Image display system

Claim 2

An image display comprising: a. a cathode ray tube; b. control means connected to said cathode ray tube for controlling the electron beam deflection of said tube to produce a major raster from a plurality of individually spaced minor rasters; and c. intensity control means connected to said cathode ray tube for varying the intensity of said electron beam between a first high level intensity for a predetermined length of time of each minor raster and a second low level intensity during the remaining time of each minor raster in response to a minor raster intensity input signal.

Claim 3

An image display comprising: a. a cathode ray tube; b. control means connected to said cathode ray tube for controlling the electron beam deflection of said tube to produce a major raster from a plurality of individually spaced minor rasters; and c. intensity control means connected to said cathode ray tube for varying the intensity of said electron beam between a first high level intensity for a predetermined length of time of each minor raster and a second low level intensity during the remaining time of each minor raster in response to a minor raster intensity input signal.

Claim 4

An image display comprising: a. a cathode ray tube; b. control means connected to said cathode ray tube for controlling the electron beam deflection of said tube to produce a major raster from a plurality of individually spaced minor rasters; and c. intensity control means connected to said cathode ray tube for varying the intensity of said electron beam between a first high level intensity for a predetermined length of time of each minor raster and a second low level intensity during the remaining time of each minor raster in response to a minor raster intensity input signal.

Claim 5

An image display as set forth in claim 1 whereiN said cathode ray tube is a dark trace storage tube.

Claim 6

An image display as set forth in claim 1 wherein means are connected to said intensity control means to operate said intensity control means between a first mode of operation wherein the intensity of each minor raster is a direct representation of its intensity input signal, and a second mode of operation wherein the intensity of each minor raster is a complement representation of its intensity input signal.

Claim 7

An image display as set forth in claim 1 wherein said cathode ray tube is a dark trace storage tube.

Claim 8

An image display comprising: a. a cathode ray tube having a major deflection coil and a minor deflection coil associated therewith, each of said coils having a horizontal deflection input and a vertical deflection input; b. a minor vertical deflection register and a minor horizontal deflection register, each having a pulse input and a register read output; c. a clock pulse generator having an output; d. means connecting the output of said clock pulse generator to the pulse input of said minor vertical deflection register; e. means connected to apply a pulse to the input of said minor horizontal deflection register each time said minor vertical deflection register reaches a predetermined count; f. a minor vertical digital to analog convertor; g. means connecting said minor vertical digital to analog convertor between the register read output of said minor vertical deflection register and the vertical deflection input of said minor deflection coil, said minor vertical digital to analog convertor producing an analog signal output proportional to the digital count in said minor vertical deflection register; h. a minor horizontal digital to analog convertor; i. means connecting said minor horizontal digital to analog convertor between the register read output of said minor horizontal deflection register and the horizontal deflection input of said minor deflection coil, said minor horizontal digital to analog convertor producing an analog signal output proportional to the digital count in said minor horizontal deflection register; j. a major vertical deflection register and a major horizontal deflection register, each having a pulse input, and a register read output; k. means connected to apply a pulse to the input of said major horizontal deflection register each time said minor horizontal deflection register reaches a predetermined count; l. means connected to apply a pulse to the input of said major vertical deflection register each time said major horizontal deflection register reaches a predetermined count; m. a major horizontal digital to analog convertor; n. means connecting said major horizontal digital to analog convertor between the register read output of said major horizontal deflection register and the horizontal deflection input of said major deflection coil, said major horizontal digital to analog convertor producing an analog signal output proportional to the digital count in said major horizontal deflection register; o. a major vertical digital to analog convertor; and p. means connecting said major vertical digital to analog convertor between the register read output of said major vertical deflection register and the vertical deflection input of said major deflection coil, said major vertical digital to analog convertor producing an analog signal output proportional to the digital count in said major vertical deflection register.

