Abstract: A device for recording/reproducing a digital pattern as a sound track of a cinefilm is disclosed. The device includes a cinefilm 1 having an image recording area 2 in which an image is recorded, a perforation section 3 for film feed and digital pattern data recording areas 5 and 6 provided in the vicinity of the perforation section 3. Plural channels of audio data are recorded as the digital patterns in the digital pattern data recording areas.

Abstract: A method and apparatus for optically reading or reproducing digital information recorded as a plurality of pits on at least one track of a movie film. A linear light source having a plurality of light elements, such as LED's, is arranged such that light from at least one of the light elements is irradiated on each of the pits. The light or optical beam from the linear light source is transmitted through the pits of the movie film and received by a light receiving element, such as a photodiode, having a single light receiving portion. The light elements of the linear light source are lit sequentially so that the digital information recorded in each line of each track may be read out at a pit unit by the light receiving element.

Abstract: In a motion picture film of the present invention, audio data digitized from right channel analog audio signals is held in a recording region provided in a left channel digital sound track having the left channel audio data recorded in it, while audio data digitized from left channel analog audio signals is held in a recording region provided in a right channel digital sound track having the right channel audio data recorded in it. With a reproducing system for reproducing the motion picture film of the present invention, unless the left and right channels are destroyed simultaneously, the audio data reproduced from the sound track is used in substitution for the audio data from the destroyed channel to compensate for playback sound interruption.

Abstract: The present invention comprises a method and apparatus for recording digital audio information using light modulation of a laser beam on cinefilm. In the invention, a laser beam of low coherence and high output is radiated from a semiconductor laser having a wide radiating area, modulated within the depth of focus of the laser beam, and then illuminated on a sound track of a cinefilm. In one embodiment the laser beam is bifurcated into first and second beams using a diffraction lattice. The invention shortens the recording time for voice data, reduces speckle noise, and eliminates the need for polarizing plates, thereby simplifying the structure and reducing the production costs of the recording apparatus.

Abstract: A film camera for recording visual images is adapted to record sound accompanying a photographic event onto the film section used for the visual image of such event. This audio recording is accomplished with light, immediately or at any time prior to taking the next photograph. The audio recording is accomplished without substantial intrusion into the photographic image. This system utilizes the film, processing, and printing currently available to the consumer or amateur photographer. The film camera captures and stores sound in a digital binary form then imprints this binary code onto film in the form of black and transparent bars adjacent the actual negative light image. A reading device (110) accesses and makes audible the recorded audio from photographs. A receptacle (139) provides storage of multiple photographs and instant access to audio and visual information stored. A processor which isolates and monitors a static electrical field surrounding the photographs in the receptacle.

Abstract: An encoding method and apparatus for audio signals for generating ten-channel audio signals from audio signals of a left channel, a left center channel, a center channel, a right center channel, a right channel, a surround left channel, a surround right channel and a sub-woofer channel, totalling at eight channels.

Abstract: A soundtrack interface for a motion picture projector allows the projector to sense dye only soundtracks or silver soundtracks. The system includes: a) an infrared filter: b) means for moving the infrared filter into the optical path between the sound system light source and photo detector when a film having a dye only soundtrack is to be projected, and for moving the infrared filter out of the optical path when a film having a silver soundtrack is to be projected; c) a preamplifier; and d) means for switching the preamplifier into a circuit between the photo detector and the sound amplifier when a film having a dye only soundtrack is to be projected and out of the circuit when a film having a silver soundtrack is to be projected.

Abstract: Digital audio signals and a conventional audio track are recorded on a motion picture film by error correction encoding digital audio data to be recorded on the film, sequentially arranging the error encoded digital audio data in a direction perpendicular to the direction of advancement of the film by utilizing two areas or more of an area in the vicinity of one end of the film which is parallel with the other end of the film and which is laid between it and one end portion of an analog sound track or an area near the other end of the analog sound track, and recording the same.

Abstract: A method and apparatus for photographically recording digital audio signals, and a medium having digital audio signals photographically recorded thereon. In a preferred embodiment, a motion picture film recorded in accordance with the invention has multiple digital audio soundtracks and an analog audio soundtrack photographically recorded thereon. Two or more channels of digital audio information can be recorded in each digital soundtrack, along with additional digital information for clocking, tracking, and error detection and correction. Each digital soundtrack is recorded in an array of bit areas arranged in row and column order. In a class of preferred embodiments, each row of digital audio bits is recorded simultaneously by exposing the film to radiation that has been modulated by a linear shutter array. The radiation transmitted by each shutter array is projected onto a row of spots. Each spot covers the full width of one of the bit areas in a row, but only part of the length of the bit area.

