US3671956A - Display system - Google Patents

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US3671956A
US3671956A US806624A US3671956DA US3671956A US 3671956 A US3671956 A US 3671956A US 806624 A US806624 A US 806624A US 3671956D A US3671956D A US 3671956DA US 3671956 A US3671956 A US 3671956A
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horizontal
screen
circuit
vertical deflection
beams
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Thomas D Kegelman
Peter R Williams
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Computer Optics Inc
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Computer Optics Inc
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G1/00—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data
    • G09G1/20—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data using multi-beam tubes
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G1/00—Control arrangements or circuits, of interest only in connection with cathode-ray tube indicators; General aspects or details, e.g. selection emphasis on particular characters, dashed line or dotted line generation; Preprocessing of data
    • G09G1/04—Deflection circuits ; Constructional details not otherwise provided for
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
    • G09G5/22—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators characterised by the display of characters or indicia using display control signals derived from coded signals representing the characters or indicia, e.g. with a character-code memory
    • G09G5/222—Control of the character-code memory

Definitions

  • ABSTRACT Trafton ArtorneyMorgan, Finnegan, Durham & Pine 57 ABSTRACT A multiple beam alpha-numeric display system wherein a plurality of text lines are formed simultaneously with the top segments of the characters in a text line being formed on a first pass and successively lower segments being formed in subsequent passes.
  • a non linear vertical sweep is used to compress the interline spacing of horizontal traces within a text line and to increase the interline spacing between text lines.
  • the multiple electron beams are oriented to cross one another at the center of the deflection yokes.
  • a stockbroker may have a desk top unit connected to the main computer assembly by telephone lines .so that infonnation such as current price quotations or backgrounddata for a corporation can be requested by means of a keyboard and, the requested data received from the computer can be displayed on a cathode ray tube.
  • Corporate executives can be similarly equipped to obtain up-to-date inventory, sales, or customer data.
  • Instantaneous cathode ray readout is preferable to print-out systems in many cases but, to date, systems capable of producing substantial quantities of data on an instantaneous read-out have not been readily available.
  • the general object of this invention is to provide a moderate cost, high density, display system with negligible distortion.
  • the scanning sequence consists of successive horizontal traces formed by means of an electron beam which gradually moves from the top to the bottom of the display, much the same as in a conventional television scanning pattern.
  • a horizontal line of characters referred to as a text line
  • a horizontal line of characters is formedby a plurality of adjacent horizontal traces, twenty horizontal traces per text line having been ,found to provide excellent character definition.
  • the top segments of each of the characters of atext line are formed during the first pass and successively-lower segments are formed on subsequent passes.
  • a horizontal line is divided up according to the number of characters on the line appearing in successive character slots and each character slot is then, further divided into character increments, twenty four horizontal increments per character having been found to produce excellent character definition.
  • the system is arranged to operate at conventional television scanning rates so that maximum use can be made of the low cost, highly developed television components.
  • Systems operating at higher scanning rates require custom designed and custom built components which are considerably more costly not only because of their custom nature but also because the cost of components generally tends to increase as a cube function according to the increases in the operating frequencies and bandwidth.
  • a conventional television scanning pattern there are a total of 525 horizontal lines (500 usable lines) and a complete frame, consisting of two interlaced display fields, is produced 30 times per second. Successive horizontal traces occur at a rate of 15.75 kilohertz and each horizontal trace has a duration of approximately 64 micro-seconds of which 50-55 micro-seconds is usable.
  • each text line consists of I characters and, therefore, successive characters formed in a horizontal trace occur at a rate of approximately 2 megahertz.
  • Control circuitry operating at a 2 megahertz rate is commercially available at moderate cost.
  • Each character is further broken down into as many as 24 horizontal increments and if on-off control of the electron'beam were to be achieved in conventional fashion, the control logic would have to operate at a rate higher than 40 megahertz.
  • the character generation logic works in combination with a delay line to achieve the desired incremental control functions without resorting to unduly high operating frequencies.
  • the scanning pattern includes 500 usable lines and 20 lines are used per text line, there is a total possibility of 25 text lines which, at characters per text line, provides a total display capability of 2,500 characters. This can be achieved if the need for blank lines between text lines is eliminated.
  • a non-linear vertical sweep is utilized to compress the interline spacing between horizontal traces within the text lines and to increase the interline spacing between the text lines.
  • character definition is a function of the number of horizontal traces per text line and the number of horizontal increments per character. As a result, reducing the interline spacing reduces the size of the character and increases the number of characters which can be displayed, but this does not sacrifice the character definition.
  • the number ,of available characters can be further substantially increased without sacrificing character definition or increasing the operating frequency or bandwidth of the system through the use of a unique multiple beam scanning arrangement.
  • a two beam system would increase the number of available display characters from 2,500 to 5,000 and a three beam system would increase the number to 7,500.