Claim 9

An image display comprising: a. a cathode ray tube having a major deflection coil and a minor deflection coil associated therewith, each of said coils having a horizontal deflection input and a vertical deflection input; b. a minor vertical deflection register and a minor horizontal deflection register, each having a pulse input and a register read output; c. a clock pulse generator having an output; d. means connecting the output of said clock pulse generator to the pulse input of said minor vertical deflection register; e. means connected to apply a pulse to the input of said minor horizontal deflection register each time said minor vertical deflection register reaches a predetermined count; f. a minor vertical digital to analog convertor; g. means connecting said minor vertical digital to analog convertor between the register read output of said minor vertical deflection register and the vertical deflection input of said minor deflection coil, said minor vertical digital to analog convertor producing an analog signal output proportional to the digital count in said minor vertical deflection register; h. a minor horizontal digital to analog convertor; i. means connecting said minor horizontal digital to analog convertor between the register read output of said minor horizontal deflection register and the horizontal deflection input of said minor deflection coil, said minor horizontal digital to analog convertor producing an analog signal output proportional to the digital count in said minor horizontal deflection register; j. a major vertical deflection register and a major horizontal deflection register, each having a pulse input, and a register read output; k. means connected to apply a pulse to the input of said major horizontal deflection register each time said minor horizontal deflection register reaches a predetermined count; l. means connected to apply a pulse to the input of said major vertical deflection register each time said major horizontal deflection register reaches a predetermined count; m. a major horizontal digital to analog convertor; n. means connecting said major horizontal digital to analog convertor between the register read output of said major horizontal deflection register and the horizontal deflection input of said major deflection coil, said major horizontal digital to analog convertor producing an analog signal output proportional to the digital count in said major horizontal deflection register; o. a major vertical digital to analog convertor; and p. means connecting said major vertical digital to analog convertor between the register read output of said major vertical deflection register and the vertical deflection input of said major deflection coil, said major vertical digital to analog convertor producing an analog signal output proportional to the digital count in said major vertical deflection register.

Claim 10

An image display as set forth in claim 5 wherein intensity control means are connected to said cathode ray tube for varying the intensity of the electron beam of said cathode ray tube between a first high level intensity and a second low level intensity during the time said minor vertical and minor horizontal deflection registers count through a complete cycle, said intensity varying between said high level and said low level in response to an intensity input signal.

Claim 11

An imaGe display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam; b. a digital comparator circuit; c. means connected to said comparator circuit for feeding a digital intensity input signal thereto; d. a counting register having an input and a register read output; e. a clock pulse generating circuit having an output; f. means connecting the output of said clock pulse generator to the input of said counting register; g. means connecting the read output of said register to said comparator, said comparator producing an output signal upon coincidence between an input signal and a register read signal; h. means connected to apply a first level intensity signal to the control grid of said cathode ray tube upon the occurrence of an intensity input signal to said comparator; i. means connected to said counting register to begin the count of said clock pulses in said register upon the occurrence of an intensity input signal to said comparator; and j. means connected to apply a second level intensity signal to the control grid of said cathode ray tube in response to an output signal from said comparator.

Claim 12

An imaGe display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam; b. a digital comparator circuit; c. means connected to said comparator circuit for feeding a digital intensity input signal thereto; d. a counting register having an input and a register read output; e. a clock pulse generating circuit having an output; f. means connecting the output of said clock pulse generator to the input of said counting register; g. means connecting the read output of said register to said comparator, said comparator producing an output signal upon coincidence between an input signal and a register read signal; h. means connected to apply a first level intensity signal to the control grid of said cathode ray tube upon the occurrence of an intensity input signal to said comparator; i. means connected to said counting register to begin the count of said clock pulses in said register upon the occurrence of an intensity input signal to said comparator; and j. means connected to apply a second level intensity signal to the control grid of said cathode ray tube in response to an output signal from said comparator.

Claim 13

An image display comprising: a. a cathode ray tube; b. means connected to said cathode ray tube to apply minor vertical and minor horizontal deflection signals thereto to deflect the cathode ray tube electron beam to produce minor rasters; c. means connected to said cathode ray tube to apply major horizontal and major vertical deflection signals thereto to deflect the cathode ray tube electron beam to closely space a plurality of said minor rasters over the face of said cathode ray tube to produce a major raster; d. intensity control means adapted to receive a train of intensity input signals, each intensity input signal in said train representing an intensity level for an individual minor raster of said major raster; and e. means connecting said intensity control means to said cathode ray tube to vary the intensity of the electron beam of said cathode ray tube between a first intensity level and a second intensity level during each minor raster in response to the intensity input signal for each minor raster.