Abstract: An add-on module for a contact printer used to manufacture a motion picture. The module enables the printing of a digital optical soundtrack on motion picture film from a sound negative using a standard contact printing process. The module includes spaced apart guide rollers and a main roller. Unexposed film is placed in contact between the main roller and the sound negative. The module further includes a fiber optic light source positioned adjacent to the sound negative for exposing the film and forming the digital soundtrack. The digital soundtrack is formed on a portion of the positive print which includes an area between each of the sprocket holes. In addition, the digital soundtrack extends from each sprocket hole to the edge of the positive print on both sides of the print.

Abstract: A camera system is disclosed that optically records audio information on a photographic film containing corresponding image information. The camera system includes a user interface coupled to a camera control processor, a recording circuit coupled to the camera control processor and a microphone, an optical encoding circuit having an input coupled to the output of the recording circuit and an output coupled to an optical write head, a shutter mechanism, and a transport mechanism for advancing film past the shutter mechanism and the optical write head.

Abstract: A camera system is disclosed that optically records audio information on a photographic film containing corresponding image information. The camera system includes a user interface coupled to a camera control processor, a recording circuit coupled to the camera control processor and a microphone, an optical encoding circuit having an input coupled to the output of the recording circuit and an output coupled to an optical write head, a shutter mechanism, and a transport mechanism for advancing film past the shutter mechanism and the optical write head.

Abstract: A method and apparatus for reading digital audio signals photographically recorded on a medium (such as motion picture film). If the medium has multiple, spatially separated digital and analog audio soundtracks, a photosensitive detector array is employed for each of the digital audio soundtrack areas, and a separate analog soundtrack read head is employed. Preferably, digital error code is recorded in a digital soundtrack area of the medium (with digital audio bits), and error detection and correction are performed on the recorded digital audio bits read from the medium. Preferably, the apparatus includes switching circuitry for substituting a corresponding analog audio signal for one or more corrupted digital soundtrack channels, when such digital soundtrack channels have an error rate which exceeds a selected threshold.

Abstract: A method of recording information onto a photographic film provided with a magnetic recording layer comprises steps of reading once the information recorded on a predetermined track of the magnetic recording layer and recording it again onto the same track. In consequence, recording of the information can be conducted using a recording signal of high signal strength to improve the reliability of the information.

Abstract: A signal conditioner is provided for the output of a digital sound source in a dual digital/analog motion picture theater sound system so that the digitally derived audio signal emulates the analog sound track signal. This allows the digital source to be easily integrated into the overall sound system, without displacing the existing analog sound track system. The theater sound playback mechanism is provided with the conditioned audio signal when the digital sound source is actuated, and receives the analog sound track signal at other times. The conditioning circuit includes an adjustable impedance to match the current from the digital sound source to the current from the analog sound track reader, a high frequency variable signal adjuster that is complimentary to a high frequency emphasis built into the theater playback system, and an optional subwoof output.

Abstract: A method is provided for assessing the effect of exposure conditions on the recording and reproduction of an optical sound track, comprising,a) providing the optical sound track with an image test pattern which is an image of a desired test pattern, the image test pattern being configured such that the image test pattern will induce a photosensor device to generate a test signal which repetitively alternates between two different states, the image test pattern being applied to the track under predetermined exposure conditions,b) optically scanning the optical sound track with the photosensor device to generate, in response thereto, the test signal which repetitively alternates between two different states,c) comparing the duration of one of the states with duration of the other state so as to obtain a time difference value, andd) comparing the so obtained time difference value with a predetermined time difference value associated with the desired test pattern, any departure from the predetermined time differe

Abstract: A pressure developing device in an image recording apparatus for recording an image on the recording medium, includes a pair of pressure developing rollers to be separated from and contacted with each other, and a pressurizing unit disposed on either one of the pressure developing rollers for pressurizing one of the pressure developing rollers toward or away from the other of the pressure developing roller. A pressure control unit controls the pressurizing unit in such a fashion that one of the pressure developing rollers is placed in contact with and pressurized against the other of the pressure developing rollers under a plurality of pressure conditions by the pressurizing unit so that the pressure strength between a pair of pressure developing rollers is gradually decreased from the center to the ends along the axial direction of the developing rollers.