  • the transverse displacement between the individual beams is minimized at the point where the beams pass through the deflection yokes. If the beams are arranged to cross one another approximately at the center of the deflection yokes, the transverse displacement is substantially eliminated.
  • the angular displacement of the beam is less critical than the transverse displacement as far as display distortion is concerned.
  • the angular displacement is minimized by arranging the beams to provide adjacent text lines of the display. Since adjacent text lines of the display are formed by different beams, any distortion created by the multiple beam system does not occur within a text line where it would be noticable and disturbing to the viewer, but instead occurs between text lines where it is generally not noticed.
  • the vertical sweep for the multiple beam system is nonlinear such that the interline spacing of horizontal traces in a text line is compressed into a fraction of the space which would otherwise be occupied by a text line.
  • the first three text lines are formed simultaneously and then the vertical deflection circuitry drops the three beams down to form the next group of text lines, etc.
  • FIG. 6 is a block diagram illustrating the overall control logic for the system
  • FIG. 7 is a schematic diagram of the character generation logic and related circuits utilized in the formation of the letter as illustrated in FIGS. 4 and and FIG. 8 illustrates the manner in which the even and odd fields are interlaced.
  • FIG. 1 For a three gun cathode ray system using a tube generally as shown in FIG. 2.
  • the cathode ray tube includes an evacuated glass envelope 1 having a phosphor coated surface 2 inside the tube at the enlarged viewing end 3.
  • the electron guns designated A, B and C, respectively, are located within the tube at the end opposite the screen.
  • the three guns are vertically aligned and oriented so that the respective beams cross at point 5 in the center of the vertical and horizontal deflection yokes 4.
  • the vertical orientation of the guns is such that trace A produced by gun A forms the first text line on the screen, while trace B from electron gun B forms the second text line and trace C from electron gun C forms the third text line, as indicated in FIG. 1.
  • trace A, B and C are actually quite close together, the actual spacing corresponding to the relative spacing of adjacent text lines.
  • each text line consists of twenty successive horizontal traces.
  • the upper 16 traces are used in the formation of upper case letters and numerals, and the lower four lines are utilized to form the stems of lower case letters such as f, g, j, p, q and y.
  • the horizontal sweep frequency is 15.75 kilohertz and, therefore, the time allocated for a horizontal trace is 64 microseconds.
  • the control logic for the system divides the horizontal sweep into 128 character slots and, hence, the individual characters appear at a rate of 2.016 megahertz. It is necessary to provide time for return of the electron beam from left to right following each horizontal sweep and therefore only approximately 100 of the 128 characters are actually used.
  • the vertical deflection signal drops all three beams simultaneously to a position where they form the second text block likewise consisting of three text lines.
  • Successive text blocks are then formed in similar fashion. Since there are twenty horizontal traces per text line and a total of 525 horizontal traces forming a complete frame for each gun, there is a total possibility of 26 text blocks. However, in order to provide sufficient time for vertical retrace of the electron beams, at least one of the text blocks would be lost.
  • a complete frame consisting of 525 lines per electron gun is provided 30 times per second.
  • all of the odd lines are provided first to form an odd field and then all of the even lines are formed to provide an even field.
  • Each field consists of 262.5 lines and a vertical scan from top to bottom of the screen occurs at a rate of 60 times per second.
  • FIG. 8 The manner in which the interlace is achieved is shown generally in FIG. 8, which for simplicity only shows the scanning pattern for one of the beams.
  • the first line begins in the upper left corner and moves to the right under control of the horizontal sweep and also moves downwardly slightly under influence of the vertical sweep.
  • Successive parallel lines 2-262 are then formed gradually moving down the screen, these being referred to as odd lines of the odd field even though numbered consecutively in FIG. 8.
  • Line 263 is split between the bottom and top of the scanning pattern. In other words, line 263 reaches the bottom of the pattern half way through the horizontal trace, at which time the vertical sweep circuit returns the beam to the top pattern.
  • the second half of line 263 therefore is located just above the right portion of line 1.
  • the next line, line 264 is midway between lines 1 and 2.
  • the first text line (following the line numbering system in FIG. 8) would consist of lines 1-10 of the odd field and lines 264-273 of the even field.
  • the vertical sweep signal is shown in FIG. 3A having a fundamental frequency of 60 hertz and being in the form of a linear ramp signal repeatedly going from negative to positive.
  • the 60 hertz fundamental frequency corresponds exactly to the formation of 262.5 horizontal traces on the screen.
  • Superimposed upon the vertical sweep signal is a diddle sweep signal as shown in FIG. 3B.
  • the diddle sweep is a linear ramp signal, going repeatedly from positive to negative.
  • the period of each ramp signal corresponds exactly to the time required for the formation of 10 horizontal traces, this being the horizontal traces of a text line formed during either the odd or even field.
