Apparatus in digital video tape recorder for detecting a sync signal in digital data

Abstract

An apparatus for a digital video tape recorder for detecting a sync signal in digital data includes: a data restoring device for producing serial data and a serial clock signal received from a reproducing head of the digital video tape device; a servo device for producing a head switching pulse and a super-video home system (S-VHS)/video home system (VHS) discriminating signal; an identification detecting device for producing a signal indicative of an end of reading one segment of tracks; and a sync signal detecting device, responsive to each signal produced by the aforementioned devices, for determining correspondence in sync patterns even in a case where not all corresponding bits coincide with one another, for removing erroneously detected sync patterns using a window situated around a position at which a sync signal is produced, and for detecting a sync signal.

What is claimed is:  
     
       1. An apparatus for a digital video tape device for detecting a sync signal in digital data, comprising: 
       data restoring means for producing serial data and a serial clock signal received from a reproducing head of the digital video tape device;  
       servo means for producing a head switching pulse and a super-video home system (S-VHS)/video home system (VHS) discriminating signal;  
       identification detecting means for producing a signal indicative of an end of reading one segment of tracks; and  
       sync signal detecting means, responsive to the serial data, the serial clock signal, the head switching pulse, the S-VHS/VHS discriminating signal, and the signal indicative of the end of the reading of one segment of tracks, for determining correspondence in sync patterns even in a case where not all corresponding bits coincide with one another, for removing erroneously detected sync patterns using a window situated around a position at which a sync signal is produced, and for detecting a sync signal.  
     
     
       2. An apparatus for a digital video tape device for detecting a sync signal in digital data, comprising: 
       data restoring means for producing serial data and a serial clock signal received from a reproducing head of the digital video tape device;  
       servo means for producing a head switching pulse and a super-video home system (S-VHS)/video home system (VHS) discriminating signal;  
       identification detecting means for producing a signal indicative of an end of reading one segment of tracks; and  
       sync signal detecting means, responsive to the serial data, the serial clock signal, the head switching pulse, the S-VHS/VHS discriminating signal, and the signal indicative of the end of the reading of one segment of tracks, for determining correspondence in sync patterns even in a case where not all corresponding bits coincide with one another, for removing erroneously detected sync patterns using a window situated around a position at which a sync signal is produced, for detecting a signal, wherein the sync signal detecting means includes:  
       means for generating a signal indicating a reading of an initial portion of a track of recorded information in response to the head switching pulse, the S-VHS/VHS discriminating signal, and a first clock signal,  
       clock converting means for producing first and second clock signals by using the serial clock signal and a matched block sync signal,  
       means for generating and outputting the matched block sync signal to the clock converting means by using the serial data, the serial clock signal, and the first clock signal, and for detecting a block sync signal, and  
       data aligning means for producing final data in response to a sync pattern by using the serial clock signal and the first and second clock signals.  
     
     
       3. An apparatus for a digital video tape device as claimed in  claim 2 , wherein the means for generating the signal indicating the reading of the initial portion of the track comprises: 
       an S-VHS discriminator for generating a signal indicating a reading of an initial portion of a given track by using the head switching pulse and the first clock signal, when reading every track in a super-video home system (S-VHS);  
       a VHS discriminator for generating a signal indicating a reading of an initial portion of a given track by using the head switching pulse and first clock signal, when every two tracks are read; and  
       a track-initial portion recognition signal selector for selecting and producing one of the signals produced from the S-VHS discriminator and the VHS discriminator in response to the S-VHS/VHS discriminating signal.  
     
