Патент USA US2129035код для вставки
Sept. 6, 1938. K. SCHLESINGER 12,129,035 TELEVISION TRANSMITTER Filed Nov. 1, 1935 11 éw7,N Jaye/1MP." mam ~v 2,129,035 Patented Sept. 6, 1938 UNITED STATES PATENT OFFICE 2,129,035 TELEVISION TRANSDHTTER . Kurt Schlesinger, Berlin, Germany, assignor to Radioaktiengesellschaft D. ’S. Loewe, Berlin Steglitz, Germany Application November 1, 1935, Serial No. 47,789 In Germany November 2, 1934 1 Claim. 5 10 15 20 25 30 35 .10 45 50 55 , (01. its-7.1) The present invention relates to a television ing line I3 is projected with excessive brightness by means of the optical system illustrated in Fig. transmitter according to the method of inter laced lines, which has already been described in ‘ 1. According to the invention, the ‘radial length principle in the application Ser. No. 36,008/35 ‘ of this starting line It is made to be greater than and which produces the synchronizing impulses the height of the image area l2. The line im~ pulses are, as well known, produced when the disc by an optical method. The invention will be explained by means of apertures pass the margin l3. Now to generate the image change impulses there are employed the accompanying drawing, in which two tangential slits l4 and I5 which are arranged Fig. 1 is a diagram showing a longitudinal sec tion of the optical arrangement according to the in the disc 9 outside of the area l2 but just within the starting line l3 which are displaced invention, whilst Fig. 2 is a plane view of the scanning disc and to one another to the extent of exactly the length Fig. 3 of the rotating diaphragm described in of one half image line, and which possess a width sometimes larger than a scanning aperture, such the speci?cation. ‘ In Fig. 1 there is illustrated a possible form of as may be conveniently produced in a mechaniembodiment of the arrangement according to cal stamping operation. When the image change slits l4 and i5 pass the invention. The light of the arc-lamp l is projected evenly by a hollow re?ector 2 over the the extended starting line l3 there must impinge surface of the film 3 and a slotted diaphragm 4. on the photo-cell, in accordance with the above, a very much greater amount of light than when The light passing through the latter is so de ?ected by means of two prisms 5 and 6 that the a scanning aperture passes the starting line, as both the width of the starting line l3 as well as diaphragm 4 is reproduced sharply simultaneous ly with the ?lm through the main lenses 1 and the height of the slits I4, 15 equal the width of 8 on the screen of the Nipkow disc 9, so that it several image points. There thus immediately appears as a white margin I3 (Fig. 2) close to a would take place the described “choking” of the vertical edge of the ?lm image I2. By means of photo-ampli?er H. According to the invention this is avoided by a regulable weakening of the an auxiliary cylindrical lens It), the light inten sity passing the. slot 4 is increased to such an light of the starting line l3. In Fig. 1 there are shown two screws l6 (one covered by the other extent that it by far exceeds all intensities pass one), which may be turned into the path of light ing the ?lm 3. According to the invention the two groups 011 over the slotted diaphragm 4. The shadow of these screws appears, therefore, on the surface signals for synchronization, viz., the line im of the disc as I6 i6’, as shown in Fig. 2. In this pulses and the image-change impulses are pro duced at the same amplitude by the following way it is easily made possible to equal the po tential of either of the long signals to that of the reasons. It has been found in practical opera tion that a “choking” of the ampli?er H is not short signals. As addition to the described ar to be avoided when the image-change impulses rangement there must be employed a diaphragm, possess a considerably greater amplitude than which is designated 18 in Fig. l, synchronously the line signals. The amount of current carried rotating at half the circumferential velocity of _ by these long signals is suf?cient in order, by the Nipkow disc 9. Fig. 3 shows the form of the diaphragm. The extensive charging of the coupling condenser of the ampli?er H, to cause a blocking of the same, diaphragm contains two spiral apertures H), which fades but slowly. A second interference which serve to expose alternately one of the ap in operation always exists when the method of erture spirals of the Nipkow disc. Further, it contains two windows 29 and El exposing alproduction in respect of the two synchroniza ternately one of the apertures l4 and i5 (Fig. tion signals is not of such a kind that these sig nals are given completely independently of the 2). (If the sequence of frame change impulses image signals amplitude. Any superposition of is desired to be reversed, the windows are to be the image and the synchronization signals must placed at Ma and Zia.) The spokes 22 and 23, which connect the outer edge with the be avoided. In Fig. 2 the Nipkow disc 9 is shown in a front inner portion of the diaphragm, are prefer ably so disposed that the shadow formed by View. It is provided with a double-spiral of aper tures as described in the application Ser. No. the same impinges on the disc following the pass ing of the windows 20, 2|. In this way there 36,008/35. The spirals of‘ this disc de?ne a trap occurs an automatic darkening of the later porezoidal screen l2, at the edge of which the start 5 10 15 20 25 30 35 40 45 50 55 2 2,129,035 tions of the return line. It is sufficient if these spokes are two or three image points in width, inasmuch as the same are relieved mechanically in the case of a steady rotation. The spokes as UK shown apply to- the ?rst stated form of dia phragm. For the complementary diaphragm the spokes must be disposed behind the windows 20a, 21a. The distance of the diaphragm from the disc must be made as small as possible, as other lo wise there will be loss of light and lack of sharp ?lm images according to the interlaced line method comprising a scanning disc provided with a spiral of apertures having two turns, a spiral aperture disc rotating at half the speed of the scanning disc and uncovering at once one of said apertures, a photo-cell arranged in operative re lationship thereto, and means for projecting an image of the ?lm to be transmitted onto said scanning disc; means for simultaneously project ing a light margin of great brightness onto said 10 ness of the shadows. The optical system accord ,. disc close to one radial edge of said image projec ing to the invention provides otherwise a guar tion. and .outreaching said edge, two circumfer antee for the accuracy of the signals by reason of ential scanning slits in said disc having a tan the main Nipkow disc 9 alone, on which there is gential distance one from another corresponding located the sharp optical reproduction. The dia to exactly the half of an image line and being 15 phragm I8 has no in?uence on the accuracy of arranged outside the area of the image projec the signals, but has the function merely of‘ a tion so as to obtain. frame change impulses by periodical covering for undesirable-passage. slots. the same said photo-cell when said margin is The same, therefore, may be produced from a passed by said slits, and two windows in said ro ?exible material with comparatively small degree tating diaphragm so arranged as to expose alter 20 of‘ accuracy, and, therefore, more simple and nately one of‘ said circumferential slits. cheaper than the Nipkow disc 9. I claim: In a television transmitter for transmitting KURT SCI-ILESINGER.