Claim 14

An image display comprising: a. a cathode ray tube; b. means connected to said cathode ray tube to apply minor vertical and minor horizontal deflection signals thereto to deflect the cathode ray tube electron beam to produce minor rasters; c. means connected to said cathode ray tube to apply major horizontal and major vertical deflection signals thereto to deflect the cathode ray tube electron beam to closely space a plurality of said minor rasters over the face of said cathode ray tube to produce a major raster; d. intensity control means adapted to receive a train of intensity input signals, each intensity input signal in said train representing an intensity level for an individual minor raster of said major raster; and e. means connecting said intensity control means to said cathode ray tube to vary the intensity of the electron beam of said cathode ray tube between a first intensity level and a second intensity level during each minor raster in response to the intensity input signal for each minor raster.

Claim 15

An image display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam, said cathode ray tube having a minor deflection coil and a major deflection coil associated therewith, each of said deflection coils having a horizontal deflection input and a vertical deflection input; b. a minor vertical deflection register; c. means connected to said minor vertical deflection register to supply clock pulses thereto to be counted by said register; d. means connected between said minor vertical deflection register and the vertical deflection input of said minor deflection coil to apply an analog signal to said vertical deflection input proportional to the count in said minor vertical deflection register; e. a minor horizontal deflection register; f. means connected to supply a pulse to said minor horizontal deflection register to be counted by said register each time said minor vertical deflection register counts through a complete cycle; g. means connecting said minor horizontal deflection register to the horizontal deflection input of said minor deflection coil to provide an analog signal to said horizontal deflection input proportional to the count in said minor horizontal deflection register; h. a major horizontal deflection register; i. means connected to supply a pulse to said major horizontal deflection register to be counted by said register each time said minor vertical and minor horizontal deflection registers count through a complete cycle; j. means connecting said major horizontal deflection register to the horizontal deflection input of said major deflection coil to provide an analog signal to said horizontal deflecTion input proportional to the count in said major horizontal deflection register; k. a major vertical deflection register; l. means connected to said major horizontal deflection register to apply a pulse to be counted by said major vertical deflection register each time said major horizontal deflection register counts through a complete cycle; and m. means connecting said major vertical deflection register to the vertical deflection input of said major deflection coil to provide an analog signal to said vertical deflection input proportional to the count in said major vertical deflection register.

Claim 16

An image display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam, said cathode ray tube having a minor deflection coil and a major deflection coil associated therewith, each of said deflection coils having a horizontal deflection input and a vertical deflection input; b. a minor vertical deflection register; c. means connected to said minor vertical deflection register to supply clock pulses thereto to be counted by said register; d. means connected between said minor vertical deflection register and the vertical deflection input of said minor deflection coil to apply an analog signal to said vertical deflection input proportional to the count in said minor vertical deflection register; e. a minor horizontal deflection register; f. means connected to supply a pulse to said minor horizontal deflection register to be counted by said register each time said minor vertical deflection register counts through a complete cycle; g. means connecting said minor horizontal deflection register to the horizontal deflection input of said minor deflection coil to provide an analog signal to said horizontal deflection input proportional to the count in said minor horizontal deflection register; h. a major horizontal deflection register; i. means connected to supply a pulse to said major horizontal deflection register to be counted by said register each time said minor vertical and minor horizontal deflection registers count through a complete cycle; j. means connecting said major horizontal deflection register to the horizontal deflection input of said major deflection coil to provide an analog signal to said horizontal deflecTion input proportional to the count in said major horizontal deflection register; k. a major vertical deflection register; l. means connected to said major horizontal deflection register to apply a pulse to be counted by said major vertical deflection register each time said major horizontal deflection register counts through a complete cycle; and m. means connecting said major vertical deflection register to the vertical deflection input of said major deflection coil to provide an analog signal to said vertical deflection input proportional to the count in said major vertical deflection register.

Claim 17

An image display as set forth in claim 9 wherein sensing means are connected to said minor vertical, said minor horizontal, said major horizontal, and said major vertical deflection registers to produce a signal indicative of the end of the raster of said cathode ray tube display each time all of said registers reach a predetermined count.

