US3806244A - Film handling apparatus - Google Patents

Film handling apparatus Download PDF

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Publication number
US3806244A
US3806244A US00189623A US18962371A US3806244A US 3806244 A US3806244 A US 3806244A US 00189623 A US00189623 A US 00189623A US 18962371 A US18962371 A US 18962371A US 3806244 A US3806244 A US 3806244A
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United States
Prior art keywords
deflector
film
mirror
claw
pulse
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Expired - Lifetime
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US00189623A
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English (en)
Inventor
O Freudenschuss
E Keznickl
H Broeckl
F Forch
G Patels
L Rollenitz
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Individual
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Individual
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Priority claimed from AT945570A external-priority patent/AT299702B/de
Priority claimed from AT998370A external-priority patent/AT298242B/de
Priority claimed from AT1045770A external-priority patent/AT301348B/de
Priority claimed from AT1060170A external-priority patent/AT303526B/de
Priority claimed from AT189371A external-priority patent/AT305771B/de
Priority claimed from AT294471A external-priority patent/AT312422B/de
Application filed by Individual filed Critical Individual
Priority to US05/441,000 priority Critical patent/US4003645A/en
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Publication of US3806244A publication Critical patent/US3806244A/en
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    • 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
    • G03B41/00—Special techniques not covered by groups G03B31/00 - G03B39/00; Apparatus therefor
    • G03B41/02—Special techniques not covered by groups G03B31/00 - G03B39/00; Apparatus therefor using non-intermittently running film
    • G03B41/04—Special techniques not covered by groups G03B31/00 - G03B39/00; Apparatus therefor using non-intermittently running film with optical compensator
    • G03B41/10—Special techniques not covered by groups G03B31/00 - G03B39/00; Apparatus therefor using non-intermittently running film with optical compensator with oscillating reflecting member

