Abstract: In a magnetic recording and reproducing apparatus, a video signal of a high-quality format which has a first given frequency band is recorded on a standard magnetic tape designed to record a video signal of a standard format having a second given frequency band narrower than the first given frequency band. In the magnetic recording and reproducing apparatus, a video signal of the high-quality format is reproduced from a standard magnetic tape.

Abstract: A crosstalk cancelling circuit for a VTR eliminates adjacent-track crosstalk in a playback down-converted chrominance signal, with the resultant signal and a playback luminance signal being supplied to respective output terminals for re-recording by another VTR. Substantially improved display image quality is obtained from the re-recorded video signals, by comparison with prior art methods.

Abstract: A luminance signal/color signal separation circuit comprises a bandpass filter which separates a first color signal partially including a luminance signal component from a composite image signal, a delay circuit which delays the first color signal to obtain a second color signal, a logic circuit which outputs a luminance component signal from the first color signal and the second color signal, a first adder/subtracter which extracts a third color signal free from the luminance signal component by combining the luminance component signal and the first color signal, and a second adder/subtracter which extracts luminance signal by combining the third color signal and the composite image signal.

Abstract: A crosstalk cancelling circuit for use in video tape recorders. The cancelling circuit comprises a first multiplier for multiplying a frequency-lowered conversion chrominance signal reproduced from a magnetic tape by a local oscillating signal with a predetermined frequency and a delay device for delaying the frequency-lowered conversion chrominance signal by one horizontal scanning period. The local oscillating signal is further supplied to a phase-shifting circuit which in turn produces either a signal leading the local oscillating signal by a phase angle of 90.degree. or a signal lagging the local oscillating signal by a phase difference of 90.degree. in synchronism with a field frequency of the frequency-lowered conversion chrominance signal.

Abstract: A luminance signal/color signal separation circuit includes a band-pass filter for picking up a color signal from a composite image signal; a delay circuit for sequentially delaying by one line the color signal picked up by the band-pass filter and obtaining three past, present and future line information; a first operation circuit for outputting a signal which takes a value having a larger absolute value when the past and future line information have the same sign, and takes an algebraic sum of the past and future line information when the past and future line information have different signs; a second operation circuit for outputting a signal which takes a value having a smaller absolute value when the output from the first operation circuit and the present line information have the same sign, and takes a reference value when the output from the first operation circuit and the present line information have different signs; and a third operation circuit for obtaining a color signal by subtracting the output

Abstract: In a YC separator for generating a chrominance signal C including no chrominance separation error by selecting a second highest potential signal of the first chrominance signal a, the second chrominance signal c' including a separation error and a reference signal, only when a picture having two different colors at a border between n-th line and (n-1)th line is displayed, a correction value of 1/2 is generated as the reference signal, in order to obtain C=1 and Y=0 for prevention of n-th line dot crawl. Further, when a vertical stripe picture (black and white lines are alternately arranged) is displayed, a chrominance signal Cc including much less unnecessary signal components can be obtained through an arithmetic circuit and on the basis of a chrominance signal Cc' including error components and an average signal D between the past and future line chrominance signals A and C, in order to eliminate cross-color at the upper and lower ends of the picture and Yc signal blur.

Abstract: In a circuit for removing crosstalk components in a carrier chrominance signal, there are provided a first delay circuit (20), an inverter (21), a first higher-voltage detecting circuit (18), a second delay circuit (22), a second higher-voltage detecting circuit (19), a third higher-voltage detecting circuit (25), a first lower-voltage detecting circuit (23), a second lower-voltage detecting circuit (24), a third lower-voltage detecting circuit (17), and an adder (26) thereby producing a crosstalk-removed carrier chrominance signal. Furthermore, the first delay circuit (20), the inverter (21), and an adder (28) form a comb filter for correcting a time delay due to said circuit for removing crosstalk components in a carrier chrominance signal.

Abstract: A recording and reproducing device for a video signal comprises a recording circuit for changing an input video signal to a recording video signal, and a reproducing circuit for changing a reproduced video signal to an output video signal. Particularly, the reproducing circuit of this device includes a first high-pass filter having a time constant Ts, a first limiter for limiting the amplitude of the output signal of the first high-pass filter, and a first coefficient multiplier circuit for multiplying an output signal of the first limiter by a first coefficient K.

Abstract: In a circuit for removing crosstalk components in a carrier chrominance signal, there are provided a first delay circuit (20), an inverter (21), a first higher-voltage detecting circuit (18), a second delay circuit (22), a second higher-voltage detecting circuit (19), a third higher-voltage detecting circuit (25), a first lower-voltage detecting circuit (23), a second lower-voltage detecting circuit (24), a third lower-voltage detecting circuit (17), and an adder (26) thereby producing a crosstalk-removed carrier chrominance signal. Furthermore, the first delay circuit (20), the inverter (21), and an adder (28) form a comb filter for correcting a time delay due to said circuit for removing crosstalk components in a carrier chrominance signal.

Abstract: A luminance signal/color signal separation circuit comprises a color signal separation circuit for obtaining a first color signal partially including luminance signal component from a composite image signal, a computation circuit for obtaining a second color signal including a color separation error signal by eliminating the luminance signal component from the first color signal to take out a signal of the second highest potential of the first and second color signals and a reference potential, thus to take out a third color signal excluding the color separation error signal, and a luminance signal separation circuit for obtaining a luminance signal from the composite signal and the third color signal.