Claim 18

An image display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam, said cathode ray tube having a minor deflection coil and a major deflection coil associated therewith, each of said deflection coils having a horizontal deflection input and a vertical deflection input; b. register means for counting input pulses applied thereto, said register having a plurality of outputs, each output representing a different bit of the digital number count in said register; c. means connected between said register means and said minor deflection coil to provide an analog signal proportional to a plurality of the least significant bits of the digital number count in said register means to said vertical deflection input of the minor deflection coil, and to provide an analog signal proportional to a plurality of the second least significant bits of the digital number count in said register means to said horizontal deflection input of the minor deflection coil; and d. means connected between said register means and said major deflection coil to provide an analog signal proportional to a plurality of the third least significant bits of the digital number count in said register means to said horizontal deflection input of the major deflection coil, and to provide an analog signal proportional to a plurality of the fourth least significant bits of the digital number count in said register means to said vertical deflection input of the major deflection coil.

Claim 19

An image display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam, said cathode ray tube having a minor deflection coil and a major deflection coil associated therewith, each of said deflection coils having a horizontal deflection input and a vertical deflection input; b. register means for counting input pulses applied thereto, said register having a plurality of outputs, each output representing a different bit of the digital number count in said register; c. means connected between said register means and said minor deflection coil to provide an analog signal proportional to a plurality of the least significant bits of the digital number count in said register means to said vertical deflection input of the minor deflection coil, and to provide an analog signal proportional to a plurality of the second least significant bits of the digital number count in said register means to said horizontal deflection input of the minor deflection coil; and d. means connected between said register means and said major deflection coil to provide an analog signal proportional to a plurality of the third least significant bits of the digital number count in said register means to said horizontal deflection input of the major deflection coil, and to provide an analog signal proportional to a plurality of the fourth least significant bits of the digital number count in said register means to said vertical deflection input of the major deflection coil.

Claim 20

An image display comprising: a. a cathode ray tube having a major deflection coil and a minor deflection coil associated therewith, each of said coils having a first deflection input and a second deflection input, each of said second deflection inputs producing a deflection of the cathode ray tube electron beam in a direction different from said first deflection inputs; b. a first minor deflection register and a second minor deflection register, each having a pulse input and a register read output; c. a clock pulse generator having an output; d. means connecting the output of said clock pulse generator to the pulse input of said first minor deflection register; e. means connected to apply a pulse to the input of said second minor deflection register each time said first minor deflection register reaches a predetermined count; f. a first minor digital to analog convertor; g. means connecting said first minor digital to analog convertor between the register read output of said first minor deflection register and the first deflection input of said minor deflection coil, said first minor digital to analog convertor producing an analog signal output proportional to the digital count in said first minor deflection register; h. a second minor digital to analog convertor; i. means connecting said second minor digital to analog convertor between the register read output of said second minor deflection register and the second deflection input of said minor deflectIon coil, said second minor digital to analog convertor producing an analog signal output proportional to the digital count in said second minor deflection register; j. a first major deflection register and a second major deflection register, each having a pulse input and a register read output; k. means connected to apply a pulse to the input of said first major deflection register each time said second minor deflection register reaches a predetermined count; l. means connected to apply a pulse to the input of said second major deflection register each time said first major deflection register reaches a predetermined count; m. a first major digital to analog convertor; n. means connecting said first major digital to analog convertor between the register read output of said first major deflection register and the first deflection input of said major deflection coil, said first major digital to analog convertor producing an analog signal output proportional to the digital count in said first major deflection register; o. a second major digital to analog convertor; and p. means connecting said second major digital to analog convertor between the register read output of said second major deflection register and the second deflection input of said major deflection coil, said second major digital to analog convertor producing an analog signal output proportional to the digital count in said second major deflection register.

