Apparatus for producing recorded traces of uniform density

Claim 2

Recording apparatus for producing on a moving record medium a trace representing the value of a data signal as said value varies with time, comprising means supporting and moving a record medium in a pre-determined fixed direction at any of at least two selectable speeds, marking means positioned relative to said medium to mark the latter only when said marking means is supplied with a marking signal, the intensity with which said marking means so marks said medium being determined by the value of said marking signal, sweep means connected to said marking means to effectively sweep the later recurrently in successive sweep periods along a path across said medium which is substantially transverse to said direction of medium movement, whereby, during each of said periods, said marking means produces a line along said path only throughout the time in that period in which said marking means is supplied with said marking signal, the intensity of said line being determined by the value of the marking siGnal producing it, variable value marking signal producing means connected to said marking means and to a source of a data signal and responsive to the value of said data signal to supply a variable value marking signal to said marking means for a predetermined, fixed, relatively short interval during each of said periods starting at a time therein dependent upon the value of said data signal in that period, said variable value marking signals thus causing said marking means to produce substantially parallel static lines across said medium, adjacent ones of which overlap in said direction of medium movement to an extent which increases as said medium speed decreases, control means connected to be responsive to said medium speed and connected to said variable value marking signal producing means to vary the value of said marking signal supplied thereby as a direct function of said medium speed, whereby the lastmentioned marking signal value decreases as said medium speed decreases, and fixed value marking signal producing means connected to said marking means and to said source of said data signal and responsive to the value of said data signal to supply a marking signal, of a fixed value which is independent of said medium speed, to said marking means throughout a portion of each of ones of said periods, said portion having a length dependent upon the difference between the data signal value in that period and the data signal value in the immediately preceding period, and starting at a time in its period dependent upon one of the lastmentioned two data signal values, said fixed value marking signals thus causing said marking means to produce substantially parallel dynamic lines across said medium, adjacent ones of which never overlap in said direction of medium movement for any of said medium speeds, whereby the density of the trace portions formed by said overlapping static lines is made to be substantially the same as the density of the trace portions formed by said non-overlapping dynamic lines for all of said medium speeds.

Claim 3

Recording apparatus for producing on a moving record medium a trace representing the condition of a data signal as said condition varies with time, comprising generating means for producing a ramp signal the value of which repeatedly sweeps progressively between first and second values in each of successive sweep periods, cathode ray tube means, means supporting a record medium relative to said tube means, said tube means including beam producing means for producing a cathode ray tube beam only when an unblanking signal is applied to said beam producing means, said tube means also including deflecting means connected to said generating means for effectively sweeping said beam in synchronism with said sweeping of said ramp signal to cause said beam, as long as it is produced during each of said periods, to produce a trace line on said medium along a path and with an intensity dependent upon the value of said unblanking signal, means for moving said medium relative to said tube means at any of at least two selectable speeds in a direction substantially at right angles to said path, comparing means connected to receive said ramp signal and an input signal representing the condition of a data signal for producing an output signal upon the occurrence in each of said sweep periods of a predetermined relationship between the values of said input and ramp signals, variable value unblanking signal producing means connected to said comparing means to receive said output signals and connected to said beam producing means to supply thereto a variable value unblanking signal for a predetermined, fixed, relatively short interval during each of said periods starting upon receipt of said output signal in that period, said variable value unblanking signals thus causing said beam to produce substantially parallel static lines across said medium, adjacent ones of which overlap in the direction of medium mOvement to an extent which increases as said medium speed decreases, control means connected to be responsive to said medium speed and connected to said variable value unblanking signal producing means to vary the value of said unblanking signal supplied thereby as a direct function of said medium speed, whereby the last-mentioned unblanking signal value decreases as said medium speed decreases, and fixed value unblanking signal producing means connected to said comparing means to receive said output signals and connected to said beam producing means to supply thereto an unblanking signal of a fixed value, which is independent of said medium speed, throughout a portion of each of ones of said periods, said portion having a length dependent upon the difference between the time of occurrence of said output signal in that period and the time of occurrence of said output signal in the immediately preceding period, and starting at a time in its period dependent upon one of the last-mentioned two times of output signal occurrence, said fixed value unblanking signals thus causing said beam to produce substantially parallel dynamic lines across said medium, adjacent ones of which never overlap in said direction of medium movement for any of said medium speeds, whereby the density of the trace portions formed by said overlapping static lines is made to be substantially the same as the density of the trace portions formed by said non-overlapping dynamic lines for all of said medium speeds.

Claim 4

Recording apparatus for producing on a moving record medium a trace representing the condition of a data signal as said condition varies with time, comprising generating means for producing a ramp signal the value of which repeatedly sweeps progressively between first and second values in each of successive sweep periods, cathode ray tube means, means supporting a record medium relative to said tube means, said tube means including beam producing means for producing a cathode ray tube beam only when an unblanking signal is applied to said beam producing means, said tube means also including deflecting means connected to said generating means for effectively sweeping said beam in synchronism with said sweeping of said ramp signal to cause said beam, as long as it is produced during each of said periods, to produce a trace line on said medium along a path and with an intensity dependent upon the value of said unblanking signal, means for moving said medium relative to said tube means at any of at least two selectable speeds in a direction substantially at right angles to said path, comparing means connected to receive said ramp signal and an input signal representing the condition of a data signal for producing an output signal upon the occurrence in each of said sweep periods of a predetermined relationship between the values of said input and ramp signals, variable value unblanking signal producing means connected to said comparing means to receive said output signals and connected to said beam producing means to supply thereto a variable value unblanking signal for a predetermined, fixed, relatively short interval during each of said periods starting upon receipt of said output signal in that period, said variable value unblanking signals thus causing said beam to produce substantially parallel static lines across said medium, adjacent ones of which overlap in the direction of medium mOvement to an extent which increases as said medium speed decreases, control means connected to be responsive to said medium speed and connected to said variable value unblanking signal producing means to vary the value of said unblanking signal supplied thereby as a direct function of said medium speed, whereby the last-mentioned unblanking signal value decreases as said medium speed decreases, and fixed value unblanking signal producing means connected to said comparing means to receive said output signals and connected to said beam producing means to supply thereto an unblanking signal of a fixed value, which is independent of said medium speed, throughout a portion of each of ones of said periods, said portion having a length dependent upon the difference between the time of occurrence of said output signal in that period and the time of occurrence of said output signal in the immediately preceding period, and starting at a time in its period dependent upon one of the last-mentioned two times of output signal occurrence, said fixed value unblanking signals thus causing said beam to produce substantially parallel dynamic lines across said medium, adjacent ones of which never overlap in said direction of medium movement for any of said medium speeds, whereby the density of the trace portions formed by said overlapping static lines is made to be substantially the same as the density of the trace portions formed by said non-overlapping dynamic lines for all of said medium speeds.