US2486717A - Synchronization of camera and television receiver tube - Google Patents

Synchronization of camera and television receiver tube Download PDF

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Publication number
US2486717A
US2486717A US655652A US65565246A US2486717A US 2486717 A US2486717 A US 2486717A US 655652 A US655652 A US 655652A US 65565246 A US65565246 A US 65565246A US 2486717 A US2486717 A US 2486717A
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US
United States
Prior art keywords
camera
television
frame
screen
shutter
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
US655652A
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English (en)
Inventor
Carl D Maurer
Walter J Swenson
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.)
Paramount Pictures Corp
Original Assignee
Paramount Pictures Corp
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 to BE475197D priority Critical patent/BE475197A/xx
Application filed by Paramount Pictures Corp filed Critical Paramount Pictures Corp
Priority to US655652A priority patent/US2486717A/en
Priority to ES0179160A priority patent/ES179160A1/es
Priority to GB21239/47A priority patent/GB681541A/en
Priority to FR1015403D priority patent/FR1015403A/fr
Application granted granted Critical
Publication of US2486717A publication Critical patent/US2486717A/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
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B15/00—Special procedures for taking photographs; Apparatus therefor
    • G03B15/08—Trick photography

Definitions

  • Another important reason why it is desirable to make such a photograph is that it provides a means for projecting a television scene upon the large screen-of a motion picture theatre with sumcient picture quality as to be regularly acceptable to paying patrons. For example, a sports event might occur in one city, be picked up and transmittedby television to another lo- 'cation in the same or another city, received at a motion picture theatre where the television receiver screen is photographed, the lm developed and immediately yprojected upon the screen for a large audience.
  • television signals are transmitted at 525.
  • Present motion picture standards involve the photographing and projecting of motion picturesat a frame frequency of 24 per second.
  • Figure 2 is an illustration of the characteristics of a motion picture camera
  • Figure 3 is an illustration coupled with a block diagram of the method and means employed in the present invention.
  • Figure 4 is a schematic or circuit diagram of the electronic circuits shown in block form in Figure 3.
  • Figure 2 is drawn to the same time scale as Figure l and illustrates the fact that in a motion picture camera the lm moves from frame to frame during an interval of approximately 1/120 of a second and is stationary for an interval of approximately 4/120 of a second, so that the time between frame is 5/1720 or 1/24 of a second.
  • N it will show on the screen before the caxxral camera will therefore miss the second half of the first field of frame number 2. However, it will record the entire second field of the second frame and the entire first field of the third frame so that it will again record an entire frame. The film then will move again and the shutter be closed during the next 1/izo of a second so that it will miss the first half of the second eld of the third frame of the television picture. The shutter 'will be open, however, for the second half of the second field of this frame, for the rst eld of the fourth frame and for the first half of the second eld of the fourth frame, again recording one entire frame.
  • the camera film will again move for 1/120 of a second while the shutter is closed and will reopen with the beginning of the fth frame so that it will record the entire fifth television frame.
  • the phase of camera lin and television frame is the saine as at frame number I so that it will be obvious that succeeding frames of film and pictures will be the same as those just described.
  • the picture taken on the film will be one which will be a record of the picture appearing on the television screen. It will not, however, be a good one because of the mechanical variations of the camera shutter. That is, in order to have a good film record the synchronization between the camera shutter and the television frame must be perfect and lthe shutter opening must be exact. While the foregoing has been described in terms of securing a picture -of exactly one full television frame during each shutter opening actually this will not occur due to these mechanical variations. As one line of a Atelevision picture occurs in approximately 64 -microseconds the action of the camera shutter must be accurate within only a few microseconds in order to obtain a uniformly good result. Such mechanical accuracy is extremely difficult and if it may be achieved at all would be inordinately expensive.
  • the camera shutter action is not accurate to this extent it will record on the lm something more or less than exactly one frame of the television picture.
  • the result of this is that if the shutter is open too long by, say 64 microseconds, one line of the television picture will be scanned twice while the shutter is open and a clark line will appear across the iilm at this point. If the shutter is open too short a time by, for example, 64 microseconds a light line will appear across the picture, where this line is not scanned during the open shutter period. Such lines are very noticeable and would be highly objectionable in a theatre projection.
  • Figure 3 illustrates one exemplicationi of the method and apparatus which we have invented for avoiding the difficulties described above.
  • a standard motion picture camera which is operated by a synchronized motor from any 60 cycle power line.
  • a pulse which may be controlled in terms of a fraction of a microsecond which occurs A24 times per second and which is 1/120 of a s'econdin' duration, and use this pulse to blank gnam the television screen tube or kinescope, synchronously with the movement of the film in the camera.
  • a television screen with short persistence luminescence which will be referred to later.
