DE1936051C3 - Process for recording line drawings on the screen of an electron beam tube and circuit arrangement for carrying out the process - Google Patents

Description

The invention relates to a method for recording line drawings on the screen of a Electron beam tube, the coordinates of individual points on the lines of the drawing with different large distances are given and with straight connecting lines between the points Lines are produced, which are approximated to the line drawings and where from the Differences in the coordinates of neighboring points differential voltages can be derived.

An electron beam tube is often used to display information calculated by computer used. Most of the time, the representations are a limited number of symbols that are Numbers, letters and characters, their recording data in an electronic memory of the recording device or in the computer. The data consist of binary numbers of the

ijioordinaten for the Por "k / nicrung on the image desired, as little data and storage space J screen and does not meet from bmärkodierten figures as an indication of claiming. iJJflgenstücke the individual image lines that make the An important requirement is. The _£. ' Each piece of bikini line is made of line width and must be even over the entire length of the line IT to a whole multiple of a small piece so that it is a satisfactory! This uniformity II: ... of the eye lies. The symbols therefore have raster - there is a very great difficulty, namely the ^"r " structure. The data of the symbols are stored in memories due to the very large differences in the lengths of the addresses. With the sections and the recording times, you do not control this address being called up by the computer. Line width is reached. Two errors occur.

Often one not only wants symbols, but also Record "line drawings", these are not constant between the line points, of lines of the same line width and any The line segments then appear like commas after Form existing drawings. Take 15 thickened one side as an example. Second is also the brightness a weather map, which apart from the symbols and the entire line of lines through the different meteorological signs also lirüenzzüge different Contains shapes such as coastline and iso-lines. uniform. The visual impression of the line is Devices that record soft weather maps are so bad.

called "plotter". In scientific computers, too, it is already known that when displaying computer calculations, functions of characters consisting of 1 gates and in which it is expedient to write the same time with the help of the plotter are automatically and immediately visible as curves recorded and intensity control of the electron beam can be fixed photographically for evaluation. men. Because of the fact that with the deflection by means of digital / the representation of such curves takes place on analog converters from the difference coordinate currents known simple way by adding rows of points. are formed, which are recorded side by side on critically damped Ab narrowing, so that the coils are switched, results in a coherent closed line signal of the course of an increasing function for aas deflection Auce. This perceives. This type of recording has, however, signal is then differentiated, amplified and has the disadvantage that a large number of points must be recorded 30 pulse shaper to the control grid of the cathode ray. Each point must be fed through an X and tube, whereby a substantially equal to a y coordinate be determined, which is generated in many single-shaped intensities. This method is calculated and possibly saved by the circuitry effort relatively simple, must be. the accuracy achieved in the constancy of the

In order to reduce this large amount of data, 35 brightness is used but for purposes where an exact In an improved recording method, one involves recording line drawings on film material Instead of dots, small lines with fixed lengths. is made, by far not sufficient. One left a certain number of line units. The present invention is therefore the task

with different angles of inclination. Based on a method for the intensity control of the to indicate rows of many of these lines of corresponding electron beam, through which a constant Inclination in any order and amount is approach- brightness of the electron beam is achieved while tion to the specified curve. the time to deflect a beam from a point to the

But here one is forced to a compromise. is equal to others.

If the line is drawn with a few line units, the invention achieves this in that the Uitte-

recorded longer, one needs 45 marginal voltages (A χ and Δ γ) ., timezanngenerators little information and storage space, but receives control, which during the same time intervals into a square, jagged and unsightly line of lines. If the lines are small enough to provide this post-horizontal and vertical deflection, the proportion of which is improved, the steepness of the slope increases proportionally to the differential voltages, the amount of data that is to be created to be addressed increases to the same extent that the amounts of the D.fferenz voltage is to be saved and saved at the same time. gen squared, the results added, the sum

