Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
147 words
A data introduction device comprising: first creation means, receiving a read code signal corresponding to data stored on a data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals.
Claim 2
Dependent Claim
147 words
A data introduction device comprising: first creation means, receiving a read code signal corresponding to data stored on a data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals.
Claim 3
Dependent Claim
65 words
A data introduction device according to claim 1, wherein said second creation means comprises: flip-flop means with a clock input connected to receive one of said first two-phase signals; delay means connected with one of outputs of said flip-flop means; and gate circuit means for receiving two outputs from said flip-flop means and an output from said delay means to generate said second two-phase signals.
Claim 4
Dependent Claim
84 words
A data introduction device according to claim 1, wherein said first creation means is a phase-lock loop, wherein said second creation means comprises: an extended window creation unit for taking in at least two-phase data each having a width of one or more bits of the data to create discrimination windows, wherein said third creation means comprises: a latch unit for latching the data within each of said discrimination windows, and a data discrimination unit for deciding if the latched data is an error.
Claim 5
Dependent Claim
23 words
A data introduction device according to claim 3, wherein said at least two phase discrimination windows have an overlapping portion with each other.
Claim 6
Dependent Claim
37 words
A data introduction device according to claim 3, wherein said data discrimination unit for deciding if the latched data is an error has a function of estimating an error on the basis of the data pattern latched.
Claim 7
Dependent Claim
229 words
A data introduction device comprising: first creation means, receiving a read code signal corresponding to data stored on a data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals; wherein said third creation means comprises: a plurality of first flip-flop means each having a clock input connected to receive said read code signal, and at least one second flip-flop means having a clock input, a signal input for receiving one of said first two-phase signals and a D input connected with each output of at least two of said plurality of first flip-flop means each connected in series to the other at least two of said plurality of first flip-flop means.
Claim 8
Dependent Claim
229 words
A data introduction device comprising: first creation means, receiving a read code signal corresponding to data stored on a data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals; wherein said third creation means comprises: a plurality of first flip-flop means each having a clock input connected to receive said read code signal, and at least one second flip-flop means having a clock input, a signal input for receiving one of said first two-phase signals and a D input connected with each output of at least two of said plurality of first flip-flop means each connected in series to the other at least two of said plurality of first flip-flop means.
Claim 9
Dependent Claim
288 words
A data introduction device comprising: first creation means, receiving a read code signal corresponding to data stored on a data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second-two phase signals; wherein said second creation means comprises: flip-flop means with a clock input connected to receive one of said first two-phase signals, delay means connected with one of outputs of said flip-flop means, and gate circuit means for receiving two outputs from said flip-flop means and an output from said delay means to generate said second two-phase signals, and wherein said third creation means comprises: a plurality of first flip-flop means each having a clock input connected to receive said read code signal, and at least one second flip-flop means having a clock input, a signal input for receiving one of said first two-phase signals and a D input connected with each output of at least two of said first plurality of first flop-flop means each connected in series to the other at least two of said plurality of first flip-flop means.
Claim 10
Dependent Claim
288 words
A data introduction device comprising: first creation means, receiving a read code signal corresponding to data stored on a data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second-two phase signals; wherein said second creation means comprises: flip-flop means with a clock input connected to receive one of said first two-phase signals, delay means connected with one of outputs of said flip-flop means, and gate circuit means for receiving two outputs from said flip-flop means and an output from said delay means to generate said second two-phase signals, and wherein said third creation means comprises: a plurality of first flip-flop means each having a clock input connected to receive said read code signal, and at least one second flip-flop means having a clock input, a signal input for receiving one of said first two-phase signals and a D input connected with each output of at least two of said first plurality of first flop-flop means each connected in series to the other at least two of said plurality of first flip-flop means.
Claim 11
Dependent Claim
201 words
A data introduction device comprising: first creation means, receiving a read code signal corresponding to data stored on a data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second-two phase signals; and data discrimination means connected with the output from said third creation means, wherein if said output has successive bits data "1"s, said data discrimination means changes into "0" the bit data "1" adjacent to the group having more bit data "O"s of bit data "O" groups before and after said successive "1"s at issue.