  • the apparatus illustrated in Figure .3 which we have found useful in practicing our invention, and which is simply illustrative of many different types of apparatus which might be used, includes a full wave rectifier I which is supplied With a voltage from a 6() cycle power line.
  • the rectier I produces a 120 cycle wave from the i 60 cycle wave. It supplies a blocking oscillator 2 which produces 120 pulses per second from the cycle wave. These pulses are supplied to a multivibrator 3 which produces 24 square waves per second each having a duration of exactly 1/120 of a second.
  • These square waves are supplied to the television tube or kinescope 4 to blank the tube during the duration of each square wave in a manner which will be well understood.
  • the camera 5 is driven by a synchronous motor from the same power line which supplies the rectifier I.
  • suitable mechanism such, for example, as a switch which opens and closes in series with a voltage source, the camera produces a series of synchronizing pulses which match those produced by the multivibrator 3.
  • the pulses from the multivibrator and those from the camera may both be applied to a cathode ray tube for visual comparison and manual adjustment of the multivibrator for synchronism with the camera. 'I'his adjustment is Very simple and once made need not be repeated during the operation. It will be noted that the multivibrator 3 produces one square wave for each ve pulses, and the synchronizing problem involves only selecting which of the ve pulses it will follow.
  • a pulse from the camera could be used as a blanking pulse for the television screen, as one simple method of automatic synchronization.
  • the blanking pulses supplied to the Itelevision tube from the multivibrator are derived fromthe local power line and not from the incoming television signal.
  • the reason for this is that the camera will be operated from the'local power line and the blanking pulses must be in synchronism with the operation of the camera. They need not, however, be in synchopposition with the television picture. That is,. we have illustrated in Figures 1 and 2 a phase of operation in which the lm begins to record at the beginning of every fourth lm frame and at the beginning of every fifth television frame in exact phase. These frames have been so illustrated for convenience of explanation. Actually, the
  • phase relationship between lm and television pictures is immaterial, the important factor being that the film be exposed for the exact duration of one television frame.
  • the safety factor permits the mechanical movement of the film without the precise timing required of a shutter where one is used with an attempt to have it open for the exact length of time of one television frame.
  • the camera 5 may be a standard motion picture camera, and if such a standard camera is used it will contain apparatus for recording sound on the film.
  • the sound accompanying the television scene being photographed may therefore be supplied to the camera in the form of an electrical signal derived from the incoming complete television signal, and photographed upon the nlm in the form of a sound track in the usual manner.
  • the film upon being developed will therefore contain the usual sound track for motion picture projection with accompanying sound by the use of the standard sound motion picture equipment found in most motion picture theatres.
  • Apparatus for photographing a scene appearing upon a television receiver which comprises a cathode ray tube, a 60 cycle power line, a full-wave rectifier connected thereto producing a cycle wave, a blocking oscillator connected to said rectifier to produce 120 pulses per second, 'a multivibrator connected to said blocking oscillator to produce 24 blanking pulses per second yeach having a duration of 1/120 second, a motion picture camera having no shutter, means for ⁇ applying said blanking pulses to the television receiver tube to blank it during .the movement of the film in the camera, means for driving said camera from said 60 cycle power line in synchronism therewith, and means for selecting the blanking pulses in synchronism with the movement of the film.
  • Apparatus for photographing a television image comprising a television tube for reproducing said image, a motion picture camera for photographing said image on said tube and a power supply for operating said tube and said camera, a rectier circuit connected to said power sup-v ply and to a rst electrical pulse generating circuit generating a series of consecutive pulses at a predetermined frequency, a second electrical pulse generating circuit connected to said first electrical pulse generating circuit and producing pulses at the frame frequency rate of said camera, said second pulse generating circuit being selectively triggered by said ⁇ first pulse generating circuit, said second pulse generating circuit being connected to said television tube to control the on and off time of the image produced by said tube and a monitoring tube connected to said second pulse generating circuit and said camera for comparing the timing of said camera and said second pulse generating circuit for synchronizing the off time of said image with the move- 'ment of the film in saidcamera.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Television Signal Processing For Recording (AREA)
  • Transforming Light Signals Into Electric Signals (AREA)
  • Endoscopes (AREA)
US655652A 1946-03-20 1946-03-20 Synchronization of camera and television receiver tube Expired - Lifetime US2486717A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BE475197D BE475197A (fr) 1946-03-20
US655652A US2486717A (en) 1946-03-20 1946-03-20 Synchronization of camera and television receiver tube
ES0179160A ES179160A1 (es) 1946-03-20 1947-07-31 UN PROCEDIMIENTO FOTOGRáFICO, CON EL APARATO CORRESPONDIENTE
GB21239/47A GB681541A (en) 1946-03-20 1947-08-05 Improvements in telecinematography
FR1015403D FR1015403A (fr) 1946-03-20 1947-08-07 Perfectionnements aux procédés et matériels photographiques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US655652A US2486717A (en) 1946-03-20 1946-03-20 Synchronization of camera and television receiver tube

