DE2544281A1 - DISPLAY SYSTEM - Google Patents

Description

The invention relates to a display system in which a The display image is generated by modulating signals which are used for point-by-point scanning on a display area are synchronized, wherein the modulated signals are derived in accordance with memory information, which relates to the mapping of the image in the display area and where the position of the image within the display area changes from a reference position defined by the memory information, depending on the control signals supplied.

Such display systems are used in aircraft in which a display for projection on a partial transparent reflector in the pilot's line of sight is generated with the display image against the background

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5973/57 / Ch / Fr

-Z-

1st October 1975

the one seen by the pilot through the windshield Scene is seen. The display is normally done by means of a cathode ray tube, with the display image Includes symbols that are projected onto the partially transparent reflector and are visible here in the pilot's observation field. The symbols displayed give an indication of various factors such as the attitude and the flight path. For example, the symbols include one or more lines that go with it are required to be superimposed with the horizon of the outer scene, regardless of the flight maneuver. One or several horizon lines in the reflector change theirs Inclination and its lateral position as a function of control signals which are generated as a function of Changes in bank and pitch of the aircraft attitude.

In certain circumstances it is desirable to have an advertisement to provide which from a conventional grid or a point-by-point sampling. The generation of the video signals for the generation of the hearing izo nt Ii never or lines should be done in accordance with a stored Information. Here, however, expensive and complicated electronic equipment is required to the necessary inclination and displacement of the line or lines according to the transverse and longitudinal inclination change to be able to display.

The task is to train the display system in such a way that that reduces the need for complicated equipment can be.

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This object is achieved with the means of claim 1.

With the display system according to the invention, the display modulation for any point of the scan of the display area derived by determining the identity of the corresponding point in the reference map or the reference image and then by reading out or some other derivation of the modulation from the stored Information which is applicable to this identified point. The display area goes through point by point a transformation backwards depending on the control signals read in. The signal modulation that is applicable by the scan can therefore be point by point from the stored information can be derived in the same Measure of how the scan progresses. In this way it is not necessary to provide additional storage capacity as would be the case if the point relating to the required notification for point information would be derived by transformation, applied to the reference image information.

The display can be made through a cathode ray tube. However, it is also possible to use a matrix display device to use. When using a cathode ray tube, the modulated signals are conventional Used to modulate the brightness of the screen point by point as it is scanned. The scanning can by means of conventional raster scanning take place in which the line tilt and the image deflection are controlled.

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The display system is described below using an exemplary embodiment explained, the explanation being based on a military aircraft. In the drawings show:

Fig. 1 is a schematic representation of the display

systems;

FIG. 2 those used in the system of FIG

Symbols;

Figure 3 is a raster scan of the display area

and certain relationships in the display system according to Fig. 2 and

Fig. 4 is a schematic representation of the electrical

circuitry for generating video signals as shown in the display Fig. 2 are required.

From Fig. 1 it can be seen that a partially transparent reflector 1 is arranged in front of the pilot in the cockpit of the aircraft in his line of sight 2 through the windshield 3. The flight and destination data are displayed by means of projection onto the reflector 1, which is inclined to the pilot's line of sight 2, so that the pilot sees the display image on the reflector 2 through the windshield 3 against the background of his field of observation. The display is projected from the screen image 4 of a cathode ray tube 5 by means of an optical system 6 which serves to focus the image seen by the pilot essentially into infinity.

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The information displayed includes, as in FIG. 2 shows an analog representation of the flight attitude, which comprises five inclination bars 10 to IA- and a flight vector symbol 15. Oeder Neicj ungsbalken consists of two spaced and aligned lines while the flight vector symbol 15 has the shape of a circle with short has lateral arms. The flight vector symbol 15 stands stationary in the center of the screen 4 of the cathode ray tube 5, so that his image is visible through the reflector 1 in a stationary manner in the pilot's field of vision. The five Inclination bars 10 to IA- move both angularly, however as well as upwards and downwards relative to the symbol 15 in accordance with the inclination or curve position (Lateral inclination) and the longitudinal inclination of the aircraft. The bars 10 to IA- remain parallel to each other and theirs Movement on the screen 4 is determined with respect to the vertical. For this purpose, the aircraft assigns a Gyroscope or other attitude sensor. The middle Line 10 is decisive for the horizontal (pitch angle Zero) and the other four lines 11 to 14 above and below are each determinative for a pitch angle of 30 each. The target information for the on-board weapon system consists of one Cross symbol 16, which moves in the display of the screen 4- so that it is the pilot in his field of observation can see through the windshield 3. This cross symbol 16 indicates a desired one Target line for the on-board weapon system or for individual parts of that. The pilot's task is to orient the aircraft until the symbol 16 is within the Flight vector symbol 15 is located, which means that the flight

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evidenced in one suitable for firing the weapon system Attitude is.