Claim 21

An image display comprising: a. a cathode ray tube having a major deflection coil and a minor deflection coil associated therewith, each of said coils having a first deflection input and a second deflection input, each of said second deflection inputs producing a deflection of the cathode ray tube electron beam in a direction different from said first deflection inputs; b. a first minor deflection register and a second minor deflection register, each having a pulse input and a register read output; c. a clock pulse generator having an output; d. means connecting the output of said clock pulse generator to the pulse input of said first minor deflection register; e. means connected to apply a pulse to the input of said second minor deflection register each time said first minor deflection register reaches a predetermined count; f. a first minor digital to analog convertor; g. means connecting said first minor digital to analog convertor between the register read output of said first minor deflection register and the first deflection input of said minor deflection coil, said first minor digital to analog convertor producing an analog signal output proportional to the digital count in said first minor deflection register; h. a second minor digital to analog convertor; i. means connecting said second minor digital to analog convertor between the register read output of said second minor deflection register and the second deflection input of said minor deflectIon coil, said second minor digital to analog convertor producing an analog signal output proportional to the digital count in said second minor deflection register; j. a first major deflection register and a second major deflection register, each having a pulse input and a register read output; k. means connected to apply a pulse to the input of said first major deflection register each time said second minor deflection register reaches a predetermined count; l. means connected to apply a pulse to the input of said second major deflection register each time said first major deflection register reaches a predetermined count; m. a first major digital to analog convertor; n. means connecting said first major digital to analog convertor between the register read output of said first major deflection register and the first deflection input of said major deflection coil, said first major digital to analog convertor producing an analog signal output proportional to the digital count in said first major deflection register; o. a second major digital to analog convertor; and p. means connecting said second major digital to analog convertor between the register read output of said second major deflection register and the second deflection input of said major deflection coil, said second major digital to analog convertor producing an analog signal output proportional to the digital count in said second major deflection register.

Claim 22

An image display comprising: a. beam generating means for producing an energy beam; b. an energy sensitive target; c. control means connected to said beam generating means for controlling the deflection of said energy beam to produce a major raster on said target from a plurality of individually spaced minor rasters; and d. intensity control means connected to said beam generating means for varying the intensity of said energy beam between a first level intensity for a predetermined length of time of each minor raster and a second level intensity during the remaining time of each minor raster in response to a minor raster intensity input signal.

Claim 23

An image display comprising: a. beam generating means for producing an energy beam; b. an energy sensitive target; c. control means connected to said beam generating means for controlling the deflection of said energy beam to produce a major raster on said target from a plurality of individually spaced minor rasters; and d. intensity control means connected to said beam generating means for varying the intensity of said energy beam between a first level intensity for a predetermined length of time of each minor raster and a second level intensity during the remaining time of each minor raster in response to a minor raster intensity input signal.

Claim 24

An image display as set forth in claim 13 wherein intensity control means are connected to said beam generating means for varying the intensity of said energy beam between a first level and a second level intensity during the time of each minor raster in response to a minor raster intensity input signal for each minor raster.

Claim 25

An image display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam, said cathode ray tube having a minor deflection coil and a major deflection coil associated therewith, each of said deflection coils having a horizontal deflection input and a vertical deflection input; b. means connected to the vertical deflection input of said minor deflection coil to produce a repeating minor vertical sweep of the electron beam of said cathode ray tube; c. means connected to the horizontal deflection input of said minor deflection coil to produce a minor horizontal deflection of the electron beam of said cathode ray tube upon completion of each minor vertical sweep; d. means connected to the horizontal deflection input of said major deflection coil to produce a major horizontal deflection of the electron beam of said cathode ray tube each time a predetermined number of minor horizontal deflections have been made; e. means connected to the vertical deflection input of said major deflection coil to produce a major vertical deflection of the electron beam of said cathode ray tube each time a predetermined number of major horizontal deflections have been made; f. an intensity control means responsive to intensity input signals; and g. means connecting said intensity control means to the control grid of said cathode ray tube to vary the intensity of the electron beam of said cathode ray tube between a first level intensity and a second leVel intensity whereby a certain number of said minor vertical sweeps occurring during each predetermined number of minor horizontal deflections will be a first level intensity and the remainder of said minor vertical sweeps occurring during the predetermined number of minor horizontal deflections will be at a second level intensity the number of minor vertical sweeps being at said first or second level intensity during each predetermined number of minor horizontal deflections being determined by the input intensity signal to said intensity control means during each predetermined number of minor horizontal deflections.