  • the diddle sweep is synchronized with the formation of the text lines and the period of each ramp signal is therefore 640 microseconds.
  • 3C is to reduce the slope of the vertical sweep for the duration of each text line.
  • the amplitude of the diddle sweep signal is adjusted to reduce the slope by somewhat more than a factor of three to thereby compress the horizontal traces making up a text line into a space somewhat less than a third of that otherwise occupied.
  • the number of horizontal traces making up a text line remains the same and, therefore, even though the character becomes smaller, there is no material sacrifice in character definition.
  • FIGS. 4 and 5 The manner in which the individual characters are produced is illustrated in FIGS. 4 and 5.
  • the capital letter 0" is formed on a grid consisting of 16 vertically separated traces designated Y -Y with each horizontal trace broken into twenty four horizontal increments designated X,-X
  • the electrical signals applied to the grid of the electron gun are shown in FIG. 5 and the resulting visible display is shown in FIG. 4.
  • the electron gun is ofi during increments X to X is on during increments X to X and is off during increments X to K
  • the result is a visible segment a as shown in FIG. 4.
  • the beam is off during increments X,-X X and X X but is on during increments X -X and X -X to provide the segments b shown in FIG. 4.
  • the beam is off during segments X X X X, X ,X and is on during segments X X and X -X to provide the segments c shown in Hg. 4.
  • the electron beam is off during segments X,X X X,-,, X -X and is on during segments X,-X-, and X -X to provide the segments d shown in FIG. 4.
  • the electron beam is off during segments X,-X X -X and X -X and is on during segments X -,-X and X -X to provide the segments e shown in FIG. 4.
  • the beam is off during segments X,, X X and X to provide the sections f shown in FIG. 4.
  • Sections g, h, i, j and k in FIG. 4 are formed respectively during the 12th through 16th horizontal traces Y -Y these segments being formed in a fashion similar to the formation of sections c, d, c, b and a respectively.
  • FIG. 6 The control system for achieving a display as shown in FIGS. 1 and 4 is shown in block diagram form in FIG. 6.
  • the timing for the entire system is controlled by a clock pulse source 20 operating at a frequency of 2.016 megahertz, this being the rate at which the segments of successive characters are produced during a horizontal trace.
  • the output of clock 20 passes through a six stage binary counter 21 to reduce the frequency to 31.5 kilohertz and then passes through a binary stage 22 to produce a 15.75 kilohertz signal, the latter being used to control the horizontal sweep and related functions.
  • the 31.5 kilohertz signal from counter 21 is supplied to a ten stage binery counter 23 which, in turn, is coupled to logic circuits 24 and 25 which detect the 520th and 525th counts respectively.
  • the 525th count corresponds exactly to 262.5 horizontal lines and provides the control signal for the vertical drive at the 60 hertz rate.
  • the output signal from circuit 25 is used to reset counter 23 upon occurrence of the 525th count.
  • the 15.75 kilohertz signal from counter 22 is supplied to a horizontal drive circuit 27 which provides a drive pulse for triggering successive linear ramp signals by means of a horizontal sweep circuit 28 which, in turn, drives a horizontal deflection amplifier 29.
  • the 60 hertz signal developed by logic circuit 25 is supplied to a vertical drive circuit 27 which provides the pulses for triggering a vertical sweep circuit 38.
  • the output of the vertical sweep circuit is supplied to a vertical deflection amplifier 39 where it is combined with a diddle sweep signal.
  • the incoming data for the system is stored in a circulating memory 30 which consists of a delay line in series with an amplifier to form a closed circulating loop. Also included in the circulating memory is control logic for organizing the received data for proper location within the circulating memory and address logic for designating the various stored signal locations.
  • the introduction of data into the memory, or the removal of data from the memory, is controlled by the 2.016 megahertz clock 20.
  • the time delay within the circulating memory is sufficient to provide storage capacity for the characters of the entire display frame, each character being in a six bit code.
  • Registers 31-36 provide temporary storage for data while being used in character generation. Each register has a capability of storing six bit character designations for an entire 128 character text line.
  • the circulating memory 30 is preferably arranged to provide serial transfer of data into the registers which can be achieved by organizing all the data for the text line with the most significant bits first and ending with all the least significant bits.
  • the six individual 128 stage shift registers can be connected in series and the data from the circulating memory passed via AND gate 41 in serial fashion.
  • the six bit designation of the first character of the text line appears on six parallel output lines from the channel 1A register, the parallel output of the register being indicated by the parallel line arrow.
  • These outputs are coupled to character generation logic unit 70 via multiple AND gates 51 capable of gating each of the individual parallel outputs.
  • Advance pulses are supplied to register 31 via AND circuit 61 from clock 20, such that each time an advance pulse is applied the six bits of the next character designation appear at the outputs which are coupled to the character generation logic.
