JPS63214082A - Projector for television - Google Patents

Abstract

PURPOSE:To have a good stop time, to eliminate the damage of a film and to reduce flickering by taking a comparatively long frame dropping time for the film, and obtain a video signal substantially similar to a 2-3 pull down system. CONSTITUTION:A light from a light source 1 reaches a TV camera 8 using a solid-state image pickup element via a condenser lens 2, a film gate 3, the film 4, a shutter 5 and a projecting lens 6, the signal is processed in the TV camera 8, and it is supplied to a frame memory 9. When the frame dropping of one frame is executed at the speed of 1/50 seconds in a time A, a picture projected during the still period (shutter opening period) of a timing A' is pickedup by the TV camera 8 and written in the frame memory 9. This opera tion is repeated thereafter, thereby, the frame dropping is executed at equal intervals at the speed of 1/50 seconds and the video signal substantially similar to the 2-3 pull down system can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a television projection device, which transmits images projected from a 35-frame film projector to a television camera (
The present invention relates to a projection device that captures an image (TV camera)'c'' and converts it into a video signal.

2. Description of the Related Art This type of projection device is used, for example, in television broadcasting stations to broadcast video signals from TV cameras, and in post-production, etc.
It is used when recording video signals from a V camera onto a VTR or the like. In this case, the projection device synchronizes with the NTSC system or PAL/SECAM system using a 2-3 pulldown system, a 2-2 pulldown system, etc., which will be described later, and converts it into a video signal.

FIG. 3 shows a timing chart illustrating the operation of an example of a conventional device (2-3 pulldown method).

In the figure, the upper row shows the field of the TV camera, and the lower two rows show the film pull-down (missing) and shutter timings of the projector. Film dropouts in a projector occur at an alternating repetition period of 2 fields and 3 fields, for example, about 1/110 seconds, and the film is then dropped for ((1/30) seconds - (1/110) seconds) or /
20) pause for (1/110) seconds).

The shutter is opened two or three times during the film's rest period (
Open during the shaded period, open during the white period), WJ between this shutter
The images displayed during this time are captured by a TV camera and converted into video signals.

Note that the extrusion that employs the 2-3 pulldown method is to synchronize 24 frames per second (60 fields) in the case of the NTSC method, since movie projectors generally operate at 24 frames/second.

Problems to be Solved by the Invention As mentioned above, the film chip moves intermittently with sudden acceleration and sudden stops, and the stopping accuracy is very strict, which causes unreasonable force to be applied to the film. In this case, in order to stop the film quickly and accurately, the film should be given an appropriate amount of r! It depends on the accuracy of the repeatable stopping accuracy of the missing bottle or sprocket over the l rub resistance film perforation (g-hole).

In the conventional device described above, the dropout time is relatively short at about 1/110 seconds, and as a result, the inertial force of the film becomes large.
There is a problem in that the stopping accuracy deteriorates and the frictional resistance increases, which may cause damage to the film. In addition, the shutter is opened and closed by the rotation of a motor, which generally causes uneven rotation, and for shutters with two or more blades, the irradiation time varies depending on the opening angle precision, which causes noticeable flicker. there were. This problem cannot be completely eliminated even if a single blade is used and a high speed motor of 360 rpm or 3000 rpm is used.

According to the present invention, it is possible to obtain a video signal substantially the same as that of the 2-3 pulldown H type with a relatively long film dropout time, the stopping accuracy is good, there is no risk of film damage, and furthermore, An object of the present invention is to provide a television projection device with less flicker.

Means for Solving the Problems As shown in FIG. 1, the apparatus of the present invention includes a projection means (12) that performs intermittent film omissions at regular intervals regardless of the various television systems, and The image of the pieces projected by the projection means is captured with a television camera.
The video signal of the image of the frame photographed by the television imaging means (8) is written to the film still yAIi1, and the next frame is missing and the video signal of that image is written. It consists of a signal writing/reading means (9) for reading out the previously written video signal and transmitting it to a plurality of television fields when the TV is in use.

The movie projector 12 performs film dropouts intermittently at regular intervals over a relatively long time of about 1750 seconds, writes the video signal to the frame memory 9 during the film rest period, and detects the next frame dropout and the previous frame during the film rest period. For example, 3 fields are read out from the video signal.

Send alternately to 2 fields.

Embodiment FIG. 1 shows a block diagram of an embodiment of the apparatus of the present invention (equally spaced pulldown method). FIG. 2 shows a timing chart explaining the operation of the device of the present invention.
The rows show the field and frame memory storage operations of the TV camera, and the bottom two rows show the timings of film loss and shutter of the projector.