Definitions

  • ABSTRACT Film handling apparatus has a continuously operated Austria 9455/70 drive for passing the film through a film gate, and a i 9983/70 tilting deflector which is moved in synchronism with Austria 10457/70 the film during'its forward tilt to compensate for the A f 0601/70 film motion in the film gate.
  • Mechanical. and electrical 'f 1893/71 drives for the deflector are described as also are en- Austria 2944/71 gy transfer means for g g the mirror to an IIIIIIIIIIIIIIIIIIIIIIIII 352/109 abrupt halt at the end of its return tilt motion.
  • FIG/5 FIG/4 mwmmmzamm 3806244 SHEET USDF11 FIG. I7
  • This invention relates to strip handling apparatus such as a cine camera or projector, utilising a strip such as a film which is moved continuously through a gate. More particularly the invention is concerned with details of an optical system having a deflector which is driven to compensate for the motion of the strip with respect to the system when the apparatus is in use.
  • the deflector with which the invention is concerned performs an oscillatory motion having a forward sweep motion during which it is synchronised with the strip movement through the gate, and a return or fly-back motion when the deflector is returned relatively rapidly to an initial position in order to commence the next forward sweep.
  • the deflecting drive producing a forward motion of the deflector to follow movement of the film and a comparatively rapid return motion
  • an arrangement for synchronizing the deflecting drive with the film drive and energy transfer means for halting in recoilless manner the defleeting drive at the end of the return motion such means transferring from the drive a quantity of energy which is substantially equal to the dynamic energy of said deflector on reaching said end.
  • the energy transfer means may operate in one of two ways.
  • cancellation of the dynamic energy of the deflector is achieved substantially instantaneously by injecting into its drive an electrical signal having an equal and opposite energy content.
  • This may be achieved with a galvanometer type deflector drive, by injecting into the galvanometer an impulse of predetermined shape.
  • This shape is preferably combined with an electrical impulse required to sweep the deflector forwardly in synchronism'with the film or strip and the two impulses are suitably provided by a double impulse generator operated in synchronism with the drive for the film.
  • the energy transfer means transfer the dynamic energy of the deflector drive to a buffer whose motion can be subsequently halted when separated by the impact from the deflector drive.
  • the mass of the buffer is matched to that of the deflector so that with impact of the latter on the former the deflector dynamic energy is transferred in toto to the buffer and its return motion is in this way brought to an abrupt halt.
  • the buffer is meanwhile jolted into motion by the impact and its energy can be dissipated thereafter in any convenient way without influencing the deflector drive.
  • strip handling apparatus having an arrangement composed of an objective lens unit disposed between a picture window in a gate and a tilt-mirror, such arrangement optically adjusting the moving image position of a guided perforated strip, the tilt-mirror being rockable about an axis under the control of a scanning mechanism which includes a claw positionally controlled by a perforation of the strip when engaged therewith and mounted on an arm so as to move arcuately about a radius which, allowing for a i 5 percent tolerance, is twice the distance of the window from the lens unit.
  • a third aspect of the invention there is provided film handling apparatus with an arrangement formed with a tilt-mirror to compensate optically for movement of the image picture of a perforated strip guided around an optically smooth partcylindrical surface, the tilt-mirror being driven to turn about an axis provided by a torsion bar having at one end a first fixture holding the torsion bar end stationary, intermediate its ends a second attachment fixture on which the tilt-mirror is mounted, and at its second end the torsion bar is provided with a third fixture to which is attached a mechanism which arcuately moves the mirror by engaging a perforation of the perforated strip while travelling around the cylindrical surface which is centred on the axis of the torsion bar.
  • strip handling apparatus having a single tiltable optical deflector to follow motion of a moving strip and which is driven through a drive coupling having two couplers which operate in succession to each produce a relatively slow forward follow motion of the deflector, each coupler being decoupled from the mirror on completion of the slow forward motion and a further driven then returning the deflector rapidly to its initial position where it is engaged by the second coupler to execute asecond forward motion during which the first coupler returns to itsinitial position.
  • FIG. 6 is an electrical block circuit showing control circuitry for a tilt-mirror drive motor
  • FIG. 7 isa block circuit showing another way of synchronizing electrically the control of the tilt-mirror drive;
  • I FIG. 8 shows diagrammatically a further. way of electrically controlling the tilt-mirror drive;
  • FIG. 9 shows a way of extracting a synchronizing impulse from a film perforation
  • FIG. 10 represents a preferred arrangement of impulse generator employing an information carrier
  • FIG. 11 shows diagrammatically signals obtained from respectively four tracks recorded on an information carrier
  • FIG. 12 shows an alternative arrangement of information carrier to that shown in FIG. 10;
  • FIG. 13 shows how an impulse may be divided between two different recording tracks
  • FIG. 14 shows diagrammatically a centrifugal governor for controlling variable electrical resistances employed in the arrangements shown in FIGS. 9 to 11;
  • FIG. 15 shows diagrammatically a further way of producing electrical impulses for controlling movement of a tilt-mirror, or other form of optical deflector and synchronised with the movement of a film strip;
  • FIG. 16 shows schematically a further arrangement using a telecentering device and a claw arm for maintaining synchronous movement between a film strip and a tilt-mirror
  • FIG. 17 shows diagrammatically an electrical waveform supplied to a ballistic galvanometer drive for a tilt-mirror
  • FIG. 18 shows an arrangement for scanning a film strip and which instead of using telecentering as in FIG. 16, uses a film gate having a zone of increased'curvature;
  • FIG. 19 shows in block diagrammatic form a circuit for triggering release of a double impulse from a magnetic field dependent resistor
  • FIG. 20 shows diagramatically, and with the help of a block circuit diagram, an arrangement for synchronizing motion of a tilt-mirror deflector with the movement of a film through a film gate;
  • FIG. '21 shows an arrangement for terminating flyback motion of a tilt-mirror in a recoilless manner and without mechanical breaking
  • FIGS. 22 and 23 respectively show modifications of the recoilless arrangement of FIG. 21;
  • FIGS. 24 and 25 show diagrammatically in respectively side and end views an arrangement for maintaining the angular movement of a tilt-mirror to half that of a claw arm by means of a torsion bar; FIG. 25 being taken in the direction of the arrow XXV in FIG. 24;
  • FIGS. 26 and 27 respectively show in side and plan views a cam-driven arrangement for maintaining forward tilt motion of a mirror deflector in step with DESCRIPTION OF PREFERRED EMBODIMENTS
  • the individual film frames are projected by means of a swivel-mounted tilting mirror and a projector objective assembly.
