US2075360A - Television apparatus - Google Patents

Television apparatus Download PDF

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Publication number
US2075360A
US2075360A US641092A US64109232A US2075360A US 2075360 A US2075360 A US 2075360A US 641092 A US641092 A US 641092A US 64109232 A US64109232 A US 64109232A US 2075360 A US2075360 A US 2075360A
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US
United States
Prior art keywords
film
scanning
light
image
television
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US641092A
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English (en)
Inventor
Schubert Georg
Moller Rolf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FIRM FERNSEH AKTIEN GES
FIRM FERNSEH AKTIEN-GESELLSCHAFT
Original Assignee
FIRM FERNSEH AKTIEN GES
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DEF73649D external-priority patent/DE681369C/de
Application filed by FIRM FERNSEH AKTIEN GES filed Critical FIRM FERNSEH AKTIEN GES
Application granted granted Critical
Publication of US2075360A publication Critical patent/US2075360A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/84—Television signal recording using optical recording
    • H04N5/843—Television signal recording using optical recording on film
    • H04N5/846—Television signal recording using optical recording on film the film moving intermittently
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/04—Synchronising

Definitions

  • Television transmission apparatus of the kind hitherto known fulfil merely the requirement for analysis or decomposition either of normal positive films with the assistance oi! so-called 5 kinematograph transmitters or of the representation of spacially disposed objects or persons with the assistance of so-called light-ray scanning transmitters, and for the purposes of transmission after conversion into electrical im- 1 pulses.
  • the single possibility of transmitting topical occurrences consists in filming the same, making from this film positive copies, and then performing transmission with the assistance of a kinematograph television transmission means.
  • This method naturally represents nothing more than a kinematographic report conveyed with the assistance of a television apparatus and has little to do with television proper, as the interval between the occurrence to be transmitted and the reproduction amounts under existing conditions to a matter of hours or, generally speaking, even days.
  • the copying process is dispensed with, so that it is possible to transmit the image or picture within a period of at the most one hour following the recordal.
  • An additional feature of the invention resides in the fact that in order to still further diminish the elapse of time between the kinematographic recordal and the television transmission the film may be analyzed or decomposed immediately following the development, possibly with the inclusion of a preliminary fixing process, fixing, washing and drying then being performed after the analysis or decomposition has taken place.
  • the time for developing may be reduced to very brief periods, say 2 seconds, inasmuch as it is not absolutely essential to develop the film in such fashion that the same provides an excellent negative such as required in connection with a normal film copy. It is merely necessary for the negative. to reveal sufficient contrast between light and dark that the photo-cell is provided with sufficient fluctuations in light during the scanning of the film, and the amplifier furnished with an input energy of such extent that the same is situated well above the level of disturbance occasioned by other effects and influences.
  • This method would accordingly enable occurrences just taking place to be transmitted to subscribers with a delay which amounts to a few seconds.
  • the film gate through which the film moves is lighted in its full expanse, and that the image is projected on to the. perforated disc, behind which there is arranged the photocell.
  • care must be taken that the film, by reason of the scanning process, is not additionally darkened, or only to such slight extent that the. differences between light and dark are still maintained as such.
  • a further possibility of avoiding additional darkening consists in lighting on each occasion only that part of the film image which corresponds with one size of image point, this being accomplished by lighting the image recess in the perforated disc in its full expanse, reproducing the perforated disc on the film by means of an objective, and arranging the photo-cell behind the film.
  • the film and the perforated disc accordingly change places as compared with the known arrangements.
  • the darkening which is possible at all in this method amounts in comparison with the normal process to the fraction derived from the number of image points.
  • the film, in the method according to the invention is passed through the scanning apparatus in a wet condition, it is desirable not to employ a normal film projector with intermittent movement, as in this way considerable demands would be imposed on the film with regard to mechanical strength and elasticity, the film, in accordance with the invention, being passed through the scanning apparatus at a constant speed.
  • An additional advantage associated with the method according to the invention resides in the fact that the energy radiated by the source of light is utilized to a considerably better extent, as on the scanning disc there requires to be lighted merely a surface which corresponds with one line. In consequence there may be employed a source of light having a heated filament.
  • the film after passing through the developing bath, and possibly also the preliminary fixing bath, is conducted in direct fashion through the scanning device, in which it is traversed by a bundle of rays.
