Abstract: A projector apparatus that may include a first plurality of adjacent translucent lenses on at least one side of an inner lens, said inner lens configured to rotate and translate about an axis (A) of the inner lens; a second plurality of adjacent translucent lenses formed on at least one side of a concave outer lens; a light source configured to direct a portion of light through the rotatable and translatable inner lens and then through the concave outer lens; and a motor configured to rotatably and translatably drive the inner lens in an oscillating manner about and along the axis of the concave inner lens (A); so that the oscillating inner lens imparts a moving textured image for modification through the fixed concave outer lens for display upon a surface, such as a ceiling to simulate a moving liquid surface.

Abstract: An image processing apparatus receives sound signals that are respectively output by a plurality of microphones, and detects a sound arrival direction from which sounds of the sound signals are traveled. The image processing apparatus calculates a sound level of sounds output from the sound arrival direction, and causes an image that reflects the sound level of sounds output from the sound arrival direction to be displayed in vicinity of an image of a user who is outputting the sounds from the sound arrival direction.

Abstract: Embodiments are described for a synchronization and switchover mechanism for an adaptive audio system in which multi-channel (e.g., surround sound) audio is provided along with object-based adaptive audio content. A synchronization signal is embedded in the multi-channel audio stream and contains a track identifier and frame count for the adaptive audio stream to play out. The track identifier and frame count of a received adaptive audio frame is compared to the track identifier and frame count contained in the synchronization signal. If either the track identifier or frame count does not match the synchronization signal, a switchover process fades out the adaptive audio track and fades in the multi-channel audio track. The system plays the multi-channel audio track until the synchronization signal track identifier and frame count and adaptive audio track identifier and frame count match, at which point the adaptive audio content will be faded back in.

Abstract: The present invention comprises a light and sound sensor system and method for repetitively measuring the luminance, chromaticity, sound, and infrared illumination in a theater to detect any changes thereto so that the images being viewed on the screen and the sound in the theater can be kept at their optimal values. In addition, in a preferred embodiment of the present invention, the system has an audio and video synchronization capability. By monitoring the audio and visual signals in real time, the exact time relationship between the signals is detected to determine whether they are properly synchronized.

Abstract: An image animation system having a plurality of individual image projectors focused onto a single focal area on a projection surface or medium. Angled optics, or a prism, may be used to direct the projections onto the single focal area. Individual still images are projected in a sequence to created a projected motion animation.

Abstract: A method includes storing at least a partial parallelization of at least two of an audio data processing, a video data processing, a synchronized processing of audio and video data from the audio data processing and video data processing, and output processing of the audio and video data from the synchronized processing.

Abstract: A recording medium, method and apparatus for managing data are discussed. According to an embodiment, the present invention provides a method of reproducing main data and additional data. The method includes receiving the additional data associated with the main data, the additional data being divided into a plurality of segment units; and reproducing the additional data in a synchronous manner with the main data using time information if indication information indicates a presence of the time information. The time information indicates a presentation time of the additional data with respect to the main data. The main data and the additional data are reproduced according to management data, the management data including link information for linking the main data and the additional data.

Abstract: The invention regards a device for recording full picture frames onto a photosensitive material, comprising at least one light source, at least two full frame devices for modulating light from the light source, imaging optics for combining the modulated light from the light modulation devices and/or combining optics, and recording the modulated light onto the photosensitive material, thus exposing the photosensitive material frame by frame, a film transportation device adapted for exposing, section for section, sections of the photosensitive material to the modulated light. The invention also regards a device for simultaneous and synchronised recording of full picture frames and sound tracks onto a photosensitive material.

Abstract: A method and device are provided for determining a reproduction position of a source of sound for audio-visual reproduction of a film scene from a plurality of individual pictures with regard to a reproduction surface having a predetermined width, and with regard to a projection source having a projection reference point. A recording position of the source of sound, a camera position during recording, and an aperture angle of the camera during recording are obtained and the determined recording position is transformed to a camera coordinate system. A reproduction position for the source of sound is calculated and used to produce sound-source positioning in a reproduction room using wave-field synthesis methods.