At the 1st vA, the light from the light source 1 passes through the condenser lens 2, the film gate 3, the film 4, the shutter (for example, a liquid crystal shutter mechanism) 5, the projection lens 6, and reaches the TV camera 8 using a solid-state image sensor. 8
The signal is processed by a well-known technique and supplied to the frame memory 9. The film 4 is given frictional resistance by a film gate 3 and is intermittently run at equal intervals by a sprocket 7. A projector 12 is composed of a light source 1 to a sprocket 7.

In Figure 2, at timing ■, 1 at a speed of 1150 seconds.
When the piece is missing, the image projected during the static period at timing ■' (shaft open period > (1/60 seconds) is imaged by the TV camera 8 and written to the frame memory 9 (F+) .When the next piece is missing at the next timing ■ at a speed of 1150 seconds, the timing ■
The image displayed at ' is written into the frame memory 9 (F2). At timings ■ and ■', the Fl video signal previously written in the frame memory 9 is read out, sent out to three TV fields, and recorded on, for example, the VTR 10.

Similarly, deletion is performed at the next timing (2), and writing to the frame memory 9 is performed at timing (2') (F3). During this time, when the transmission of the previous Fl video signal is completed, the F2 video signal previously written in the frame memory 9 is read out, transmitted to the two TV fields following Fl, and recorded on the VTR 10. Thereafter, similar operations are repeated.

In this way, in the present invention, the dropout is performed at equal intervals at a speed of 1150 seconds, and the video signal written in the frame memory 9 during the rest period is read out and sent out repeatedly in three fields and two fields alternately. Although it operates in the evenly spaced pulldown method, it is essentially the same as shown in Figure 3.
-3 It is possible to obtain the same video signal as the pulldown method.

In this case, the missing time is 1750 seconds, which is about twice as long as the conventional device, so the inertial force of the film is small, making it possible to improve the stopping accuracy, and the film frictional resistance is small, so the film is not damaged. There is no danger. Furthermore, since the film is only cut out at equal intervals, the film transport mechanism can be simplified compared to conventional devices. Furthermore, since a liquid crystal is used for the shutter 5, the on/off time error can be reduced.
It produces less flicker than with a mechanical shutter.

Note that the above embodiment is for the 60 fields/second NTSC system, but the 50 fields/second PAL/SEC system is used.
In the case of the AM method, the film advance is 25 frames/second, and 1
The structure may be such that the information is always sent to two fields for each piece.

As described above, image blurring of the film can be improved by making the film dropout period relatively long, but this can be further reduced by using the following method.

The aperture (window) of the projector is made larger than the film standard, and the correction circuit 11 shown in FIG. The end face shake is detected as a pixel change, time axis correction is performed based on this, and the result is supplied to the frame memory 9. In this way, vertical vibration can be contained within one horizontal scanning line, horizontal vibration can be contained within one pixel, and errors in the intermittent film feeding mechanism can be further reduced.

It goes without saying that the correction circuit 11 may be built into the TV camera 8.

Effects of the Invention According to the present invention, the film dropout time can be reduced to 1150, for example.
Since it can take a relatively long time of about 8 seconds, the inertial force of the film is small, the stopping accuracy is good, and J'! 5. Since the resistance is small, there is no risk of damaging the film, and since there is no constant period, the film running mechanism of the projector can be simplified, and furthermore, it is possible to correct the shake of the vertical and horizontal edges of the image. Therefore, it has features such as being able to obtain high-quality images.

[Brief explanation of the drawing]

FIG. 1 is a block system diagram of one embodiment of the device of the present invention, and FIG.
3 and 3 are timing charts for explaining the operation of the device of the present invention and the conventional device, respectively. 1...Kikaze, 3...Film gate, 4...Film, 5...Shutter, 8...TV camera, 9...
-Frame memory, 10...VTR, 11...correction circuit, 12...projector.

Claims (2)

[Claims] (1) A projection means that performs intermittent film omissions at regular intervals regardless of the various television formats, and a television imaging means that uses a television camera to capture images of the frames projected by the projection means during the period when the film is stationary. , The video signal of the image of the frame captured by the television imaging means is written during the above-mentioned film standstill period, and when the next frame is missing and the video signal of that image is being written, the video signal written earlier is written. 1. A television projection apparatus comprising: signal writing/reading means for reading and transmitting signals to a plurality of television fields. (2) The television imaging means uses a solid-state image sensor, detects the vertical and horizontal shake of the image produced by the projection means as pixel changes based on the obtained pixels, and detects the fluctuation of the vertical and horizontal edges of the image produced by the projection means as pixel changes, and adjusts the time axis accordingly. 2. The television projection apparatus according to claim 1, further comprising means for correcting and taking out the image.