Repetition reduced digital data record and playback system
First Claim
1. An apparatus for recording on a data record a repetition reduced digital representation of a signal, said signal having periodic time intervals and the digital representation having plural digital data words, wherein each said data word corresponds to the signal occurring during an associated time subinterval, the digital representation also having a plurality of sets of said data words with each set corresponding in number to the number of time subintervals of one of said periodic intervals, and each data word of each set being associated with a time subinterval occurring at a different position in time from the beginning of a periodic interval, said apparatus comprising:
- recirculating storage means for storing one of said sets of data words;
comparator means for comparing each stored data word of the stored set applied by said storage means to one input of the comparator means with a received data word applied to another input of the comparator means, the compared stored data word being associated with a first subinterval of one periodic interval and the compared received data word being associated with a second subinterval of another periodic interval subsequent to said one periodic interval, the first and second subintervals each occurring at the same position in time from the beginning of its periodic interval,said comparator means including output means for replacing the compared stored data word in said storage means with the compared received data word when the compared received data word differs from the compared stored data word by a predetermined value, the compared received data word being stored in said storage means as an updated data word; and
variable bandwidth recording means including changed data memory means coupled to the output means of said comparator means for storing said updated data words received from said comparator means, intermittent recording control means for causing said memory means to produce an intermittent output of updated data words, and recording means for recording the intermittent output of updated data words on the data record.
6 Assignments
0 Petitions
Accused Products
Abstract
A record and playback system for reducing repetition redundancy is described in which during recording, a partially repetitive signal, such as a television signal, is converted into digital data words each representing the signal occurring during a particular TV line subinterval. A comparator unit receives the data words and compares each received word with a word from a recirculating storage that corresponds to the same line subinterval in its frame as that of the compared received data word. When the compared words differ by a predetermined value, the received word replaces the stored word in the storage and is also stored in a changed data memory as an updated data word along with address words. A recording control circuit intermittently causes the read out of data from the changed data memory for recording at selected positions of a data record. The storage includes alternately operating first and second recirculating storages which each store a set of data words equal in number to the number of data words of one-half a TV frame. Audio data words are stored for recording during vertical blanking intervals of the signal. On playback, a record pickup intermittently reads data words from the record to a record pickup memory whenever this memory is nearly empty. A composite signal generator reconstructs the recorded television signal from data words it receives from the display storage and display control.
34 Citations
30 Claims
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1. An apparatus for recording on a data record a repetition reduced digital representation of a signal, said signal having periodic time intervals and the digital representation having plural digital data words, wherein each said data word corresponds to the signal occurring during an associated time subinterval, the digital representation also having a plurality of sets of said data words with each set corresponding in number to the number of time subintervals of one of said periodic intervals, and each data word of each set being associated with a time subinterval occurring at a different position in time from the beginning of a periodic interval, said apparatus comprising:
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recirculating storage means for storing one of said sets of data words; comparator means for comparing each stored data word of the stored set applied by said storage means to one input of the comparator means with a received data word applied to another input of the comparator means, the compared stored data word being associated with a first subinterval of one periodic interval and the compared received data word being associated with a second subinterval of another periodic interval subsequent to said one periodic interval, the first and second subintervals each occurring at the same position in time from the beginning of its periodic interval, said comparator means including output means for replacing the compared stored data word in said storage means with the compared received data word when the compared received data word differs from the compared stored data word by a predetermined value, the compared received data word being stored in said storage means as an updated data word; and variable bandwidth recording means including changed data memory means coupled to the output means of said comparator means for storing said updated data words received from said comparator means, intermittent recording control means for causing said memory means to produce an intermittent output of updated data words, and recording means for recording the intermittent output of updated data words on the data record. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for recording on a digital optical data record a repetition reduced digital representation of an analog television signal, the television signal having frames which each contain a first and second field with a vertical blanking interval at the end of each field, each field having lines with a horizontal blanking interval at the end of each line, said apparatus comprising:
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digitization means for converting said television signal into a digital signal having data words, each data word representing the television signal occurring during a particular line subinterval, a set of successive data words representing a line, the digital signal also having a plurality of groups of said sets with each group representing one-half the lines of a frame; recirculating storage means coupled to an output of said digitization means and including a first and second recirculating storage means, wherein said first recirculating storage means receives and stores one of said groups and said second recirculating storage means receives and stores another of said groups, the lines represented by said one stored group being at different positions in a frame than the lines represented by said another stored group; comparator means for comparing each stored data word of the stored sets applied by said storage means to one input of said comparator means with a received data word applied by said digitization means to another input of the comparator means, the compared stored data word representing the television signal occuring during a first line subinterval of one frame and the compared stored data word representing the television signal occurring during a second line subinterval of another frame subsequent to said one frame, the first and second line subintervals each occuring at the same position in time from the beginning of its frame, wherein when the compared received and compared stored data words differ by a predetermined value the compared stored data word is replaced in its recirculating storage means with the compared received data word and the compared received data word is stored as an updated data word; word identification means for generating position code words identifying the frame, line and line subinterval position of said updated data words; changed data memory means connected to the outputs of said comparator means and said word identification means for receiving and storing said position code words and said updated data words; intermittent recording control means connected to said memory means for causing said memory means to produce an intermittent output of updated data words and position code words; and recording means for recording the intermittent output of updated data words and position code words on the data record. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A playback apparatus for reconstructing a signal having periodic time intervals from a data record containing a repetition reduced digital representation of the signal, each said periodic time interval having a set of subintervals and the digital representation including digital data elements each corresponding to a particular subinterval of a particular one of said periodic intervals, a set of said digital data elements corresponding to the set of subintervals of one such periodic interval, said apparatus comprising:
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intermittent record pickup means for reading data from the record; record pickup memory means coupled to said record pickup means for temporarily storing the data read from the record and for causing said intermittent record pickup means to intermittently read the record when said memory means contains less than a predetermined amount of stored data; display control means for receiving data stored in said memory means and for causing an output of data from said memory means; display recirculating storage means coupled to said display control means for receiving and storing data elements, wherein said storage means stores the set of data elements corresponding to the set of subintervals of one periodic interval, said display control means including means for replacing each data element stored in said storage means with data elements from the data record which correspond to the same subinterval in a following periodic interval of the signal; and reconstructed signal generating means for periodically receiving the set of stored data elements stored in said storage means and for reconstructing said signal. - View Dependent Claims (23, 24, 25, 26)
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27. A record and playback apparatus for recording on a digital optical data record a repetition reduced digital representation of a television signal and for playing back the data record to reconstruct the television signal, said apparatus comprising:
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digitization means for converting the television signal into a digital signal having data words, each data word representing the television signal occuring during a particular line subinterval, a set of successive data words representing a line, the digital signal also having a plurality of groups of said sets with each group representing a frame; recirculating storage means coupled to an output of said digitization means for receiving and storing the group representing the data words during one frame; comparator means for comparing each of said stored data words stored in said recirculating storage means with a received data word received from said digitization means which corresponds to the same line and line subinterval in a subsequent frame following the frame containing the stored data word, wherein when the compared received and compared stored data words differ by a predetermined value the compared stored data word is replaced with the compared received data word is stored as an updated data word; word identification means for generating position code words identifying the frame, line and line subinterval position of said updated data words; changed data memory means connected to the outputs of said comparator means and said word identification means for receiving and storing said position code words and said updated data words; intermittent recording control means connected to said changed data memory means for causing said changed data memory means to produce an intermittent output of updated data words and position code words; and recording means for recording the intermittent output of updated data words and position code words on the data record; intermittent record pickup means for reading data from the record; record pickup memory means coupled to said record pickup means for temporarily storing the data read from the record and for causing said intermittent record pickup means to intermittently read the record when said changed data memory means contains less than a predetermined amount of stored data; display control means for receiving data stored in said record pickup memory means and for causing an output of data from said record pickup memory means; display recirculating storage means coupled to said display control means for receiving and storing data words, wherein said display recirculating storage means stores the group of data words corresponding to the line subintervals of one frame, said display control means including means for replacing each data word stored in said display recirculating storage means with data words from the data record which correspond to the same line and line subinterval in a following frame of the television signal; and composite signal generating means for periodically receiving each group of stored data words stored in said display recirculating storage means and for reconstructing said television signal. - View Dependent Claims (28, 29, 30)
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Specification