The electrical time base and video signals required to display the flight and sighting data on the screen k are fed to the cathode ray tube 5 from a pulse generator 17. The pulse generator 17 generates a rasterized time base and relevant video signals in accordance with the signals supplied to it from suitable attitude and other sensors 18 and a target computer 19. In this connection it should be mentioned that the display effected by the video signals can contain more information than is shown in FIG. Any further information can be presented in digital and / or analog form. In either case, the information is displayed by brightness modulation η of the display grid of the cathode ray tube, which is generated by the line tilt and image deflection signals supplied from the pulse generator 17 to the deflection system of the tube. The video signals which are required for the different parts of the symbols (10 to 16) are generated separately in the pulse generator 17 and then mixed with one another and in this way arrive at the grid electrode ^ of the cathode ray tube 5. Each signal is derived in accordance with the successive points in time in the time base grid at which an illumination occurs in order to achieve a display of the relevant symbol or the symbol group in a suitable position on the screen 4 ·.

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The video signals, consisting of successive light pulses, required to display the representation of each symbol or a group of symbols, are derived in the pulse generator 17 from stored information which is sufficient for a point-by-point display of the symbol or the group of symbols on the screen k for a given attitude , usually the wing position. Changes in the display due to a change in the attitude of the aircraft are achieved in accordance with the bank and roll angles of the aircraft. At that point in time, the line tilt and the image deflection define the point in the area of the screen 4 at which the cathode ray is directed. By referring to the time base signals, the stored information, and the measured pitch and roll angles, it is possible in this way to generate video signals which are needed to produce a desired display of any flight attitude.

The video signals could also be derived by using the stored information subjected to a transformation is made in accordance with the pitch and pitch angles, so that in this way a point-to-point representation of the symbol or group of symbols in Dependence on the measured attitude is defined. The light pulses would then be derived from a comparison mismatch between this previously defined mapping and the point-to-point step of the cathode ray with the line tilt and the image deflection. Here however, considerable storage capacity is required

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necessary to see the result of the transformation for the Readings point by point in accordance with the timebase signals to hold on.

This is avoided in the system according to the present invention. Here, the video signals are derived for each successive point on the screen k at which the cathode ray is directed in accordance with the progress of the line tilt and the image deflection, the corresponding point is calculated in the mapping of the given flight position. The appropriate light pulse is then output directly from the stored information relative to the zero reference mark. The entire display area is therefore recorded point by point by a transformation, depending on the attitude, in order to determine by comparison with the stored given attitude mapping which points of the display area should light up. The transformation is preferably carried out incrementally.

As can be seen from FIG. 3, the display image on the screen 4- can be viewed as a matrix of elementary regions n _s which are defined by a series of points (x 1, y,). In the horizontal direction these points are each at a distance of ή, χ, and in the vertical direction at a distance of Ay. In the horizontal direction this corresponds to the line tilt deflection, while the vertical direction corresponds to the image deflection. The cathode ray is clocked successively through these points, with the deflection starting at point 0.0 and the cathode ray continuing horizontally and gradually.

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steps by steps Δχ, along line y. = 0. After passing through this line, the cathode ray returns to the y-axis (x, = 0) and steps through the next line, where y, Ay, is greater than before. The jump from ^ x, the line jump by Ayj in every line ir.d, is continued until the entire display area has been swept over.

