Synchronizing signal separating apparatus and method

Claim 1

A processing apparatus, implemented in analog or digital form or both, for recovering synchronizing information from a video type signal including: circuitry responsive to said video type signal to provide a first reference taking signal which is responsive to and occurs after a falling sync edge and to further provide at least a second reference taking signal which is responsive to and occurs after a rising sync edge; circuitry responsive to synchronizing pulses of said video type signal and said first and second reference taking signals to generate at least a first reference level signal in response to said first reference taking signal and a second reference level signal in response to said second reference taking signal, said reference level signals representing different levels of said synchronizing pulses; and circuitry responsive to said synchronizing pulses of said video type signal and a level responding to said reference level signals to generate recovered synchronizing pulses.

Claim 3

An apparatus, in analog or digital form or both, for recovering synchronizing information from a video type signal including: clamping circuitry responsive to said video type signal to provide a clamped signal; circuitry responsive to said clamped signal to provide a plurality of reference taking signals; circuitry responsive to synchronizing pulses of said video type signal and said plurality of reference taking signals to generate at least a first reference level signal and a second reference level signal, said reference level signals representing different levels of said synchronizing pulses; and circuitry responsive to said synchronizing pulses and a level responding to said reference level signals to generate recovered synchronizing pulses, with said reference taking signals being independent of said level responding to said reference level signals.

Claim 4

An apparatus, in analog or digital form or both, for recovering synchronizing information from a video type signal including: clamping circuitry responsive to said video type signal to provide a clamped signal; circuitry responsive to said clamped signal to provide a plurality of reference taking signals; circuitry responsive to synchronizing pulses of said video type signal and said plurality of reference taking signals to generate at least a first reference level signal and a second reference level signal, said reference level signals representing different levels of said synchronizing pulses; and circuitry responsive to said synchronizing pulses and a level responding to said reference level signals to generate recovered synchronizing pulses, with said reference taking signals being independent of said level responding to said reference level signals.

Claim 13

A method for processing a sync portion of a video type signal, said sync portion having a plurality of levels, comprising steps of: a) a first separation of said sync portion to generate a first separated sync signal; b) generating a plurality of level signals each being representative of a level of said sync portion, at least one of which level signals is also generated in response to an edge of said first separated sync signal and is delayed at least 0.1 μs with respect thereto; c) providing a reference signal in response to said plurality of level signals; d) a second separation of said sync portion in response to said reference signal to provide a second separated sync signal which is a version of said sync portion.

Claim 14

A method for processing a sync portion of a video type signal, said sync portion having a plurality of levels, comprising steps of: a) a first separation of said sync portion to generate a first separated sync signal; b) generating a plurality of level signals each being representative of a level of said sync portion, at least one of which level signals is also generated in response to an edge of said first separated sync signal and is delayed at least 0.1 μs with respect thereto; c) providing a reference signal in response to said plurality of level signals; d) a second separation of said sync portion in response to said reference signal to provide a second separated sync signal which is a version of said sync portion.

Claim 16

A method of detecting a sync pattern in a video type signal including the steps of: a) detecting the occurrence of a known first event and generating a marking signal in response thereto; b) delaying said marking signal by an amount which will provide a delayed version thereof before the expected occurrence of a known second event; c) detecting an edge of said second event of transition from one state to another; d) comparing said delayed version of said marking signal and said second event to ensure a proper relationship thereof.

Claim 17

A method of detecting a sync pattern in a video type signal including the steps of: a) detecting the occurrence of a known first event and generating a marking signal in response thereto; b) delaying said marking signal by an amount which will provide a delayed version thereof before the expected occurrence of a known second event; c) detecting an edge of said second event of transition from one state to another; d) comparing said delayed version of said marking signal and said second event to ensure a proper relationship thereof.

Claim 20

A method of detecting a sync pattern in a video type signal including the steps of: a) detecting the occurrence of a transition of a known direction and at least a minimum amplitude and generating a marking signal in response thereto; b) delaying said marking signal by an amount which will provided a delayed version thereof at or before the expected occurrence of a known second event; c) detecting said second event which includes an edge of transition from one state to another; d) comparing said delayed version of said marking signal and said second event to ensure a proper relationship thereof.