Publications (1)

Publication Number Publication Date
US2486717A true US2486717A (en) 1949-11-01

Family

ID=24629794

Family Applications (1)

Application Number Title Priority Date Filing Date
US655652A Expired - Lifetime US2486717A (en) 1946-03-20 1946-03-20 Synchronization of camera and television receiver tube

Country Status (5)

Country Link
US (1) US2486717A (fr)
BE (1) BE475197A (fr)
ES (1) ES179160A1 (fr)
FR (1) FR1015403A (fr)
GB (1) GB681541A (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2604535A (en) * 1948-12-01 1952-07-22 Gen Precision Lab Inc Synchronizing and phasing system for television recorders
US2611027A (en) * 1948-07-10 1952-09-16 Jr John Hays Hammond Television still-picture transmitting and recording system
US2783300A (en) * 1950-05-18 1957-02-26 Raibourn Paul Film recording from television receiver cathode ray tube
US2859275A (en) * 1951-04-02 1958-11-04 Paramount Pictures Corp System for recording television images on film
US3317663A (en) * 1962-11-05 1967-05-02 Optische Ind De Oude Delft Nv Device for cinematographically recording the screen image of television display tubes
US20040004113A1 (en) * 1999-06-21 2004-01-08 Lincoln Global, Inc., A Delaware Corporation Coded welding consumable

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB394496A (en) * 1931-03-28 1933-06-29 Manfred Von Ardenne Television method
US2251786A (en) * 1938-09-30 1941-08-05 Rca Corp Television recording apparatus
US2373114A (en) * 1941-06-21 1945-04-10 Du Mont Allen B Lab Inc Television film recording and projection

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB394496A (en) * 1931-03-28 1933-06-29 Manfred Von Ardenne Television method
US2251786A (en) * 1938-09-30 1941-08-05 Rca Corp Television recording apparatus
US2373114A (en) * 1941-06-21 1945-04-10 Du Mont Allen B Lab Inc Television film recording and projection

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2611027A (en) * 1948-07-10 1952-09-16 Jr John Hays Hammond Television still-picture transmitting and recording system
US2604535A (en) * 1948-12-01 1952-07-22 Gen Precision Lab Inc Synchronizing and phasing system for television recorders
US2783300A (en) * 1950-05-18 1957-02-26 Raibourn Paul Film recording from television receiver cathode ray tube
US2859275A (en) * 1951-04-02 1958-11-04 Paramount Pictures Corp System for recording television images on film
US3317663A (en) * 1962-11-05 1967-05-02 Optische Ind De Oude Delft Nv Device for cinematographically recording the screen image of television display tubes
US20040004113A1 (en) * 1999-06-21 2004-01-08 Lincoln Global, Inc., A Delaware Corporation Coded welding consumable

Also Published As

Publication number Publication date
FR1015403A (fr) 1952-09-29
BE475197A (fr)
GB681541A (en) 1952-10-29
ES179160A1 (es) 1948-01-16

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