A favorable recording method is to be square rooted and after passing through a non-A minimum number of points on the linearitäter between control voltage beam current and trace in different sizes and suitable overall brightness compensating Korrerturgliedcs set to Inwählten intervals and these points 55 tensitätssteuerung ^d e ^s _u ^{E] ect} . ^r .?, ^nenstr . ^Ahls _T ^d ^ "i · _m " _be connected to one another by straight lines. It is an advantageous further development of the

arises as To (Ay Ax and) gebildu m and achieve the best possible approximation differential voltages tion is an arc through which the target is the fact that ^d \ ^{S} 'mme} / "V \ ä? nH rn curve is approximated., must be multiplied by a factor (r, and r.) in curve segments we, Jen, dal small radii of curvature many points close to the values of both ^ ¹ ^ ⁸ »« "™ ^""JJS ₈ ^. be present, in curved pieces with and after passing a .K; orrecting the radius of curvature too large, fewer points are required - compensation for the non-linear elements, and with straight pieces they only need a beam pipe to control the intensity of the beam at the beginning and at the ground to be. That serve so. w.-n ,,, * H _n R di

The line drawings are effective despite the very 6 ₅ Furthermore, it is bes ° ^^^ ' _O % IJ _Z different point spacings in the line management sum and the amount, the difference de difference smooth. They satisfy the stresses (Ax : and Δy) formed with J * «™ requirements for accuracy with _{just a few points and satisfy the factor (r x} and K ₁ ) multiplied and a summation

that the amount of the difference between the F i g. 3 graphical explanations for an approximation

Differential voltages and those with another to carry out the process,

Factor (Z) multiplied sum of the differential voltage F i g. 4 a circuit arrangement for DurcMüh-

voltages are subtracted from each other and the thereby tion of this approximation,

resulting difference with a further factor (K ₈ ) s F i g. 5 graphic explanations for one more

multiplied and unipolar to further inputs of the approximation for carrying out the invention,

Summer is performed and that the output F i g. 6 a circuit arrangement for implementing

the total voltage occurring after this extended approximation.

Passing the correction element to compensate for the recording of any representations

Nonlinearity of the cathode ray tube to the inten- io the screen of a cathode ray tube happens

sität control of the beam is used. in a conventional way by adding one to a point

It can preferably be provided that one electron beam is bundled in two orthogonal

Distances between neighboring points on the line string coordinate directions, preferably

evaluating circuit when crossing a horizontal (jc-direction) and vertical (y-direction)

or several specified step values the voltage), deflected and thereby more or less bright

voltage values Δ χ and Δγ is keyed by one or more or even dark. By specifying a

Factors reduced and the time intervals for the coordinate pairs χ and γ is the position of a

Deflection of the electron beam by the same factor point on the screen and determined by

enlarged, so that in all positions of the circuit deflection currents or voltages, which this coordinate

Line segments of the same brightness are recorded, assigned to ao nata, controllable.

A circuit arrangement for carrying out the target a certain point on the screen procedure is characterized by a common clock for the sawtooth generators controlled by a computer or a memory, this is done by the numerical values of the function coordinates controlled by the differential voltages χ and γ of the point, which are offered in binary amplifiers to square the difference voltage. The number of digits in these binary quantities, through one to the outputs of the function numbers, depends on the resolution, the more strongly connected adders and through one of the electron beam points on the screen connected to the output of the adder, which should be enough. As a practical example, the following output signal of the adder may be square digits. The usable shield diameter be functional amplifier, which by the non-linearity 30 carries about 210 mm, so that a square field of the electron beam tube compensating correction with the side lengths of Ϊ50 mm can be used. The gate member with an intensity control electrode of the electron beam point has a diameter of electron beam tube is connected. 0.05 mm. In each coordinate direction are then

Another advantageous embodiment of the Er- 3000 positions possible, in the entire field 9 · 10 ^e . To the

finding can consist of the sawtooth 35 specification of the position or the data technology

generators by means of a common clock generator, the usual expression for “addressing” a

and can be switched off that one of the difference points in the field is a 12-digit each for χ and γ

voltages an adder and binary number forming a summation sign are required.

one of the differential voltages a differential signal The F i g.l represents any curve,

(\ ΔΧ - ΛΥ \) forming the first subtractor to which a 40 is to be recorded on the screen.

