example using the A conversion circuit,
Figure 3 is a block diagram of the main parts showing an embodiment using a correction counter and a main counter, Figure 4 is a waveform diagram of each part of the device for creating a film shift waveform, and Figure 4A is an example of the embodiment of Figure 3. FIG. 5 is a waveform diagram showing the vertical deflection operation, and FIGS. 6 to 9 are waveform diagrams showing the vertical deflection operation for motion picture films of various frame numbers. 1... Movie film, 3, 4... Capstan, 5... Motor, 7... Film speed detection disc, 12...・Flying spot scanner, 16... Standard vertical deflection signal generation circuit, 17... Mixing circuit, 18, 19...
...Dichroitsch mirror, 20, 21, 22...
... Photomultiplier tube, 27 ... Switching pulse generation circuit, 28 ... First counter, 29 ...
...Second counter, 30...First D-A conversion circuit, 31...Second D-A conversion circuit, 32.
...First gate circuit, 33...Second gate circuit, 35...Selector 36...
・D-A conversion circuit, 40... Main counter, 4
1...Correction counter, 42...D
-A conversion circuit.

Claims (1)

[Scope of Claims] 1. A television screen projection device that continuously runs a perforated movie film and scans each frame of the movie film for flying points to extract a television signal, the device comprising: detects the running speed of the movie film and outputs a pulse train signal corresponding to the speed, integrates this pulse train signal to determine the film running length, detects the perforations of the movie film or marks provided on each frame, and outputs a perforation signal. When performing horizontal and vertical deflection to scan a predetermined range of film frames while moving the flying spot to follow the running of the film on the flying spot scanner tube surface, the vertical deflection immediately after the perforation signal is performed. In an apparatus in which scanning is switched from a frame being scanned to an adjacent frame by a synchronization signal, and each frame is scanned an integral number of television field periods, a pulse train signal corresponding to the film running speed is input. Two counting means are provided to measure the amount of movement of the film frame, and one of the counting means which is at rest is set to start counting by the normalized perforation signal, and the vertical synchronization signal immediately after the perforation signal is set. A continuous running type film scanning device, characterized in that the other counting means during counting is reset by the above-mentioned counting means, and the vertical deflection voltage at the scanning start point of the next frame is determined based on the contents of the one counting means. . 2. A television screen projection device that continuously runs a motion picture film having perforations and scans each frame of the motion picture film to extract a television signal, which detects the running speed of the motion picture film. outputs a pulse train signal corresponding to the speed, integrates this pulse train signal to determine the film travel length, detects the perforations of the movie film or the marks provided on each frame to create a perforation signal, and sends the film to a flying spot scanner. When performing horizontal and vertical deflection to scan a predetermined range of film frames while moving the flying point to follow the running of the film on the tube surface, a vertical synchronization signal immediately after the perforation signal is used to In an apparatus in which scanning is switched from a frame being scanned to an adjacent frame, and each frame is scanned an integral number of television field periods, the film frame is moved by inputting a pulse train signal corresponding to the film running speed. Two counting means are provided for measuring the quantity, one counting means is set to be at rest in response to a synchronized perforation signal, and the other counting means is set to be counted continuously immediately after each perforation signal. The counting means is reset by a vertical synchronization signal, and the contents of the counting means set by the normalized perforation signal are added to the counting means reset by the vertical synchronization signal immediately after perforation. Continuous film transport device.