     
       4. An apparatus for a digital video tape device as claimed in  claim 2 , wherein the block sync signal detecting means comprises: 
       first pattern match detecting means for receiving serial data and a serial clock signal and for detecting most significant bit, 6 bits of data from an expected position of the data;  
       second pattern match detecting means for detecting bits, up to four bits maximum, other than the bits detected in the first pattern match detecting means, even if errors occur;  
       an AND gate for outputting a logical product of outputs produced from the first and second pattern match detecting means;  
       matched block sync signal detecting means for window-processing an output of the AND gate, and for producing a matched block sync signal;  
       BSYNC 1  detecting means for converting the output of the AND gate into a block sync signal having a width of the first clock signal;  
       window processing means for defining a window by using the first clock signal, the segment-end signal, and the signal indicating the reading of the initial portion of a track, and for removing block sync signals erroneously detected in the AND gate; and  
       final block sync signal detecting means for window-processing an output of the BSYNC 1  detecting means with an output of the window processing means, and for removing the block sync signal erroneously detected in the AND gate, to produce a final block sync signal.  
     
     
       5. An apparatus for a digital video tape device as claimed in  claim 4 , wherein the window processing means comprises: 
       an I window processor for generating a window signal for detecting an initial block sync signal in a plurality of tracks, by using the signal indicating the reading of the initial portion of a track, an output signal of the BSYNC 1  detecting means, and the first clock signal;  
       an N window processor for generating a window signal for causing a predefined window to open or close in response to counted values by using as a clear signal the block sync signal, the first clock signal, and the window signal of the I window processor; and  
       a D window processor for generating a window signal for causing a predetermined window to open for a predetermined block duration upon receipt of the segment-end signal and for causing the window to close upon receipt of the block sync signal.  
     
     
       6. An apparatus for a digital video tape device as claimed in  claim 2 , wherein the clock converting means includes: 
       a first clock generator for producing a clock signal having a constant duty cycle, by using the serial clock signal; and  
       a second clock generator for producing a clock signal having a duty cycle varying with receipt of the block sync signal, by using as a clear signal the matched block sync signal from the matched block sync signal detecting means.  
     
     
       7. An apparatus for a digital video tape device as claimed in  claim 2 , wherein the data aligning means includes: 
       first delay means for delaying the serial data N times by the serial clock to produce parallel data;  
       second delay means for receiving the parallel data output by the first delay means and for delaying the parallel data output by the first delay means by the second clock signal from the second clock generator; and  
       third delay means for latching the output of the second delay means by the clock signal of the first clock generator, and for producing an output.  
     
     
       8. An apparatus for a digital video tape device for detecting a sync signal in digital data, comprising: 
       data restoring means for producing serial data and a serial clock signal received from a reproducing head of the digital video tape device;  
       servo means for producing a head switching pulse and a super-video home system (S-VHS)/video home system (VHS) discriminating signal;  
       identification detecting means for producing a signal indicative of an end of reading one segment of tracks; and  
       sync signal detecting means including:  
       a track-initial portion recognition signal generating means for generating a signal indicative of an initial portion of the tracks,  
       a window signal generating means for generating a window signal using a segment end signal from the identification detecting means and the signal indicative of the initial portion of the tracks,  
       a block sync signal detecting means for detecting a block sync signal region provided from the data restoring means, and  
       a sync signal processing means for processing a sync signal detected from a window signal region provided from the window signal generating means as if the sync signal is matched for the sync signal with an error of less than a preset number of bits.  
     
     
       9. The apparatus for a digital video tape device as claimed in  claim 8 , wherein the track-initial portion recognition signal generating means comprises: 
       an S-VHS discriminator for generating a signal indicating a reading of an initial portion of a given track by using the head switching pulse and the first clock signal, when reading every track in a super-video home system (S-VHS);  
       a VHS discrimination for generating a signal indicating a reading of an initial portion of a given track by using the head switching pulse and first clock signal, when every two tracks are read; and  
       a track-initial portion recognition signal selector for selecting and producing one of the signals produced from the S-VHS discriminator and the VHS discriminator in response to the S-VHS/VHS discriminating signal.  
     