Rectifier is connected downstream, with the input In order to manage with as little control data as possible,

terminals of a summer are connected, which are a few points P ₁ , P ₁ . ■ .P _n on the curve

Output through which the nonlinearities of the electron selected. The distances are very different

Beam compensating correction element with one and so chosen that straight connecting pieces

Control electrode of the electron beam tube connected between neighboring points (shown in dashed lines)

that is. the closest possible approximation to the target curve

This embodiment can preferably still offer.

The curve piece PfP * 'S * through the coordinates X ₁ , gange (C, C _n ), which via Speff diodes on from y _t for point P _x and x * y _t föf point P _t intended to subtract further! and voltage dividers to _{visibly record the connecting line P 1} -P ₁ , standing correction elements are connected by the electron beam having to travel from P ₁ to P, the subtracters each have a first input with a finite speed and one that is unipolar with the Difference signal correct brightness pass through. (\ Δ Χ-ΔΥ \) of the first subtracter acted The path which is to take the beam is, which is, and by the subtracters each have a negative 55 hypotenuse of the right triangle with the input of the connected to the voltage divider catheti Δ χ and Δγ, where dx = ** - X ₁ and sen, the stress values of which from correction factors is Δγ = y _t -γ _χ

/ _ ZK ₁ \. . . . ,. .. -_,.,. "" _ If the connecting lines between neighboring

(Z, _ ·.) _Exist and the ^^ ^ ^^ g ^ ^ atrfge2efcfmet

are bound. &>, this has the consequence that the drawing-up The invention is very different in the following on the basis of the speed and that the drawings are explained in more detail; it shows the brightness of the point of light or the intensity of the figure. 1 a polygon that has to be controlled by a curve on the electron beam so that all are approximated, line pieces are the same or approximately equally bright airf-Fig. 2 a circuit arrangement for recording 65 are drawn. The jet stream fs is thus - ¹ »of line segments of different lengths in equal times, depending on the abtenkgesctr Speed, and with a regulated speed and regulated jet stream, f) h - E · ^ Δ : c * -f Δγ * · f _Un .

7 8

Here £ is a setting constant and / nn is a straight line 71 through the point Ax = Ay = 1,

tion to correct the nonlinearities between them intersects the ordinate at 0.68.

Control voltage and beam current as well as between the straight line 71 can be determined by adding the straight lines 72

Beam current and point brightness on the screen. and 73 are won. The straight line 72 is through

D'e simulation of the function f) becomes with the help of 5 the equation the structure according to FIG. 2 possible

Biacht. The differential voltages Δ χ and Ay are h) A = r _x {Ax - \ - Ay) applied to terminals 1 and 2 and are connected to

the functional amplifiers 53 and 54, which are illustrated, where r i = 0.5, and the straight line 73

Form squares / 1 x ² and / Iv ² . The result voltage through the equation voltages on lines 55 and 56 are calculated using

of the adder 57 is added, and the sum is square rooted by i) B = r _a | Jx- / ly |, the functional amplifier 59, so that at the output of the line 60 one of the size \ Ax * + Ay pro where r _{a is} equal to lies on the ordinate through the proportional tension. _{This voltage should correspond to the amount r 2} enclosed by the 15 straight lines 71 and 72, namely the beam current of the electron beam tube 22 and thus Hch ~ 0.18.

the brightness of the point of light to be recorded The electronic implementation of the addition of the

steer. So that the proportionality is maintained, both equations h) and i) show the circuit diagram

the control voltage is built up via the correction element according to FIG. 4th

61 = / n "pre-distorted in such a way that the non-linear ao. The voltages Ax

Distortion applied between control voltage and beam and Ay . Ax is sent simultaneously to the adder

current as well as beam current and luminous intensity of the 74, the subtracter 75 and the sawtooth generator 63

