Digital line graphics control on range scalable radar crt display

Claim 2

In a cathode-ray tube display system having digital means for deflection of an electron beam in said tube, said digital deflection means including a deflection control unit for storing a number inversely proportional to the range of a radar sweep to be displayed and range counting means for counting a number of clock pulses equal to said stored number to control said deflection means in displaying a radar sweep, an improvement comprised of means for selecting the frequency of said clock pulses to be inversely proportional to said range and directly proportional to said number, thereby causing the displayed range to be a function of range scale, range and azimuth detecting means for detecting predetermined counts of clock pulses in said range counting means, and means for intensifying said electron beam during said predetermined counts, thereby intensifying said radar sweep displayed along one or more predetermined segments of the same lengths and positions for any range scale selected through coordinated selection of the number stored in said range counting means and selection of said clock pulse frequency.

Claim 3

Apparatus as defined in claim 1 wherein said clock frequencies are generated by a binary counter having at least n cascaded stages, where n is the number of range scales from which selection is made, and the n range scales are from 2*m miles through 2n 1m miles, a source of clock pulses at a fixed frequency counted by said binary counter, and means for selectively gating out from the successive stages 1 through n for the respective range scales 2*m through 2n 1m miles as selected.

Claim 4

Apparatus as defined in claim 2 wherein said range counting means is a binary counter and said number stored in said range counting means is selected to be 2p o through 2p (n 1) for respective range scales 2*m through 2n 1m, where p is an arbitrary whole integer selected to yield a maximum count for the greatest range scale that produces the minimum resolution desired in said range sweep.

Claim 5

Apparatus as defined in claim 3 wherein said range counting means is a sweep range counter into which is entered the maximum sweep range count of the range selected for display, and wherein said integer p is selected to yield a maximum count of 2n 1m for the maximum range of 2n 1m.

Claim 6

Apparatus as defined in claim 3 wherein said range counting means is a binary count down counter having p stages and is preset for the respective 2*m through 2n 1m range scales by entering a binary digit 1 in the most significant pth stage for the maximum range scale of 2n 1m and in successively lower stages for the successively lower range scales.

Claim 7

Apparatus as defined in claim 5 including means for selecting range sweeps to be intensified by said intensifying means, and means responsive to said radar sweep selecting means for inhibiting said intensifying means during all range sweep displays except the range sweeps selected.

Claim 8

In a radar cathode-ray tube display system having x- and y-axis deflection systems, and having a selectable range scale for all radar video data, apparatus for display of a reference line segment or spaced segments during a predetermined radar range sweep without alteration in segment length, or alteration in spacing between segments, as a function of radar range selection, said apparatus comprised of: means for providing clock pulses at a plurality of different frequencies for different radar ranges to be selected; means for selecting an appropriate one of said clock pulse frequencies for a desired radar range; digital range counting means having a number of stages for counting clock pulses at the frequency selected for timing a sweep of a cathode-ray tube beam for the range selected; means for detecting when said predetermined radar sweep is to take place next; and intensifying means responsive to said last named means and to at least one of said stages of said digital range counting means selected for intensifying said beam during said sweep for at least one segment of said sweep, where the segment intensification is determined by the stage or stages selected from said counter, whereby segment intensification occurs for the same segment length or lengths with constant spacing for any radar scale selected.

Claim 9

In a radar cathode-ray tube display system having x- and y-axis deflection systems, and having a selectable range scale for all radar video data, apparatus for display of a reference line segment or spaced segments during a predetermined radar range sweep without alteration in segment length, or alteration in spacing between segments, as a function of radar range selection, said apparatus comprised of: means for providing clock pulses at a plurality of different frequencies for different radar ranges to be selected; means for selecting an appropriate one of said clock pulse frequencies for a desired radar range; digital range counting means having a number of stages for counting clock pulses at the frequency selected for timing a sweep of a cathode-ray tube beam for the range selected; means for detecting when said predetermined radar sweep is to take place next; and intensifying means responsive to said last named means and to at least one of said stages of said digital range counting means selected for intensifying said beam during said sweep for at least one segment of said sweep, where the segment intensification is determined by the stage or stages selected from said counter, whereby segment intensification occurs for the same segment length or lengths with constant spacing for any radar scale selected.

Claim 10

Apparatus as defined in claim 7 wherein said range counting means is a count-down counter preset for each range sweep to a number inversely proportional to the range of a range sweep to be displayed as selected for a desired range scale.

Claim 11

Apparatus as defined in claim 8 wherein said clock pulse frequencies are generated by a binary counter having at least n cascaded stages, where n is the number of range scales from which selection is made, and the n range scales are from 2*m miles through 2n 1m miles, a source of clock pulses at a fixed frequency counted by said binary counter, and means for selectively gating out from the successive stages 1 through n for the respective range scales 2*m through 2n 1m miles as selected.

Claim 12

Apparatus as defined in claim 9 wherein said range counting means is a binary counter and said number stored in said range counting means is selected to be 2p o through 2p (n 1) for respective range scales 2*m through 2n 1m, where p is an arbitrary whole integer selected to yield a maximum count for the greatest range scale that produces the minimum resolution desired in said range sweep.

Claim 13

Apparatus as defined in claim 10 wherein said range counting means is a sweep range counter into which is entered the maximum sweep range count of the range selected for display, and wherein said integer P is selected to yield a maximum count of 2n 1m for the maximum range of 2n 1m.

Claim 14

Apparatus as defined in claim 11 including means for selecting range sweeps to be intensified by said intensifying means, and means responsive to said radar sweep selecting means for inhibiting said intensifying means during all range sweep displays except the range sweeps selected.

Claim 15

Apparatus as stated in claim 7, wherein means for detecting when said predetermined radar sweep is to take place next, comprises in combination: a comparator for comparing azimuth with heading; a first flip-flop circuit responsive to output from the comparator and to the means for providing clock pulses; a gate responsive to output from the first flip-flop circuit and to the means for providing clock pulses for providing setting capability for the next of the clock pulses; and a second and third flip-flop circuit, the second circuit being responsive to output of the gate and to the means for providing clock pulses for enabling the third circuit, and the third circuit being responsive to the second circuit for controlling intensity of the sweep.