Pulse discrimination system

Claim 2

A pulse discrimination system comprising: a source of data pulses occurring in groups separated from each other by intervals of time, the first pulse of each group being indicative in peak amplitude of the signal level of the other pulses in the group, and the pulses in different groups being subject to variations in their signal levels; means for amplitude discriminating the data pulses from noise at an adjustable threshold level; and means responsive to the peak amplitude of the first pulse of each group for setting the adjustable threshold level of the amplitude discriminating means at a value directly related to the peak amplitude of the first pulse so as to enable the data pulses of each group to be discriminated from noise.

Claim 3

The pulse discrimination system of claim 1, in which the first pulse of each group is a control pulse that is separated from the remaining pulses of the group by an interval of time, the only significance of the control pulse as data being to set the threshold level.

Claim 4

The pulse discrimination system of claim 1, in which the threshold level of the discriminating means is adjustable over a continuous range.

Claim 5

The pulse discrimination system of claim 1, in which the threshold level is set at a value proportional to the peak amplitude of the first pulse of each group.

Claim 6

The pulse discrimination system of claim 1, in which the discriminating means comprises a comparator having first and second inputs and an output that gives an indication when the signal on the first input exceeds the signal on the second input; and the threshold level setting means comprises a capacitor, means responsive to the difference between the amplitude of the voltage across the capacitor and the amplitude of the first pulse of each group for charging the capacitor during intervals of time in which the first pulse occurs, means for holding the voltage across the capacitor during intervals of time in which the remaining pulses of each group occur, and means for coupling the capacitor to the second input of the comparator during intervals of time in which the remaining pulses of each group occur.

Claim 7

The pulse discrimination system of claim 1, in which the source of data pulses comprises a magnetic disc file storage medium on which the data is stored in the form of spatially distributed magnetic flux variations, the flux variations corresponding to each group of data pulses being located in close physical proximity to each other on the storage medium, and a transducer for converting the flux variations to electrical pulses.

Claim 8

The pulse discrimination system of claim 6, in which the data is represented on the storage medium as binary flux reversals, the threshold level setting means produces an electrical signal proportional to the peak amplitude of the first pulse of each group, and the means for discriminating the data pulses comprises a peak detector that gives an indication of the occurrence of the peaks of a signal applied to its input; means for connecting the output of the transducer to the input of the peak detector; a comparator having first and second inputs and an output that gives an indication when the signal on the first input exceeds the signal on the second input; means for connecting the output of the transducer to the first input of the comparator; means for connecting the threshold level setting means to the second input of the comparator; and means responsive to the coincidence of an indication from the comparator and an indication from the peak detector for producing an indication of the occurrence of a data pulse.

Claim 9

The pulse discrimination system of claim 7, in which the threshold level setting means comprises a capacitor, means responsive to the difference between the amplitude of the voltage across the capacitor and the amplitude of the first pulse of each group for charging the capacitor during intervals of time in which the first pulse occurs, means for holdinG the voltage across the capacitor during intervals of time in which the remaining pulses of each group occur, and means for coupling the capacitor to the second input of the comparator during intervals of time in which the remaining pulses occur.

Claim 10

The pulse discrimination system of claim 8, in which a bistable device is provided having first and second stable states, the capacitor charging means being operative when the bistable device is in the first state and the capacitor holding being operative when the bistable device is in the second state, means are provided for setting the bistable device in the first state prior to the occurrence of the first pulse of each group, and means are provided for resetting the bistable device in the second state after the occurrence of the first pulse of each group.

Claim 11

The pulse discrimination system of claim 9, in which the means for setting the bistable device in the first state comprises magnetic flux variations recorded on the storage medium in a definite predetermined location relative to the flux variations corresponding to the groups of data pulses and a transducer for converting the flux variations to electrical pulses.

Claim 12

The pulse discrimination system of claim 10, in which the means for resetting the bistable device in the second state comprises a reset comparator having first and second inputs and an output that gives an indication when the signal on the first input exceeds the signal on the second input, means for connecting the output of the transducer to the first input of the reset comparator, a signal source having a constant amplitude connected to the second input of the reset comparator, and means responsive to the coincidence of an indication from the reset comparator and an indication from the peak detector for producing a reset signal for the bistable device.