  • the registers are designed so that data can be recirculated within the register as many times as desired.
  • Registers 32 and 33 are similarly constructed and operate in a similar fashion.
  • the registers receive data in serial fashion via AND gates 42, 43 and are coupled to the character generation logic 70 via multiple AND gates 52 and 53, respectively. Advance pulses are received via AND gate 61.
  • Registers 31-33 make up the A channel registers and provide temporary storage for data of an entire text block.
  • the B channel registers 34-36 are also similarly constructed and operate in a similar fashion. They receive data in serial form via AND circuits 44 and 46 and are coupled to the character generation logic via multiple AND circuits 54-56. Advance pulses are supplied from clock 20 at the 2.016 megahertz rate via AND circuit62.
  • the A and B channel registers operate alternatively so that one set of registers can be used to control the character generation logic during formation of a text block, while the other set of registers is receiving data from circulating memory 30.
  • This control over the operation of the A and B channel registers is achieved by means of flip-flop circuit 60.
  • flip-flop circuit 60 When the flip-flop circuit is in the I state, multiple AND circuits 51-53 are enabled thereby coupling the A channel registers to the character generation logic, and AND gate 61 is enabled to permit the advance pulses from clock 20 to pass into registers 31-33.
  • AND circuits 44-46 are enabled so that data can be transferred from the circulating memory into the B channel registers.
  • flip-flop circuit 60 when flip-flop circuit 60 is in the 0 state, advance pulses are supplied to the B channel registers via AND gate 62 and the B channel registers are coupled to the character generation logic via multiple AND circuits 54-56 whereas the circulating memory is coupled to the A channel registers via AND circuits 41-43.
  • the Y-odd and Y-even registers and 81 are each ten stage recirculating shift registers utilized to circulate a single bit which designates the successive horizontal lines of the odd and even fields respectively.
  • register 80 designates the ten successive lines of a text line whereas during formation of the odd field the 10 successive lines of a text line are designated by shift register 81, thereby making up the total of 20 lines per text line.
  • the ten parallel outputs of register 80 are coupled to the character generation logic via multiple AND gates whereas the 10 individual outputs of register 81 are similarly coupled to the character generation logic via multiple AND gates 86.
  • Advance pulses are supplied to the advance inputs A" of registers 80 and 81 from counter 22 via AND circuits 83 and 84 respectively.
  • Flip-flop circuit 82 receives a signal from count logic 25 which is applied to the binery input of the flip-flop circuit so that the flip-flop changes state in synchronism with the beginning of each successive field.
  • the flip-flop circuit is in the 1 state during formation of the odd field and therefore AND circuit 83 is enabled to apply the advance pulses to register 80, and multiple AND gates 85 are also enabled thereby coupling the output of register 80 to the character generation logic.
  • Flip-flop circuit 82 is in the 0 state during formation of the even field and in this state flip-flop circuit 82 enables AND circuit 84 so that advance pulses are supplied from counter 22 to register 81 via AND circuit 84, and the flip-flop circuit also enables multiple AND gates 86 to couple the output of register 81 and the character generation logic.
  • Pulses are supplied to the reset inputs R" of registers 80 and 81 to insure that the registers begin the stepping sequence on the initial line during the formation of the first text block.
  • the reset pulse for register 80 is derived from count logic circuit 25 which produces the pulse which triggers the vertical sweep.
  • the register advances in repetitive 10 step sequences during the formation of 26 successive text blocks, i.e. lines 1-260 of the scanning pattern.
  • the counting sequence of registers 81 should commence after a one-half line delay following commencement of the vertical sweep, i.e. at the beginning of line 264 as designated in FIG. 8.
  • the half line delay is provided by flip-flop circuit 90 and associated AND gate 91.
  • the signal developed by count logic circuit 25 signifies commencement of a vertical sweep at the beginning of the even field, and this signal is applied to the set input of flip-flop circuit 90 to place the flip-flop circuit in the 1 state.
  • Flip-flop circuit 90 is connected to condition AND circuit 91 when in the 1 state.
  • the pulse developed by counter 22 passes through conditioned AND gate 91 to reset register 81.
  • register 81 commences its counting sequence on line 264 and thereafter repeatedly counts in a ten step sequence during formation of the twenty six text blocks of the even field.
  • OR circuit 87 When the circulating bit in either the Y-odd or Y-even registers 80 or 81 returns to the first stage of the register a pulse is developed by means of OR circuit 87 signifying that the lines forming a text block have been completed and the formation of a new text block is about to commence.
  • the output of OR circuit 87 is coupled to the binery input of flip-flop circuit 60 to change the state of the flip-flop circuit so that a different one of the A or B channel registers is coupled to the character generation logic for formation of the next text block.
  • the output of OR circuit 87 is also supplied to circulating memory 30 to initiate transfer ofa new set of data into that one of the A or B channel registers not then connected to the character generation logic.