Claim 21

A method of detecting a sync pattern in a video type signal including the steps of: a) detecting the occurrence of a transition of a known direction and at least a minimum amplitude and generating a marking signal in response thereto; b) delaying said marking signal by an amount which will provided a delayed version thereof at or before the expected occurrence of a known second event; c) detecting said second event which includes an edge of transition from one state to another; d) comparing said delayed version of said marking signal and said second event to ensure a proper relationship thereof.

Claim 22

The method of detecting a sync pattern in a video type signal including the steps of: a) detecting the occurrence of a level of a component of said sync pattern for a known amount and time and generating a marking signal in response thereto; b) delaying said marking signal by an amount which will provide a delayed version thereof at or before the expected occurrence of a known second event; c) detecting said second event which includes an edge of transition from one state to another; d) comparing said delayed version of said marking signal and said second event to ensure a proper relationship thereof.

Claim 23

The method of detecting a sync pattern in a video type signal including the steps of: a) detecting the occurrence of a level of a component of said sync pattern for a known amount and time and generating a marking signal in response thereto; b) delaying said marking signal by an amount which will provide a delayed version thereof at or before the expected occurrence of a known second event; c) detecting said second event which includes an edge of transition from one state to another; d) comparing said delayed version of said marking signal and said second event to ensure a proper relationship thereof.

Claim 24

A method for detecting an occurrence of a sync signal of a known pattern including the steps of: a) detecting a first transition of a known direction and amplitude; b) delaying an indication of the occurrence of said first transition for a known amount of time; c) detecting a second transition of a known direction and amplitude; d) detecting the approximate coincidence of said delayed indication and said second transition.

Claim 25

A method for detecting an occurrence of a sync signal of a known pattern including the steps of: a) detecting a first transition of a known direction and amplitude; b) delaying an indication of the occurrence of said first transition for a known amount of time; c) detecting a second transition of a known direction and amplitude; d) detecting the approximate coincidence of said delayed indication and said second transition.

Claim 26

A method for detecting an occurrence of a sync event of a known pattern including the steps of: a) detecting a first transition of a known direction and amplitude; b) delaying an indication of the occurrence of said first transition for a known amount of time; c) detecting a second transition of a known direction and amplitude; d) detecting the approximate coincidence of said delayed indication and said second transition; e) checking if said first or second occurrence takes place in an expected relationship to a previous event.

Claim 27

A method for detecting an occurrence of a sync event of a known pattern including the steps of: a) detecting a first transition of a known direction and amplitude; b) delaying an indication of the occurrence of said first transition for a known amount of time; c) detecting a second transition of a known direction and amplitude; d) detecting the approximate coincidence of said delayed indication and said second transition; e) checking if said first or second occurrence takes place in an expected relationship to a previous event.

Claim 28

A method for detecting an occurrence of a sync event of a known pattern including the steps of: a) detecting a first transition of a known direction and amplitude; b) delaying an indication of the occurrence of said first transition for a known amount of time; c) detecting a second transition of a known direction and amplitude; d) detecting the approximate coincidence of said delayed indication and said second transition; e) checking if said first or second occurrence takes place in an expected relationship to a later event.

Claim 29

A method for detecting an occurrence of a sync event of a known pattern including the steps of: a) detecting a first transition of a known direction and amplitude; b) delaying an indication of the occurrence of said first transition for a known amount of time; c) detecting a second transition of a known direction and amplitude; d) detecting the approximate coincidence of said delayed indication and said second transition; e) checking if said first or second occurrence takes place in an expected relationship to a later event.

Claim 36

The method of identifying the occurrence of a sync event in a video type signal including the steps of: receiving said video type signal; detecting a known first event in said video type signal; detecting a known second event in said video type signal; detecting a known third event in said video type signal; determining the relationship of said first and said second and said third events, and should said relationship match known parameters identify the occurrence of said sync event.

