DE2160444C3 - Device for displaying vectors - Google Patents

Description

The invention relates to a device for displaying vectors with X and Y components determined by input signals by deflecting a display element, with an X deflection device for deflecting the an / eigeorgans along the -Y axis and with a ^ deflection device for deflecting the Display member along the K-axis, the ^ deflection device being coupled to an X deflection control circuit. which supplies an analog X-deflection signal with exponential Veilaut on cm from the beginning to the end value changing input signal, the K-deflection device is connected to a V deflection control circuit, which also changes from the beginning to the end value K input signal an analog K- Deflection signal with an exponential curve delivers the Y deflection control circuit and the V deflection control circuit such that the time constant of the λ 'deflection signal is equal to the time constant of the K deflection signal and the exponential deflection signals by controlled changing of the time constants in the sense of straightening to be changed.

A device of the aforementioned type is known from DT-OS 15 24 435. In the known device the controlled changing of the time constants of the exponential deflection signals takes place with the aid of an the inputs of the deflection windings provided s damping resistances, which after applying the respectively from the start to the end value changing input signal are switched on one after the other, un. the Damping of the deflection windings progressively from an overly damped condition to a critical one ίο <* edänipüen condition to change and thus the through make the deflection windings flowing deflection currents linear. The connection of the damping resistors takes place under the control of a binary counter in which one of the difference between the start and end value The binary value corresponding to the input signals is stored and then created by applying Clock signals is gradually reset to zero, with each countdown step of each deflection winding in each case a further damping resistor is switched on, so that the display element is linear with constant speed is deflected. In this known arrangement are therefore time-dependent step-by-step deflection complex control devices (binary counter, clock signal source, means for generating a binary value corresponding to the difference between the start and end value of the deflection signal) is required. . ......

From US-PS 33 33 147 a device is already known for displaying vectors in which the deflection control circuits have a fixed time constant, so that the delivered deflection signal changes exponentially with a fixed time constant. at the representation of a long vector therefore elapses a relatively long period of time before the display element has reached the corresponding endpoint.

It is also already known (IBM Technical Disclosure Bulletin. Vol. 6, No. 12 May 1964 p. 19.20) the Representation "of vectors of appropriate length with a correspondingly adapted time constant. The time constants suitable for the representation of a vector are made prior to the representation of the vector is set and the vector is then displayed with the set time constant.

The invention is based on the object of a

To create device of the type mentioned at the beginning,

which is characterized by its simple structure and with itself relatively long vectors in a very short time can be represented easily and reliably.

This task is solved by a device of the type mentioned at the beginning, which is characterized according to the invention. that upon achievement predetermined values of the exponential deflection voltage the time constants in the two deflection control circuits together dera t are changed so that a steeper exponential curve is achieved.

In the case of the device n; ith of the invention a change in the time constant of the exponential deflection voltages when predetermined values are reached, so that even when displaying Linger vectors, the desired end point is reached within a very short time will.

According to one embodiment of the invention, the X deflection control circuit and the V deflection control circuit each contain an integration amplifier. According to a further embodiment of the invention, the X deflection control circuit and the V deflection control circuit each contain a switching network which stores the end point, soon the X or V deflection signal

a predetermined minimum deviation from the final value reached by the last-mentioned embodiment, a further shortening the time required for displaying a vector sewährleistet, as the t I representation of a vector already canceled, I t before the display element, the final asympto-I j diagram and therefore time-consuming Annäherunf executes at the I ί exact end point.

I I The invention will now be closer to hand

I I drawings explained.