  • the mirror is so moved that motion of the film is compensated and a stationary picture is formed on the projector screen or framed in the camera window.
  • a special arrangement produces electrical impulses from optical markings on the film, for example from the perforations, and these impulses control with the film movement the synchronous movement of the mirror.
  • the electrical control of position results in such a way that extremely short fly-back times for the mirror achieved without the presence of other moving parts in the optical path, in FIGS. 1 to 20.
  • FIG. I shows a film strip 1 which is continuously moved by known means across a film gate 2 having a window 3 and associated with two rollsor guide, pins 4 provided for properly positioning the film on the film gate;
  • a light source comprising a lamp 5, mirror 6 and condensing lens 7, illuminates as evenly as possible the window 3 which is filled by two picture frames of the film strip.
  • the brightness information arriving from the film 1 and window 2 encounters the tilting-mirror 8 positioned by the spindle of a tilt motor 9 and is transmitted through an objective assembly 10 to the projector screen or similar surface.
  • the synchronisation of the film movement with the mirror movement necessary for faultless presentation of the film is achieved with a synchronizing arrangement consisting of a lamp 12, an optical system 13 and a light receiver 14.
  • the light from the lamp 12 reflected from the film is transmitted through the optical system 13 to the receiver 14 which converts the light into electrical current.
  • the arrival of a perforation or a non-reflecting zone of the film margin in the optical path produces an electrical pulse in the receiver output, which is amplified by amplifiers 15 and 16 and used to control the positioning of the tiltmirror 8.
  • the entire assembly comprising the parts 12, 13 and 4 is displaceable longitudinally of the film.
  • FIG. 2 is shown another driving system of a tiltingmirror.
  • the light from a projector lamp (not shown) is transmitted as before through the window 3 of a film gate 2 onto a movably mounted tiltable-mirror 8 which reflects the light through the objective assembly 10 onto ascreen 11.
  • the mirror is movably mounted with the help of a woven or plastics strip 17 and is tiltable against an angle stop 18.
  • a reciprocating pulsed system similar to a dynamic loudspeaker, drives the free end of the mirror with the help of a lacquer stiffened woven or plastics strip 19. In this way linear motion is converted into a tilting motion of the mirror.
  • the diaphragm arrangementnecessary for centering the magnetic coil does, however, impart a dynamic couple to the surrounding air so that an oscillatory drive of this design for the mirror developes more noise than a motor constructed on the principle of a galvanometer.
  • FIG. 3 shows one possible arrangement of such a galvanometer motor.
  • a static iron core 21 Located between poles of a magnet 20 are a static iron core 21 and a spindle 22 on which a coil 23 is rotatably mounted, the spindle being held in its initial position by a spring 24.
  • a damping liquid 25 provides damping. It can also be advantageous to utilise copper or aluminium frames to produce damping by eddy-current effect. Liquid damping has, however, the advantage that the liquid enables lower natural resonance frequencies of the oscillatory system to be damped so that a more sensitive motor can be used.
  • FIG. 4 a motor which is provided with a known deflecting arrangement.
  • the coil is mounted on a torsion strip 26, whose cross-section is so chosen that it readily permits torsional oscillations while preventing oscillations normal to the torsional axis.
  • a suitable profile for the torsion spring is one of generally cruciform cross-section.
  • FIG. 5 shows a possible current waveform through the oscillatory coil of the motor enabling on extremely short fly-back time to be achieved.
  • a reverse current impulse of magnitude U is generated, the impulse being triggered from the synchronizing signal of the film and accelerating the oscillatory coil and thus the mirror very rapidly to its initial position.
  • the oscillatory coil after its operation would move beyond the initial position and begin to execute a damped oscillation that would be useless for the intended operation.
  • a braking pulse is applied for a suitable time T to the oscillatory system as a continuation of the reverse pulse and has a magnitude U the braking pulse halting the oscillatory coil at the end of the time T
  • the oscillatory coil is still when a further sawtooth waveform current beings the deflec tion of the mirror over a period T;,.
  • a current buildup process is accordingly avoided and the mirror executes an exact tilting motion.
  • FIG. 6 is shown a block diagram of the electrical circuit of the motor.
  • the synchronizing impulse from the film perforation enters the amplifier at 28.
  • the amplifier 15 drives a sawtooth generator 29 which has amplitude and linearity regulators 30 and 31, respectively, and also a double impulse generator 32 having controls 32 and 33 for regulating the times T, and T
  • the sawtooth waveform and the double impulse are added to one another in a mixing circuit 34 to obtain the waveform of the shape shown in FIG. 5, which controls by way of an output stage 35 the motor 9.
  • the frequency of the sawtooth generator 29 can be matched to different film velocities.
  • FIG. 7, like FIG. 6, shows in block diagrammatic form, a motor control circuit providing indirect synchronisation.
  • the frequency of an oscillator 36 is compared in a phase comparator 37 with a synchronizing impulse and a regulating voltage produced by the comparator so controls the oscillator 36 that the frequency and phase of the oscillator output and the synchronizing impulses coincides.
  • FIG. 8 shows another possible arrangement for the mirror-tilting mechanism.
  • the synchronizing marks on the film border are imaged by means of an optical system consisting of illuminating components 5 to 7, the tilt-mirror 8 and the objective 10, on two light detectors such as photo-cells 39 and 40.
  • the motor 9 With the assistance of a differential amplifier 41, the motor 9 is now so controlled that the image of the synchronizing m'ark always falls evenly on both photo-cells. Departure of the synchronizing mark from the window 3, produces in the amplifier 41 a pulse which controls the rapid return motion of the mirror to its starting position.
  • an unbiased mirror-tilting motor 9 the existing rectangular double impulse from the generator 38,. Oh-
  • FIG. 9 shows a possible arrangement of generating impulses from the perforations and which is also usable with a flank film.
  • the film 1 travels between two electrodes which are constructed as a condenser.
  • an impulse for controlling the motor 9 can be generated by a frequency discriminator connected to the oscillator 43 each time the oscillator frequency assumes a value significant of the presence of a perforation between the condenser electrodes.
  • a frequency discriminator connected to the oscillator 43 each time the oscillator frequency assumes a value significant of the presence of a perforation between the condenser electrodes.
  • an information carrier constructed as a disc 45, for a synchronous production of the desired impulses.
  • the disc is driven by a sprocket wheel 46 whose teeth 47 engages in the film perforations.
  • the impulses are represented on the disc 45 as cutouts 48,49 provided in a control track on the margin of the disc. These cut-outs are illuminated by a schematically depicted projection system having a small lamp and a lens 51, in such a way that light from the projection system falls on a photoelectric transducer 52.