Claim 26

An image display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam, said cathode ray tube having a minor deflection coil and a major deflection coil associated therewith, each of said deflection coils having a horizontal deflection input and a vertical deflection input; b. means connected to the vertical deflection input of said minor deflection coil to produce a repeating minor vertical sweep of the electron beam of said cathode ray tube; c. means connected to the horizontal deflection input of said minor deflection coil to produce a minor horizontal deflection of the electron beam of said cathode ray tube upon completion of each minor vertical sweep; d. means connected to the horizontal deflection input of said major deflection coil to produce a major horizontal deflection of the electron beam of said cathode ray tube each time a predetermined number of minor horizontal deflections have been made; e. means connected to the vertical deflection input of said major deflection coil to produce a major vertical deflection of the electron beam of said cathode ray tube each time a predetermined number of major horizontal deflections have been made; f. an intensity control means responsive to intensity input signals; and g. means connecting said intensity control means to the control grid of said cathode ray tube to vary the intensity of the electron beam of said cathode ray tube between a first level intensity and a second leVel intensity whereby a certain number of said minor vertical sweeps occurring during each predetermined number of minor horizontal deflections will be a first level intensity and the remainder of said minor vertical sweeps occurring during the predetermined number of minor horizontal deflections will be at a second level intensity the number of minor vertical sweeps being at said first or second level intensity during each predetermined number of minor horizontal deflections being determined by the input intensity signal to said intensity control means during each predetermined number of minor horizontal deflections.

Claim 27

An image display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam, said cathode ray tube having minor deflection means and major deflection means associated therewith, each of said deflection means having a first direction deflection input and a second direction deflection input; b. means connected to the first direction deflection input of said minor deflection means to produce a repeating minor first direction sweep of the electron beam of said cathode ray tube; c. means connected to the second direction deflection input of said minor deflection means to produce a minor second direction deflection of the electron beam of said cathode ray tube upon completion of each minor first direction sweep; d. means connected to the second direction deflection input of said major deflection means to produce a major second direction deflection of the electron beam of said cathode ray tube each time a predetermined number of minor second direction deflections have been made; e. means connected to the first direction deflection input of said major deflection means to produce a major first direction deflection of the electron beam of said cathode ray tube each time a predetermined number of major second direction deflections have been made; f. intensity control means responsive to intensity input signals; and g. means connecting said intensity control means to the control grid of said cathode ray tube to vary the intensity of the electron beam of said cathode ray tube between a first level intensity and a second level intensity whereby a certain number of said minor first direction sweeps occurring during each predetermined number of minor second direction deflections will be at a first level intensity and the remainder of said minor first direction sweeps occurring during the predetermined number of minor second direction deflections will be at a second level intensity, the number of minor first direction sweeps being at said first or second level intensity during each predetermined number of minor second direction deflections being determined by the input intensity signal to said intensity control means during each predetermined number of minor second direction deflections.

Claim 28

An image display comprising: a. a cathode ray tube having a control grid for controlling the intensity of the tube electron beam, said cathode ray tube having minor deflection means and major deflection means associated therewith, each of said deflection means having a first direction deflection input and a second direction deflection input; b. means connected to the first direction deflection input of said minor deflection means to produce a repeating minor first direction sweep of the electron beam of said cathode ray tube; c. means connected to the second direction deflection input of said minor deflection means to produce a minor second direction deflection of the electron beam of said cathode ray tube upon completion of each minor first direction sweep; d. means connected to the second direction deflection input of said major deflection means to produce a major second direction deflection of the electron beam of said cathode ray tube each time a predetermined number of minor second direction deflections have been made; e. means connected to the first direction deflection input of said major deflection means to produce a major first direction deflection of the electron beam of said cathode ray tube each time a predetermined number of major second direction deflections have been made; f. intensity control means responsive to intensity input signals; and g. means connecting said intensity control means to the control grid of said cathode ray tube to vary the intensity of the electron beam of said cathode ray tube between a first level intensity and a second level intensity whereby a certain number of said minor first direction sweeps occurring during each predetermined number of minor second direction deflections will be at a first level intensity and the remainder of said minor first direction sweeps occurring during the predetermined number of minor second direction deflections will be at a second level intensity, the number of minor first direction sweeps being at said first or second level intensity during each predetermined number of minor second direction deflections being determined by the input intensity signal to said intensity control means during each predetermined number of minor second direction deflections.

Claim 29

An image display as set forth in claim 16 wherein said cathode ray tube is a dark trace storage tube.