  • the scanning device Upon this scanning process any drops of water possibly adhering to the film as a result of the development might naturally give rise to disturbances. Under certain circum stances, therefore, it may be desirable to remove the drops of water, or also the complete coating of moisture, from the film before the latter is conducted through the scanning device, use being made of a rapidly acting drying process.
  • This may consist in drying the film in a current of hot air, or passing the same through a bath of alcohol and then drying, or in removing the drops of water by a scraping device.
  • the drops of water might also be removed by the inclusion of a rearwardly moved compensating loop between the developing and the scanning means, or the different methods might be suitably combined.
  • the lapse of time between the actual recordal and the scanning operation is to be reduced to all possible extent, as already stated. The same depends solely on the length of the film between the exposure window and the scanning window or gate and also on the rate at which the film is moved. It will accordingly be desirable to place the recording apparatus and the scanning apparatus as close together as possible, and to include the developing process between the two.
  • the film therefore, is preferably passed in direct fashion from the recording apparatus to the developer, and after leaving the developing bath is conducted immediately through the window of the scanning device. The time for which the film requires to remain in the developer cannot be reduced beyond a certain extent.
  • the film requires under all circumstances to be handled very carefully and so guided that the emulsion is not damaged.
  • the film therefore, requires to be guided merely laterally, or in such fashion that the same at the middle enters intocontact with guide or feed rolls only on the celluloid side. For this reason it is accordingly desirable to employ a small size of image.
  • the length of film which must be introduced into the developer amounts in the case of 25 image changes per second and when employing a narrow film 7 mm. in the upright direction, assuming the time for development to be 2 seconds, to only approximately 35 cm. It will be obvious that even when employing a normal kinematograph film 8 millimetres in height it will still be possible to accommodate the requisite length of film in the developing bath.
  • the film should not be guided in a tensioned state between recording apparatus, developing bath and scanning apparatus, as generally speaking it will not be convenient to attain synchronous drive of these three apparatus by a mechanical coupling. If, therefore, synchronous motors are employed phase displacements arising from fluctuations in load and potential are not to be avoided. The compensating loops should accordingly be so calculated that the maximum phase displacements occurring may still be compensated.
  • the film is preferably conducted over two closely disposed transport rolls, the axial spacing of which is so calculated that the distance between two corresponding teeth is a multiple of the spacing of the perforations, so that the film is properly tensioned.
  • storage drum for reception of the wet film requires to be constructed accordingly.
  • the film will accordingly be applied to a spiral of such pitch that adjacently disposed pieces of film cannot touch, the film, for example, being placed in a spirally constructed groove, or being wound with the interposition of two distance bands, which cover only the side edges of the film.
  • the entire spool is preferably located in a drum filled with water. The film thus stored may be additionally treated later for other purposes.
  • Figure 1 is a line diagram of a transmitter.
  • Figures 2 and 3 are an elevation and a side view of developing tank 4 of Figure 1.
  • Figure 4 shows the scanning device used at the transmitter.
  • FIG. l of the drawings A very convenient form of embodiment of the invention is illustrated in purely diagrammatical form in Fig. l of the drawings.
  • I is the camera for making the photographic recordal, to which camera the film 2 is fed from the stor age drum 3.
  • the film 2 moving in the direction of the arrows passes after exposure into the apparatus 4, in which the same is subjected to a preliminary chemical treatment, whether for the purpose of mere development or for development and fixing.
  • the film thereupon passes to the scanning device 5, and after leaving the same is taken up by the spooling device 6.
  • Figs. 2 and 3 show a possible form of embodiment in respect of the apparatus 4, Fig. 2 being a front elevational view and Fig. 3 a side elevation.
  • the trough 1 which is filled with developer, contains two rolls 8 and 9, which are connected with each other through the medium of the gear wheels H) and H and a chain I2, and are operated in common by the synchronous motor through the medium of the gear wheel I3. Beyond this there are mounted at each of the two ends of the roller 9 two rims having teeth l4, over which the film is now conducted in the manner indicated in the drawings. At the point of the teeth M'the film is pressed lightly against the rolls 8 and 9 by two pressure rollers l 5. The film is introduced in such fashion that the sensitized face is situated towards the outside.
  • the rolls 15 are so constructed that the same press the film against the rollers 8 and 9 merely laterally in the vicinity of the perforations.
  • Fig. 4 there is shown a convenient arrangement of the scanning device in cross-section.
  • the filamentary light source l6 situated vertically in the plane of the drawings lights through the medium of a condenser system ll that part of the scanning disc l8 which is traversed by the scanning apertures situated in a circle concentrically to the axis of rotation l9.