  • the transducer delivers a stronger or weaker output signal which varies continuously with the strength of the light allowed through the cut-outs 48,49.
  • the output signal of the transducer 52 will also exhibit a sawtooth development and, after the attainment of a certain level will fall suddenly again to zero so that, a galvanometer constructed as in FIG. 3, for example, is returned to an initial position under the action of the force of a restoring spring 24.
  • a braking impulse is supplied subsequently to the frame by means of the cut-out 49.
  • FIG. 1 1 illustrates another arrangement in which four different control tracks are provided on an information carrier not shown in detail.
  • Sawtooth waves are recorded on the track 53, which serve as the tilt control of the mirror 8 with forward movement of the strip,
  • the track 54 contains oppositely directed sawteeth for enabling projection to occur during reverse running of the film.
  • the double impulses which are provided in the track 55 are supplied to the electric motor oscillatory system either directly, for example by means of a second galvanometer coil winding, or indirectly, by way of a mixing stage.
  • the sawtooth signal 56 finally serves for synchronisation of a sound recording and extends preferably over more than the illustrated impulse s,'for example over a span of 16 impulses.
  • a disc 57 arranged in much the same way as the disc 45, is formed with recorded tracks 53- 55, which in the illustrated embodiment are read by means of magnetic pick-up heads 58-60.
  • a regulator controlling the amplitude of the double impulse generator in accordance with the film velocity and also, if the occasion arises, the amplitude of the sawtooth generator 29 by adjustment of the resistances of the regulators 32, 33 and 30, 31, respectively.
  • these resistances can be constructed as centrifugally controlled resistors as may be visualised from the schematically shown arrangement in FIG. 14 where a centrifugal governor controls the tapping points of the two resistors disposed on diametrically opposite sides beneath the governor.
  • FIG. 15 A'further form ofcontrolfor use with the invention is illustrated in FIG. 15. 'In this case a lamp is again provided for illuminating the perforation ofa film strip 1, whereby the image of the perforation is projected onto a generally rectangular photo-electric transducer 67 by means of a schematically indicated optic 1 0 and a screen 66 formed with a slit.
  • a vignetting mask 68 is disposed between the screen 66 and the transducer 67 and is formed with a triangular slot 69 which limits the length of the slit image projected onto the transducer 67, in accordance with the position at which the image appears.
  • the projected images of the slit in the screen 66 travel in corresponding manner over the vignetting mask 68, the transmitted slit images maintaining lengths corresponding to the breadths of the triangular slot 69 and producing from the transducer 67 a larger or smaller output signal.that possesses a sawtooth wave shape as a consequence of the triangular slot 69.
  • the sawtooth, so formed is led through a threshold limiting switching circuit 70, for example a Schmidt-Trigger, which triggers operation of a double impulse generator 38 on one side and-extends on the Within the scope of the invention many differentv construetions are imaginable.
  • the sawtooth can also have zero gradient i.e. have the same current magnitude.
  • FIG. 16 where parts having the same function as corresponding parts in Figures already described, bear the same reference numerals.
  • the film 1 is pulled across the film gate 2 containing the windows 3 at a uniform speed.
  • the drive is obtained from a drive roll A which cooperates with a roller 4.
  • the film gate is additionally formed with another o'pening or slit 3a in which the toe of a film feed claw 73 can engage.
  • the film feed claw 73 is supported on a claw arm 72 and is pressed by an angle spring 74 towards the film 1 and its perforations, respectively.
  • the claw arm 72 is attached to the coil 23 of the galvanometer 9 on the pivot 22 of which the mirror 8 is fastened by means of a holder 76 and a clamping screw 71.
  • the galvanometer is suitably constructed without a restoring bias and its film-following motion is controlled by the claw 73. To this end it continuously receives from the double impulse generator a voltage U;,, see FIG. 17.'The voltage U ensures that the claw 73 is not dragged from the perforation of the film momentarily engaged, as formerly commonly occurred. On the contrary, the leading end of the claw 73 lies against the leading edge of the momentarily engaged perforation, looking in the direction of movement of the film, instead of being pulled as formerly.
  • the thrust of the claw 73 is naturally very small indeed and is only just sufficient to hold the leading end of the claw 73 in position at the forward end of the engaged perforation. It is thus assured that the side of the momentarily-engaged perforation engaged in the projector is the same side-as that engaged by the filmdrive claw in the camera. In this way tolerances in the spacing of the perforations do not affect the positioning of the mirror.
  • a lug 77 At the end of the movement of the claw 73 and claw arm 72 synchronised with the film speed, a lug 77 nevertheless it is clear that these parts are arranged across the path of the lug 77.
  • the arrangeent of the v light path assembly is not essential to the invention.
  • the lamp 78 and device 79 can also arrange for the lamp 78 and device 79 to lie on the same side of the lug 77, in this case the device 79 receiving light by way of a mirror formed, for example, by a reflecting surface on the lug 77.
  • a change in the output of the device 79 is produced by the lug 77 in the beaminterception position, whereupon fly-back impulse with a voltage U, and braking impulse with the voltage U, are released by a switching stage 8.
  • the claw 73 when the claw 73 is constructed as a pawl with 'a slanting trailing surface, it does not require an additional arrangement in order to reposition the galvanometer coil 23 and the claw arm 72 and extract the claw 73 from the perforation. his clear that the moment of the claw arm 72 on the coil pivot 23 should be compensated, Also the galvanometer 9 is correspondingly damped, for example by utilising a short-circuited coil and/or by designing the amplifier 35v with a very small output impedance. To attain an effective electrical damping a sufficiently strong magnetic excitation of the galvanometer is necessary. For example, the field strengths in question should approach around 5000 gauss.
  • a further problem with utilising a claw lies in the fact that, with its angular movement, for example corresponding to one frame on the filml, the mirror 8 although mounted on the same axis, is required to move through only half the angle of the claw arm 72 as the angle between the incident and reflected beam on the mirror is doubled. This problem may be solved in different ways.
  • the mirror 8 is part of an optical system having a forward lens group 10 and a rear lens group 10a. This optical system produces a telecentering effect on the light path, whereby the mirror 8 is arranged approximately in the zone of highest concentration of the light beams from the lens 10 so that it can be made very small.
  • the object distance g between the forward lens group 10 and the picture window 3 corresponds in the illustrated example to the focal length of the lens group 10, so that a parallel beam of light is produced behind the I lens group 10.
  • An exceptional freedom from distortion is achieved by the utilisation of the set forth optical system, enabling the mirror '8'to be extremely small.
  • the radius r of the claw arm 72 with the claw 73 is now dimensioned, according to a development of the invention, to be twice as large as the focal length of the lens group 10.
