US1928553A - Method of scanning images in television - Google Patents

Description

p 1933- R. BARTHELEMY ET AL ,928,553

METHOD OF SCANNING IMAGES IN TELEVISION Filed Sept. 12, 1930 2 Sheets-Sheet 1 Ni .1 Fl

Se t. 26,1933. R. BARTHELEMY ET AL 1,928,553

' METHOD OF SCANNING IMAGES IN TELEVISION Filed Sept. 12, 1930 2 Sheets-Sheet 2' Patented Sept. 26;, 1933" r l i I 1,928,553 I METHOD or Somme nwaons IN I 'rELnvrsroN Rene Barthelemy, Fontenay aux Roses, and Jean lLe Duc, Vancresson, France, assignors to Compagnie pour'la Fabrication des Compteurs et Materiel dlflsines a Gas, Seine, France, a joint-stock company of France Application September 12, 1930, Serial No.

481,493, and in France September 25, 1929 4 Claims. (or. 178-6) In the present systems usedfor television, the These discswill be homothetic. As shown in image is scanned at the transmitting end and Fig. 3, the holes are located along two semireconstructed at the receiving end by making use spirals of opposite pitch.- I of two perpendicular movements, one at high fre- A particular case is provided by telecin'ema- 5 quency, 400 to 500 cycles per second and the tography where the continuous displacement of '55, other at low frequency, to cycles per second. the film at the transmitting end calls for discs The low frequency scanning of thefield produces having different perforations at the transmitting on the eye the impression that the background and receiving ends, for scanning in the two/opof the image is continually moving in a fixed diposite directions. This solution is however pracio rection, namely that in which the image is being ticable and its only drawback is thatit requires 60," i

scanned. an additional scanning disc at thetransmitting The present invention isconcerned with a sysend. In this case, the holes will be distributed tem that obviates this drawback, and gives the over two semi-spirals not only of differentkbut observer an impression of fixedness of the backalso of contrary pitch. The receiving. disc will 1 ground of the reconstituted image. not be changed whether television or" telecine- "(s,

According, to the present invention, the image matography be involved and this is the essential is scanned twice, in opposite directions, in less practical condition. y y l I a T 6 o a S fi b at the sending and at v The same disc can likewise be used for send I the receiving end in order toavoid the illusion of mg cinematographic and lined images or even the displacement of the background of theimage for the television of animated subjects andthe in a fixed direction. teleprinting of documents; to this end; in the I The invention has been illustrated diagramcase of cinematography and even in the case of matically in. the accompanying drawings, in teleprinting, an intermittent movement will be which: I imparted to the film as is accomplished in or- Fig. 1 shows the image being scanned in one dinary moving picture technique andjadvantage direction and f v c will be taken of theinstant ofdwell ofisaidfilm Fig. 2 shows the image being scanned in the opto scan the image just as if a fixed image were posite direction. A concerned. v v Fig. 3 shows a scanning disc the holes of which The novel result will be to simplify the trans- 3 lie on two semi-spirals. mitting mechanism by making it more general Instead of sending out successively the contiguin character and by increasing the rapidityof ous modulated luminousbands resulting from the the teleprinting processes. l ordinary scanning operation, only half these Y We claim: p bands, for x mpl r n in n y ne 1. A method of scanningimages in television, 351321101 Out of two- T total Scanning Op on in telecinematography and the like, which consists 85.,- the direfltiOn f1 (Fig 1) W e accomplished in in scanning one in every two bands of a series of" half the usual time and a surface of constant adjacent bands, of an image and traversing said illumination at the transmitting end will be repreimage from end to end in a directional; right sented by a plurality of dark bands alternating angles to said bandshalf the lines'of theirnage 4 with light bandsas shown in Fig. l. beingthus scanned in a very short timeless than 9.0;

The oth half of the bands Will be xp o y one twentieth of a second, the whole image being Sca i the'image in the pp t d tion, scanned in less than one tenth of a second,iand i. e. f2 and gives the result illustrated in Fig. 2. in then traversing said image in the opposite The superposition of the two images in less direction and scanning those bandsnot'scanned 45 t 1% 86001161, gives the u image i which during the first traverse of theimage. 95. the two impressions of displacement are in op- 2. In a television apparatus, a scanningdisc position and cancel out on the eye of the observer. having not more than two series of holes lying This will be readily carried into effect by suitalong two semi-spirals of opposite and "contrary ably locating the holes both in the discs at the pitch and so arranged that the bands scanned 50'sending and in the ones at the receiving end. through the holes ofone semi-spiral alternate in position with those scanned through the holes of the other spiral.

3. The method of scanning a picture in a television system comprising scanning certain of the 5 picture elements throughout the whole picture in one direction and thereafter scanning the other elements in another direction.

4. The method of scanning a picture in a tele-

Images