  • the scanning apertures are reproduced on the film 2 by means of the objective 20.
  • the film is held in a tensioned condition between the two transport drums 2
  • the light falling through the film traverses the lens 25 and then strikes the light-responsive layer of the cell 27.
  • the fluctuations in current supplied by the photo cell are conducted in the usual manner to an amplifier.
  • the lens 25 is preferably so arranged and also possesses such optical data that it reproduces the objective 28 on the layer 26.
  • a light filter may be provided in the path of the rays, preferably in the vicinity of the condenser system H.
  • F and 22 on the one hand and the scanning disc F8 on the other hand are mechanically coupled with each other with a certain transmission ratio and are driven by a synchronous motor; or alternatively separate synchronous motors may be employed for each of the two operating elements.
  • analyzing element there may be employed a Nipkow disc or a scanning disc in which the apertures are situated in a circle concentrically to the axis of rotation.
  • Naturally other equivalent means may be employed, for example Weills reflector wheels or other refiectory wheels, the refiectory faces of which are situated parallel to the axis of rotation.
  • the sound may for this purpose be fixed according to one of the known sound-recording processes, and transmitted with corresponding delay simultaneously with the image.
  • the film serving for transmission of the image it is possible on the film serving for transmission of the image to simultaneously record the sound according to one of the known light-sound processes and to transmit the same together with the image, whereby synchronism between sound and image is of necessity obtained automatically.
  • the sound might equally well be recorded on a second, separate film.
  • the first method however, ofiers greater advantages with regard to synchronization.
  • the sound strip is developed together with the image strip, and since the same is treated according to the same process, for example, has also not been fixed, or merely preliminarily fixed, it requires to be illuminated with red light.
  • Another method consists in recording the sound in the known manner on a steel wire, and performing transmission synchronously with the image.
  • a developed but still light sensitive film carrying said images, said film having its maximum sensitiveness to light over a predetermined band of wavelengths, and means for successively scanning elementary areas of said film to produce a television signal, said means including a source of light having a wavelength lying outside the range of said predetermined band.
  • an undeveloped film carrying said images and having an emulsion thereon of. maximum sensitivity to one portion of the light spectrum, means for applying a developing agent to said film, and means for successively scanning elemental areas of said developed film with light corresponding to a different portion of the spectrum, while said film is still light sensitive, to produce a television signal.
  • an undeveloped film carrying said images and having thereon an emulsion with maximum sensitivity to light in the range of 0422-0492 microns
  • means for applying a developing agent to said film and mean for successively scanning elemental areas of said developed film With light in the range of 0.64'7-0.800 microns, to which said film is relatively insensitive, while still light sensitive, to produce a television signal.
  • the method of generating television signals which includes the steps of exposing a motion picture film to photograph the image to be transmitted, partially processing said film to develop said image, scanning said film by illuminating one picture point thereof at a time while still sensitive to certain wave lengths of light, with a wavelength band to which the film is relatively insensitive, and varying an electrical current in response to the light transmitted by said film to generate the required signal.
  • permanently recording changing scenes which includes the steps of exposing a motion picture film which is sensitive to a limited band of wavelengths to photograph such scenes, partially processing said film to develop and fix the latent images thereon, scanning said film with light of wavelengths to which said film is relatively insensitive while said processing is incomplete and the film is still capable of being afiected by wavelengths of said first-mentioned band, and. then 10 carrying said processing to completion.

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  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Particle Formation And Scattering Control In Inkjet Printers (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Details Of Cameras Including Film Mechanisms (AREA)
  • Facsimile Scanning Arrangements (AREA)
US641092A 1931-11-05 1932-11-03 Television apparatus Expired - Lifetime US2075360A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE409400X 1931-11-05
DEF73649D DE681369C (de) 1932-06-30 1932-06-30 Zwischenfilmsender mit einer Aufnahmekamera und angeschlossenen Sendegeraeten

Publications (1)

Publication Number Publication Date
US2075360A true US2075360A (en) 1937-03-30

Family

ID=31888969

Family Applications (1)

Application Number Title Priority Date Filing Date
US641092A Expired - Lifetime US2075360A (en) 1931-11-05 1932-11-03 Television apparatus

Country Status (4)

Country Link
US (1) US2075360A (de)
BE (1) BE391947A (de)
FR (3) FR43616E (de)
GB (2) GB409400A (de)

Also Published As

Publication number Publication date
FR43616E (fr) 1934-07-19
FR43617E (fr) 1934-07-19
GB409400A (en) 1934-05-03
FR744606A (de) 1933-04-21
GB410338A (en) 1934-05-17
BE391947A (de)

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