  • the galvanometer is advantageously constructed without a restoring bias. It is clear from the above description, that the claw arm 72 is not required to apply any mechanical force. For this reason the claw arm 72 may be formed as a slender needle. Its mass is therefore extremely small. If desired, it is also readily possible to apply a biasing force in one or other direction. This biasing force operates, referring to the galvanometer in FIG. 16 in the clockwise sense, so that it is necessary to apply to the galvanometer a sawtooth voltage in place. of the constant voltage U On the other hand, if the biasing ,force is applied in the counterclockwise direction, the voltage applied in the time t, (FIG. 17) can be reduced. In circumstances when the mechanical biasing force is of the same magnitude over the entire angular range of movement of the claw it is sufficient to reduce the applied voltage in the time t, to
  • the voltage in the time can be correspondingly shaped, for example, as an oppositely directed sawtoothto the sawtooth illustrated in FIG. 5.
  • the time intervals t ,t shown inFIG. 17 correspond to the time intervals T,,'T in FIG. 5.
  • the above-described dimensioning of the length of the claw arm 72 may be also applied to another optical system which does not employ telecentered optical paths, as is shown in FIG. 18.
  • a magnetic field dependent resistor 81 (FIG. 19) can be provided on the movable part of the galvanometer 9 inside the magnetic field, the resistor triggering the release of th'e double impulses by way of a switching stage. With the circuitry shown in FIG. 19 a steady voltage corresponding to the voltage U, is supplied to a mixing stage 34, onto which, in this case, is
  • FIG. 20 A further possibility is illustrated in FIG. 20.
  • the arrangement shown is in this case similar to that of FIGS. 1 and 6.
  • light from a lamp 5 is projected by way of a condenser 7, the picture window and the tiltmirror 8 onto a screen 11a of, for example, a television tube.
  • Conforming likewise to the block diagram of FIG. 6, are an amplifier 15, a saw-tooth generator 29 with resistor 31 for amplitude adjustment, a mixing stage 34, output amplifier 35 and double impulse generator 38.
  • FIG. 20 A further possibility is illustrated in FIG. 20.
  • the arrangement shown is in this case similar to that of FIGS. 1 and 6.
  • light from a lamp 5 is projected by way of a condenser 7, the picture window and the tiltmirror 8 onto a screen 11a of, for example, a television tube.
  • Conforming likewise to the block diagram of FIG. 6, are an amplifier 15, a saw-tooth generator 29 with resistor 31 for amplitude adjustment, a mixing stage 34, output amplifier 35
  • the synchronizing control is to the same extent modified as a semi-reflecting sheet 82 is additionally provided in between the tilt-mirror 8 and the screen 11a, to direct light through an objective 87 and a screen 88 with a rectangular opening onto a flat sensitive surface of a photo diode 89.
  • the screen 88 has its opening so constructed that, during projection, the picture of the perforation falls partially on the screen 88 and partially through its opening onto the photo diode 89.
  • the output signal from the photo diode 89 is then processed in a differential amplifier 90 which receives a reference voltage from a further photo-electric transducer 91 illuminated directly by the lamp 5. If the scanning of the picture is error-free, the differential amplifier 90 delivers a standard voltage of value 0. In either case, however, the output of the amplifier 90 becomes greater or smaller, a positive or negative control voltage is made available which is supplied to the sawtoothgenerator 29 and used to control the steepness of the sawtooth. Should, therefore, the former steepness setting of the'sawtooth generator not precisely agree, such setting is brought back to the optimum value by means of the illustrated control circuit. Moreover, synchronous oscillations of the film can also be compensated by this control circuit;
  • the film 1 is led along an arcuately curved path by means of a film gate (not shown).
  • the film is continuously driven by means of a driving arrangement exemplified by a capstan A with a pressure roller 4.
  • the tilt-mirror 8 rockable about the axis 22, is disposed in the geometric centre of the arcuately curved path and in the path of a light beam from the light producing assembly 5,7.
  • a film picture is projected by the light generating assembly 5,7 onto a conjugate flat sur-' face 11 with the help of the tilt-mirror 8 which follows the movement of the film picture.
  • the details of the projection arrangement not essential to the invention are only schematically depicted.
  • Thedrive for the tilt-mirror is obtained from an arm 72 connected to the mirror 8 and rockable around the axis 22, a known drag-elaw 110 being carried by the arm 72.
  • the drag claw locates in the perforation of the film and participates in its movement once for each frame of the film.
  • the drag claw is turnable about an axis 111 and is held by a spring 112 in a position at which it engages a stop 113.
  • a fixed stop 72 pushes in the leading face of a limb of the drag claw 110 against the weak thrust of the spring 112, whereby the claw is extracted from the film perforation.
  • the arm 72 then returns quickly to its original position under the action of the spring which, referring to FIG. 1, gives the arm 72 a turning movement in the clockwise direction.
  • the mass of the arm 72 and all the masses attached to it must be braked. This is the more critical as the fly-back time ought to be kept very short and also high velocities occur.
  • the braking occurs, in accordance with the embodiment of the invention, through the use of a buffer 115 whose mass related ,to the impact point P. between the arm 72 and the buffer I15 is selected to equal the magnitude of the mass of the arm 72 and the masses connected to it.
  • the arm 72 strikes against the buffer so that the arm 72 is brought to a standstill and the entire energy of the arm 72 is transferred to the buffer 115 where it is absorbed by a spring 116.
  • the buffer 115 is subsequently moved by the spring 116 back towards a cushioning stop 117. There is sufficient time with the arrangement for the return motion of the buffer 1 because the arm 72 has in the meantime recommenced its correspondingly slow forward movement.
  • the impact point P lies substantially on a line b which connects the centres of inertia M and S of the arm 72 and the buffer 115 respectively to one another.
  • the entire mass of the arm 72 together with the masses trated at the centre of inertia M, and the same is valid for the centre of inertia S of the buffer 115.
  • the above advantage is realised by the buffer 115 being attached to an arm 118 which turns about the same shaft 22 as the arm 72. In such a construction'it is under some circumstances advantageous for the pivot shafts of the arm 72 and the buffer 115 to be structurally separate from one another, however in axial alignment.
  • the invention is however in no way limited to the illustrated arrangement of buffer. It is sufficient,for instance, that the location of the impact point A is arranged where the path of movement of the buffer 115 is tangential to the arc with the radius of gyration of the arm 72.
  • FIGS. 22 and 23 explain in detail examples of such an arrangement.
  • an arcuate path b is pro. vided forthe buffer 115a which has a centre of inertia S and which isattached to an arm 118a so as to be swingable about a pivot point W.
  • the centre of inertia of the claw arm 72 swings along an arcuate path b".
  • the arcuate paths meet one another tangentially.