Abstract: A laser diode (4) emits a beam which is reflected by a plane mirror (12) and by a spherical focusing mirror (2) in order to form a beam (40) which is focused on a read window which is a segment of a read line (6). Said line extends transversely relative to a film (16) running over a drum (20) which rotates about an axis (22). The window occupies the width of the soundtrack on the film. The light passing through said soundtrack is received by a photo cell (34) which provides the sound signal. The invention is particularly applicable to sound motion pictures.

Abstract: In a video camera having a zoom lens and a microphone pickup for recording sound associated with the video images, the acoustic focus (or acoustic acceptance angle) of the microphone pickup is varied between uni-directional and omni-directional in synchronism with the zoom lens control of the camera in order to correlate the optical field of view of the lens with the acoustic field of view of the microphone for optimum coordination of picture and sound.

Abstract: Motion picture film transport of the kind used in a telecine apparatus uses a common film lacing path between a picture gate and a sound gate for films of different gauges. An audio delay circuit delays the audio signal generated at the sound gate for at least one of the film gauges to maintain synchronism between the audio and video output signals.

Abstract: Photographic film is provided with a magnetic recording layer applied to at least one edge surface thereof in the longitudinal direction of the film and substantially over the entire thickness thereof. A magnetic head of a recording-reproducing system is positioned upon recording or reproduction so that a magnetic field is established in the direction of thickness of the film or the direction of width of the magnetic recording layer.

Abstract: Sound is recorded on a motion picture filmstrip (20) by taking periodic samples (15) of an analog signal (13), digitizing each sample in the form of a sixteen-bit binary word (40), (41), (43), and representing each binary word on the filmstrip in the form of a group of bits (8) composed of black dots (26) and transparent spaces (28). Each dot represents a binary ZERO and each space a binary ONE. The groups of binary bits are disposed in a digitized soundtrack (8) on the filmstrip, between the visual frames (50) and the sprocket holes (54), either in lieu of or in addition to the regular analog "variable area" soundtrack (48). On the digitized soundtrack, the groups of bits are arranged in parallel rows (42) which are oriented orthogonally to the direction of elongation of the filmstrip. Each row consists of a group of starting bits (44), followed by three groups of binary bits, for the left (40), right (41) and center ( 43) audio tracks, respectively.

Abstract: Apparatus for reproducing motion picture photographic (optical) sound-tracks is disclosed in which significant information regarding track placement, slit illumination, azimuth and impulse noise is derived by dynamically processing and comparing the signals obtained by reading each half of a bilateral sound-track. In a further embodiment a pair of detector elements monitors the septum between two tracks in order to detect lateral film misalignment.

Abstract: An electro-optical, motion picture, film sound track recording and playback system in which a complex audio signal wave is successively sampled and digitally encoded according to pulse-code modulation techniques (PCM) extant in the communications art. The digital codes are optically applied to the film sound track and are played back by optical detection as the film runs through a projector. The advantages of PCM signal-to-noise improvement are obtained, and means for the individual sample codes to be "scrambled" on recording and "unscrambled" on replay are shown. The scrambling greatly increases the difficulty of surreptitious copying by "film pirates". One embodiment shown applies and detects the individual code bits through individual optical fibers and the other applies and detects codes serially using a modulated laser source and a controllable refraction optical crystal or a Bragg Cell to scan across the sound track to emplace (and replay) individual sample codes.

Abstract: Optical sound reproduction method and apparatus are provided for use with motion picture film having an optical dye sound track. The sound track preferentially modulates visible radiation while the silicon photoreceptor incorporated in the sound reproduction apparatus preferentially responds to infrared radiation. By positioning a suitable energy conversion device between the sound track and the photoreceptor, the modulated visible radiation--prior to striking the photoreceptor--is transduced into modulated radiation of longer wavelength nearer to the infrared portion of the spectrum. The signal provided by the photoreceptor is correspondingly enhanced since the impinging radiation has been shifted in wavelength toward the preferential response region of the photoreceptor. One suitable energy convertor is a fluorescing layer that absorbs visible radiation and emits radiation of longer wavelength in response thereto.