Claim 13

A pulse discrimination system comprising: a source of data pulse signals occurring in groups separated from each other by intervals of time, the data pulse signals of each group having substantially the same signal level, and the data pulse signals of different groups being subject to variations in their signal levels; a source of control pulse signals respectively associated with the groups of data pulse signals, each control pulse signal occurring in the interval of time preceding the associated group of data pulse signals, and each control pulse signal being representative of the signal level of the data pulse signals of the associated group; means coupled to the source of data pulse signals for indicating those portions of the data pulse signals that exceed a controllable threshold level; and means responsive to the control pulse signal associated with each group of data pulse signals for controlling the threshold level of the indicating means in accordance with the signal level represented by such control pulse signal.

Claim 14

A pulse discrimination system comprising: a source of data pulse signals occurring in groups separated from each other by intervals of time, the data pulse signals of each group having substantially the same signal level, and the data pulse signals of different groups being subject to variations in their signal levels; a source of control pulse signals respectively associated with the groups of data pulse signals, each control pulse signal occurring in the interval of time preceding the associated group of data pulse signals, and each control pulse signal being representative of the signal level of the data pulse signals of the associated group; means coupled to the source of data pulse signals for indicating those portions of the data pulse signals that exceed a controllable threshold level; and means responsive to the control pulse signal associated with each group of data pulse signals for controlling the threshold level of the indicating means in accordance with the signal level represented by such control pulse signal.

Claim 15

The pulse discrimination system of claim 12, in which the threshold level is controllable over a continuous range.

Claim 16

The pulse discrimination system of claim 13, in which the source of data pulses and the source of control pulses are spatially distributed magnetic flux reversals on a magnetic storage medium, the flux reversals of each group of data pulses and its control pulse being located in close physical proximity to each other, and transducing means for converting the flux reversals to electrical pulses.

Claim 17

The pulse discrimination system of claim 14, in which the data is represented by the presence and absence of data pulses in successive bit cells and the control pulses are separated from the groups of data pulses to which they relate by at least one bit cell.

Claim 18

A pulse discrimination system comprising: a source of binary data pulses to be discriminated from noise, the data pulses occurring in groups separated from each other by intervals of time, the first pulse of each group being indicative in peak amplitude of the signal level of the other pulses in the group, and the pulses in different groups being subject to variations in their signal levels; a peak detector that gives an indication of the occurrence of the peaks of a signal applied to its input; means for connecting the source to the input of the peak detector; a comparator having first and second inputs and an output that gives an indication when the signal on the first input exceeds the signal on the second input; means for connecting the source of data pulses to the first input of the comparator; a source of reference signals that vary as a function of the signal level of the data pulses; means for connecting the source of reference signals to the second input of the comparator; and means responsive to the coincidence of an indication from the comparator and an indication from the peak detector for producing an indication of the occurrence of a data pulse.

Claim 19

A pulse discrimination system comprising: a source of binary data pulses to be discriminated from noise, the data pulses occurring in groups separated from each other by intervals of time, the first pulse of each group being indicative in peak amplitude of the signal level of the other pulses in the group, and the pulses in different groups being subject to variations in their signal levels; a peak detector that gives an indication of the occurrence of the peaks of a signal applied to its input; means for connecting the source to the input of the peak detector; a comparator having first and second inputs and an output that gives an indication when the signal on the first input exceeds the signal on the second input; means for connecting the source of data pulses to the first input of the comparator; a source of reference signals that vary as a function of the signal level of the data pulses; means for connecting the source of reference signals to the second input of the comparator; and means responsive to the coincidence of an indication from the comparator and an indication from the peak detector for producing an indication of the occurrence of a data pulse.