ί [Fig. 1 is a simplified representation of a

II cathode ray tube and associated circuitry;
I {Fig. 2 is a vector representation;

I i Fig.3 is a schematic representation of a

I circuit to explain the idea of the invention;

1 I Fig.4 shows in schematic form in the frame

f the invention, circuitry used with the \ _r compared to F i g. 3 additional components;
% j Fig. 5 shows the switching of the time constant

| * <Inventive device during the presentation of a vector with the t '\.
| h ^; In the figures, similar parts are identical

P ₁ \ denotes reference symbols. The front of the in

^ j Fig. 1 labeled 10 cathode ray tube is with

^ j provided a fluorescent screen 12 on which the between

a? ί two vertical baffles 16 and two horizontal ones

f _v j baffles 18 through electron beam 14

Γ "'hits. The voltage on the vertical pair of plates 16 is

^f j set with control circuits 42 for the V-deflection.

* <I the tension / between the horizontal pair of plates

'■ 18 with corresponding control circuits 44 for the

1 ■ X deflection.

- Electron beam 14 goes from a beam generator

"*; 38 from. Among other things a heating coil 20. a

f cathode 30. a control grid 32, an acceleration 35 V ₂ If) = -

anode 34. and another accelerating anode 36

1 ; includes. The heating coil becomes one with the current

'f AC voltage source 22 heated, while DC

f voltage and control circuits for the beam generator in the

Block 40 are summarized. The structure of the voltage sources 22 and 40 is known per se and does not require any further explanation. The following description refers primarily to the control circuits

; 1 42 and 44 for the Y deflection and X deflection, respectively.

^; i In the in 1 i g. 2 is the vector diagram shown

the starting point of the vector with the coordinates .Yi.

; Vi, denotes, the end point with the coordinates X ₂ ,

' Y ₂ . The l. Luminous spot on display screen 12 of the in V i g. 1

; shown cathode ray tube moves between

j look at the start point and the end point

'running back and forth, drawing the

Vector on. The / wipe the start and end point

; located straight line wiul in the following as a vector ray

designated. The end point of a vector can be the

Represent the starting point of a following vector. ss

If the first luminous spot is to cover a straight path when moving back and forth, the coordinates \ (t) unil \ (t) / ti of each 1 must meet the following conditions!

an operational amplifier A 12. The negative input terminal of this operational amplifier is connected to the grounded resistor R 25. The output terminal of the operational amplifier labeled Vj (t) is connected via resistor R 24 to the negative input terminal and via a further resistor R 23 to the negative input terminal of an integrating amplifier A 3, the positive input terminal of which is grounded. The output of the lntegrierverstärkers A 3 is fed back via capacitor C5 to the negative input terminal and connected through resistor R 17 to the positive input terminal of the operational amplifier A 12th The output signal of the integrating amplifier A 3 appears at the output terminal labeled V ₂ (t).

In the one shown in FIG. In the circuit shown in FIG. 3 , the voltage applied to the input terminal V \ (t) is a step function corresponding to the expression (Vr Vi) or (Xi-X \) in equation (3). The voltage appearing at the output terminal V ₂ (t) represents the expression ( Y2-y (t)) or (X ₂ -x (t)) 'm equation (3). It follows from the fundamentals of the theory of operational amplifiers that the voltage appearing at the output terminal Vi (t) of the operational amplifier A 12 is given by the following equation:

I /, (f) = Ml + R24R25),

where ε denotes the expression for the voltage deviation, which is determined in more detail by equation (6).

The integrating amplifier A 3 combines the voltages V ^ f'J and V ^ rj via the integral equation

jY, (f) df + K ₂₁ ,,

where V20 denotes the initial value of V _2.

If the values of the resistors R 16 and R 17 are the same, the following expression results for the voltage deviation:

Substituting the expression for ε from equation (6) into equation 4 gives the following expression

V, (f), (V ₁ IfI + V ₂ If)) (I + R24 R25). (7)

Using the expression for Vj (t) of equation (7) in equation (5) gives:

V, (fl = - _Ί,. _ "- (I 4- R24IR25) -

Y ₂

vl / 1

ν,

(31

4 I, (ι) df) 4 V ₂₁₁ .

The simplified ι in FIG. The deflection circuit shown in 3 can form a part (K \ stcuerkreises 42 of the Y deflection or of the Steuererkiι ims 44 of the λ deflection. The resistor R 16 connected to the input terminal κ Viffj Equation (8) can be summarized in a single constant, the value of which is given by the resistors R 23, R 24 and R 25 and the capacitor ("5 and denoted by 1 / Γι. Others