     
       10. The apparatus for a digital video tape device as claimed in  claim 8 , wherein the block sync signal detecting means comprises: 
       first pattern match detecting means for receiving serial data and a serial clock signal and for detecting most significant bit, 6 bits of data from an expected position of the data;  
       second pattern match detecting means for detecting bits, up to four bits maximum, other than the bits detected in the first pattern match detecting means, even if errors occur;  
       an AND gate for outputting a logical product of outputs produced from the first and second pattern match detecting means;  
       matched block sync signal detecting means for window-processing an output of the AND gate, and for producing a matched block sync signal;  
       BSYNC 1  detecting means for converting the output of the AND gate into a block sync signal having a width of the first clock signal;  
       window processing means for defining a window by using the first clock signal, the segment-end signal, and the signal indicating the reading of the initial portion of a track, and for removing block sync signal erroneously detected in the AND gate, and  
       final block sync signal detecting means for window-processing an output of the BSYNC 1  detecting means with an output of the window processing means, and for removing the block sync signal erroneously detected in the AND gate, to produce a final block sync signal.  
     
     
       11. The apparatus for a digital video tape device as claimed in  claim 8 , wherein the window signal generating means comprises: 
       an I window processor for generating a window signal for detecting an initial block sync signal in a plurality of tracks, by using the signal indicating the reading of the initial portion of a track, an output signal of the BSYNC 1  detecting means, and the first clock signal;  
       an N window processor for generating a window signal for causing a predefined widow to open or close in response to counted values by using as a clear signal the block sync signal, the first clock signal, and the window signal of the I window processor; and  
       a D window processor for generating a window signal for causing a predetermined window to open for a predetermined block duration upon receipt of the segment-end signal and for causing the window to close upon receipt of the block syn signal.  
     
     
       12. An apparatus for detecting a sync signal in digital data in a digital recording device comprising: 
       
         data restoring means for producing serial data and a serial clock signal received from a reproducing head of the digital recording device;  
       
       
         a signal generator for producing an initializing signal corresponding to a segment start in the digital data;  
       
       
         a detector for detecting a format of a reproducing operation of the digital data;  
       
       
         identification detecting means for producing a signal indicative of an end of reading one segment of tracks; and  
       
       
         sync signal detecting means, responsive to the serial data, the serial clock signal, the initializing signal, the format of the reproducing operation, and the signal indicative of the end of the reading of one segment of tracks, for determining correspondence in sync patterns even in a case where not all corresponding bits coincide with one another, for removing erroneously detected sync patterns using a window situated around a position at which a sync signal is produced, and for detecting a sync signal, wherein the sync signal produces a segment start signal using the initializing signal, the segment start signal being received by the identification detecting means. 
       
     
     
       13. The apparatus according to  claim 12 , wherein the initializing signal includes a head switching pulse. 
     
     
       14. The apparatus according to  claim 12 , wherein the one segment of tracks includes a video data. 
     
     
       15. An apparatus for detecting a sync signal in digital data in a digital recording device comprising: 
       
         data restoring unit producing serial data and a serial clock signal received from a reproducing head of the digital recording device;  
       
       
         a signal generator for producing an initializing signal corresponding to a segment start of the digital data;  
       
       
         a detector for detecting a format of a reproducing operation of the digital data;  
       
       
         an indicator producing a signal indicative of an end of reading one segment of tracks; and  
       
       
         sync signal detector, responsive to the serial data, the serial clock signal, the initializing signal, the format of the reproducing operation, and the signal indicative of the end of the reading of one segment of tracks, determining correspondence in sync patterns even in a case where not all corresponding bits coincide with one another, for removing erroneously detected sync patterns using a window situated around a position at which a sync signal is produced, and for detecting a sync signal,  
       
       
         wherein the sync signal produces a segment start signal using the initializing signal, the segment start signal being received by the indicator. 
       
     
     
       16. The apparatus according to  claim 15 , wherein the initializing signal includes a head switching pulse. 
     
     
       17. The apparatus according to  claim 15 , wherein the one segment of tracks includes a video data. 
     
     
       18. A method for detecting a sync signal in digital data in a digital recording device comprising: 
       
         producing serial data and a serial clock signal received from a reproducing head of the digital recording device;  
       
       
         generating an initializing signal corresponding to a segment start, the initializing signal being used to produce a segment start signal;  
       
       
         detecting a format of a reproducing operation;  
       
       
         producing a signal indicative of an end of reading one segment of tracks; and  
       
       
         determining correspondence in sync patterns even in a case where not all corresponding bits coincide with one another, removing erroneously detected sync patterns using a window situated around a position at which a sync signal is produced, and detecting a sync signal, responsive to the serial data, the serial clock signal, the initializing signal, the format of the producing operation, and the signal indicative of the end of the reading of one segment of tracks. 
       
