Magnetic video recording/reproducing apparatus for video signals of different aspect ratios adapter unit

A magnetic video recording/reproducing apparatus having a recording circuit for recording two kinds of video signals based on different aspect ratios a.sub.1 and a.sub.2, where a.sub.1 >a.sub.2, and a reproduction circuit for reproducing recorded video signals, said apparatus comprising:

• a Y/C separation circuit including a filter which receives a composite video signal to be recorded, separates from the composite video signal a luminance signal and a chrominance signal and outputs the luminance and chrominance signals;
• a luminance signal recording processing circuit including a pre-emphasis circuit which receives the luminance signal from said Y/C separation circuit and applies pre-emphasis to at least the luminance signal and an FM modulator circuit which FM modulates the luminance signal to which pre-emphasis has been applied into an FM modulated luminance signal;
• a chrominance signal recording processing circuit including a frequency converter circuit which receives the chrominance signal from said Y/C separation circuit and down converts said chrominance signal from an original frequency band of said chrominance signal to a lower frequency band within a frequency band of said FM modulated luminance signal;
• a Y/C recording mixer circuit including an adder circuit which adds the FM modulated luminance signal from said luminance signal recording processing circuit and the down converted chrominance signal from said chrominance signal recording processing circuit to provide a frequency multiplexed signal;
• a recording amplifier circuit including an amplifier circuit which amplifies the frequency multiplexed signal from said Y/C recording mixer circuit to a power level necessary for recording said frequency multiplexed signal on a magnetic recording medium;
• a recording head for receiving the amplified frequency multiplexed signal from said recording amplifier circuit and recording the amplified frequency multiplexed signal on the magnetic recording medium;
• a reproducing head for reproducing the frequency multiplexed signal recorded on said magnetic recording medium;
• a reproducing amplifier circuit including an amplifier circuit which amplifies a voltage of the reproduced frequency multiplexed signal from said reproducing head to a voltage level suitable for reproduction signal processing;
• a luminance signal reproduction processing circuit including an FM demodulator circuit which receives the amplified reproduced frequency multiplexed signal from said reproducing amplifier circuit and frequency-separates therefrom at least the FM modulated luminance signal and demodulates the FM modulated luminance signal into a base band luminance signal, and a de-emphasis circuit which applies de-emphasis to the base band luminance signal;
• an aspect ratio decider circuit for receiving one of the amplified reproduced frequency multiplexed signal from said reproducing amplifier circuit and the base band luminance signal from said luminance signal reproduction processing circuit, deciding which one of the two aspect ratios a.sub.1 and a.sub.2 the received signal is based on, and outputting a logical signal indicating a result of the decision;
• a first clock signal generator circuit including a phase locked loop circuit responsive to the base band luminance signal from said luminance signal reproduction processing circuit to generate and output a first clock signal which is phase locked with a synchronization signal included in said base band luminance signal;
• a second clock signal generator circuit including a circuit responsive to the first clock signal from said clock signal generator circuit to generate and output second and third clock signals having frequencies related to each other by a ratio of a.sub.1 :a.sub.2 ;
• a counter circuit which counts the first clock signal from said first clock signal generator circuit, the counter circuit being reset in each of a plurality of horizontal periods of the base band luminance signal;
• a third clock signal generator circuit for generating and outputting a sixth clock signal having a constant frequency which approximately equals a mean value of the frequency of the second clock signal from said second clock signal generator circuit and a seventh clock signal having a constant frequency which approximately equals a mean value of the frequency of the third clock signal from said second clock signal generator circuit;
• a luminance signal compression/expansion circuit for receiving the base band luminance signal from said luminance signal reproduction processing circuit, applying time compression/expansion processing to the base band luminance signal using a memory having a capacity of at least one horizontal line of the base band luminance signal and outputting a processed base band luminance signal, said luminance signal compression/expansion circuit receiving the logical signal from said aspect ratio decider circuit, the second and third clock signals from said second clock signal generator circuit, the sixth and seventh clock signals from said third clock signal generator circuit, and an output signal of said counter circuit, wherein when said logical signal indicates that the signal received by said aspect ratio decider circuit is based on the aspect ratio a.sub.1, said luminance signal compression/expansion circuit writes the base band luminance signal in said memory using the second and third clock signals in accordance with the output signal of said counter circuit and