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    Improvements in recording television pictures on cinematograpic film
    41.
    发明专利
    Improvements in recording television pictures on cinematograpic film 未知

    公开(公告)号：GB784856A

    公开(公告)日：1957-10-16

    申请号：GB424954

    申请日：1954-02-12

    Applicant: SOC NOUVELLE OUTIL RBV RADIO

    IPC: C07C45/50 ,  H04N5/84

    Abstract: 784,856. Television. SOC. NOUVELLE DE L'OUTILLAGE R.B.V. ET DE LA RADIOINDUSTRIE. Feb. 12, 1954 [Feb. 21, 1953; March 16, 1953], No. 4249/54. Class 40 (3). In an arrangement for recording interlaced television images on intermittently moving kinematographic film by exposing the film during alternate field scans of the cathode-ray tube 6 which reproduces the images the fields which occur when the film is obturated being photographically effective (due to the " afterglow " of the tube) in the subsequent exposure period the gain of the video amplifier 3 which supplies the television signals to the tube 6 is controlled in accordance with a gain control voltage having the waveform shown at J (Fig. 4), the positively-going portions occurring during the non-exposure and the negatively going portions occurring during the exposure of the film in order to compensate for the light decay characteristic of the screen of tube 6. As shown, the gain of amplifier 3 is controlled by clamping its control grid to the potential of waveform J by means of a clamp circuit 11 controlled by clamping pulses occurring during line retrace periods so that its gain remains constant during line-trace periods but varies from one line to the next in accordance with the variation of waveform J. The output of amplifier 3 is then supplied to the tube 6 via a second amplifier 14 the control grid of which is clamped to a reference potential (to restore the D.C. level) by means of a second clamp circuit 15 also controlled by pulses occurring during the line retrace periods. To compensate for the " gamma " effect of tube 6 the signals are initially (prior to input amplifier 3) amplified in an amplifier having a suitable characteristic and the gain of which is controlled in similar manner to that of amplifier 3 (Fig. 8, not shown). Specification 640,186 is referred to.

    46.
    发明专利
    未知

    公开(公告)号：FR1098672A

    公开(公告)日：1955-08-17

    申请号：FR1098672D

    申请日：1954-01-23

    Applicant: SOC NOUVELLE OUTIL RBV RADIO

    Inventor： ERNYEI H ,  SIMONDCOTE P

    IPC: H04N5/18 ,  H04N5/38 ,  H04N5/40

    Abstract: 794,348. Television. SOC. NOUVELLE DE L'OUTILLAGE R.B.V. ET DE LA RADIOINDUSTRIE. Jan. 24, 1955 [Jan. 23, 1954], No. 2128/55. Class 40 (3). In a negative feedback loop for stabilizing the black level in a radiated television signal, the radiated signal is rectified at 22 and applied to a first gate V4A which is rendered conducting during a period extending over the black-level back porch so as to pass a current proportional to the actual black level radiated. A second gate V4B, connected in parallel with the first at the anode, conducts at a level corresponding to the correct black level and is rendered non- conducting during the black-level porch. The commoned anodes produce therefore output pulses whenever the current levels in the two gates differ and these pulses are applied through stages V5 and V6 to control the level in a D.C. restoration circuit which functions to clamp the video signal applied to modulate the transmitter. The D.C. restoration circuit may be of the type described in U.S.A. Specification 2,299,945. The switching of gates V4A, V4B is effected by a trigger circuit V1A, V1B which is triggered on the rear edge of the line synchronizing pulse so as to produce an output pulse during the back porch interval. The pulse is applied via phase inverter V2 directly to the grid of gate V4B and via stage V3 to the cathode of gate V4A. The pulses employed to actuate the D.C. restoration circuit are of shorter duration than switching pulses.

    Improvements to infra-red sensitive luminescent materials
    50.
    发明专利
    Improvements to infra-red sensitive luminescent materials 未知

    公开(公告)号：GB818069A

    公开(公告)日：1959-08-12

    申请号：GB3576455

    申请日：1955-12-13

    Applicant: SOC NOUVELLE OUTIL RBV RADIO

    IPC: C09K11/56

    Abstract: In the production of an infra-red phosphor consisting of strontium sulphide, activators (Pb, Cs, Sm) and lithium fluoride as an auxiliary flux (see Group XL (a)), the strontium sulphide is obtained from a highly purified stronium nitrate (see below) by reaction with sulphuric acid and further reduction by ammonia or hydrogen at 1000 DEG C. The lithium fluoride is prepared by passing ammonia through distilled hydrofluoric acid until neutralization and reacting the ammonium fluoride so produced with lithium sulphate purified in the same manner as strontium nitrate below. The strontium nitrate is purified from heavy metal insoluble material by successive contacting of an aqueous solution thereof with a solution of oxyquinoline in chloroform or carbon tetrachloride followed by successive contacting of the strontium nitrate solution with a solution of diphenylthiocarbazone in the same solvents. The strontium nitrate is thereafter crystallized. Alternatively the strontium nitrate solution may be adjusted to a pH 4 by adding ammonia or acetic acid and a solution of oxyquinoline in chloroform added. After successive washings at this pH a second series of operations is performed at a pH=7 and then a similar washing procedure is performed with a solution of diphenylthiocarbazone in carbon tetrachloride pH's of 4, 7 and 10 successively. The strontium nitrate so purified is treated with twice distilled sulphuric acid and the strontium sulphate precipitate is washed with distilled ethyl alcohol, vacuum dried and reduced in an alumina crucible at 1000 DEG C. with ammonia or hydrogen. Specifications 659,455, 650,458 and 650,459, [all in Group XL (a)], are referred to.

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