Abstract: A frequency measuring circuit measures the period between successive pulses of an input signal and converts the pulse count to a measured frequency value. The measured frequency signal is filtered to eliminate spurious noise and a variable threshold is generated by comparing the measured frequency and the filtered frequency. Only frequency signals qualified by the variable threshold are accepted as valid and provided as the output.

Abstract: A method and system for composite system phase control in a signal processor such as a television video recorder operating in a genlocked system. A synchronizing signal, preferably a frame-rate horizontal reset pulse, is generated in response to coincidence between predetermined parts of two timing reference signals, in particular color television frame-rate horizontal line reference pulses and clock pulses derived from the color subcarrier. Possible coincidence ambiguity between the two timing reference signals exists when transitions in the two signals occur within a predetermined time period. The phase of one of the reference signals, the subcarrier frequency clock, is shifted 180 degrees (one-half cycle) to eliminate the potential coincidence ambiguity.

Abstract: Information related to the beginning of data and the phase of color burst on consecutive horizontal scan lines of a digital color television signal is encoded into a variable width pulse. A first transition of that pulse has a predetermined phase relationship with the beginning of data on each line. A second transition of the variable width pulse is formed by providing a delayed transition with respect to the first transition in a variable delay circuit. The second transition is delayed by different amounts of delay, each corresponding to a particular predetermined color burst phase on that particular line.

Abstract: A method and apparatus for the extraction of luminance information from an analog composite video signal. Non-luminance information in the video signal is 180.degree. out of phase between adjacent lines in adjacent fields of a video signal. Appropriately filtered adjacent fields are summed to cancel non-luminance information, leaving the desired luminance information. A field store is employed to allow the summing of adjacent fields by storing the present field to be summed with the next field of the video signal.

Abstract: A digital effects loop is inserted in the video and key signal buses which extend to a mixer of a switcher apparatus, and a digital effects unit is coupled to the loop. Circuitry is included in the loop to interrupt the particular bus or buses and the signal or signals are re-routed to provide inputs to the digital effects unit. The latter supplies transformed video and/or key signals back to the continuation of the respective interrupted bus or buses, and then to the mixer to be used thereby in place of the original signals.

Abstract: A digital effects unit is integrally combined with a video switcher apparatus by interrupting various selected video signal and control paths in the switcher and, in particular, the mix effects signal from the first mixer and the pattern signal from the pattern generator, and re-routing the corresponding signals to respective inputs of the digital effects unit. The resulting manipulated video and key output signals therefrom are supplied to a second, downstream mixer which combines the digital effects with conventional switcher effects.

Abstract: An apparatus and method for controlling the position of a web containing location identifying information thereon. In particular, a means for measuring displacement of the web independent of the location information is employed to measure the displacement of the web in a cyclic manner such that the measuring cycle is in the expected displacement intervals between identifying information. A difference between a desired position of the web determined by an operator controlled reference displacement position of the web is determined, and used for controlling the position of the web to the desired position.

Abstract: A new automatic tracking method is disclosed for the accurate positioning of a magnetic head with information previously recorded on the magnetic tape. If a moveable magnetic head is used, the position thereof is first normalized. Thereafter tracking is automatically adjusted based on a repetitive sampling process in which the results are mathematically averaged to determine a precise center position. Finally, new video material is physically positioned on the magnetic track according to a single offset error measurement and this single offset error is stored and used in all subsequent edit operations.

Abstract: A nonmagnetic holder is made having a plurality of precisely located parallel grooves. Each groove has a reference lateral surface provided therein. Individual magnetic transducers are inserted in each groove with a lateral surface abutting the reference lateral surface within that groove. The transducers are preferably made by well known batch fabrication techiques. A locating element, such as a leaf spring, is provided in each groove to urge the transducer core against the reference surface and to firmly hold the transducer in a desired position during alignment and assembly. The modular structure allows inspecting the individual transducers for mechanical or electrical damages and their replacement, if necessary, prior to the final assembly. The multichannel head is then integrally joined together, for example by bonding. The rejection rate of the resulting modular multichannel head is significantly reduced.

Abstract: An adaptive chrominance separator is provided which responds to horizontal high frequency luminance detail as well as to vertical chrominance detail. The luminance and chrominance levels are detected and an adaptive decision is made, depending upon the relative levels, of whether to use a bandpass filter, a comb filter or the averaged outputs of both filters, to provide more accurate separation of the chrominance.