Transformation of equation (8) leads to the following integral equation:

~ J K ₁ U) dt - - V ₂ U) - j V ₂ U) Ut + V ₂₀ . s

(9)

V \ is a step function, so that at time zero V _{] 0 can be used} for V] and later V] ₂ for Vi. Applying the Laplace transform results in the solution of equation (9)

WU)

I ₁₁₁ R

110)

If the voltages are reinserted into the expressions for the X and V coordinates, the following equations result for the vertical and horizontal deflection circles:

Y ₂ - yU) (V,

V ₁ Ie

ι,

X ₂ - -v (f) - (A ', A, Ie

(Ha)

(lib)

After dividing equations (Ha) and (11b), equation (3) is obtained. As long as the Time constant Ti for the vertical and horizontal deflection circles has the same value. shorten the Exponential terms and the luminous spot follow a straight line, although the tension in each Deflection circle is a time-dependent exponential function. To generate an accurate vector ray, you must the components of the two deflection circles must be matched to one another accordingly.

In Fig. 4, the arrangement shown schematically in Fig. 3 is shown in detail and the operational amplifier A 12 by a pair of operational amplifiers Ai. A 2 replaced. The arrangement of Figure 4 must be present in both the X and K deflection circuits.

The input connection of the circuit shown in FIG. 4, labeled _{X c} , ng in the example , is connected to two resistors R 16 and R 18, which in turn are connected to feedback resistors R 17 and R 19, respectively. The junction of resistors R 18 and R 19 is connected to suitable control circuits for the time constant, which are shown schematically by block 100 . The connection point of the resistors R 16 and R 17 is connected to the positive input terminal of the operational amplifier A 1. The output of the operational amplifier A 1 is connected to the positive input terminal of the operational amplifier A 2, the output of which is connected to the junction of two resistors R 5 and /? 8. The output terminal of the operational amplifier A 1 is connected to the feedback resistor R 1, which in turn reacts to the negative input terminal of the operational amplifier in the manner shown in FIG. 3 and 4 shown manner is switched back.

The grounded resistor R25 of Fig. 3 is replaced by a pair of resistors R 2 and R 3 , which are optionally effective by gate circuits with the field effect transistors Qb and Q 12 in the circuit. The field effect transistors are controlled by the control circuits 100 for the time constants when the deflection voltages reach certain values. Similarly, the output of operational amplifier A 2 is fed back to the negative input terminal through resistor R5. Resistor R5 is connected to resistors R4, R6 and Rl , which are optionally switched on by gate switching with the field effect transistors Q 18, ζ) 23 and Q 29 controlled by the control circuit 100. Resistor R 23 of FIG. 3 is replaced by resistors R 8, R 10 and R 11 and a potentiometer R 12. These circuit elements are activated by suitable switches, e.g. B. Field effect transistors (? 35, Q 54 and (? 55 switched on and off, with the switch control from block: l 00) .

The parallel b / w. .Series connection of several resistors results in very different net resistance values depending on the interconnection of certain resistors. In the in F i g. 4 replace combinations of the resistors R \ to R \ 2 and the operational amplifiers A 1 and A 2, the resistors R 23, R 24 and R 25 or operational amplifier A 12 of the circuit shown in FIG. The optional operation of the gates constructed with field effect transistors Qb, Q \ 2, Q 18, C> 23 and Q 29 result in different resistance values, which in turn determine the effective time constant of the deflection circuits 42 or 44. As mentioned earlier, the field effect transistors Qb. ς) 12th C? 18. C> 23 and (? 29 through the control circuit 100 for the time constant, when certain deflection voltages are reached.