Rohres are compensated. This pre-distorted span- passed for the horizontal deflection and A γ to the

voltage reaches the control electrode, second inputs of 74 and 75, as well as the saw

of the pipe. »5 tooth generator 64 for vertical deflection. By doing

Simultaneously with the functional amplifiers 53 and 54 functional element 74, a simple adder, is

verden by / Ix and Ay the sawtooth generators 63 the sum Ax - \ - Ay formed and via line76

and 64 controlled. The slopes of the fed to the summer 77. In the functional

Lines 67 and 68 supplied sawtooth currents are stronger 75 the difference Ax-Ay is formed, the

proportional to the voltages Ax and Ay. The clock 30 via the line 78, the rectifier 79 and the

Generator 65 simultaneously delivers via line 66 to line 80 to the second input of summer 77

both sawtooth generators start and stop pulses. The rectifier 79 has the task of

with always the same intervals. During each inter-difference /1.x -Ay take effect according to their amount

valls will leave a line segment between two neighboring ones.

Written in dots. The deflection currents for the basic 35 Correction of the non-linearity between control positions voltage and brightness of the electron beam tube are added to lines 67 and 68 added up. happens, as already described, with the help of the

This proposed solution that has just been described can use correction amplifier 61

lead to technical difficulties in borderline cases. and 64 supply via lines 67 and 68 the

Is the ratio between the maximum and minimum 40 currents for horizontal and vertical deflection,

possible jet speed is very large, so it is as in the description of FIG. 2 already

difficult to explain the function Π with sufficient detail, uniformly rising (or falling) currents,

ability to replicate. When electronically squaring their rate of change d // df proportional

and in the subsequent root extraction, however, can be to Ax or Ay . The clock generator 65 delivers

residual errors still occur, especially with small 45 via line 66 to the deflection amplifier start

Jet velocities. and Siop pulses with always the same intervals.

The following suggestion avoids this computation. During each interval there is a line segment between

operations are written using an approximation of two adjacent points,

method. If only additive is used, it offers the approximation achieved with the straight line 71

Arithmetic operations with a lower electronic 50 suffice in many cases because you accordingly have the

Effort sufficiently satisfactory results. FoI brightness of the electron beam is controlled unc

lowing considerations lead to the new solution: the eye for density and width fluctuations dei

recorded lines not very sensitive! st

g) It should be V ~ F-ydx * + Ay *. Nevertheless, a demand for better quality can be made

55 approach to the target curve 70 can be met. Instead of de

The constant F is used to normalize the straight line 71 becomes a line consisting of two or more i

tion of the world ₇ ¹ - enclosed With constant Ay Weineren, straight pieces are produced which are al

β y ₂ e 5 «-» ei ivviisuiuiciu ιιγ polygon of the target curve fits the better

grow Ax from 0 to Ax - Ay. V then has the in the greater the number of pieces

F i g. 3 curve shown by curve 70. 60 F i g. Figure 5 shows the improvement using voi

_& in Weins ", value _is J- A, ""A _r MA, - 0. ™ <£ J" · 3g? ZS £ 3 £%

his greatest Ay at Ax = Ay. The curve 70 applies to, for example, Aχ - 0.5 Ay.

Any sizes of Ax and Ay _f where Ax and Ay is the Linienzitg81 / 82, as can be interchanged from the drawing. fig can be seen by adding the * "- ■ ¹ ^ _n 72, $

A straight line 71 is drawn through curve 70, and 85 is obtained, although ei «. jjative as

in such a way that the closest possible approximation to that of the straight line 85 (shown in dotted lines) is suppressed

Curve 70 is reached. For example, it'll be a must. The addition of the straight lines 72 and &

happens in the same way as in FIG. 4 The summands r, (Ax - \ - Δγ) and K ₁ -IAx- Ay \

at the straight lines 72 and 73 was described. For this purpose, lines 76 and 80 are available as electrical

the equation j) of the straight line 85 is to be added. Potentials available. Via the voltage divider

For equation h) the factor r _t = 0.5, for _{a <c} . . _... Z-ff ....

