Video signal processing apparatus and method for the time base compensation

A video signal processing apparatus for processing a luminance signal and a color signal of a video signal reproduced from a recording medium, comprising:

• first time base compensator means for reducing time base errors in said luminance signal to produce a time base compensated luminance signal;
• said first time base compensator means including first memory means for storing said luminance signal;
• second time base compensator means for reducing time base errors in said color signal to produce a time base compensated color signal;
• said second time base compensator means including second memory means for storing said color signal;
• first clock means for producing a write clock signal synchronized with said video signal;
• means for producing a stable clock signal;
• second clock means for producing a read clock signal synchronized with the stable clock signal;
• controller means for writing said luminance signal and said color signal into said first memory means and said second memory means, respectively, in response to said write clock signal and for reading said luminance signal and said color signal from said first memory means and said second memory means, respectively, in response to said read clock signal;
• said controller means being operative to control the reading of said luminance signal and said color signal from said first memory means and said second memory means such that corresponding portions of said luminance signal and said color signal are read therefrom at different respective times with a predetermined time difference therebetween;
• means for producing a dropout signal indicating a dropout of the reproduced video signal;
• one of said first and second time base compensator means being operative to reduce time base errors in said dropout signal in common with a respective one of the luminance and color signals to produce a time base compensated dropout signal;
• and
• dropout compensation means coupled with one of the first and second time base compensator means for compensating for dropouts in a respective one of the time base compensated luminance and color signals in response to said time base compensated dropout signal.

A video signal processing apparatus for processing a luminance signal and a color signal of a video signal reproduced from a recording medium, comprising:

• reproducing means for reproducing said video signal from a recording medium;
• first time base compensator means for reducing time base errors in said luminance signal to produce a time base compensated luminance signal;
• said first time base compensator means including first memory means for storing said luminance signal;
• second time base compensator means for reducing time base errors in said color signal to produce a time base compensated color signal;
• said second time base compensator means including second memory means for storing said color signal;
• first clock means for producing a write clock signal synchronized with said video signal;
• means for producing a stable clock signal;
• second clock means for producing a read clock signal synchronized with the stable clock signal;
• controller means for writing said luminance signal and said color signal into said first memory means and said second memory means, respectively, in response to said write clock signal and for reading said luminance signal and said color signal from said first memory means and said second memory means, respectively, in response to said read clock signal;
• said controller means being operative to control the reading of said luminance signal and said color signal from said first memory means and said second memory means such that corresponding portions of said luminance signal and said color signal are read therefrom at different respective times with a predetermined time difference therebetween;
• said reproducing means including a rotary drum operative to produce a drum phase signal indicating a rotational phase of said rotary drum and servo control means for controlling the rotational phase of said rotary drum such that its drum phase signal coincides with a servo reference signal;
• switching means for selectively switching the first and second time base compensators from an inactive state to an active state thereof;
• means for producing a stable reference signal synchronized with said stable clock signal;
• means for producing said servo reference signal such that said servo reference signal is synchronized with said stable reference signal during the active state of said first and second time base compensators;
• and
• means for adjusting the phase of said stable reference signal to establish a predetermined relationship thereof with the phase of said drum phase signal prior to switching the first and second time base compensators from an inactive state to an active state.

A video signal processing apparatus for processing a luminance signal and a color signal of a video signal reproduced from a recording medium, comprising:

• reproducing means for reproducing said video signal from a recording medium;
• first time base compensator means for reducing time base errors in said luminance signal to produce a time base compensated luminance signal;
• said first time base compensator means including first memory means for storing said luminance signal;
• second time base compensator means for reducing time base errors in said color signal to produce a time base compensated color signal;
• said second time base compensator means including second memory means for storing said color signal;
• first clock means for producing a write clock signal synchronized with said video signal;
• means for producing a stable clock signal;
• second clock means for producing a read clock signal synchronized with the stable clock signal;
• controller means for writing said luminance signal and said color signal into said first memory means and said second memory means, respectively, in response to said write clock signal and for reading said luminance signal and said color signal from said first memory means and said second memory means, respectively, in response to said read clock signal;
• said controller means being operative to control the reading of said luminance signal and said color signal from said first memory means and said second memory means such that corresponding portions of said luminance signal and said color signal are read therefrom at different respective times with a predetermined time difference therebetween;
• said reproducing means including a rotary drum operative to produce a drum phase signal indicating a rotational phase of said rotary drum and servo control means for controlling the rotational phase of said rotary drum such that its drum phase signal coincides with a servo reference signal;
• said apparatus further comprising switching means for selectively switching the first and second time base compensators from an inactive state to an active stated based on one of the state of a user actuable switch and an operational state of said reproducing means;
• means for producing a stable reference signal synchronized with said stable clock signal;
• means for producing said servo reference signal such that said servo reference signal is synchronized with said stable reference signal during the active state of said first and second time base compensators;
• and
• means for adjusting the phase of said stable reference signal to establish a predetermined relationship thereof with the phase of said drum phase signal prior to switching the first and second time base compensators from an inactive state to an active state.