Claim 37

The method of identifying the occurrence of a sync event in a video type signal including the steps of: receiving said video type signal; detecting a known first event in said video type signal; detecting a known second event in said video type signal; detecting a known third event in said video type signal; determining the relationship of said first and said second and said third events, and should said relationship match known parameters identify the occurrence of said sync event.

Claim 38

A method for detecting in a video type signal an occurrence of a sync portion having a sync tip and a back porch, including the steps of: a) clamping said video type signal with a sync tip clamp to provide a clamped signal; b) low pass filtering said clamped signal to provide a filtered signal; c) measuring the level of one of said sync tip or said back porch during the time period starting at least 0.1 microsecond after the start of said sync tip or reference level and ending before the end of said sync tip or reference level; d) in response to said level of c) generating a 50% level signal representative of the midpoint between said sync tip and said back porch; e) comparing said filtered signal and said 50% level signal to generate a logic level sync signal which is a version of said sync signal; f) in response to a previous logic level sync signal from step e), generating a window signal representative of the expected occurance of a current logic level sync signal; g) comparing said window signal to said logic level sync signal output of step e) and passing said logic level sync signal if it occurs within said window signal and blocking said logic level sync signal otherwise.

Claim 39

A method for detecting in a video type signal an occurrence of a sync portion having a sync tip and a back porch, including the steps of: a) clamping said video type signal with a sync tip clamp to provide a clamped signal; b) low pass filtering said clamped signal to provide a filtered signal; c) measuring the level of one of said sync tip or said back porch during the time period starting at least 0.1 microsecond after the start of said sync tip or reference level and ending before the end of said sync tip or reference level; d) in response to said level of c) generating a 50% level signal representative of the midpoint between said sync tip and said back porch; e) comparing said filtered signal and said 50% level signal to generate a logic level sync signal which is a version of said sync signal; f) in response to a previous logic level sync signal from step e), generating a window signal representative of the expected occurance of a current logic level sync signal; g) comparing said window signal to said logic level sync signal output of step e) and passing said logic level sync signal if it occurs within said window signal and blocking said logic level sync signal otherwise.

Claim 41

An apparatus for detecting in a video type signal the occurrence of a 2 level sync portion having a sync tip and a reference portion, including: a) circuitry for detecting the presence of a pattern of values representing said sync portion and operative to generate a first signal in response to the occurance thereof, said pattern including said reference portion followed by said sync tip for a known duration followed by said reference portion; b) a delaying circuit for generating a delayed signal a delay period after said first signal, said delay period being the period until the next expected occurance of said pattern of values as detected by a); c) a coincidence circuit responsive to the coincidence of said delayed signal and said next occurance of said pattern of values and operative to generate an output signal, which output signal signifies the occurrence of said sync portion, said coincidence circuit further operative to couple said output signal to said delaying circuit b).

Claim 42

An apparatus for detecting in a video type signal the occurrence of a 2 level sync portion having a sync tip and a reference portion, including: a) circuitry for detecting the presence of a pattern of values representing said sync portion and operative to generate a first signal in response to the occurance thereof, said pattern including said reference portion followed by said sync tip for a known duration followed by said reference portion; b) a delaying circuit for generating a delayed signal a delay period after said first signal, said delay period being the period until the next expected occurance of said pattern of values as detected by a); c) a coincidence circuit responsive to the coincidence of said delayed signal and said next occurance of said pattern of values and operative to generate an output signal, which output signal signifies the occurrence of said sync portion, said coincidence circuit further operative to couple said output signal to said delaying circuit b).

Claim 45

A method for processing a data portion of a video type signal which includes a sync pulse, said sync pulse having a plurality of levels including a first level which is lower than the highest data level and a second level which is higher than the lowest data level, comprising steps of: a) determining the value of said first level; b) determining the value of said second level; c) establishing an upper data reference level in response to the value of a); d) establishing a lower data reference level in response to the value of b); e) generating a plurality of data slice levels in response to the levels of c) and d); f) comparing said data portion to said data slice levels of e) to determine which data level said data portion occupies at given instances.