Abstract: A motion picture camera having a start sequence digital circuit, by which various component elements in the camera related to photographic operations are sequentially and automatically operated with a predetermined relationship, when the trigger operating member of the camera is actuated, and a stop sequence digital circuit, by which the abovementioned various elements are sequentially and automatically stopped with a predetermined relationship, when the trigger operating member is released.

Abstract: A sound motion picture camera capable of overlapping exposures by automatically controlling the sequence of a first step beginning with stopping of the take-up spool in a film cassette from further rotation in response to initiation of an overlapping exposure operation and terminating with a predetermined length of film being accumulated in the cassette in the form of a slack loop, a second step of rewinding the length of the looped film without further exposing the film and a third step of transporting the rewound film in the forward direction again while exposing the film again, characterized by the provision of control means for allowing release of a head pad from pressure contact against the magnetic head when the above second step starts.

Abstract: In the disclosed sound motion picture camera, a sound overlap device keeps the sound level constant during a predetermined time after the start of a fade out operation, then gradually lowers the sound level and then gradually raises the sound level during the start of a fade in operation.

Abstract: In a motion picture camera capable of using a sound film, a blocking device for selectively stopping operation of a shutter and a shifting device for moving a pinch roller to or out of resilient contact with a capstan are controlled by a common electromagnetic device operating in response to actuation of a trigger device.

Abstract: A synchronized audio visual system including an audio program source capable of producing a film advance signal at predetermined intervals and a projector interconnected therewith. The projector has a source of light for passing light through an aperture in the projector and film is directed along a pathway into and out of alignment with the aperture for projection of individual frames thereof in sequence. A motor is used for initiating advance of the film in response to advance signals from the audio source in a predetermined sequence. The motor directs an advance mechanism including a rotating member with a drive projection extending therefrom for rotating into and out of engagement with film support and drive structure for the film. The period of advance of the film is controlled by each stroke of the rotating member and is related to a film advance signal from the audio source.

Abstract: Sound is recorded on color movie film using conventional techniques preferably by variations in density and printed in color such as cyan. Noise reduction on playback is achieved by utilizing a light source generating frequencies capable of being modulated by the color of the sound track and preferably high in infrared frequencies. The infrared frequencies do not see the color sound track but are responsive to noise and other impurities. The modulating signal will be affected by both the colored sound track and impurities. All light frequencies passing through the sound track are directed to a filter such as a dichroic cold mirror which passes the IR frequencies to a first detector and reflects the sound track modulated signal plus noise to a second detector. Apparatus is described for algebraically combining the output of both detectors to thereby cancel the effects of the noise signal from the desired sound track modulated signal.

Abstract: A vibration isolating mounting arrangement for a sound accessory for a motion picture viewer is provided. The mounting arrangement includes an accessory mounting plate which precisely engages a portion of the viewer for locating the plate with respect to a film cassette receiving well in the top of the viewer. An audio component arrangement is provided which includes an audio transducer and means for advancing the audio tape past the transducer. These audio components are mounted to an audio component plate which is supported in overlying relationship with respect to the accessory mounting plate and the audio components carried thereby. The mounting between the two parallel plates is designed to effect vibration isolation between the plates, thus isolating the audio components carried by the upper plate from vibrations present in the viewer during its operational modes.

Abstract: In the disclosed motion picture projector the original sound recorded on the main magnetic stripe along one edge of a film stripe also having a magnetic balance stripe along the other edge of the same film surface, is reproduced by a recording-reproducing head. A second recording-reproducing head records the signal on the balance stripe. While the original sound signal is being heard, the first recording-reproducing head overlaps a second sound signal on the main stripe. A part of the original sound signal on the main stripe may be erased and a new signal recorded in its place.

Abstract: A motion picture film projector includes a sound head for playing back or for recording a sound track on the film. Absolute synchronism between the picture and sound is assured by the use of a single motor and common shaft to move the film past the sound head and to rotate the optical rectification system. In one embodiment, the sound head is mounted on the concave side of a stationary arcuate film guide opposite the sound track, and the film is driven past the sound head by a sprocket wheel mounted on the common shaft adjacent the optical rectification system.