A video signal processing apparatus for processing a luminance signal and a color signal of a video signal reproduced from a magnetic tape, comprising:

• reproducing means having a magnetic head for reproducing said video signal from said magnetic tape;
• first time base compensator means for reducing time base errors in said luminance signal to produce a time base compensated luminance signal;
• said first time base compensator means including first memory means for storing said luminance signal;
• second time base compensator means for reducing time base errors in said color signal to produce a time base compensated color signal;
• said second time base compensator means including second memory means for storing said color signal;
• first clock means for producing a write clock signal synchronized with said video signal;
• means for producing a stable clock signal;
• second clock means for producing a read clock signal synchronized with the stable clock signal;
• controller means for writing said luminance signal and said color signal into said first memory means and said second memory means, respectively, in response to said write clock signal, and for reading said luminance signal and said color signal from said first memory means and said second memory means, respectively, in response to said read clock signal;
• said controller means being operative to control the reading of said luminance signal and said color signal from said first memory means and said second memory means such that corresponding portions of said luminance signal and said color signal are read therefrom at different respective times with a predetermined time difference therebetween;
• said reproducing means being operative to transport said magnetic tape past said magnetic head (i) in a first operational mode at a speed corresponding with a recording speed of said video signal, and (ii) in a second operational mode at a speed differing from said recording speed;
• said apparatus further comprising means for disabling the operation of the first and second time base compensator means when said reproducing means is in said second operational mode.

A video signal processing apparatus for processing a luminance signal and a color signal of a video signal reproduced from a recording medium, comprising:

• first time base compensator means for reducing time base errors in said luminance signal to produce a time base compensated luminance signal;
• said first time base compensator means including first memory means for storing said luminance signal;
• second time base compensator means for reducing time base errors in said color signal to produce a time base compensated color signal;
• said second time base compensator means including second memory means for storing said color signal;
• first clock means for producing a write clock signal synchronized with said video signal;
• means for producing a stable clock signal;
• second clock means for producing a read clock signal synchronized with the stable clock signal;
• controller means for writing said luminance signal and said color signal into said first memory means and said second memory means, respectively, in response to said write clock signal and for reading said luminance signal and said color signal from said first memory means and said second memory means, respectively, in response to said read clock signal;
• the first and second memory means including respective first and second read address generating means for generating corresponding first and second read addresses;
• said controller means being operative to provide respective first and second read address control signals to said first and second read address generating means to control the generation of said first and second read addresses such that corresponding portions of said luminance signal and said color signal are read from said first and second memory means at different respective read times with a predetermined time difference therebetween.

A method of processing a video signal reproduced from a recording medium, the video signal including a luminance signal and a color signal, comprising the steps of:

• processing one of said luminance signal and said color signal of the reproduced video signal such that a predetermined delay is introduced in said one of said luminance and said color signal;
• reducing time base errors in said luminance signal by storing said luminance signal in a first memory means in response to a write clock signal synchronized with said video signal, producing a stable clock signal and reading said luminance signal from said first memory means in response to a read clock signal synchronized with the stable clock signal;
• and
• reducing time base errors in said color signal by writing said color signal in a second memory means in response to said write clock signal and reading said color signal from said second memory means in response to said read clock signal such that corresponding portions of said luminance signal and said color signal are delayed by respectively different amounts so that said predetermined delay introduced in said one of said luminance signal and said color signal is compensated.

A method of processing a video signal reproduced from a recording medium, the video signal including a luminance signal and a color signal, comprising the steps of:

• reducing time base errors in said luminance signal by storing said luminance signal in a first memory means in response to a write clock signal synchronized with said video signal, producing a stable clock signal and reading said luminance signal from said first memory means in response to a read clock signal synchronized with the stable clock signal;
• reducing time base errors in said color signal by writing said color signal in a second memory means in response to said write clock signal and reading said color signal from said second memory means in response to said read clock signal such that corresponding portions of said luminance signal and said color signal are read from the first and second memory means at different respective times with a predetermined time difference therebetween;
• producing a dropout signal indicating a dropout of the reproduced video signal;
• reducing time base errors in said dropout signal in common with the reduction of time base errors in a respective one of the luminance and color signals to produce a time base compensated dropout signal;
• and
• compensating for dropouts in at least one of the time base compensated luminance and color signals in response to said time base compensated dropout signal.

A method of processing a video signal reproduced from a recording medium, the video signal including a luminance signal and a color signal, comprising the steps of:

• reproducing said video signal from a recording medium with the use of a rotary drum operative to produce a drum phase signal indicating a rotational phase of the rotary drum;
• reducing time base errors in said luminance signal by storing said luminance signal in a first memory means in response to a write clock signal synchronized with said video signal, producing a stable clock signal and reading said luminance signal from said first memory means in response to a read clock signal synchronized with the stable clock signal;
• reducing time base errors in said color signal by writing said color signal in a second memory means in response to said write clock signal and reading said color signal from said second memory means in response to said read clock signal such that corresponding portions of said luminance signal and said color signal are read from the first and second memory means at different respective times with a predetermined time difference therebetween;
• producing a stable reference signal synchronized with said stable clock signal;
• prior to storing said luminance signal and said color signal in said first and second memory means, adjusting the phase of said stable reference signal to establish a predetermined relationship thereof with the phase of said drum phase signal;
• producing a servo reference signal synchronized with said stable reference signal;
• and
• controlling the rotational phase of said rotary drum such that its drum phase signal coincides with said servo reference signal.