reads the base band luminance signal written in said memory from said memory using the seventh clock signal in accordance with the output signal of said counter circuit to time-expand a horizontal center portion of the base band luminance signal by a.sub.1 /a.sub.2, and during a blanking period of the base band luminance signal including the synchronization signal, to pass the base band luminance signal without subjecting it to compression/expansion, and when said logical signal indicates that the signal received by said aspect ratio decider circuit is based on the aspect ratio a.sub.2, said luminance signal compression/expansion circuit one of a (a) passes the base band luminance signal without subjecting it to compression/expansion and (b) writes the base band luminance signal in said memory using the second and third clock signals in accordance with the output signal of said counter circuit and reads the base band luminance signal written in said memory from said memory using the sixth clock signal in accordance with the output signal of said counter circuit to pass the base band luminance signal without subjecting it to compression/expansion during the blanking period of the base band luminance signal including the synchronization signal and time-compress the base band luminance signal by a.sub.2 /a.sub.1 during a remaining period of the base band luminance signal;
• a chrominance signal demodulator circuit including one of (a) a demodulator circuit which receives the amplified reproduced frequency multiplexed signal from said reproducing amplifier circuit and frequency-separates therefrom the down converted chrominance signal and demodulates the down converted chrominance signal into two base band color difference signals and (b) a demodulator circuit which receives the amplified reproduced frequency multiplexed signal from said reproducing amplifier circuit and frequency-separates therefrom the down converted reproduced chrominance signal and up converts the down converted chrominance signal back to the original frequency band of the chrominance signal and thereafter demodulates the up converted chrominance signal into two base color difference signals;
• a color difference signal compression/expansion circuit for receiving the two base band color difference signals from said chrominance signal demodulator circuit, applying time compression/expansion processing to the two base band color difference signals using a memory having a capacity of at least one horizontal line of each of the two base band color difference signals and outputting two processed base band color difference signals, said color difference signal compression/expansion circuit receiving the logical signal from said aspect ratio decider circuit, the second and third clock signals from said second clock signal generator circuit, the sixth and seventh clock signals from said third clock signal generator circuit, and the output signal of said counter circuit, wherein when said logical signal indicates that the signal received by said aspect ratio decider circuit is based on the aspect ratio a.sub.1, said color difference signal compression/expansion circuit writes the two base band color difference signals in said memory using, in accordance with the output signal of said counter circuit, one of (a) said second and third clock signals and (b) fourth and fifth clock signals obtained by frequency dividing said second and third clock signals by a frequency division ratio k, and reads the two base band color difference signals written in said memory from said memory using, in accordance with the output signal of said counter circuit, one of (a) said seventh clock signal and (b) a ninth clock signal obtained by frequency dividing said seventh clock signal by the frequency division ratio k, to time-expand a horizontal center portion of each of the two base band color difference signals by a.sub.1 /a.sub.2, and during the blanking period of the base band luminance signal, to pass the two base band color difference signals without subjecting them to compression/expansion, and when said logical signal indicates that the signal received by said aspect ratio decider circuit is based on the aspect ratio a.sub.2, said color difference signal compression/expansion circuit one of (a) passes the two base band color difference signals without subjecting them to compression/expansion and (b) writes the two base band color difference signals in said memory using one of (a) the second and third clock signals and (b) the fourth and fifth clock signals, in accordance with the output signal of said counter circuit and reads the two base band color difference signals written in said memory from said memory using one of (a) said sixth clock signal and (b) an eighth clock signal obtained by frequency dividing said sixth clock signal by said frequency division ratio k, in accordance with the output signal of said counter circuit, to pass the two base band color difference signals without subjecting them to compression/expansion during the blanking period of the base band luminance signal and to time-compress the two base band color difference signals by a.sub.2 /a.sub.1 during the remaining period of the base band luminance signal;
• and
• a chrominance signal modulator circuit including a modulator circuit which receives the two processed base band color difference signals from said color difference signal compression/expansion circuit and modulates the two processed base band color difference signals into a quadrature two-phase modulated signal including a chrominance sub-carrier signal.