Abstract: A cine camera for taking talking pictures comprises a film-feeding mechanism which includes a driven capstan and a pinch roller normally spaced therefrom to facilitate insertion of a section of film therebetween when the camera casing is loaded with a sound-film cassette. A sensor, upon detecting the presence of such cassette in a receiving chamber of the casing, causes the pinch roller to move closer to the capstan, either via a mechanical linkage or by deactivating a detent normally blocking a displacement of the pinch roller under spring pressure. This displacement under the control of the sensor may establish a standby position, with the pinch roller still separated from the capstan by a clearance wider than the film thickness, that clearance being subsequently reduced by the operation of a trigger, a mode-selector switch or the like to clamp the film between pinch roller and capstan.

Abstract: A sound motion picture camera capable of using a sound film is disclosed. The camera includes a film receiving chamber having an image recording location and a sound recording location, a first film feeding device for intermittently transporting a film loaded in the chamber from the image recording location toward the sound recording location, a second film feeding device for transporting the film transported by the first film feeding means further downstream from the sound recording location at a substantially constant speed, a switching device interposed between the first and second film feeding devices and a control device for controlling the operation of the film feeding devices.

Abstract: A motion picture camera is adapted to receive a film magazine containing a roll of sound recordable photographic film. A housing forms a chamber to receive the magazine. A cover opens and closes the chamber. A recording system records sound signals on the film. A setting arrangement engages the recorder system and the film with each other so as to record signals. The setting arrangement is movable into a first position where the film engages the recorder and a second position where the film is disengaged from the recorder so as to be incapable of recording sound signals. A transport device is coupled to the setting arrangement in the first position when the recorder is in the first position. An interconnecting system responds to closure of the cover for moving the setting arrangement from the second position to the first position so that the camera can be set for sound signal recording in response to the closing of the cover.

Abstract: The film is provided with an audio track comprised of recorded sections alternating with unrecorded sections. An adjustable mixer having first and second inputs is connected to the input of the sound-reproducing unit. A first signal-transmission path extends from the output of the audio head for the audio track to the first input of the mixer. A second signal-transmission path extends to the second input of the mixer and transmits a second audio signal thereto. A control head located upstream of the audio head senses the presence or absence of recorded information on the audio track and controls the operation of an attenuator connected in the second signal-transmission path. The control head is connected to the attenuator via a time-delay circuit which introduces a time delay corresponding to the distance between the two heads.

Abstract: A sound motion picture projection system which can be formed by a combination of a silent film projector and a sound recording and reproducing unit, wherein a silent film projector and a separate sound recording and reproducing unit are provided and minor modification is given to said silent film projector so that said silent film projector can be used as a projection unit only with said minor modification.

Abstract: In a sound movie camera, an arrangement comprising a recess in the housing of the camera for accommodating an extendable supporting rod or band at the free end of which is connected a microphone. In a preferred embodiment, the extendable supporting member is accommodated in a grip handle of the movie camera.

Abstract: A multipurpose audio/visual film cassette including supply and takeup spools in which opposite ends of a film strip are coupled for alternate winding and unwinding during passage through a first path for film exposing, processing and projecting operations with an audio tape also coupled at least on one end with the supply spool and interwound with the film strip to pass through a separate path, and a separating web is coupled at least on one end to the supply spool and preferably extending directly to the takeup spool in a third path. The separating web is arranged to overlie the side of the film strip on which processing fluid is deposited so as to be wound in convolutions between such side and the sound tape in order to prevent adherence of the sound tape to the film strip as a result of being interwound therewith before the processing fluid has dried.

Abstract: A trigger device for a sound motion picture camera actuates a capstan drive mechanism of the camera at an initial stage of advancing movement of a reciprocatable trigger member and claw and shutter drive mechanism of the camera simultaneously with resilient contact of a pinch roller holder with a capstan at a final stage of the advancing movement of the trigger member. A locking member releasably locking a pinch roller holder at its retracted position wherein the pinch roller is separated from the capstan, is disposed in the path of the advancing movement of the trigger member at a position wherein it is disabled by the trigger member at the final stage of the advancing movement of the trigger member.

Abstract: An audio drive system having a pinch roller mounted in slightly trailing arrangement to the point of the initial engagement of the audio tape with the capstan so that, as the audio tape passes from the pinch roller and capstan, it is displaced from the original tape path to curl into a free loop and provide isolation between the continuous motion of the audio tape and the intermittent advancement for photographic motion.