Abstract: A method for identifying of tokens in a video sequence is described. First, the video sequence is scanned for boundaries between consecutive parts of the sequence where the appearance of the tokens is expected. After that step, candidate regions are pre-selected and classified in parts of the video sequence adjacent to detected boundaries, and tokens are located in the candidate regions. Information carried on the tokens is located, interpreted, and merged into consistent sets of information after passing a confidence analysis. In parallel a change in the visual appearance of a token, signaling a special event, is detected.

Abstract: A device for synchronizing an audio signal with a film comprising frames having imprinted time codes. A detector detects the imprinted time code for the sequence of frames to obtain a detected sequence of time codes. A time code generator generates a sequence of synthesis time codes based on an initial value. A decoder decodes a time code of the detected sequence of time codes obtain the initial value. A comparator compares a detected time code and a corresponding synthesis time code and, when a phase deviation is found to be above a deviation threshold value, a time code manipulator manipulates the synthesis time code for this frame in so far that it is changed with regard to its temporal length. An audio processor provides the samples of the audio signal associated with this frame in a time-controlled way in response to a detection of the synthesis time code for a frame.

Abstract: A synchronization device for providing an optical synchronization signal in computer controlled picture recordings of a motion picture camera is provided. The synchronization device includes a signaling device for generating an optical synchronization signal, whereby the optical synchronization signal of the synchronization device is triggered by a computer that controls the picture recordings. By providing a number of optical signaling elements, the signaling device is configured to provide different optical signals for synchronizing the picture recording of the motion picture camera.

Abstract: With the method for generating a slide show in harmony with music, the user is able to compose an attractive and interesting slide show by a convenient and simple method. The steps of the method comprises: analyzing audio data to obtain reference points, wherein the reference points include at least one beat point of said audio data; obtaining image effects for images; selecting at least one first level point and at least one second level point from the reference points; and composing a slide show of the images with the image effects in association with the audio data, wherein the image effects are controlled according to the first level point and the displaying of the images is controlled according to the second level point.

Abstract: A recording medium and a method and apparatus for managing data are provided. The method includes recording additional data in a data file separate from a file containing main data and recording navigation information that links the main data and the additional data. The additional data are segmented into a plurality of predetermined units, each of the predetermined units including time information indicating a presentation start time of the corresponding unit.

Abstract: A method for presenting secondary information to a video-viewing audience comprises projecting video images onto a screen and projecting invisible light signals encoded to represent secondary information associated with said video images onto the screen concurrently with said video images.

Abstract: The present invention concerns a clapper device and method for synchronizing the auditory and visual elements in motion picture film production. The device has a standard clapper, a means of receiving timecode from an audio recorder (by wireless transmission or by cable or by some other means), a visual display for indicating a machine readable code indicating the stage of the filming process, onboard processing and storage, and a data entry means. The timecode information and machine code displayed corresponding to the point of time when the clapper is closed are used to synchronize the auditory and visual elements after digitization of the same.

Abstract: A method for modifying an audio visual recording originally produced with an original audio track of an original speaker, using a second audio dub track of a second speaker, comprising analyzing the original audio track to convert it into a continuous time coded facial and acoustic symbol stream to identify corresponding visual facial motions of the original speaker to create continuous data sets of facial motion corresponding to speech utterance states and transformations, storing these continuous data sets in a database, analyzing the second audio dub track to convert it to a continuous tune coded facial and acoustic symbol stream, using the second audio dub track's continuous time coded facial and acoustic symbol stream to animate the original speaker's face, synchronized to the second audio dub track to create natural continuous facial speech expression by the original speaker of the second dub audio track.

Abstract: A portable electronic image displayer and audio player, including: a digital memory for storing digital images; a digital memory for storing an audio recording; a display for displaying stored digital images; a music analyzer for analyzing the stored audio recording and for determining when to display a sequence of stored digital images according to the stored audio recording; and an audio reproducer for playing the audio recording.

Abstract: A film camera is disclosed which is equipped with a device for recording synchronizing data, for use in automated post processing, wherein, for example, timing data is exposed onto the film by means of an optical display element activated by an activator unit and with a rotary shutter positioned so that at a first half rotation of the shutter the light entering through the camera objective is deflected through the viewfinder and during the second half rotation of the shutter the light enters an image window and wherein the activator unit comprises a shutter drive which controls the actuation of the shutter over which the rotating shutter is held in an arrested position covering the image window during exposure of the film by the optical display element.