  • OR circuit 87 is coupled to diddle drive circuit 88 which develops a pulse for triggering a new diddle sweep via circuit 89 so that the diddle sweeps are in exact synchronism with the formation of the successive text blocks.
  • the diddle sweep circuit 89 provides the linear ramp signal as shown in FIG. 3B and the output of the sweep circuit is supplied to amplifier 39 where it is combined with the vertical sweep signal developed by circuit 38.
  • the signal at the output of amplifier 39 is supplied to the vertical deflection coils and corresponds to the signal shown in FIG. 3C.
  • the character generation logic and associated channel gates 71-73 and delay line 74 are described more fully hereinafter in connection with FIG. 7. Basically, the character generation logic receives signals from either the A channel registers 31-33 or the B channel registers 34-36 designating the character (in six bit code) then being formed, and at the same time the character generation logic receives a signal from either register 80 or 81 indicating the particular line of the text block then being formed. In response to these inputs the character generation logic energizes selective ones of 24 output lines per channel according to the on-off control desired for a particular electron gun. If, for example, electron gun A is to form line Y of the letter (see FIGS.
  • the 24 output lines from character generation logic 70 which are coupled to channel one gates 71 are designated X1-X24 (corresponding to the X1-X24 designations in FIGS. 4 and 5) of which lines X8-X17 would be energized for line Y in the formation of the letter 0".
  • the channel one gates include twenty four individual AND gates connected respectively to successive ones of lines Xl-X24 and to 24 successive outputs of a 24 stage delay line 74.
  • the output of the 2.016 megahertz clock 20 is coupled to delay line 74 and the delay line provides 24 successively delayed pulses in the 50 nanosecond interval between successive clock pulses.
  • the successively delayed pulses provided by delay line 74 pass through the AND gates corresponding to energized lines X8-X17 to thereby enable electron gun A to provide the character segment a as shown in FIG. 4.
  • the output of the channel one gates is supplied to an amplifier 75 which, in turn, is coupled to the grid of electron gun A.
  • Registers 32 and 35 in similar fashion operate in combination with the channel two gates 72 and amplifier 76, and registers 33 and 36 operate in conjunction with the channel three gates 73 and amplifier 77.
  • FIG. 7 The character generation circuitry for the system disclosed in FIG. 6 is shown in more detail in FIG. 7. For simplicity, only a portion of the complete character generation logic is shown, namely that portion used in the formation of the capital letter 0 corresponding to the illustrations in FIGS. 4 and 5. However, it is to be understood that a complete set of alpha-numeric characters can be developed according to the concepts illustrated in FIG. 7. Also, for simplification, only the logic for one channel is illustrated. AND gates 101-110 and OR circuit 111 correspond for example, to the channel one gates 71 in FIG. 6, and would be duplicated for other channels.
  • Delay line 74 can be of any suitable design capable of being triggered at a 2.016 megahertz rate and of dividing the approximately 50 nanosecond interval between triggering pulses into 24 successively delayed pulses without significant deterioration of pulse width or amplitude.
  • a suitable delay line is disclosed in co-pending application, Ser. No. 806,472, filed on even date herewith, now U.S. Pat. No. 3,622,809, and incorporated herein by reference.
  • the delay line disclosed in the corresponding application includes a series ofinverting amplifier stages connected in cascade, the pulse passing down the amplifier chain being delayed by the successive turn-on time delays of each successive stage.
  • the amplifier stages are connected to associated AND gates such as AND gates 101-110 in FIG.
  • each of the AND gates 101-110 has two inputs derived from delay line 74 and a third input which is one of the lines X,X from the character generation logic.
  • AND gates 180 and 181 are complementary AND gates which are utilized to determine when the outputs of on of the registers 31-36 designate the letter O.
  • the six bit code for the letter O is, for example 001 l l 1.
  • AND gate 180 is used to detect the presence of the ones and AND gate 181 is used to detect the presence of the zeros.
  • AND circuit 182 is, in turn, coupled to enable AND gates 151-156.
  • the respective outputs of the Y-odd and Y-even registers and 81 are connected to respective inputs of OR circuits 141-146 as designated in FIG. 7.
  • the 10 successive outputs of the Y-odd register are designated Y,, Y Y Y Y Y Y Y Y Y and the 10 successive outputs of the Y-even register 81 are Y Y Y Y Y Y Y Y Y, and Y
  • OR circuits 141-146 are coupled to amplifiers 161-166 respectively, which, in turn, are connected to lines 171-176.
  • lines 172-176 are connected to the X lines designated in FIG. 7 via the OR circuits 121-130.
  • OR circuits 121-130 would also receive similar inputs from character generation logic for other characters. 0, they produce corresponding output signals causing AND circuit 182 to produce an output.