the equation i) if the factor IC ₁ = 0.1 is chosen, 5 «Mer forms the factor ^, the corresponding result is obtained

and j) get the factor K _% = 0.12. These quantities voltage to the second negative input of the sub-

are divided on the ordinate. trahierers 88, at its first entrance via the

The equation for straight line 85 is: Line 80 unipolar the differential voltage \ Ax — Ay \

located. The result voltage on line 89 can be positive

j) C = K _t \ Αγ — 2 Ax \ . be io tive or negative. But only the positive value should

are used according to the left positive

For them it is to be demanded that their values of K ₂ = 0.12 branch of the straight line 85 in F i g. 5. With the help of the blocking at JjC = O decrease with increasing Ax until at diode 90 the negative voltage is blocked. The Ax = 0.5 Δγ the value zero is reached. If the voltage continues to be positive , the sign changes via the line 91 to the increasing Ax value until the summator 77. In order for the straight line 85 to be the correct one at Ax = 1, the value C = —K _t . To maintain this negative slope, this voltage on the branch drawn with one dotted line should not be used. The straight line 85 intersects the factor K _t at Ax = 0.5 Δγ , as is also the case with the factors r, ordinate. The kink is above this point and r or JT _{1 has} occurred. The total voltage of the polygon. ao on the line 60, the correction finally happens-The break point is given by the equation: member 61 and controls in the known way the \ Δχ -Δγ \ beam current of the electron beam ^{tube 22. The Ab k} ) ^z - ~ A _x4 .A _v ' deflection of the beam by means of the deflection device 21

^Ύ happens in the same times through the saw

where Z is an auxiliary variable for determining the straight lines as tooth generators 63 and 64, as already described. 85 is, with which the interchangeability of Ax and Δγ An extension of the circuit to even greater ones is obtained. Any degree of accuracy can be achieved. In the case of our example, it should be Ax = ¹ I ₃ Ay, borrowed. With each kink around which the polygon course _ l- ¹ /, _ _{x /} grows, the number of aggregates 86, ^z ~ 1, 1 / ~~ ' ³ · ³ ° ^{Μ and} 9 ° increases by one each. t) ie factors K ₁ ... K _n and J * . _n . . Furthermore, the values for Z ₁ ... Z _n are advantageously determined for the practical implementation of the operation with graphically? u. For this purpose, a drawing of electronic means is expedient to manufacture the sliding blocks that are opposite to FIG. 5 consequently chungk) to be transformed into: must be expanded. The individual routes of the

Π \ Δχ-Δν \ -Ζ (Αχ + Δν) P = 0 ³⁵ ° ^lv ß ^onzu g ^will be up to the intersection with the

1) \ Δχ Δγ \ Ζ [Δχ + Δγ) ^υ > ordinate extended. The divided on the ordinate where we give the equation of a length at the inflection point, in a corresponding scale, the Ax = ¹ UAy intersecting the zero line values * .... The projections of the inflection points are obtained that are used to realize the straight line 85 the abscissa provide the values for determining Z turns. 40 The factors Z can be used by inserting the positive branch lying through half of the zero line, whereby the relationship obtained from the projection between Δ χ slope of the straight line is chosen so that it goes through and Ay into the Equation k) can be obtained
the point Jx = 0 and C- = Κ _% Δγ goes. A modification should not be mentioned. If the required right branch with negative values becomes too large with the spacing of the points, it is expedient for the electronic implementation by means of diodes 45 to block the setting variables, namely the recording. ,,,, ■. _{iU ( f} ^{time and the} beam current, according to the switching

F, g. 6 shows a Devonian armor switch to switch 2 and 6 in adapted stages;

construction, which explained this on the basis of FIG. 5, criteria for this switchover are the input

improved approximation method realizes tensions Δ χ and Ay rang »" «»

The adders 74, 75, the rectifier 79, furthermore 50. The changeover occurs when the dei is exceeded

the summer 77 and the correction element 61 are distance limits that the intervals sien start

from Fig. 4 known to the sum A + B, which by and stop pulses of the betweenMari

Summing 77 is formed, the equations are so for large ",", * "

to add further straight lines from which the polytime is not disproportionate

gonzug the approximation curve exists. They are C, 55 not too big, Da ™ «».