Abstract: Displaying visual information from a motion picture in a visual field within a designated extent of a related aural field supports editing of a spatial audio effect for the motion picture. The extent of a related aural field also is displayed. Information specifying a point of origin of a sound used in the spatial audio effect with respect to the visual field is received for each of a number of frames of a portion of the motion picture. This information may be received from a pointing device that indicates a point in the displayed extent of the aural field, or from a tracker that indicates a position of an object in the displayed visual information, or from a three-dimensional model of an object that indicates a position of an object in the displayed visual field. Using the specified point of origin and the relationship of the visual and aural fields, parameters of the spatial audio effect may be determined, from which a soundtrack may be generated.

Abstract: In a system and method for dynamically synchronizing a digital soundtrack with a moving picture in motion picture media, the system includes a device for presenting the motion picture media, wherein the motion picture media further includes an analog soundtrack. The digital soundtrack further includes a variable delay to compensate for the distance between a frame in the moving picture and a portion of the digital soundtrack corresponding thereto. A synchronizing device is correlated to a digital soundtrack pickup and an analog soundtrack picture in a feedback loop. A processor in the synchronizing device is adapted to process the digital soundtrack and the analog soundtrack to generate a control signal based on the difference between the location of a transient reference in the analog soundtrack and the same transient in the digital soundtrack, and to use the control system to adjust the variable delay in the digital soundtrack for synchronization thereof.

Abstract: Method, system and computer program product are provided for selectively separately updating multiple system time clocks or synchronously updating the multiple system time clocks (STCs). Separate or simultaneous updating of the system time clocks is attained by selectively adjusting the addresses to the system time clocks in updatable address register fields. A first address value is provided to a first address register associated with a first STC register and a second address value is provided to a second address register associated with a second STC register. Independent updating of the first STC register and the second STC register is performed when the first address value and the second address value are different, while synchronous updating is performed when the first address value and the second address value comprise a common address value. The technique can be extrapolated to any number of clocks to be updated.

Abstract: A synchronous control device having a memory 101 for storing block data blocked in terms of a pre-set data amount, a clock generating circuit 102 for generating input side clocks which are based on a data rate to be synchronized, and a memory control unit 103 for generating output side clocks C.sub.out responsive to input side clocks C.sub.in from the clock generating circuit 102. The memory 101 stores the block data on the block basis, based on the input side clocks C.sub.in from the clock generating circuit 103, and outputs the stored block data based on the output side clocks C.sub.out from the memory control circuit 103. The memory control circuit 103 detects a difference between the input data volume and the output side data volume in the memory 101 for varying the speed of the output side clocks responsive to the amount of the detected difference so that the output side clocks will be synchronized with the input side clocks C.sub.in from the clock generating circuit 103.

Abstract: A system to create, for screening purposes, an adjustable, pre-selectable synchronous relationship between motion picture film segments and their matching audio files, by transferring the audio to a digital format, storing the audio files on a portable or removable computer storage device, such as a compact disk, and utilizing a computer program to define and maintain the synchronous relationship. The system provides the ability to screen continuously, multiple rolls of film each having a plurality of film segments with the appropriate synchronized digital audio files.

Abstract: A motion-pictures and audio synchronization controller for extending and reproducing compressed motion-pictures and audio multiplexed data and outputting motion-pictures synchronously with audio comprises a selector for adjusting time between a system clock reference added to compressed motion-pictures and audio multiplexed data and picture time stamp, a system time counter for generating a system time clock output from an output of the time adjustment selector and a picture frame synchronization signal, an audio synchronization comparator for comparing a system time clock output from the system time counter with a delayed audio time stamp and outputting an audio output start signal, and a picture synchronization comparator for comparing the system time clock output from the system time counter with a delayed picture time stamp and outputting a picture output start signal.

Abstract: This invention discloses an apparatus for apparatus for conducting a comparison of a plurality of versions of a movie which differ at least in their audio channels and for generating an editing list for an output movie on the basis of the comparison, the apparatus comprising a movie version synchronizer operative to compare a plurality of movie versions which differ at least in their audio channels and generating a signal representing the mutual synchronization of the plurality of movie versions and an output movie generator receiving the synchronization signal and operative to generate a signal representing an output movie editing list for an output movie.