Abstract: A video signal recording apparatus comprises a sampling circuit for sampling an input video signal by a signal having a predetermined frequency f.sub.s, a circuit for obtaining a multiplexed signal by multiplexing a reference burst signal to the output sampled signal of the sampling circuit, and a circuit for recording the multiplexed signal on a recording medium. A video signal recording and reproducing apparatus comprises in addition to the constituting elements of the recording apparatus, a circuit for reproducing the recorded multiplexed signal from the recording medium, a circuit for obtaining from the reproduced multiplexed signal first and second reproduced sampled signals having a relative time difference of one horizontal scanning period, a circuit for generating first and second sampling pulses having the same frequency f.sub.s and having phases which mutually differ by 180.degree.

Abstract: A noise reduction circuit for use in a video signal recording and/or reproducing apparatus for eliminating noise components from an input luminance signal comprises a high pass filter circuit for extracting a high frequency signal component from the input luminance signal, a first limiter circuit for limiting the high frequency signal component at a first limiting level, a multiplier circuit for determining the degree of preemphasis and/or deemphasis by multiplying a predetermined coefficient to the limited signal, summing and subtracting circuits respectively for adding and subtracting the output signal of the first amplifying means to and from the input luminance signal, and a feedback loop for feeding back the output signal of the high pass filter circuit to its input port. The feedback loop comprises a second multiplier circuit which modifies the amplitude of the signal passing therethrough by a second level which is set substantially higher than the first level of the first limiter circuit.

Abstract: A noise reduction circuit for a video signal recording and/or reproducing apparatus comprises a high pass filter for extracting high frequency signal component form the input luminance signal, a limiter circuit for limiting the high frequency signal component, a multiplier for determining the degree of preemphasis and/or deemphasis by multiplying the limited signal, and summing and subtracting circuits respectively for adding and subtracting the high frequency signal component processed by the limiter circuit and the multiplier to and from the original luminance signal. The limiter circuit has an amplitude characteristic which changes a gradient so as to have a characteristic curve of at least three different gradient slopes interconnected in succession with an increase in amplitude of the signal supplied thereto.

Abstract: A video signal recording and playback apparatus in which in a record mode operation a frequency-modulated luminance signal and a carrier chrominance signal whose frequency has been converted to a one lower than that of the luminance signal are written superposed on each other in a magnetic recording medium and, in a playback mode operation, the signal read out of the recording medium is separated into a reproduced color signal and a reproduced luminance signal, then the two reproduced signals are subjected to predetermined signal processing by individual signal processing systems, and then the processed signals are mixed by a mixer to produce a reproduced color video signal. The mixer to which the reproduced luminance signal is applied is preceded by a comb filter which is operable using a chrominance subcarrier frequency of the reproduced chrominance signal as a reference.

Abstract: A video signal recording apparatus comprises a sampling circuit for sampling an input video signal by a signal having a predetermined frequency f.sub.s, a circuit for obtaining a multiplexed signal by multiplexing a reference burst signal to the output sampled signal of the sampling circuit, and a circuit for recording the multiplexed signal on a recording medium. A video signal recording and reproducing apparatus comprises in addition to the constituting elements of the recording apparatus, a circuit for reproducing the recorded multiplexed signal from the recording medium, a circuit for obtaining from the reproduced multiplexed signal first and second reproduced sampled signals having a relative time difference of one horizontal scanning period, a circuit for generating first and second sampling pulses having the same frequency f.sub.s and having phases which mutually differ by 180.degree.

Abstract: A color video signal recording and reproducing apparatus comprises a first circuit for delaying by a time period T a reproduced time-compressed line-sequential color difference signal in which time-compressed first and second color difference signals are alternately transmitted in time sequence for every time period T, a second circuit for delaying a reproduced luminance signal by a time period 2nT+.alpha., where n=1 or 2 and 0.ltoreq..alpha..ltoreq.

Abstract: A helical scan type magnetic recording and reproducing apparatus comprises a rotary body which is wrapped with a magnetic tape on an outer peripheral surface thereof over a predetermined angular range and has a tape guide for guiding a part of the magnetic tape, and n pairs of rotary heads mounted on the rotary body. Each pair out of the n pairs of rotary heads is constituted by two rotary heads which are mounted at mutually opposite positions on a rotational plane of the rotary body at the same height position, and each pair out of the n pairs of rotary heads is mounted at different positions in an axial direction of the rotary body.

Abstract: A noise reduction system for reducing noise in a video signal comprises a pre-emphasis circuit for subjecting the video signal which is supplied to a transmission system to a pre-emphasis in a vertical direction of a picture and in a direction oblique to the vertical direction, and a de-emphasis circuit for subjecting the pre-emphasized video signal obtained through the transmission system to a de-emphasis complementary to the pre-emphasis.

Abstract: Disclosed is a noise reduction circuit for reducing noise contained in a luminance signal, wherein a first subtractor has a first input terminal connected to be responsive to the luminance signal. A low-pass filter passes a low-frequency component of the output of the first subtractor to a second subtractor which combines it with the luminance signal to extract high-frequency noise contained therein. The extracted noise is limited in amplitude by a limiter and applied through a feedback circuit to the second input terminal of the first subtractor. The noise reduction circuit operates as if it were a low-pass filter having a cutoff frequency which increases as a function of the level of the luminance signal to reduce the length of time in which smear and noise tend to occur in response to high amplitude luminance signals.