C ₁ ... C _n . For now we will be satisfied with C; that evaluates and Ay to 'S ^ SSSSH 33

Does an approximation corresponding to Fig. 5 mean one or more?

with only one kink point that the drawing desires, optionally -

(F i g. 5) taken and calculated factors reduced. To the same

"■"'=0.5; K ₁ = 0.1; * = 0.12 and Z - _V , * Ä? ¹ "** '* « *** <** clock intervals

For this purpose 2 sheets of drawings

Claims (7)

Patent claims: 1. Method for recording line drawings on the screen of an electron beam tube, whereby the coordinates of individual points on the lines of the drawing are given with differently large distances, with straight connecting lines between the points of the line drawings producing approximately the same lines and from Differential voltages are derived from the differences in the coordinates of neighboring points, characterized in that the differential voltages (Axuno Δγ) control sawtooth generators, which deliver sawtooth currents for horizontal and vertical deflection during the same time intervals with correct axis allocation, the steepness of which is proportional to the differential voltages »« t, that at the same time the The magnitudes of the difference spawnings are squared, the results are added, the sum is square rooted and, after passing through a correction element (61) that compensates for the non-linearities between control voltage, beam current and brightness, for Intensity control of the electron beam is used. 2. Approximation method in the intensity control for the method according to claim 1, characterized in that the sum and the difference of the Differen7spannungen (Ax and Δγ) are formed and multiplied by a factor (^ ₁ and r ₂ ), that the amounts bc ^: the resulting voltages are added νηά after passing a correction element to compensate for the non-linearity of the electric beam tube to control the intensity of the beam. 3. The method according to claim 2, characterized in that the sum and the amount of the difference between the differential voltages {Δ χ and Δ γ) are formed, multiplied by a factor each (r _x and AT ₁ ) and fed to a summer (77) that the amount of the difference between the differential voltages and the sum of the differential voltages multiplied by a further factor (Z) are subtracted from each other and the resulting difference is multiplied by a further factor (K ₂ ) and sent unipolar to further inputs of the adder (77 ) and that the total voltage occurring at the output of the adder (77) after passing the correction element (61) is used to compensate for the non-linearity of the electron beam tube to control the intensity of the beam. 4. The method according to claim 1 to 3, characterized in that a circuit evaluating the distances between adjacent points on the trace reduces the voltage values Ax and Ay by one or more factors and the time intervals for the deflection of the electron beam when one or more predetermined step values are exceeded enlarged by the same factor, so that line segments of the same brightness are recorded in all positions of the circuit. 5. Circuit arrangement for performing the method according to claim 1 with sawtooth generators controlled by the differential voltages for the X and 7 deflection, characterized by a common clock generator (65) for the toothed tooth generators (63, 64), by FunUians amplifiers (53) controlled by the differential voltages , 54) to square the difference voltages, by an adder (57) connected to the outputs of the functional amplifier (53, 54) and by a further functional amplifier (59) connected to the output of the adder (57) and squareing the output signal of the adder (57) ), which is connected to an intensity control electrode of the electron beam tube through the correction element (61) which compensates for the non-linearity of the electron beam tube. 6. Circuit arrangement for performing the method according to claim 2 with sawtooth generators controlled by the differential voltages for the X and f deflection, characterized in that the sawtooth generators (63), 64) can be switched on and off by a common clock generator (65), that an adder (74), which forms a sum signal from the differential voltages, and a first subtractor (75), which is followed by a rectifier (79j) and which is followed by a rectifier (79j), which forms a differential signal (\ AX-AY \) from the differential voltages, are connected to the input terminals of an adder (77) whose output is connected to a control electrode of the beam tube via the correction element (61) which compensates for the nonlinearities of the electron beam. 7. Circuit arrangement according to claim 6 for carrying out the method according to claim 3, characterized in that the adder (77) has further inputs (C, C _n ) which are connected via blocking diodes to further subtractors (88, 88/1) and voltage dividers ( 86, 86/2) existing correction elements are connected, that the subtractors (88, SSn) each have a first input to which the difference signal (\ A X-AY]) of the first subtractor (75) can be applied in unipolar fashion, and that the Subtractors (88, 88 ″) each have a negative input which is connected to voltage dividers (86, 86/1) whose voltage divider values are derived from correction factors [Z, '- exist and those with the adder 74 are connected.