Abstract: An optical sound head (L), comprising a red laser diode (11) and a inspection window (90), allowing easy functional inspection, but also simple adjustment during manufacture. The laser diode (11) and all optical (10) and electronic (20) assemblies to be adjusted to a specimen, are accommodated in a replaceable assembly (1), for easy and repeatable (A) replacement. A minimum signal-to-noise ratio for analogue sound scanning is achieved by an additional aperture (15), reducing the light intensity applied to the center of an aperture slot (8). Both apertures (8, 15) are preferably designed as unsupported, laser-cut metal sheets.

Abstract: In a motion picture film/audio recording system where a camera produces a motion picture film, a corresponding video signal, and associates with both the motion picture film and video signal a first time code signal providing a correspondence standard between the motion picture film and the video signal, and a camera status signal representative of whether the camera is on or off, and a sound recorder which produces an audio signal, a second time code signal having a known relationship to the first time code signal, and a recorder status signal representative of whether the sound recorder is on or off, a viewing system for the motion picture film includes an interface module that receives the camera status signal and the recorder status signal, and generates a save signal whenever the camera status or the recorder status signals indicate that the camera or the recorder is on.

Abstract: A magnetic read/write head suspension assembly for achieving high magnetic head compliance with at least one edge track of the MOF layer of relatively stiff photographic filmstrips particularly during photofinishing operations. The filmstrip has an emulsion layer side opposite to the MOF layer side and exhibits a positive cross-film curvature toward the emulsion side when unrestrained. Filmstrip edge guides including parallel angled channels extending in a film transport path receive the filmstrip edge regions. One or more magnetic read/write head is mounted in the edge guides with the magnetic head gap length oriented in alignment with the angle of the MOF layer of the filmstrip edge region received in the channel and makes compliant line contact of the magnetic head gap with the MOF layer side in the edge region without imparting drag on the central region of the filmstrip.

Abstract: A data demultiplexer for separating multiplex data including at least coded video data, coded audio data, timing data indicative of a video decoding start time, timing data indicative of an audio decoding start time, and timing data indicative of a system clock reference time. The demultiplexer comprises a circuit for separating the multiplex data into the component data, and comparators for comparing input data with the reference timing data. When the timing data indicative of a video decoding start time is inputted and detected, the video data is written in a video code buffer at the maximum transfer rate. During such time period, the reference timing data indicative of the current time is monitored, and the operation of decoding the video data is started when the reference timing data has become equal to the video timing data.

Abstract: Method and apparatus for applying encoded data on the balance stripe of sound track, the data for providing information for editing an associated film without recording the data on the film. The present invention teaches an apparatus for applying code for synchronizing sound on a single strip of the sound track with an associated film. The apparatus includes a code box for generating the code, which relates the position of the film relative to the sound track. The code box is coupled to an editing flatbed for providing pulses related to the movement of the sound track. A sound module is coupled to the code box for applying the code to the balance stripe.

Abstract: A GPS receiver comprises a data output port for communicating time code information formatted according to standards published by the Society of Motion Picture and Television Engineer (SMPTE). Such time code information is input to independent sound, film and video recorders at a performance event to create tracks on each recording for re-synchronizing the pictures and sounds in post-performance editing.

Abstract: Dynamic range and passband problems in cinema sound transmission are solved by using a laser disk (9) read by a laser disk player (10, 11, 12) synchronized (14) with the original sound track of the film. Problems relating to splices in the film are solved by reading the sound in advance, in storing it in a memory (13), in reading it back subsequently from the memory, and, where necessary, in causing the memory read back system to jump (24) in order to avoid reproducing sound that corresponds to images that have been removed from the film.

Abstract: A digital sound system for motion picture films employs a digital time code on the film to trigger the transfer of sound data from a digital audio store to a FIFO memory. The digital audio data is read out from the FIFO memory and played back in the theater at a constant rate, with any jumps in the digital time code handled by making a corresponding jump within the digital audio store but not in the FIFO memory. Readout from the FIFO memory and clocking of the digital-to-analog converters (DACs) used for theater playback is synchronized to the AC mains that powers the theater projector, and thus allows for an uninterrupted audio playback even if time code entries on the film are obliterated. The FIFO memory need only have enough capacity to accommodate the maximum audio store access time, and can be quite small.