  • AND circuit 182 is, in turn, coupled to enable AND gates 151-156.
  • the respective outputs of the Y-odd and Y-even registers 80 and 81 are connected to respective inputs of OR circuits 141-146 as designated in FIG. 7.
  • the 10 successive outputs of the Y-odd register are designated Y Y Y Y-,, Y,, Y Y Y Y Y and the 10 successive outputs of the Y-even register 81 are Y Y Y Y Y Y Y Y,,,, Y and Y
  • OR circuits 141-146 are coupled to amplifiers 161-166 respectively, which, in turn, are connected to lines 171-176.
  • the next line which would be produced would be the third line Y;,.
  • line Y When line Y is energized a signal is produced on the output of OR circuit 144 which, in turn, energizes line 174.
  • Line 174 energizes lines X -X and X,,-X to provide output pulses on corresponding intervals to thereby develop segments 0 as shown in FIG. 4. Thereafter, the remaining odd lines of the text line are formed in succession. Subsequently, when the even field is being formed, the lines Y Y Y etc. will be energized in succession to thereby complete development of the letter 0"on the viewing screen.
  • the A channel registers 31-33 receive advance pulses from clock 20 advancing the data in these registers so that the 128 character designations of the text line appear at the output of the registers in sequence.
  • a pulse is supplied to delay line 74 which, in turn, develops pulses through channel gates 71-73 to turn on and turn off electron guns A, B and C for appropriate increments during the formation of each successive character.
  • This control is achieved by means of the character generation logic which has activated selective ones of the gates in channel gate circuits 71-73 according to the character designations provided by registers 31-33.
  • the first set of horizontal traces are completed in 64 microseconds at which time the upper segments of all characters in the first three text lines (first text block) have been formed on the screen.
  • the A channel registers 31-33 Upon completion of the first set of horizontal traces, the A channel registers 31-33 have recirculated the data and the data has therefore returned to its initial position with the first character designations of the text lines appearing at the outputs of the registers. Accordingly,the data in the A channel registers is ready for commencement of a second set of horizontal traces.
  • counter 22 provides a pulse which is supplied to horizontal drive circuit 27 to trigger a new horizontal sweep. The same pulse is also applied to register 80 via AND circuit 83 to advance the register to the next horizontal line designation.
  • the next horizontal line designation provided by register 80 is line Y
  • the second set of horizontal traces corresponding to line Y of the first text block is then formed according to the successive character designations under control of A channel registers31-33 as further broken into successive horizontal increments by means of delay line 74, character generation logic 70 and the channel gate circuits 71-73.
  • count logic circuit 25 provides a pulse signifying the completion of 262.5 lines of the scanning pattern, this being the end of the odd field.
  • the pulse from logic circuit 25 is supplied to vertical drive circuit 37 to trigger and a new vertical sweep and to flip-flop circuit 90 to place this circuit in the 1 state.
  • the next pulse provided by counter 22 occurs upon commencement of line 264 which is the uppermost complete line of the even field.
  • the pulse from counter 22 triggers a new horizontal sweep via circuits 27-29, passes through AND circuit 91 to reset register 81, and passes through OR circuit 93 to reset flip-flop circuit 92 to again enable amplifiers 75-77.
  • register 81 When register 81 is reset, its output designates lines Y which is the uppermost line of the first text block in the even field.
  • logic circuit 25 Upon completion of 262.5 lines of the even field, logic circuit 25 again produces a pulse which signifies both the end of the even field and the end of a frame consisting of 525 complete lines. This pulse from logic circuit 25 is applied to the vertical drive circuit 37 to trigger a new vertical sweep and is also applied to reset register 80. The same pulse returns flipflop circuit 82 to the 1 state which, in turn, resets flip-flop circuit 92 via OR circuit 93. Data for the first text block has previously been loaded into A registers 31-33. Thus, the sequence is complete and has returned to the starting point and, therefore, the system automatically commences producing another frame.
  • An instantaneous alpha-numeric visual read-out system comprising a phosphor screen visible to viewers;
  • horizontal and vertical deflection means for controlling the position of said electron beam on said screen
  • a horizontal deflection drive circuit for energizing said horizontal deflection means to obtain repetitive horizontal traces of said electron beam across said screen
  • each text line display including a plurality of successive horizontal traces
  • a vertical deflection drive circuit for energizing said vertical deflection means to compress the interline spacing within a text line and to increase the interline spacing between text lines including circuit means for generating a vertical sweep signal,
  • circuit means for generating a diddle sweep signal with a repetition period corresponding to the number of horizontal traces which occur during a vertical sweep of said vertical sweep signal
  • circuit means for combining said vertical sweep signal and said diddle sweep signal and applying the combined signal to said deflection means.
  • Apparatus according to claim 1 comprising a plurality of electron beams each adapted for scanning said screen, the positions of said beams being controlled by said horizontal and vertical deflection means.
