JP2961670B2 - Optical digital recording playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reproducing apparatus for optical digital recording, and more particularly to a reproducing apparatus for an audio signal digitally recorded on a movie film.

[0002]

2. Description of the Related Art Conventionally, an audio signal recorded on a motion picture film has been optically or magnetically recorded as an analog signal on a sound track between video and perforation. However, of course, the playback sound quality of the audio signals recorded on these soundtracks cannot be prevented from starting to deteriorate from the first time the film is shown due to the attachment of dust, scratches on the film due to screening, etc. I could not do it.

[0003]

It is apparent that it is desirable to record and reproduce an audio signal as a digital signal in order to prevent such deterioration in sound quality. However, most projectors now incorporate an optical or magnetic analog audio signal playback device. For this reason, it is practically impossible to record a sound signal on a motion picture film as a digital signal to a current sound track section, because it requires modification of these projectors. In addition, it is impossible to provide a track for digital recording separately from the conventional sound track due to the space of the film.

For this reason, attempts have been made to optically record digital signals as black and white dots arranged two-dimensionally in a space between perforations used for driving a film. This audio signal is recorded as discrete signals separated by perforations, and from the viewpoint of the amount of information, the capacity of a signal arranged one-dimensionally along the running direction of the film is insufficient, and the capacity of the film is insufficient. It must be a two-dimensional record arranged in a direction perpendicular to the running direction. The present invention
It is an object of the present invention to obtain a device for reproducing a recording signal which has not been seen in the related art.

[0005]

In order to achieve the above object,
In the present invention, in order to reproduce a digital signal optically recorded during perforation, a signal recording portion of a continuously running film is illuminated by a pulsed light source such as a xenon discharge tube, and a data block image is formed by a CCD or the like. Is detected as a time-series signal by projecting onto a photosensitive surface of a charge accumulation type image pickup tube and sequentially transferring accumulated electrifications until the projection of the next block.

[0006]

First, the recording of a signal to be reproduced will be examined. FIG. 2 shows a case where digital recording is performed on a 35 mm film, and the size of the digital data block 3 recorded between the perforations 2 of the film 1 is 2.0 × 1.
You can see it as 8mm. Approximately 2.9 perforations
mm, but the perforation edge is easily damaged by the feed dog, and if the block size is larger than that, the data may be damaged by the damage. In this area, 1
In the case of recording with a dot having a size of 0 μ × 10 μ, 36 Kbit can be recorded in one block. Even if the block size is 1.7 × 1.4 mm for security, if the dot size is reduced to 5 μ × 5 μ, 95.2 Kbit recording becomes possible. In any case, information that can be recorded in one block is obtained. The amount is as large as this, and it is possible to sufficiently cope with a CCD or the like having about 200,000 pixels. In a movie, 24 frames are projected per second and there are four perforations per frame, so that 96 data blocks must be detected and reproduced per second. Therefore, the repetition time of the block detection is 10.4 ms. In FIG. 2, reference numeral 4 denotes a video unit, and 5 denotes a sound track. In order to read such two-dimensionally arranged data, it is common to scan with a light beam. However, assuming that the film continuously travels, the time required for the above data block to pass the reading position is about 3. It is 9 ms, and it is impossible to scan all the data in the above-mentioned block within the above-mentioned time because the reading light beam must be narrowed down, because of insufficient light quantity. For this reason, a continuously running data block is illuminated by a pulsed light source having a light emission time of 1 to 2 ms or less, and the data block image is projected on the photosensitive surface of a charge storage type imaging tube such as a CCD, and the projection of the next block is performed. A continuous audio signal can be obtained by sequentially transferring the stored electrification and detecting it as a time-series signal.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a reproducing apparatus according to the present invention will be described in detail with reference to embodiments. FIG. 1 is a conceptual diagram showing an example of the data block detection unit. Many projectors intermittently feed the film, but continuous feed is provided outside the loop provided before and after the aperture gate, and the point where the sound reading unit is provided in this continuous feed unit is the same as that of the conventional sound track. Same as reading. The film 1 has a gate 6 in order to prevent the reading portion from moving right and left.
Run inside. The shoe 7 is closed after the film is mounted to prevent the film from deviating from the gate. The gate and the shoe are provided with windows 6 ', 7' for reading the corresponding value of the data block.

The reading optical system includes a xenon discharge tube 8 as a light source, a condensing lens 9 for condensing light from the light source and illuminating a data block, a reading objective lens 10 and a CC.
D or Vidicon (trademark) or the like and a charge storage type imaging tube 11. The pulsed light emission time of the xenon discharge tube is about 1 to 2 ms, but if a shorter light emission time is required, a suitable light source such as a pulsed laser can be used. Further, if the image obtained by the objective lens 10 is enlarged to fill the entire photosensitive surface of the imaging tube 11, small data can be easily read. However, in consideration of the displacement of the data block due to the damage of the perforation edge, it is better to set the size to leave an appropriate margin.

In FIG. 1, reference numeral 12 denotes a constant speed sprocket for feeding the film. The position detecting device 13 magnetically detects the teeth 14 of the sprocket to control the light emission timing of the light source 8. Needless to say, this timing may be detected by another method, for example, by optically detecting the position of perforation. To detect this position, tooth 1
Although some errors are caused due to errors in the shape of No. 4 and damage to the edges of the perforations, no problem occurs when reading is started by the reading start signal inserted at the beginning of the data block. Although there is a problem that the data amount is reduced to half, a bi-phase in which the inversion in the middle of the signal is 1 may be adopted in consideration of the reliability of the data.

[0010]

As described above, the optical digital recording reproducing apparatus of the present invention can detect a digital audio signal recorded discretely as a still image while the film is running and read it as a continuous audio signal. Moreover, the reading device can be easily attached to the conventional projection device, and can be read and reproduced simultaneously with the conventional analog sound track, so that not only can the conventional audio recording be digitized, but also the number of recording channels can be increased. It can also be used for

[Brief description of the drawings]

FIG. 1 shows one of data block detection units of a reproducing apparatus of the present invention.
Conceptual diagram showing an example

FIG. 2 is a conceptual diagram of a data block when digitally recording on 35 mm film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film 2 Perforation 3 Digital data block 4 Image part 5 Sound track 6 Gate 7 Shoe 6 ', 7' Reading window 8 Xenon discharge tube 9 Condensing lens 10 Reading objective lens 11 CCD 12 Constant speed sprocket 13 Position detecting device 14 Teeth

Claims (2)

(57) [Claims] 1. A signal recording section of a continuously running film is illuminated by a pulsed light source to reproduce a digital signal optically recorded during perforation,
An optical digital recording reproducing apparatus characterized in that a data block image is projected on a photosensitive surface of a charge storage type image pickup tube, and the accumulated electrification is sequentially transferred until the next block is projected, thereby detecting a time series signal. 2. A pulsed light source, an irradiation optical system for irradiating a perforation unit, a charge storage type image pickup tube, an objective lens for forming an image of the perforation unit on a photosensitive surface of the image pickup tube, a perforation position detecting device, and the pulsed light source 2. The reproducing apparatus according to claim 1, further comprising a lighting control circuit for illuminating a data block recorded during the perforation by pulse lighting according to the perforation position signal.