Abstract: An audio visual story-telling toy projects pictures on a surface such as a ceiling or a wall while a story recorded on an audio cassette is played. The toy is a small, self-contained unit which includes a tape player and a synchronized picture strip projector. The toy includes an insertable, removable cartridge containing film with picture frames sequenced to correspond to the story on the tape.

Abstract: A variable speed film transport interlock control system for allowing a plurality of film audio elements to be run in synchronization with each other with at least one film element running at a different selected speed than the other elements and permitting internal generation of quadrature control signals by an internal microprocessor. The system generates a modified drive signal from a selected standard system drive signal or microcomputer generated signal such that the modified signal corresponds to a speed with a fixed ratio to the speed of the selected unprocessed drive signal under all operating conditions. This permits the modified signal to drive a film transport device, such as a recorder or reproducer, at a different speed than other transport devices while maintaining synchronization with the other devices during forward or reverse, stopping and starting, high speed or low speed operation.

Abstract: An apparatus for transferring in synchronism, onto a common recording support, the images of an cinematographic film and the sound recorded during shooting on a separate support, comprises a telecine apparatus ensuring reading of the cine film. A microcomputer has an input connected to a reader of time codes borne by the cine film. A first output of the microcomputer is connected to a stage controlling the supply of an electric motor ensuring advance of the cine film in the telecine apparatus. A second output of the microcomputer is connected to a coder and a third output is connected to a first input of a comparator with two inputs of which the second input is connected to the head for reading the time codes on the magnetic tape, the output of the comparator is connected to a stage controlling supply of an electric motor of the servo-controlled magnetic tape recorder and the third output of the microcomputer is also connected to a device for recording time codes on the third track of the video tape.

Abstract: A method and apparatus for recording a digital signal such as a modified SMPTE time code on motion picture film as it is being intermittently advanced by a motion picture camera. The recorded time code includes a set of timing bits followed immediately by a set of synchronization bits. In one embodiment, the time code is recorded as a continuous signal with the last bit recorded for each frame having an extended length, to ensure that uncertainties in the specific times at which the camera begins and ends its advancement of the film don't result in the recording of a bit that is shorter than a nominal bit duration. In a second embodiment, an addition set of synchronization bits is recorded at the beginning of each frame, so that a time code reader assumes it corresponds to the previous frame and properly decodes the following sets of timing bits and synchronization bits as corresponding to the current frame.

Abstract: A motion picture film which includes a row of sprocket holes along one marginal edge portion and a longitudinally extending area carrying a photo-sensitive layer for photographing a selected scene, or series of scenes in a succession of stationary frames, the film being characterized in that one of its marginal edge portions carries a latent-image numerical identification of each of the successive frames in binary code form adjacent each said frame. A post-production film-making system is also described with means for transferring the binary numbers from the film to a magnetic medium and means for reading and visually displaying in arabic form the numbers on the film and the magnetic medium.

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 post production facility comprising apparatus for editing motion picture film and sound film and performing additional functions of sound mixing, displacing, etc. wherein the apparatus may perform all the functions normally associated with film editing and the physical arrangement of the film and sound tape are parallel and adjacent to each other to simplify the editing process. The apparatus comprises an upright console containing four motion picture reels, a plurality of idler pulleys, an editing module, a series of tension pulleys and a drive sprocket. The console control section is disposed at the bottom of the facility and is substantially perpendicular to the upright portion for ease of operation and contains substantially all the controls. An intermediate section is disposed at a 45.degree. angle to the upright console and houses a viewing screen and splicer mount.

Abstract: The present invention relates to a synchronization system of a cine-projector with a sound tape reproducer. It is characterized in that the phase of a signal corresponding to the film feeding speed of the film projector and that of a signal corresponding to the standard speed coming from the sound tape reproducer are compared with each other so as to control the film feeding speed of the cine-projector by means of the comparison output corresponding to the phase difference. In order to accomplish this, between the driving source for driving the internal mechanism of the cine-projector and the driving member for the internal mechanism, a transmission speed varying mechanism is provided in such a manner that the transmission speed varying mechanism is controlled by means of the film speed control driving source to be driven by the comparison output so as to maintain the synchronized state.