  • An instantaneous alpha-numeric visual read-out system comprising a phosphor screen visible to viewers;
  • horizontal and vertical deflection means for controlling the positions of said beams on said screen, said electron beams being oriented to cross one another substantially at the center of said horizontal and vertical deflection means;
  • a horizontal deflection drive circuit for energizing said horizontal deflection means to obtain repetitive horizontal traces of said beams across said screen
  • a vertical deflection drive circuit for energizing said vertical deflection means to move said beams vertically to achieve the desired interline spacing between horizontal traces.
  • Apparatus according to claim 5 wherein said means providing a plurality of electron beams comprises a plurality of separate electron guns oriented to produce electron beams which cross substantially at the center of said horizontal and vertical deflection means.
  • each of said multi-line text displays is produced by a single one ofsaid electron beams.
  • An instantaneous alpha-numeric read-out system comprising a cathode ray tube including at least one electron beam;
  • a memory for storing coded data designating the characters of a display frame
  • a pair of alternately operable registers coupled to said memory each capable of storing coded data designating characters to be displayed in a text line on said cathode ray tube;
  • a pulse source connected to said alternately operable registers to advance said data in one of said registers for providing successive character designations at a rate controlled by said pulse source while the other of said registers receives data from said memory;
  • circuit means for providing successive horizontal trace designations for traces of said electron beam
  • character generation circuit means operatively connected to said cathode ray tube, said alternately operable registers and said circuit means to control the intensity of said electron beam according to said successive horizontal trace and character designations; horizontal deflection circuit means coupled to said cathode ray tube to control the horizontal position of said electron beam;
  • first counter means connected to said pulse source and operative to produce an output pulse after receiving a predetermined number of pulses from said pulse source
  • said first counter means being connected to said horizontal deflection circuit means to trigger successive horizontal sweeps of said electron beam
  • second counter means coupled to said pulse source and said vertical deflection circuit means to trigger successive vertical sweeps of said electron beam in response to a predetermined number of pulses from said pulse source.
  • Apparatus according to claim wherein the total number of horizontal traces of a display frame is an odd number and wherein said second counter means produces a pulse triggering a new vertical sweep each time one half the total number of horizontal traces of a display frame have been completed to provide two interlaced display fields per display frame.
  • Apparatus according to claim 13 wherein the total number of horizontal traces of a display in 525 and the number of horizontal traces in a display field is 262.5.
  • Apparatus according to claim 10 wherein said alpha-numeric displays appear in successive text lines, each text line including a predetermined number of successive horizontal traces formed by said electron beam; and wherein said circuit means for providing successive horizontal trace designations resets each time said predetermined number of horizontal traces have been designated.
  • said vertical deflection circuit means provides a linear vertical sweep signal; and further comprising a diddle sweep circuit operatively coupled to said vertical deflection circuit means to superimpose a diddle sweep signal upon said vertical sweep signal, said diddle sweep circuit being coupled to said circuit means and operative to initiate anew diddle sweep each time said circuit means is reset.
  • said cathode ray tube includes a plurality of electron beams and wherein the system includes a separate pair of alternately operable registers for storing coded data designating successive characters for each of said electron beams, one register at a time of each of said pairs being advanced by pulses from said pulse source.
  • An instantaneous read-out system comprising:
  • horizontal and vertical deflection means for controlling the position of said electron beam on said screen
  • a horizontal deflection drive circuit for energizing said horizontal deflection means to obtain repetitive horizontal traces of said electron beam across said screen, each horizontal trace being divided into a predetermined number of horizontal increments; storage means for storing coded data designating the characters of a display frame,;
  • a pair of alternately operable registers coupled to said storage means each capable of storing coded data for designating characters of a complete text line display;
  • circuit means coupled to said registers to advance the data in one of said registers in synchronism with the movement of said electron beam during each horizontal trace while the other of said registers is connected to receive data from said storage means;
  • decoding means coupled to the one of said registers being advanced in synchronism with said electron beam for designating selected ones of said horizontal increments for display according to the coded character then designated;
  • An instantaneous alpha-numeric visual read-out system comprising a phosphor screen visible to viewers;
  • horizontal and vertical deflection means for controlling the positions of said beams on said screen, said electron beams being oriented to cross one another substantially at the center of said horizontal and vertical deflection means;
  • a horizontal deflection drive circuit for energizing said horizontal deflection means to obtain repetitive horizontal traces of said beams across said screen
  • each of said multi-line text displays being produced by a single one of said electron beams, and said electron beams simultaneously produce a group of adjacent text lines corresponding to the number of electron beams in the apparatus;
  • a vertical deflection drive circuit for energizing said vertical deflection means to move said beams vertically to achieve the desired interline spacing between horizontal traces.