Abstract: A door operating mechanism for a magnetic tape cassette, such mechanism including a door latch mechanism provided in the cassette capable of rotating a door assembly of the cassette from the fully closed to the fully opened position and designed to prevent the engagement of the door assembly with the tape run contained within the cassette.

Abstract: A plurality of input video signals (including background) are combined in accordance with priority. Each video signal comprises data samples corresponding to respective discrete locations on a viewing plane. The signals are preferably from an ADO transformation system wherein such data samples correspond to elements of an image lying in an image plane displaced from the viewing plane. Input key signals correspnding to respective locations are associated with respective input signals. Priority is shown determined from respective sets of plane defining signals as a sequence of depth signals corresponding to the depth coordinates of the respective image plane at the respective locations. The depth signals are used to produce respective weighting signals.

Abstract: An improved magnetic particulate pigment suitable for use in recording media and media employing it are disclosed. The particles of the pigment comprise a magnetic core with an epitaxial layer containing approximately 0.05-2.0% of the total pigment as zinc ion. A process for preparing such particles is also disclosed.

Abstract: A capstan servo for moving video tape with variable speed during playback controls the tape speed according to time period inputs. The input specifies the number of seconds per hour of program length, for example, that a segment of recorded video information is to be expanded or compressed compared relative to its normal real time playback length. The speed of tape transport during playback is varied by locking the reproduced control track vertical sync signal to a synthesized time adjustable reference signal.

Abstract: There is disclosed herein an apparatus and method for accurately ascertaining the time of occurrence of passage of the leading and trailing edges of an input pulse through the 50% amplitude level. The apparatus implements the transfer function 1 - cos(wt) where t is equal to the round trip delay through a delay line, and w is the angular velocity of each fourier component of the input signal. In one embodiment, a summing resistor and a delay line having a characteristic impedance equal to that of the resistor are used. The output of the delay line is coupled to one input of a comparator, and the other input is coupled to the junction between the summing resistor and the delay line. Another embodiment uses two matched delay lines, two factoring circuits, a summing circuit and a comparator to implement the same transfer function.

Abstract: A signal generator for generating a clocked PAL reference video signal from a single signal source wherein a counter-divider extracts subcarrier frequency component from the PAL reference video signal and modulator means in combination with a counter-divider extracts a horizontal frequency component from the PAL reference video signal, the single signal source permitting the signal components extracted therefrom to be fixed in a precise mathematical relationship.

Abstract: A reference track is recorded in a longitudinal direction on a recording medium. During recording of an information signal along parallel tracks on the medium a deviation of the reference track in a transverse direction from its nominal position with respect to the medium transport is detected by one or more sensor heads mounted in a fixed relationship with respect to the medium transport. A positionably mounted data head is moved in transverse direction in accordance with the sense and magnitude of the detected deviation, thereby maintaining the data head in a known geometric relationship with the reference track during the recording process. During playback the same reference track may be utilized to follow the thusly recorded parallel tracks.

Abstract: A silent audio switch provides switching between multiple audio sources while eliminating the "pop" caused by switching spikes. Two internal buses are used for each visible external bus, whereby a new audio signal is first switched to an off-air bus opposite an on-air bus, any switching spike is allowed to subside, and then a fast mix is made between the two buses to derive the new audio signal as the switch output signal.

Abstract: In a time base correction system, a composite color television analog signal derived from a prerecorded tape is converted by an analog-to-digital (A/D) converter to a digital signal having horizontal sync and color burst signal components. The digitized sync and burst signals are processed on a line-by-line basis to provide an error signal between input video and a sampling clock in the form of a binary control word. The error signal is applied to a digital frequency synthesizer which generates a clock at the subcarrier frequency to achieve precise adjustment of frequency and phase of the A/D sampling clock with respect to the video signal. An analog phase locked loop operating at four times the subcarrier frequency feeds back a 4.times. subcarrier sampling clock to the analog-to-digital converter with adjustable frequency and phase.

Abstract: A synthetic control track signal is provided for a magnetic video tape recording and/or reproducing machine having a motor driven capstan and capstan servo which controls the speed of the tape during recording and reproducing. The synthetic signal enables the capstan servo to operate when the control track signal has not been recorded or has been improperly recorded. The synthetic signal is generated from vertical synchronization information extracted from the video information extracted signal.