Claim 12
Dependent Claim
201 words
A data introduction device comprising: first creation means, receiving a read code signal corresponding to data stored on a data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second-two phase signals; and data discrimination means connected with the output from said third creation means, wherein if said output has successive bits data "1"s, said data discrimination means changes into "0" the bit data "1" adjacent to the group having more bit data "O"s of bit data "O" groups before and after said successive "1"s at issue.
Claim 13
Dependent Claim
155 words
A data introduction method comprising: a first creation step of receiving a read code signal corresponding to data stored on a data recording medium to create repeatedly first two phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; a second creation step of receiving said first two-phase signals to create second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two phase signals; and a third creation step of receiving said read code signal and said second two-phase signals to create a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals.
Claim 14
Dependent Claim
155 words
A data introduction method comprising: a first creation step of receiving a read code signal corresponding to data stored on a data recording medium to create repeatedly first two phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; a second creation step of receiving said first two-phase signals to create second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two phase signals; and a third creation step of receiving said read code signal and said second two-phase signals to create a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals.
Claim 15
Dependent Claim
63 words
A data introduction method according to claim 9, wherein said second creation step comprises the steps of: supplying one of said two-phase signals to a clock input of said flip-flop means; delaying an output from said flip-flop means; and supplying two outputs from said flip-flop means and an output from said delay means to gate circuit means to generate said second two-phase signals.
Claim 16
Dependent Claim
85 words
A data introduction method according to claim 9, wherein said first creation step is performed by a phase-lock loop, wherein said second creation step comprises the step of: creating at least two-phase discrimination windows each having a width of one or more bits of the data, and wherein said third creation step comprises the steps of: latching the data within each of said discrimination windows, and deciding if the latched data is an error based on the data pattern latched for all the discrimination windows.
Claim 17
Dependent Claim
24 words
A data introduction method according to claim 11, wherein said data is corrected not to include successive bits "1"s in a normally operated state.
Claim 18
Dependent Claim
241 words
A data introduction method comprising: a first creation step of receiving a read code signal corresponding to data stored on a data recording medium to create repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; a second creation step of receiving said first two-phase signals to create second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and a third creation step of receiving said read code signal and said second two-phase signals to create a second code signal corresponding to said read code signal which shifts during one phase period of said second two phase-signals; wherein said third creation step comprises the steps of: supplying said read code signal to clock inputs of a plurality of first flip-flop means; and supplying one of said first two-phase signals to a signal input of at least one second flip-flop means and supplying to a D-input of said at least one second flip-flop means each output of at least two of said plurality of first flip-flop means each connected in series to the other of said at least two of said plurality of first flip-flop means.
Claim 19
Dependent Claim
241 words
A data introduction method comprising: a first creation step of receiving a read code signal corresponding to data stored on a data recording medium to create repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; a second creation step of receiving said first two-phase signals to create second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and a third creation step of receiving said read code signal and said second two-phase signals to create a second code signal corresponding to said read code signal which shifts during one phase period of said second two phase-signals; wherein said third creation step comprises the steps of: supplying said read code signal to clock inputs of a plurality of first flip-flop means; and supplying one of said first two-phase signals to a signal input of at least one second flip-flop means and supplying to a D-input of said at least one second flip-flop means each output of at least two of said plurality of first flip-flop means each connected in series to the other of said at least two of said plurality of first flip-flop means.
Claim 20
Dependent Claim
291 words
A data introduction method comprising: a first creation step of receiving a read code signal corresponding to data stored on a data recording medium to create repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; a second creation step of receiving said first two-phase signals to create second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and a third creation step of receiving said read code signal and said second two-phase signals to create a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals; wherein said second creation step comprises the steps of: supplying one of said first two-phase signals to a clock input of flip-flop means; delaying one of outputs of said flip-flop means; and supplying two outputs from said flip-flop means and said delayed output to gate circuit means to generate said second two-phase signals, and wherein said third creation step comprises the steps of: supplying said read code signal to clock inputs of a plurality of first flip-flop means; and supplying one of said first two-phase signals to a signal input of at least one second flip-flop means and supplying to a D-input of said flip-flop means each output of at least two of said plurality of first flip-flop means each connected in series to the other of said at least two of said plurality of first flip-flop means.