Abstract: A film loop size control is described for use in a camera in which the film s advanced intermittently past an image recording station by a first drive means and advanced continuously past a sound recording station by a second drive means. A detector which senses the size of the film loop between the image recording station and the sound recording station causes a control means to actuate only the second drive means whenever the detector senses a slack film loop when the film is stationary. The second drive means then advances the film past the sound recording station to remove the slack from the film loop. When the detector senses an absence of slack in the film, the control means de-actuates the second drive means. A switch is included which is adapted to be actuated when the film slack has been reduced for actuating both the first and the second drive means for advancing the film past the image recording station and the sound recording station.

Abstract: A sound cine camera with a cassette-receiving compartment, in which a pinch roller is movable toward a continuously rotating capstan to drive a motion-picture film, is provided with a manually operable control member whose displacement into an off-normal position, against the force of a restoring spring, prepared or completes an energizing circuit for the film drive. The control member is linked with a pinch-roller support through a releasable coupling which remains effective only as long as the compartment cover or a latch thereof is in a closure position. Clamping pressure is exerted upon the pinch roller by a biasing spring engaging its support and acting upon the control member through a camming or toggle mechanism which reduces the holding force required to maintain that pressure when the control member is in its off-normal position.

Abstract: In a sound recording portion of a sound motion picture camera, a film strip is continuously advanced by a capstan and a pinch roller. The pinch roller is movable between its retracted position where it is spaced apart from the capstan and its operative position where it is pressed against the capstan to pinch the film strip therebetween. The pinch roller is supported on a pivotable member which is capable of pivoting from a first position in which it holds the pinch roller in the retracted position to a second position in which it holds the pinch roller in the operative position. The pivotable member is moved between the two positions driven by a reciprocating plate member which is moved back and forth in translational movement by an electric motor through a cam mechanism. The electric motor is energized in response to depression of the shutter button of the camera and deenergized when the pivotable member is pivoted to its second position.

Abstract: A motion-picture camera optionally loadable with silent-film and sound-film cassettes has a reversible film-feeding mechanism including a reciprocable transport claw and a catch engageable with a takeup reel through a coupling within the cassette including a rewind stop. A spring-loaded stud close to the catch enables the rewind stop to be disengaged in a sound-film camera whereby the film can be transported backward for trick cinematography such as superposition of scenes. During the first run of such a double exposure, a step-down transmission can be activated to slow the windup of the film within its cassette if the latter is of the silent-film type, thereby creating a reserve length of film that can be rewound on the supply reel. In the presence of a sound-film cassette, as determined by a sensor which could be the aforementioned stud, this stepdown transmission is disabled inasmuch as the disengagement of the rewind stop allows the film to be reverse-driven without such reserve length.

Abstract: A film projector system including a sealed film cassette removeably mounted ithin an aperture in the projector and driving means in said projector mechanically engaging coupling means extending through said cassette for driving the sealed film between hubs sealed in said cassette intermittently past a film projection location in said cassette and continuously past a sound detection location therein, with the projection plane of the film at said projector locations being disposed normal to the projector optical projection optical sound beams and twisted ninety degrees with respect to the plane of that portion of the film wound on said hubs so that the projector beams do not pass between the film hubs.

Abstract: A sound motion picture projection apparatus provided with pressure pad means operable to press a film against magnetic sound recording and reproducing head means disposed along a path of the film for sound recording and/or reproduction. Urging means urge the pressure pad means toward its film pressing position. Externally operable means are provided for shifting the pressure pad means from its film pressing position to a released position against the urging force of the urging means. Releasable locking means are provided for holding the pressure pad means in the released position against the urging force of the urging means; and film detecting means are disposed in said sound film path behind the magnetic head means to detect introduction of the film into the sound film path and to release the locking of the pressure pad means by the locking means.

Abstract: A cine camera for taking talking pictures, in which a film is moved intermittently past an image gate by a reciprocating traction claw and continuously past a recording head by a rotating capstan coacting with a pinch roller, includes a latch by which the pinch roller can be held spaced from the capstan in an inactive position. The latching of the pinch roller in this inactive position, against the force of a biasing spring providing the necessary contact pressure during filming, is accomplished upon deactivation of the film drive by the residual kinetic energy of an inertial mass such as a flywheel which is coupled with either the capstan drive or the claw drive. The latch is released upon actuation of a trigger, either directly or through the intermediary of the claw drive. The biasing spring may be part of a toggle mechanism tripped by a presetting member, such as a sensor detecting the presence of a sound-film cassette in the camera.