     
     
       19. A method for detecting a sync signal in digital data in a digital recording device comprising: 
       
         producing serial data and a serial clock signal received from a reproducing head of the digital recording device;  
       
       
         generating an initializing signal corresponding to a segment start, the initializing signal being used to produce a segment start signal;  
       
       
         detecting a format of a reproducing operation;  
       
       
         producing a signal indicative of an end of reading one segment of tracks; and  
       
       
         responsive to the serial data, the serial clock signal, the initializing signal, the format of the reproducing operation, and the signal indicative of the end of the reading of one segment of tracks, determining correspondence in sync patterns even in a case where not all corresponding bits coincide with one another, removing erroneously detected sync patterns using a window situated around a position at which a sync signal is produced, and detecting a sync signal. 
       
     
     
       20. A method for detecting a sync signal in digital data for a digital video tape device, the method comprising the steps of: 
       
         producing serial data and a serial clock signal received from a reproducing head of the digital video tape device;  
       
         producing a head switching pulse and a super - video home system  ( S - VHS ) /video home system  ( VHS )  discriminating signal;    
       
         producing a signal indicative of an end of reading one segment of tracks; and  
       
         determining, in response to the serial data, the serial clock signal, the head switching pulse, the S - VHS/VHS discriminating signal, and the signal indicative of the end of the reading of one segment of tracks, correspondence in sync patterns even in a case where not all corresponding bits coincide with one another, for removing erroneously detected sync patterns using a window situated around a position at which a sync signal is produced, and for detecting a sync signal.   
     
     
       21. The method according to  claim 20 , wherein the step of determining correspondence in sync patterns includes the steps of: 
         generating a signal indicating a reading of an initial portion of a track of recorded information in response to the head switching pulse, the S - VHS/VHS discriminating signal, and a first clock signal;    
       
         producing first and second clock signals by using the serial clock signal and a matched block sync signal;  
       
       
         outputting the matched block sync signal to the clock converting means by using the serial data, the serial clock signal, and the first clock signal, and for detecting a block sync signal; and  
       
       
         producing final data in response to a sync pattern by using the serial clock and the first and second clock signals. 
       
     
     
       22. The method according to  claim 21 , wherein the step of generating a signal indicating a reading of an initial portion of a track includes the steps of: 
         generating from an S - VHS discriminator a signal indicating a reading of an initial portion of a given track by using the head switching pulse and the first clock signal, when reading every track in a super - video home system;    
       
         generating from a VHS discriminator a signal indicating a reading of an initial portion of a given track by using the head switching pulse and first clock signal, when reading every two tracks are read; and  
       
         selecting and producing one of the signals produced from the V - VHS discriminator and the VHS discriminator in response to the S - VHS/VHS discriminating signal.   
     
     
       23. The method according to  claim 21 , wherein the step of detecting the block sync signal includes the steps of: 
       
         receiving serial data and a serial clock signal;  
       
       
         detecting, in response to the receiving step, a most significant bit,  6  bits of data from an expected position of the data and outputting a first output signal;  
       
       
         detecting bits, up to four bits maximum, other than the bits detected in the step of detecting the most significant bit, even if errors occur, and outputting a second output signal;  
       
       
         outputting a logical product of the first and second output signals as a third output signal;  
       
         window - processing the third output signal and producing a matched block sync signal;    
       
         converting the third output signal into a block sync signal having a width of the first clock signal and outputting a fourth output signal;  
       
         defining a window by using the first clock signal, the segment - end signal, and the signal indicating the reading of the initial portion of a track, and removing block sync signals erroneously detected in the step of outputting the logical product, the defining step producing a fifth output signal; and    
         window - processing the fourth output signal with the fifth output signal and removing the block sync signal erroneously detected in the step of outputting the logical product to produce a final block sync signal.   
     