If every point (x. »Y _ri ) of the area is viewed as a mapping of a point (x, y) of a given attitude image (reference image) after rotating the image by an angle jo around a point (x, y) then applies:

x = x + (χ, -χ) cosei + (y.-y) sinci ρ c dc 'dc'

^y p ^{= y} c

x_ = LXjCos0 + y.sin ^ J + [x - χ cosji »- y si ηψ j

ρ " ^u d ^ψ 'd"

= Lx, sin ^ + y, COS (JiI + Ly + χ sin ^ - y coso j

From these equations it can be seen that for a movement from the point (Xj> y _d ) to a point (x. + Äx.jy.) In the horizontal deflection of the cathode ray, the corresponding movement of the given attitude mapping is determined by:

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x + Δχ = χ + Λχ
ρρ p ^

In this way, η ^ x. in horizontal scanning the new coordinates in the reference flight attitude image obtained by adding ^ x, cosfi to one Value of χ and by subtracting Ax.sin ^ from the value

In a corresponding manner it can be seen that for a movement from the point (x ^> Yj) to a point (x _rf > y ^ + Ay.) In the vertical scan, the corresponding movement in the given flight position is mapped; by:

^X _P ^{+ Ax} _P = ^X p

For an increase by Ay. in the vertical scan, the new coordinates of the reference attitude map are obtained by adding Ay ^ sin ^ to the value χ and Ay , cos |) to the value y.

The principles of the foregoing considerations apply to the generation of the video signals required for display as shown in Fig. 2. Specifically, they apply to the transformation of the rotating symbols to display the bank (angle (j>)) of the aircraft Transformation as required

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before implementation due to a change in pitch is made in accordance with the calculation corresponding linear shifts.

The circuitry within the pulse generator 17 for generating the video signal for displaying the group of La ngs ne ig ungssy Mbole 10 to 14 of Fig. 2 is shown in Fig. 4. The operation will be explained with reference to changes in the cross neig ungswi nkels 6 .

Two arithmetic units 20 and 21, which are used to calculate serving the instantaneous values of χ and y Signals in accordance with these values to one Address memory 22. The memory 22 stores binary information according to the point to point formation of the transverse inclination bar η according to the wing position of the aircraft. A light or display pulse is output from memory to cathode ray tube as a function of whether at the identified address a Storage value one or zero is present, that is, whether the point (x, y) in the reference flight attitude image is light or dark is. Of course it is possible to have more than one piece of information to save at any point. For example, it is possible to save a color information and this to the Cathode ray tube to transmit in case there is it is desirable to send a color image to the pilot, in which the symbols have different colors to have.

Each arithmetic unit 20 and 21 includes four adding circuits 23 to 26 and two registers 27 and 28, the latter being connected to the output of the adder 23 or

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254A281

6973/57 / Ch / Fr - 12 - -1. October 1975

are connected and a return line is provided to the respective adder. The adder 23 of the unit receives from the outside a signal representative of the product of Δχ, (normally constant) and coso, while the unit 21 is supplied with a signal which is representative of -Ax.sinff). On the other hand, the adders 24 · of the units 20 and 21 are supplied from the outside with such signals which are representative of Ay.sin ^ and Δγ , οοβφ . These signals fed to the adders 23 and 2k from the outside are generated by a unit within the generator 17, which generates these incremental signals in accordance with the transverse inclination angle and the increasing change corresponding to Δχ. and Ay the line tilt and image deflection pulses generated. The unit generating the incremental signals calculates the values of sino ¹ and cos0 on the basis of the attitude information given by the sensors 18. This unit outputs the incremental signals in accordance with the advance of the pulses which are supplied to the cathode ray tube 5 and which are generated by a time base generator in the pulse generator.

The registers 27 and 28 of the unit 20 accumulate the Values of the functions (x. + Ax.) Cos ^ and (y, + Ay,) sinji. Those of the unit 21 accumulate the values of the functions - (Xj + Δχ,) sinÄ and (y. + Ay,) cos ^. The sum of the two functions accumulated in each unit 20 and 21 is derived by the adder 25 and the instantaneous values of χ and y for addressing the memory 22 are then derived in the adder 26 of the two units 20 and 21. On the unit 20, the output of the

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6973/57 / Ch / Fr - 13 - October 1, 1975

Adder 25 added by the adder 26 to the calculated one Value of:

χ - χ cosjÄ - y sino .... (1)

ccc ^r

In the unit 21 the output of the adder 25 is added in the adder 26 to the calculated value of:

y + x are - y cos0 .... (2)

cc "c ^r .