Claim 46

A method for processing a data portion of a video type signal which includes a sync pulse, said sync pulse having a plurality of levels including a first level which is lower than the highest data level and a second level which is higher than the lowest data level, comprising steps of: a) determining the value of said first level; b) determining the value of said second level; c) establishing an upper data reference level in response to the value of a); d) establishing a lower data reference level in response to the value of b); e) generating a plurality of data slice levels in response to the levels of c) and d); f) comparing said data portion to said data slice levels of e) to determine which data level said data portion occupies at given instances.

Claim 51

The method of recovering sync from a video type signal including the steps of: a) coupling said video type signal through a capacitor or other circuit thereby establishing a level shifted signal having a sync portion; b) comparing said level shifted signal to a first known reference to provide a compared signal; c) selectively adding a current to said level shifted signal wherein the amount and/or polarity of said current is responsive to said compared signal and the D.C. level of said level shifted signal is changed in response to said current; d) comparing said level shifted signal to a second known reference to provide a second compared signal, which second compared signal is a logic level representation of said sync portion.

Claim 52

The method of recovering sync from a video type signal including the steps of: a) coupling said video type signal through a capacitor or other circuit thereby establishing a level shifted signal having a sync portion; b) comparing said level shifted signal to a first known reference to provide a compared signal; c) selectively adding a current to said level shifted signal wherein the amount and/or polarity of said current is responsive to said compared signal and the D.C. level of said level shifted signal is changed in response to said current; d) comparing said level shifted signal to a second known reference to provide a second compared signal, which second compared signal is a logic level representation of said sync portion.

Claim 59

The method of detecting a sync segment of a video type signal which may be an HDTV signal including the steps of: a) responding to sync pulses by inspecting said video type signal for the occurrence of a first transition in a known direction between a plurality of levels of known amounts followed at a known time by a second transition in a known direction between said plurality of levels and providing a sync signal in response thereto; b) delaying said sync signal for a period corresponding to the expected period until the next arriving one of said sync pulses satisfying step a) thereby providing a delayed sync signal; c) inspecting said delayed sync signal of step b) and a next arriving sync signal from step a) and in response to the substantial coincidence thereof providing a segment signal indicating the arrival of said sync segment.

Claim 60

The method of detecting a sync segment of a video type signal which may be an HDTV signal including the steps of: a) responding to sync pulses by inspecting said video type signal for the occurrence of a first transition in a known direction between a plurality of levels of known amounts followed at a known time by a second transition in a known direction between said plurality of levels and providing a sync signal in response thereto; b) delaying said sync signal for a period corresponding to the expected period until the next arriving one of said sync pulses satisfying step a) thereby providing a delayed sync signal; c) inspecting said delayed sync signal of step b) and a next arriving sync signal from step a) and in response to the substantial coincidence thereof providing a segment signal indicating the arrival of said sync segment.

Claim 61

The method of providing an output segment signal indicating the presence of sync segments of a video type signal which may be an HDTV signal including the steps of: a) delaying said output segment signal for a period corresponding to the expected period between said sync segments, thereby providing a delayed signal having delayed indications of said sync segments; b) inspecting said video type signal for the occurrence of a first transition in a known direction between a plurality of known levels followed a known time later by a second transition in a known direction between said plurality of levels and providing a sync signal having current indications of each said occurrence; c) responding to said delayed signal of step a) and said sync signal of step b) in response to the coincidence of said delayed indication and said current indication to provide said output segment signal.

Claim 62

The method of providing an output segment signal indicating the presence of sync segments of a video type signal which may be an HDTV signal including the steps of: a) delaying said output segment signal for a period corresponding to the expected period between said sync segments, thereby providing a delayed signal having delayed indications of said sync segments; b) inspecting said video type signal for the occurrence of a first transition in a known direction between a plurality of known levels followed a known time later by a second transition in a known direction between said plurality of levels and providing a sync signal having current indications of each said occurrence; c) responding to said delayed signal of step a) and said sync signal of step b) in response to the coincidence of said delayed indication and said current indication to provide said output segment signal.