     
       24. The method according to  claim 23 , wherein the step of defining a window includes the steps of: 
       
         generating a first window signal to detect an initial block sync signal in a plurality of tracks, by using the signal indicating the reading of the initial portion of a track, the fourth output signal of the converting step, and the first clock signal;  
       
       
         generating a second window signal to cause a predefined window to open or close in response to counted values by using as a clear signal the block sync signal, the first clock signal, and the first window signal; and  
       
         generating a third window signal to cause a predetermined window to open for predetermined block duration upon receipt of the segmented - end signal for causing the window to close upon receipt of the block sync signal.   
     
     
       25. The method according to  claim 21 , wherein the step of producing first and second clock signals includes the steps of: 
       
         producing a clock signal having a constant duty cycle, by using the serial clock signal; and  
       
       
         producing a clock signal having a duty cycle varying with receipt of the block sync signal, by using as a clear signal the matched block sync signal. 
       
     
     
       26. The method according to  claim 21 , wherein the step of producing final data includes the steps of: 
       
         delaying the serial data N times by the serial clock to produce parallel data;  
       
       
         delaying the parallel data by the second clock signal and producing a delayed parallel data; and  
       
       
         latching the delayed parallel data by the clock signal and producing an output. 
       
     
     
       27. The method according to  claim 20 , wherein the step of determining correspondence in sync patterns comprises the steps of: 
       
         generating a signal indicative of an initial portion of the tracks;  
       
       
         generating a window signal using the signal indicative of the end of reading one segment of tracks and the signal indicative of the initial portion of the tracks;  
       
       
         detecting a block sync signal region in response to the step of producing serial data and serial clock signals; and  
       
       
         processing a sync signal detected from a window signal region provided from the step of generating the window signal as if the sync signal is matched for the sync signal with an error or less than a preset number of bits. 
       
     
     
       28. The method according to  claim 27 , wherein the step of generating a signal indicative of an initial portion of the tracks includes the steps of: 
         generating from an S - VHS discriminator a signal indicating a reading of an initial portion of a given track by using the head switching pulse and the first clock signal, when reading every track in a super - video home system;    
       
         generating from a VHS discriminator a signal indicating a reading of an initial portion of a given track by using the head switching pulse and first clock signal, when reading every two tracks are read; and  
       
         selecting and producing one of the signals produced from the S - VHS discriminator and the VHS discriminator in response to the S - VHS/VHS discriminating signal.   
     
     
       29. The method according to  claim 27 , wherein the step of detecting the block sync signal includes the steps of: 
       
         receiving serial data and a serial clock signal;  
       
       
         detecting, in response to the receiving step, a most significant bit,  6  bits of data from an expected position of the data and outputting a first output signal;  
       
       
         detecting bits, up to four bits maximum, other than the bits detected in the step of detecting the most significant bit, even if errors occur, and outputting a second output signal;  
       
       
         outputting a logical product of the first and second output signals as a third output signal;  
       
         window - processing the third output signal and producing a matched block sync signal;    
       
         converting the third output signal into a block sync signal having a width of the first clock signal and outputting a fourth output signal;  
       
         defining a window by using the first clock signal, the segment - end signal, and the signal indicating the reading of the initial portion of a track, and removing block sync signals erroneously detected in the step of outputting the logical product, the defining step producing a fifth output signal; and    
         window - processing the fourth output signal with the fifth output signal and removing the block sync signal erroneously detected in the step of outputting the logical product to produce a final block sync signal.   
     
     
       30. The method according to  claim 27 , wherein the step of defining a window includes the steps of:  generating a first window signal to detect an initial block sync signal in a plurality of tracks, by using the signal indicating the reading of the initial portion of a track, the fourth output signal of the converting step, and the first clock signal;    
       
         generating a second window signal to cause a predefined window to open or close in response to counted values by using as a clear signal the block sync signal, the first clock signal, and the first window signal; and  
       
         generating a third window signal to cause a predetermined window to open for predetermined block duration upon receipt of the segmented - end signal and for causing the window to close upon receipt of the block sync signal.