The point of changing the time constants of the deflection circles during the formation of a vector ray let! referring to FIG. Are illustrate 5, in which the voltage at ι two associated deflection plates of the cathode ray tube at an arbitrary time as well as the desired voltage to the achievement of the end point of the vector beam entered as an exponential function with the initial time constant T]. If the time constant T _{1 were to be maintained} unchanged over the entire length of the vector beam, the time required to achieve a sufficiently small voltage deviation EPE at the end point of the vector beam would be inadmissibly long, as can be seen from the dashed extension of the initial curve in FIG. 5 can be seen. At a certain th Umschaltparinung V _s , one or more of the field effect transistors Qb. Q \ 2. QM, QTZ or Q 29 actuated so that a new time constant T ₂ becomes effective. The new time constant remains in effect until the next switching point mn of the voltage Vs? is reached, whereupon a new time constant Ti is set.

To simplify the description, FIG. 5 only two switching voltages are given, but the number of possible time constants essentially depends on the number of gates used. The average slope of the time-dependent voltage curve indicates an approximate measure of the speed with which the light spot passes over The screen 12 of the cathode ray tube runs from the start to the end point.

If the in F i g. 5 reaches the range of the permissible voltage deviation EPE , the slope of the curve approaches the value zero and thus an asymptote results on the curve. The inclination representing the writing speed is given by the expression dVzftJ / dt, which is obtained by differentiating equation (5) on both sides:

d Γ ₂ (η -ι

d / "Γ, Λ 23 ''

By monitoring the voltage V ₃ (t) it can be determined when the writing speed has reached the minimum permissible value and when the end point has been reached with the desired accuracy.

As soon as the voltage Vi (t) has reached the minimum permissible value in the described arrangement, the endpoint signal is generated, which closes the circuit of the field effect transistor ζ) 35 and opens that of the field effect transistor ζ) 55. Capacitor C 5 remains charged and the voltage Vi (t) reached is held constant until the next vector is recorded. The end point of a vector that has just been recorded thus becomes the starting point of the next vector.

With the change in the slope of the curve shown in Fig. 5, the writing

speed of the cathode ray at the switching points, which means a change in the intensity of the light spot. As the average slope of the curve, however, during the entire recording of the vector beam within certain limit values remains, the change in luminosity is small and can, for. B. be kept below 10%, what for that is practically imperceptible to the human eye. Suitable feedback signals from the control circuits 100 for the time constant to the DC voltage supply 40 changes the Light intensity can be compensated if necessary.

The arrangement described thus enables a precise display of a vector on the luminescent screen a cathode ray tube with relatively simple means.

For this purpose 2 sheets of drawings 609 683/175

Claims (3)

Patent claims: J. Apparatus for displaying vectors with X and Y components determined by input signals by deflecting a display element, with a ^ deflection device for deflecting the display element along the X axis and mii c.er y deflection device for deflecting the display element along the V-axis, the λ'-deflection device being coupled to an X-deflection control circuit, which supplies an analog X-deflection signal with an exponential curve in response to an input signal changing from the start to the end value, the V-deflection device is connected to a K-deflection control circuit , which also change from the start to the end value from the Y input signal supplies an analog V deflection signal with an exponential curve, the X deflection control circuit and the V deflection control circuit are dimensioned such that the time constant of the X deflection signal is equal to the time constant of the K deflection signal and the exponential deflection signals are controlled by changing them the time constants are changed in the sense of straightening, characterized in that when predetermined values of the exponential deflection voltage are reached, the time constants in the two deflection control circuits are changed jointly in such a way that a steeper exponential curve is achieved. 2. Apparatus according to claim 1, characterized in that the -Y-Ablenksteusrschalt and the V-deflection control circuit each have an integration amplifier contain. 3. Apparatus according to claim 1, characterized in that the X-deflection control circuit and the V-deflection control circuit each have a switching network (C5. Ζ) 54. Q 55), which stores the end point as soon as the X or V deflection signal has reached a predetermined minimum deviation from the end value f £ "P £ yerreichi.