  • An instantaneous alpha-numeric visual read-out system comprising a phosphor screen visible to viewers;
  • horizontal and vertical deflection means for controlling the positions of said beams on said screen, said electron beams being oriented to cross one another substantially at the center of said horizontal and vertical deflection means;
  • a horizontal deflection drive circuit for energizing said horizontal deflection means to obtain repetitive horizontal traces of said beams across said screen
  • a vertical deflection drive circuit for energizing said vertical deflection means to move said beams vertically to achieve the desired interline spacing between horizontal traces; and wherein said vertical deflection drive circuit so energizes said vertical deflection means that the interline scan within said text lines is less than the interline scan spacing between text lines, and

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Controls And Circuits For Display Device (AREA)
  • Digital Computer Display Output (AREA)
  • Electron Sources, Ion Sources (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)
  • Video Image Reproduction Devices For Color Tv Systems (AREA)
US806624A 1969-03-12 1969-03-12 Display system Expired - Lifetime US3671956A (en)

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US80662469A 1969-03-12 1969-03-12

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US (1) US3671956A (xx)
JP (1) JPS4919926B1 (xx)
BE (1) BE747184A (xx)
CH (1) CH539896A (xx)
DE (1) DE2010936A1 (xx)
FR (1) FR2037939A5 (xx)
GB (3) GB1303181A (xx)
NL (1) NL7003542A (xx)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2399071A1 (fr) * 1977-07-28 1979-02-23 Int Computers Ltd Appareil d'affichage visuel de donnees
US4470042A (en) * 1981-03-06 1984-09-04 Allen-Bradley Company System for displaying graphic and alphanumeric data
US4871949A (en) * 1987-01-23 1989-10-03 Albert Abramson Cathode ray tube
US6807676B1 (en) * 1995-07-14 2004-10-19 General Instrument Corporation Methods of formatting data to maximize the readability and the amount of song identification information displayed on a limited number of lines

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1560553A (en) * 1976-02-20 1980-02-06 Int Computers Ltd Visual display apparatus
DE3630174A1 (de) * 1986-09-04 1988-03-10 Agfa Gevaert Ag Verfahren zum punkt- und zeilenweisen aufbelichten einer kopiervorlage

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3140473A (en) * 1956-12-24 1964-07-07 Ibm Information storage system
US3284663A (en) * 1963-05-17 1966-11-08 Rca Corp Display systems
US3345458A (en) * 1963-10-16 1967-10-03 Rca Corp Digital storage and generation of video signals
US3388391A (en) * 1965-04-07 1968-06-11 Rca Corp Digital storage and generation of video signals
US3400377A (en) * 1965-10-13 1968-09-03 Ibm Character display system
US3423749A (en) * 1966-03-30 1969-01-21 Ibm Character positioning control
US3449620A (en) * 1965-05-28 1969-06-10 Philips Corp Device for reproducing information on the screen of a cathode-ray tube
US3503063A (en) * 1964-05-07 1970-03-24 Rank Precision Ind Ltd Electric discharge tubes

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3140473A (en) * 1956-12-24 1964-07-07 Ibm Information storage system
US3284663A (en) * 1963-05-17 1966-11-08 Rca Corp Display systems
US3345458A (en) * 1963-10-16 1967-10-03 Rca Corp Digital storage and generation of video signals
US3503063A (en) * 1964-05-07 1970-03-24 Rank Precision Ind Ltd Electric discharge tubes
US3388391A (en) * 1965-04-07 1968-06-11 Rca Corp Digital storage and generation of video signals
US3449620A (en) * 1965-05-28 1969-06-10 Philips Corp Device for reproducing information on the screen of a cathode-ray tube
US3400377A (en) * 1965-10-13 1968-09-03 Ibm Character display system
US3423749A (en) * 1966-03-30 1969-01-21 Ibm Character positioning control

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2399071A1 (fr) * 1977-07-28 1979-02-23 Int Computers Ltd Appareil d'affichage visuel de donnees
US4470042A (en) * 1981-03-06 1984-09-04 Allen-Bradley Company System for displaying graphic and alphanumeric data
US4871949A (en) * 1987-01-23 1989-10-03 Albert Abramson Cathode ray tube
US6807676B1 (en) * 1995-07-14 2004-10-19 General Instrument Corporation Methods of formatting data to maximize the readability and the amount of song identification information displayed on a limited number of lines

Also Published As

Publication number Publication date
GB1303184A (xx) 1973-01-17
JPS4919926B1 (xx) 1974-05-21
GB1303183A (xx) 1973-01-17
NL7003542A (xx) 1970-09-15
DE2010936A1 (de) 1970-09-24
BE747184A (fr) 1970-08-17
CH539896A (fr) 1973-07-31
FR2037939A5 (xx) 1970-12-31
GB1303181A (xx) 1973-01-17

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