  • The-pivot point W need'not necessarily be arranged in the illustratedmanner. It could, for example, also lie in the region of the pivot shaft 22 to result in a very flat intersection of the arcuate paths b and b", respectively.
  • I v a y In the illustrated examples of FIGS. 21 and 22, the masses of the buffers 115 and 115a, respectively, as referred to the impact point P are determined from the formula for calculation of a moment of inertia:
  • the torsional movement at the centre of the torsion bar amounts to precisely half the torsional movement at the clamping point of the arm 72.
  • Possible inaccuracies can be adjusted out by displacement of one of the fixtrues, preferably the claw arm clamping fixture.
  • FIG. 25 explains how the'individual parts are connected to the torsion bar 22.
  • the torsion bar22 is fixed by means of a grub screw 215 in a pedestal 216.
  • pedestal is slidable lengthwise of the axis of the torsion bar 22 inside a slot provided in a base plate 217 and is positionally fixed by means of a bolt 218.
  • the attachment point-for the grub screw 215 can be displaced along the axis of the torsion bar 22 by sliding the pedestal.216 after'the screw 215 and bolt 218 have been slackened.
  • the claw arm 72 is attached to the other end of the torsion bar.
  • the arm 72 can also be displaced along the axis of the torsion bar 22 to make adjustments, after loosening of its clamping screw 119.
  • the spacing between the attachment points of the screws 215 and 119 is 2a.
  • the mirror is fixed a distance a from the attachment points of the screws 215 and 1l9, respectively, by means of a clamp 120 having a clamping screw 121 so that the mirror is also fixed in the middle of the torsion bar 22.
  • the torsion'bar 22 is fixedly held at one end in the pedestal 216 whereas its end to which the claw arm 72 is attached participates in a torsional movement corresponding to the turning movement of the arm 72, the torsional movement in the middle of the torsion bar 22 is exactly half. In this way an angular movement of the arm -72 amounting to an angle a is transmitted to the mirror in the ratio a. In this manner not only is the desired reduction of the arms movement, and also, if the occasion arises, by shifting the arm 72 lengthwise of the axis of the torsion bar 22.
  • a shaft 301 is provided on a small film projector whose individual parts are not illustrated, the shaft carrying a sprocket wheel 302 constructed in conventional manner. Furthermore a tiltmirror 303 is pivoted for swinging movement about airs 551; 304, 305. Thetilt-ini r ror 303 isbias edin a counterclockwise direction (see FIG. 26) by an angle spring 306 shown in FIG. 27. The axle pins 304, 305 project into support bores provided in support cheeks 307, 308. In this way the mirror is lightly pivotally turnable and possesses a small mass.
  • FIG. 28 shows the arrangement of the sensing levers 309, 310 in exploded form. It is apparent that the camming profiles of the cams 313, 314 are angularly displaced about half a cam projection with respect to one another.
  • Two pawl carriers 315, 316 are pivoted to the axle. pin 303 and operate between the tilt-mirror 303 and the sensing levers 309, 310. As is clearly shown in FIGS. 26 and 28 the axle pin 304 passes in this case through elongated slots 317, 318 formed in both pawl carriers.
  • the pawl carriers 315, 316 are biased on the one hand by tension springs 319,320 and are braced on the other hand by extensions 321, 322 which rest on studs 323 and 324, respectively, provided on the sensing levers 309,310.
  • the pawl carries 315, 316 are respectively provided with control levers 327, 328.
  • the control levers 327, 328 are turnable about a pivot shaft 329.
  • Control cams 330, 331 are provided to control the movements of the control levers 327, 328 which ride on such control cam profile, respectively, as shown in FIG. 26.
  • the control cams 330, 331 are displaced a half division from one another in similar manner to the cams 313, 314.
  • control levers 327, 328 lie on the control cams 330, 331 and on the other side on the pawl carrie 315, 316.
  • Projecting camming surfaces on the control cam 330, 331 respectively produce an angular movement of respective control levers in the counter clockwise direction to displace the associated pawl carriers 315, 316 together with their respective elongated slots 317, 318 in relation to the axle pin 304.
  • the pawls are suitably provided with a springy portion of the same mass as the tilt-mirror 303.
  • the movement is transferred from the mirror 303 to the springy portion in accordance with the laws of elastic impact in such a way as to enable the mirror to be moved by the individual pawls without further oscillatory movement.
  • FIG. 30 shows an arrangement in which the mirror 303 is controlled by traction claws 332, 333 instead of by cams.
  • These traction claws 332, 333 are mounted on pivots 336, 337 provided on claw levers 334, 335 and are spring loaded by angle springs 338, 339.
  • the claw levers 334, 335 are mounted on a common axis 340 which is arranged eccentrically to the axis of the tiltmirror 303.
  • Each of the claw levers 334, 335 has a respective pawl 341, 342 for the tilt-mirror 303.
  • the pawls 341, 342 are secured in adjustable manner in elongated slots 343, 344 provided on the claw levers 334, 335.
  • Each of the pawls 341, 342 is mounted on a respective springy strip 345, 346 and is provided on its leading end with a respective ramp surface 347, 348.
  • the claw lever 335 is provided with a cranked end i 349 with which it can engage from one side behind a film 1 travelling across a film gate 350, so that the claw lever 333 co-operates with the same row of film perforations as the claw lever 332.
  • the alternately operating traction claws provide the drive for the tilt-mirror 303 starting from the initial position illustrated in FIG. 30, the tilt-mirror 303 is moved by the pawl 341 in unison with the transport of the film 1 in the direction of the arrow 352 as a result of the traction of the claw 332 engaged in one of the perforations of the film.
  • the claw levers 334 As the claw levers 334,
  • the mirror 303 is automatically released from its operating pawl at this intersection point and returns under the influence of a restoring spring 306a to the initial position.
  • the operating claw levers 334 and 335 respectively continue to participate in the movement of the film until stops 353, 354, which are positionally fixed but which if necessary can be adjustable,. strike against respective arms of the angleshaped traction claws 332, 333 whereupon the traction claw is extracted from the perforation of the film.
  • the pawl 342 strikes the edge of the tilt-mirror with its ramp surface 348 which is resiliently deflected thereby so as to engage once again behind the mirror 303.
  • the forces absorbed by the pawls 341, 342 are, comparatively speaking, negligible, the bending moments exercised by the spring strips 345, 346 can also be comparatively small.
  • Film handling apparatus for a film comprising a film gate defining a window, drive means continuously operable to continuously through said film gate, optical means defining an optical path extending to said window, a deflector in said optical path, an axis about which said deflector is rockable, deflector drive means operable in one direction to produce a forward motion of said deflector and operable in the reverse direction to produce an accelerated return motion of said deflector, an electrical pulse-generating circuit controlling operation of said deflector drive means, an arrangement synchronizing the application of said pulse generating circuit on said deflector drive drive said film means with movement of said film through said film gate, and
  • said electrical pulse generating circuit and synchronizing arrangement including:

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Facsimile Scanning Arrangements (AREA)
  • Mechanical Optical Scanning Systems (AREA)
  • Projection Apparatus (AREA)
US00189623A 1970-10-20 1971-10-15 Film handling apparatus Expired - Lifetime US3806244A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US05/441,000 US4003645A (en) 1970-10-20 1974-02-11 Film-handling apparatus

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
AT945570A AT299702B (de) 1970-10-20 1970-10-20 Aufnahme- oder Wiedergabegerät mit optischem Ausgleich der Bildfeldwanderung
AT998370A AT298242B (de) 1970-11-05 1970-11-05 Aufnahme- oder Wiedergabegerät
AT1045770A AT301348B (de) 1970-11-19 1970-11-19 Einrichtung zum optischen Ausgleich der Bildfeldwanderung eines Informationsträgers bei einem Aufnahme-oder Wiedergabegerät
AT1060170A AT303526B (de) 1970-11-24 1970-11-24 Aufnahme- oder Wiedergabegerät
AT189371A AT305771B (de) 1971-03-04 1971-03-04 Aufnahme- oder Wiedergabegerät
AT294471A AT312422B (de) 1971-04-06 1971-04-06 Aufnahme- oder Wiedergabegerät

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US05/441,000 Division US4003645A (en) 1970-10-20 1974-02-11 Film-handling apparatus