Claim 20

A pulse discrimination system comprising: a source of data pulses to be discriminated from noise, the data pulses occurring in groups separated from each other by intervals of time, the first pulse of each group being indicative in peak amplitude of the signal level of the other pulses in the group, and the pulses in different groups being subject to variations in their signal levels; a comparator having first and second inputs and an output that gives an indication when the signal on the first input exceeds the signal on the second input; means for connecting the source to the first input; a source of reference signals the amplitude of which varies in direct relationship to the signal level of the data pulses; means for connecting the source of reference signals to the second input of the comparator; and a utilization circuit connected to the output of the comparator.

Claim 21

A pulse discrimination system comprising: a source of data pulses to be discriminated from noise, the data pulses occurring in groups separated from each other by intervals of time, the first pulse of each group being indicative in peak amplitude of the signal level of the other pulses in the group, and the pulses in different groups being subject to variations in their signal levels; a comparator having first and second inputs and an output that gives an indication when the signal on the first input exceeds the signal on the second input; means for connecting the source to the first input; a source of reference signals the amplitude of which varies in direct relationship to the signal level of the data pulses; means for connecting the source of reference signals to the second input of the comparator; and a utilization circuit connected to the output of the comparator.

Claim 22

A pulse discrimination system comprising: a source of data pulses occurring in groups separated from each other by intervals of time, the data pulses of each group having substantially the same signal level and the data pulses of different groups being subject to variations in their signal levels; a source of control pulses respectively associated with the groups of data pulses, each control pulse occurring in the interval of time preceding the associated group of data pulses, and each control pulse having a signal level indicative of the signal level of the data pulses of the associated group; means for amplitude discriminating the data pulses from noise; means for generating a control signal proportional in amplitude to the peak amplitude of the control pulses; and means responsive to the control signal for enabling the amplitude discriminating means to discriminate the data pulses of the group associated with each control pulse from noise.

Claim 23

A pulse discrimination system comprising: a source of data pulses occurring in groups separated from each other by intervals of time, the data pulses of each group having substantially the same signal level and the data pulses of different groups being subject to variations in their signal levels; a source of control pulses respectively associated with the groups of data pulses, each control pulse occurring in the interval of time preceding the associated group of data pulses, and each control pulse having a signal level indicative of the signal level of the data pulses of the associated group; means for amplitude discriminating the data pulses from noise; means for generating a control signal proportional in amplitude to the peak amplitude of the control pulses; and means responsive to the control signal for enabling the amplitude discriminating means to discriminate the data pulses of the group associated with each control pulse from noise.

Claim 24

The pulse discrimination system of claim 18, wherein the amplitude discriminating means has an adjustable threshold level above which data pulses are discriminated from noise; and wherein the means for enabling the amplitude discriminating means includes means responsive to the peak amplitude of each control pulse for setting the adjustable threshold level at a value so as to enable the data pulses of each group to be discriminated from noise.

Claim 25

A data storage system comprising: a magnetic storage medium on which data is stored in groups; means for reading the data stored on the storage medium as relative motion takes place between the storage medium and the reading means, the reading means producing an output signal in which the first data pulse of each group is indicative in peak amplitude of the signal level of the other data pulses in the group and the data pulses in different groups are subject to variations in their signal levels; means for amplitude discriminating the output signal from the reading means such that a data pulse is indicated when the output signal exceeds a particular value; and means responsive to the peak amplitude of the first data pulse oF each group for changing the particular value in direct relationship to the peak amplitude of such first data pulse so as to amplitude discriminate the output signal as the different groups are read by the reading means.

Claim 26

A data storage system comprising: a magnetic storage medium on which data is stored in groups; means for reading the data stored on the storage medium as relative motion takes place between the storage medium and the reading means, the reading means producing an output signal in which the first data pulse of each group is indicative in peak amplitude of the signal level of the other data pulses in the group and the data pulses in different groups are subject to variations in their signal levels; means for amplitude discriminating the output signal from the reading means such that a data pulse is indicated when the output signal exceeds a particular value; and means responsive to the peak amplitude of the first data pulse oF each group for changing the particular value in direct relationship to the peak amplitude of such first data pulse so as to amplitude discriminate the output signal as the different groups are read by the reading means.