Signals in accordance with these calculated values are generated by the units 20 and 21 depending on the inputted values of χ and y and the values of si np and cos0 calculated as described above from the attitude information output from the sensors 18 became.

In the scanning raster, the registers 27 and 28 of both units 20 and 21 are set to zero when the cathode ray is directed to the starting point 0,0. The generated values of χ and y are then equal to the values of the functions (1 and 2). As soon as the cathode ray scans across the screen 4, the value Δχ, co-sji is added to the value χ. At the same time the value Ax. Are subtracted from y, which

d ^τ ρ

takes place in each case via the adders 23 of the units 20 and 21. At the end of each line scan, the registers 27 are set to zero and via the adders 24 of the units 20 and 21 becomes the value χ the value Ay.sina and the value Ay.cosp is added to the value y. At the end of each ■ Image scan registers 27 and 28 are set to zero.

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When the cathode ray travels through the raster scan, becomes its position at successive points in time transferred back to the coordinates point by point (x, y) the jet position in relation to the reference attitude mapping derive. These coordinates are used to address the memory 22, whereby a suitable light information regarding the beam position which is applied to the cathode ray tube 5 is read out.

The memory 22 can store image information which concerns each individual line or other symbol element of an element family in the desired display On the other hand, it can store information that is sufficient is to define only a single line, along with information on the distance and the orientation of a single part of this family. For example, image information relating to a individual line of the family of the longitudinal inclination bar η 10 to 14- are saved together with a suitable one Information regarding the distance (y-distance) of the individual parts of this family, so that the entire fern 11 ie the Bars 10 to 14 can be displayed.

The use of raster scanning and the creation of symbols in accordance with such sampling makes it possible to derive images from a television or infrared camera, combining these images can be with the video signals, which are fed to the tube 5 from the pulse generator 17. Such cameras namely, usually use raster scan and

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the representation of the video signal symbols by means of the same scan has the advantage that any scan conversions, as is usually the case with different scanning systems are required to be avoided. The television or infrared camera, for example, can have the same exterior Capture the scene as the pilot does when he looks in line of sight 2, with the signals derived from the camera can be used on the. Screen 4 an image of the scene which thus appears in the reflector 3 and the actual image that the pilot sees through the windshield sees through, is superimposed. In the case of poor visibility, this can result in a brightening of the observation field can be achieved.

- 16 claims

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Claims (8)

6973/57 / Ch / Fr - 16 - October 1, 1975 Expectations (nzeigesyste m in which a display image is generated is synchronized by modulating signals which are used for point-by-point scanning on a display area the modulated signals are derived in accordance with memory information, which relates to the mapping of the image in the display area and where the position of the Image within the display area changes defined by a reference mapping or position by the Spe icher inf ormat ion, as a function of supplied control signals, characterized in that a transformation is dependent is carried out by the control signals at successive Points of the scan to identify corresponding points of the stored To derive reference mapping or reference position and that the modulated signals are derived in accordance related to the stored information on the points identified in this way. 2. Display system according to claim 1, characterized in that g e k e η η ze It means that a memory storing the information relating to the reference map is selected is given by the successive results of the transformation and this from the stored information emits a sequence of modulated signals as a function of the control signal. - 17 - 609815/0458 6973/57 / Ch / Fr - 17 - October 1, 1975 3. Display system according to claim 1 or 2, characterized in that the transformation is incremental in accordance with the point-wise Scanning takes place. A-. A display system according to any one of claims 1 to 3, wherein the display is made by means of a cathode ray tube, in this way I do not indicate that the modulated Signals control the brightness of the CRT display points. 5. Display system according to one of claims 1 to 4-, characterized geke indicated that the control signals are generated as a function of changes the attitude of the aircraft. 6. A display system according to claim 5, wherein the scan is a raster scan which is defined by a point-by-point line scan, characterized in that the transformation is carried out incrementally as a function of the increments of each coordinate, depending on sin ^ S and cos ^, where i is the transverse tilt angle of the aircraft. 7. Display system according to claim 5 or 6, characterized in that the display image consists of one or more horizontal lines. 8. Display system according to one of claims 5 to 7, characterized It indicates that the display is in line of sight on a semi-transparent screen of the pilot of the aircraft. 6098TS / 0458 Blank page