Publications (1)

Publication Number Publication Date
US3806244A true US3806244A (en) 1974-04-23

Family

ID=27542400

Family Applications (1)

Application Number Title Priority Date Filing Date
US00189623A Expired - Lifetime US3806244A (en) 1970-10-20 1971-10-15 Film handling apparatus

Country Status (5)

Country Link
US (1) US3806244A (de)
DE (1) DE2146319B2 (de)
GB (1) GB1367792A (de)
IT (1) IT938616B (de)
NL (1) NL7114437A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4760443A (en) * 1985-07-10 1988-07-26 Technolizenz Establishment Display means
US20060261680A1 (en) * 2005-05-04 2006-11-23 Samsung Electro-Mechanics Co., Ltd. Vibration type tilting device and image projection device having the tilting device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19731531B4 (de) * 1997-07-23 2006-02-16 Bts Holding International Bv Infrarotabtastung von Perforationslöchern

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2843006A (en) * 1952-09-09 1958-07-15 Eastman Kodak Co Continuous feed motion picture projector
US3067284A (en) * 1960-01-11 1962-12-04 Bush And Rank Cintel Ltd Apparatus for deriving television signals from cinematographic film
US3450470A (en) * 1965-10-04 1969-06-17 Augusto Gentilini Cinema projector for films with single lateral perforation for each frame and with optical compensation of the uniform motion of the film
US3539250A (en) * 1968-03-07 1970-11-10 Bell & Howell Co Continuous film motion projector with mirror drive system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2843006A (en) * 1952-09-09 1958-07-15 Eastman Kodak Co Continuous feed motion picture projector
US3067284A (en) * 1960-01-11 1962-12-04 Bush And Rank Cintel Ltd Apparatus for deriving television signals from cinematographic film
US3450470A (en) * 1965-10-04 1969-06-17 Augusto Gentilini Cinema projector for films with single lateral perforation for each frame and with optical compensation of the uniform motion of the film
US3539250A (en) * 1968-03-07 1970-11-10 Bell & Howell Co Continuous film motion projector with mirror drive system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4760443A (en) * 1985-07-10 1988-07-26 Technolizenz Establishment Display means
US20060261680A1 (en) * 2005-05-04 2006-11-23 Samsung Electro-Mechanics Co., Ltd. Vibration type tilting device and image projection device having the tilting device

Also Published As

Publication number Publication date
DE2146319B2 (de) 1980-12-18
GB1367792A (en) 1974-09-25
DE2146319A1 (de) 1972-08-10
IT938616B (it) 1973-02-10
NL7114437A (de) 1972-04-24

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