Abstract: A system for synchronizing projection of a movie film with playback of a sound recording made simultaneously with filming of the movie by simple and economical adapter means compatible with existing camera, projector and sound equipment without substantial modification. The invention utilizes "home movie" type camera and projector equipment, with a tape recorder-playback unit as the sound system. The camera is powered from a power supply having a switch operated by the "play" button of the tape recorder, thereby starting and stopping operation of the camera and tape unit simultaneously during filming and recording. The tape drive motor is powered from a selectively controllable voltage supply, and is not connected to the supply through the normal electrical system of the tape unit, as is conventional.

Abstract: A movie sound camera wherein the motor for the sound shaft of the sound recording unit is started by a self-arresting rotary programming device prior to completion of the circuit of a sound amplifier, and the circuit of the amplifier is completed prior to starting of the motor for the pull down in response to movement of camera release from the idle position. When the release is returned to the idle position, the programming device automatically arrests the motor for the pull-down prior and the motor for the sound shaft subsequent to opening of the amplifier circuit. The programming device further controls the sequence in which the film is pressed against the sound shaft and biased against the second recording head of the recording unit in response to movement of release from the idle position. The programming device forms part of a control unit and is rotated by a motor which is started in response to movement of release to or from the idle position.

Abstract: This specification discloses a motion picture projector device as audio-visual aid and an audio-visual system using the same. The device uses a film structure including an image information recording zone, a row of perforations along one side edge of the film, and a balance zone juxtaposed with said row of perforations along the one side edge of the film and having various signals recorded thereon in a straight line. These signals include a non-normal projection mode speech information signal, a transfer instruction signal for instructing the transfer of said non-normal projection mode speech signal to a record information member, a transfer stop instruction signal for stopping the transfer, and a reproduce instruction signal for instructing a reproduce mechanism to reproduce the non-normal projection mode speech information signal transferred to said record member.

Abstract: Disclosed is a digital control system and method for synchronizing audio-visual equipment for the presentation of film slides with corresponding sound narrations. As the film passes through conventional projecting equipment each slide receives a sequential address. Simultaneously, the sound narrations, passing through the audio equipment on a continuous media, receive identification numbers from a pulse generating means indicative of the outset of each narration, which numbers are stored in the system correlated with the proper sequential address. Means are further provided for skipping ahead or back to desired film slides rapidly, without loss of synchronization between the audio and visual portions of the program.

Abstract: A switch adapted to cooperate with the pull-down claw of a silent movie camera for transmitting an electrical signal each time a frame of movie film is advanced past the shutter of the camera includes an insulating base adapted to be positioned within the film receiving compartment of a movie camera so as to fit around the film gate, the base having a grounding contact arm engaging the gate so as to be grounded through the camera and a contact finger insulated from the gate and disposed for intermittent engagement with the reciprocating pull-down claw which serves to close the switch each time a frame of film is advanced past the shutter.

Abstract: If a cine film is to be projected to the accompaniment of a sound track on a separate tape it is necessary to cheek that the film and the sound track are correctly coordinated. This is ensured by reading a code mark from the sound track and using it to slow or stop the motion of the film. The point at which the film motion is slowed or stopped is used to evaluate the relative position of the film with respect to the sound track and thus check that correct coordination is present. This evaluation may take place visually or automatically. In the latter case the prolonged presence of a correlation marking on the film in a sensing position can be used to signal the existence of correlation whereas the absence of such marking may energize a warning lamp or deactivate the film drive.

Abstract: The invention provides a system for developing sync pulses when PICOR is used on sound film systems. The sprocket holes in the feed track of the film are used in conjunction with a light source and a photocell to develop sync pulses which are required to synchronize a rotating electronic switch with periodic sequential information recorded on the sound track of the film.

Abstract: In a movie camera a control frequency generator for producing a picture and sound synchronizing sinusoidal control frequency using a rotating member of the camera such as a running gear made from a soft magnetic material and having a magnetically discontinuous region formed therein, a permanent magnet having one pole thereof placed in the vicinity of the discontinuous region, and a magnetic flux sensing device placed between the region and the pole of the permanent magnet for sensing the flux changes within the magnetic circuit during rotation of the camera gear and thereby producing the synchronizing control frequency.