Claim 21
Dependent Claim
291 words
A data introduction method comprising: a first creation step of receiving a read code signal corresponding to data stored on a data recording medium to create repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; a second creation step of receiving said first two-phase signals to create second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and a third creation step of receiving said read code signal and said second two-phase signals to create a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals; wherein said second creation step comprises the steps of: supplying one of said first two-phase signals to a clock input of flip-flop means; delaying one of outputs of said flip-flop means; and supplying two outputs from said flip-flop means and said delayed output to gate circuit means to generate said second two-phase signals, and wherein said third creation step comprises the steps of: supplying said read code signal to clock inputs of a plurality of first flip-flop means; and supplying one of said first two-phase signals to a signal input of at least one second flip-flop means and supplying to a D-input of said flip-flop means each output of at least two of said plurality of first flip-flop means each connected in series to the other of said at least two of said plurality of first flip-flop means.
Claim 22
Dependent Claim
191 words
A data introduction method comprising: a first creation step of receiving a read code signal corresponding to data stored on a data recording medium to create repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; a second creation step of receiving said first two-phase signals to create second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and a third creation step of receiving said read code signal and said second two-phase signals to create a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals; and if said output has successive bits data "1"s, changing into "O" the bit data "1" adjacent to the group having more bit data "O"s of bit data "O" groups before and after said successive "1"s at issue.
Claim 23
Dependent Claim
191 words
A data introduction method comprising: a first creation step of receiving a read code signal corresponding to data stored on a data recording medium to create repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal; a second creation step of receiving said first two-phase signals to create second two-phase signals, one of which is phase offset from the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said second two-phase signals is twice as long as that of said first two-phase signals; and a third creation step of receiving said read code signal and said second two-phase signals to create a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals; and if said output has successive bits data "1"s, changing into "O" the bit data "1" adjacent to the group having more bit data "O"s of bit data "O" groups before and after said successive "1"s at issue.
Claim 24
Dependent Claim
178 words
A data introduction system comprising: pulse detecting means for receiving a signal corresponding to data stored on a data recording medium and shaping its waveform to provide a read code signal; and data introducing means comprising: first creation means, receiving a read code signal corresponding to the data stored on the data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal, second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset form the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said two-phase signals is twice as long as that of said first two-phase signals, and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals.
Claim 25
Dependent Claim
178 words
A data introduction system comprising: pulse detecting means for receiving a signal corresponding to data stored on a data recording medium and shaping its waveform to provide a read code signal; and data introducing means comprising: first creation means, receiving a read code signal corresponding to the data stored on the data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal, second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset form the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said two-phase signals is twice as long as that of said first two-phase signals, and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals.
Claim 26
Dependent Claim
63 words
A data introduction system according to claim 16, wherein said second creation means comprises: flip-flop means with a clock input connected to receive a first two-phase signal; delay means connected with one of outputs of said flip-flop means; and gate circuit means for receiving two outputs from said flip-flop means and an output from said delay means to generate said second two-phase signals.
Claim 27
Dependent Claim
105 words
A data introduction system according to claim 16 wherein said first creation means is a phase-locked loop (PLL) circuit for receiving the output data from said pulse detecting means to generate a clock phase-locked with said data, wherein said second creation means comprises: an extended window creation unit for taking in at least two-phase data each having a width of one or more bits of the data to create discrimination windows, and wherein said third creation means comprises: a latch unit for latching the data within each of said discrimination windows, and a data discrimination unit for deciding if the latched data is an error.
Claim 28
Dependent Claim
262 words
A data introduction system comprising: pulse detecting means for receiving a signal corresponding to data stored on a data recording medium and shaping its waveform to provide a read code signal; and data introducing means comprising: first creation means, receiving a read code signal corresponding to the data stored on the data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal, second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset form the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said two-phase signals is twice as long as that of said first two-phase signals, and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals wherein said third creation means comprises: a plurality of first flip-flop means each having a clock input connected to receive said read code signal, and at least one second flip-flop means having a clock input, a signal input for receiving one of said first two-phase signals and a D input connected with each output of at least two of said plurality of first flip-flop means each connected in series to the other of said at least two of said plurality of first flip-flop means.