A magnetic video recording/reproducing apparatus having a recording circuit for recording two kinds of video signals based on different aspect ratios a.sub.1 and a.sub.2, where a.sub.1 >a.sub.2, and a reproduction circuit for reproducing recorded video signals, said apparatus comprising:

• a Y/C separation circuit including a filter which receives a composite video signal to be recorded, separates from the composite video signal a luminance signal and a chrominance signal and outputs the luminance and chrominance signals;
• a luminance signal recording processing circuit including a pre-emphasis circuit which receives the luminance signal from said Y/C separation circuit and applies pre-emphasis to at least the luminance signal and an FM modulator circuit which FM modulates the luminance signal to which pre-emphasis has been applied into an FM modulated luminance signal;
• a chrominance signal recording processing circuit including a frequency converter circuit which receives the chrominance signal from said Y/C separation circuit and down converts said chrominance signal from an original frequency band of said chrominance signal to a lower frequency band within a frequency band of said FM modulated luminance signal;
• a Y/C recording mixer circuit including an adder circuit which adds the FM modulated luminance signal from said luminance signal recording processing circuit and the down converted chrominance signal from said chrominance signal recording processing circuit to provide a frequency multiplexed signal;
• a recording amplifier circuit including an amplifier circuit which amplifies the frequency multiplexed signal from said Y/C recording mixer circuit to a power level necessary for recording said frequency multiplexed signal on a magnetic recording medium;
• a recording head for receiving the amplified frequency multiplexed signal from said recording amplifier circuit and recording the amplified frequency multiplexed signal on the magnetic recording medium;
• a reproducing head for reproducing the frequency multiplexed signal recorded on said magnetic recording medium;
• a reproducing amplifier circuit including an amplifier circuit which amplifies a voltage of the reproduced frequency multiplexed signal from said reproducing head to a voltage level suitable for reproduction signal processing;
• a luminance signal reproduction processing circuit including an FM demodulator circuit which receives the amplified reproduced frequency multiplexed signal from said reproducing amplifier circuit and frequency-separates therefrom at least the FM modulated luminance signal and demodulates the FM modulated luminance signal into a base band luminance signal, and a de-emphasis circuit which applies de-emphasis to the base band luminance signal;
• an aspect ratio decider circuit for receiving one of the amplified reproduced frequency multiplexed signal from said reproducing amplifier circuit and the base band luminance signal from said luminance signal reproduction processing circuit, deciding which one of the two aspect ratios a.sub.1 and a.sub.2 the received signal is based on, and outputting a logical signal indicating a result of the decision;
• a first clock signal generator circuit including an oscillator circuit for generating and outputting a first clock signal having a constant frequency which is an integer multiple of a horizontal synchronization frequency of the base band luminance signal;
• a second clock signal generator circuit including a circuit responsive to the first clock signal from said first clock signal generator circuit to generate and output second and third clock signals having frequencies related to each other by a ratio of a.sub.1 :a.sub.2 ;
• counts the first clock signal from said first clock signal generator circuit, the counter circuit being reset in each of a plurality of horizontal periods of the base band luminance signal;
• a luminance signal compression/expansion circuit for receiving the base band luminance signal from said luminance signal reproduction processing circuit, applying time compression/expansion processing to the base band luminance signal, and outputting a processed base band luminance signal, said luminance signal compression/expansion circuit receiving the logical signal from said aspect ratio decider circuit, the second and third clock signals from said second clock signal generator circuit, and an output signal of said counter circuit, wherein when said logical signal indicates that the signal received by said aspect ratio decider circuit is based on the aspect ratio a.sub.1, said luminance signal compression/expansion circuit uses said second and third clock signals in accordance with the output signal of said counter circuit to time-expand a horizontal center portion of the base band luminance signal by a.sub.1 /a.sub.2, and during a blanking period of the base band luminance signal including a synchronization signal, to pass the base band luminance signal without subjecting it to compression/expansion, and when said logical signal indicates that the signal received by said aspect ratio decider circuit is based on the aspect ratio a.sub.2, said luminance signal compression/expansion circuit one of (a) passes the base band luminance signal without subjecting it to compression/expansion and (b) passes the base band luminance signal without subjecting it to compression/expansion during the blanking period of the base band luminance signal including the synchronization signal and time-compresses the base band luminance signal by a.sub. 2 /a.sub.1 during a remaining period of the base band luminance signal;