Claim 29
Dependent Claim
262 words
A data introduction system comprising: pulse detecting means for receiving a signal corresponding to data stored on a data recording medium and shaping its waveform to provide a read code signal; and data introducing means comprising: first creation means, receiving a read code signal corresponding to the data stored on the data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal, second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset form the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said two-phase signals is twice as long as that of said first two-phase signals, and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals wherein said third creation means comprises: a plurality of first flip-flop means each having a clock input connected to receive said read code signal, and at least one second flip-flop means having a clock input, a signal input for receiving one of said first two-phase signals and a D input connected with each output of at least two of said plurality of first flip-flop means each connected in series to the other of said at least two of said plurality of first flip-flop means.
Claim 30
Dependent Claim
318 words
A data introduction system comprising: pulse detecting means for receiving a signal corresponding to data stored on a data recording medium and shaping its waveform to provide a read code signal; and data introducing means comprising: first creation means, receiving a read code signal corresponding to the data stored on the data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal, second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset form the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said two-phase signals is twice as long as that of said first two-phase signals, and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals wherein said second creation means comprises: flip-flop means with a clock input connected to receive a first two-phase signal, delay means connected with one of outputs of said flip-flop means, and gate circuit means for receiving two outputs from said flip-flop means and an output from said delay means to generate said second two-phase signals, and wherein said third creation means comprises: a plurality of first flip-flop means each having a clock input connected to receive said read code signal, and at least one second flip-flop means having a clock input, a signal input for receiving one of said first two-phase signals and a D input connected with each output of at least two of said plurality of first flip-flop means each connected in series to the other of said at least two of said plurality of first flip-flop means.
Claim 31
Dependent Claim
318 words
A data introduction system comprising: pulse detecting means for receiving a signal corresponding to data stored on a data recording medium and shaping its waveform to provide a read code signal; and data introducing means comprising: first creation means, receiving a read code signal corresponding to the data stored on the data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal, second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset form the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said two-phase signals is twice as long as that of said first two-phase signals, and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals wherein said second creation means comprises: flip-flop means with a clock input connected to receive a first two-phase signal, delay means connected with one of outputs of said flip-flop means, and gate circuit means for receiving two outputs from said flip-flop means and an output from said delay means to generate said second two-phase signals, and wherein said third creation means comprises: a plurality of first flip-flop means each having a clock input connected to receive said read code signal, and at least one second flip-flop means having a clock input, a signal input for receiving one of said first two-phase signals and a D input connected with each output of at least two of said plurality of first flip-flop means each connected in series to the other of said at least two of said plurality of first flip-flop means.
Claim 32
Dependent Claim
232 words
A data introduction system comprising: pulse detecting means for receiving a signal corresponding to data stored on a data recording medium and shaping its waveform to provide a read code signal; data introducing means comprising: first creation means, receiving a read code signal corresponding to the data stored on the data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal, second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset form the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said two-phase signals is twice as long as that of said first two-phase signals, and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals; and data discrimination means connected with the output from said third creation means, wherein if said output has successive bits data "1"s, said data discrimination means changes into "O" the bit data "1" adjacent to the group having more bit data "O"s of bit data "O" groups before and after said successive "1"s at issue.
Claim 33
Dependent Claim
232 words
A data introduction system comprising: pulse detecting means for receiving a signal corresponding to data stored on a data recording medium and shaping its waveform to provide a read code signal; data introducing means comprising: first creation means, receiving a read code signal corresponding to the data stored on the data recording medium, for creating repeatedly first two-phase signals, the waveforms of which are inverse to each other in a substantially equal period on the basis of a change in the waveform of said read code signal, second creation means, receiving said first two-phase signals, for creating second two-phase signals, one of which is phase offset form the other of said second two-phase signals so as to be overlapped with each other, wherein a period of said two-phase signals is twice as long as that of said first two-phase signals, and third creation means, receiving said read code signal and said second two-phase signals, for creating a second code signal corresponding to said read code signal which shifts during one phase period of said second two-phase signals; and data discrimination means connected with the output from said third creation means, wherein if said output has successive bits data "1"s, said data discrimination means changes into "O" the bit data "1" adjacent to the group having more bit data "O"s of bit data "O" groups before and after said successive "1"s at issue.