• a chrominance signal demodulator circuit including one of (a) a demodulator circuit which receives the amplified reproduced frequency multiplexed signal from said reproducing amplifier circuit and frequency-separates therefrom the down converted chrominance signal and demodulates the down converted chrominance signal into two base band color difference signals and (b) a demodulator circuit which receives the amplified reproduced frequency multiplexed signal from said reproducing amplifier circuit and frequency-separates therefrom the down converted chrominance signal and up converts the down converted chrominance signal back to the original frequency band of the chrominance signal and thereafter demodulates the up converted chrominance signal into two base band color difference signals;
• a color difference signal compression/expansion circuit for receiving the two base band color difference signals from said chrominance signal demodulator circuit, applying time compression/expansion processing to the two base band color difference signals, and outputting two processed base band color difference signals, said color difference signal compression/expansion circuit receiving the logical signal from said aspect ratio decider circuit, the second and third clock signals from said second clock signal generator circuit, and the output signal of said counter circuit, wherein when said logical signal indicates that the signal received by said aspect ratio decider circuit is based on the aspect ratio a.sub.1, said color difference signal compression/expansion circuit uses, in accordance with the output signal of said counter circuit, one of (a) said second and third clock signals and (b) fourth and fifth clock signals obtained by frequency dividing said second and third clock signals by a same frequency division ratio, to time-expand a horizontal center portion of each of the two base band color difference signals by a.sub.1 /a.sub.2, and during the blanking period of the base band luminance signal, to pass the two base band color difference signals without subjecting them to compression/expansion, and when said logical signal indicates that the signal received by said aspect ratio decider circuit is based on the aspect ratio a.sub.2, said color difference signal compression/expansion circuit one of (a) passes the two base band color difference signals without subjecting them to compression/expansion and (b) passes the two base band color difference signals without subjecting them to compression/expansion during the blanking period of the base band luminance signal and time-compresses the two base band color difference signals by a.sub.2 /a.sub.1 during the remaining period of the base band luminance signal;
• and
• a chrominance signal modulator circuit including a modulator circuit which receives the two processed base band color difference signals from said color difference signal compression/expansion circuit and modulates the two processed base band color difference signals into a quadrature two-phase modulated signal including a chrominance sub-carrier signal.

A magnetic video recording/reproducing apparatus comprising:

• wide aspect ratio decoding means for decoding a received video signal to output a wide aspect ratio video signal having an aspect ratio which is greater than an aspect ratio of a conventional video signal if the received video signal is a wide aspect ratio video signal, and for outputting the received video signal without converting the aspect ratio of the received video signal if the received video signal is a conventional video signal;
• recording means for recording the output video signal from the wide aspect ratio decoding means on a magnetic video tape;
• reproducing means for reproducing the video signal recorded on the magnetic video tape to produce a reproduced video signal having an aspect ratio which is the same as the aspect ratio of the recorded video signal;
• aspect ratio detecting means for detecting the aspect ratio of the reproduced video signal;
• aspect ratio converting means responsive to the aspect ratio detecting means for converting the reproduced video signal to a converted video signal having an aspect ratio which is different from the aspect of the reproduced video signal;
• first output means for outputting the reproduced video signal;
• and
• second output means for outputting the converted video signal.