JPS638475B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a display of the type in which successive elements of a display area of a display device continuously increase in brightness during raster scanning of the area in accordance with the symbology to be displayed. Regarding the system.

In particular, the display system of the present invention is a head-up display system of an aircraft, that is, a display of symbolic symbols generated on a cathode tube screen provides an image of the display against the background of the external scenery through the windshield of the aircraft. , a system adapted to be projected onto a partially transparent reflector in the line of sight of the pilot or other crew members of the aircraft.

The display symbology includes one or more straight lines necessary to maintain levelness in the external view seen through the reflector, regardless of the aircraft's pitch.

For this purpose, the arrangement of one or more of these "horizontal" lines in the display is
In accordance with the control signals that dictate the change in attitude of the aircraft in each case of bank and pitch, it changes during a heel and likewise during a lateral displacement. When raster scanning is used, a change in the angle of slope is usually accompanied by a change in the clarity or sharpness of the associated line, and the greater the degree of sharpness attenuation, the more generally The tilt angle from the example is small.

Phenomena such as the appearance of steps or slanting eyes are commonly experienced, and also slight changes in the angle of inclination immediately disrupt the movement of the linear display and even cause an oscillatory back-and-forth splitting movement. The large increase in the number of straight scans in the raster, together with the corresponding increase in the sharpness with which the display symbology is depicted, acts to reduce the appearance of steps or nicks. .

However, there is usually a standard raster (eg, 625 straight lines) that is used in practice, and there are economic or spatial limitations regarding the amount of information storage and the process that can impart sharpness to the image. Furthermore, the signals for symbolic symbol displays are conveniently and more economically generated using digital technology, so that the configuration of essentially discontinuous elements of symbolic symbol displays can added to the effect.

The display representation of each "horizontal" line is essentially caused by increasing the brightness of successive elements across the screen of a cathode ray tube, for example, and these elements for a non-sloping line are Slanted line displays are associated with each other on successive vertically spaced scan lines of a raster, as opposed to being joined together in one series along a book or more horizontal scan lines. It is made based on the series without.

A first object of the present invention is to use the present invention to achieve an improved display in a display device,
In particular, it is an object of the present invention to provide a display system that can be used to reduce the appearance of steps or indentations when displaying symbolic symbols.

According to one aspect of the invention, the degree of brightness enhancement imparted to each of the separate elements is characterized in that the degree of brightness enhancement imparted to each of the separate elements is varied according to the degree of area occupied by the symbol. Provided with different types of display systems.

According to the invention, a display is generated by selectively brightening successive elements of the display area in relation to a given raster scan while that scan is being performed. By modulating the degree to which the brightness increase is applied, many of the undesirable stair-step phenomena or other visually distracting effects commonly experienced can be eliminated or reduced. It has been recognized that both can be substantially reduced.

More specifically, even when it is desired to ideally increase the brightness of only a part of the elements of any display area depending on the clarity of the symbol signal, the conventional method prior to the present invention does not increase the brightness of the display area. Since it is difficult and expensive to provide a device for increasing the brightness of only a portion of the elements, it has become necessary to sufficiently increase the brightness of all elements in the display area.

However, the present invention allows the degree of brightness or brightness enhancement applied to any such element to easily reach a state close to the ideal state, corresponding to the portion that is ideally sufficiently brightened. It is possible.

The degree of brightness may ideally have a proportional relationship to the area of the element that is sufficiently brightened, but in general there is no relationship that proves visually satisfactory. It will be seen that it is non-linear and can be determined by experiment to be the optimum condition in any particular case.

Although the present invention has been developed as described above with reference to a particular reference for displaying simple straight lines, the present invention nevertheless addresses the undesirable visual effects in other symbolic symbols. It should be understood that this can be applied in a similar manner as in the previous case to reduce the effects of

Furthermore, although the present invention is applicable to display systems in general and may be particularly useful in things such as aircraft head-up display systems, it is not limited to such special uses. Of course.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A display system according to the present invention applied to a military aircraft equipped with a head-up display will be described below with reference to preferred embodiments shown in the drawings.

As shown in FIG. 1, a partially transparent reflecting mirror 1 is
It is provided inside the pilot's cabin of the aircraft, in front of the pilot and within his line of sight 2 through the aircraft's windshield. The display of flight and weapon aiming information is mounted on the reflector 1 which is inclined to the line of sight 2 so that the pilot can see through the windshield 3 the image displayed in the reflector 1 against the background of the outside scenery. is projected on.

The display is projected from the screen 4 of the cathode ray tube 5 by means of an optical system 6 which serves to focus the image seen by the pilot at approximately infinity.

The displayed information consists of five pitch lines numbered 10 through 14 (each separated by two intervals and aligned) and a flight vector symbol 15 (hereinafter referred to as Symbols and descriptions), including a similar representation of the flight position (circular shape with short arms extending sideways).

The flight vector symbol 15 is stationary in the center of the screen 4 of the cathode ray tube 5, so that its image is stationary in the field of view of the pilot through the reflector 1. However, the five pitch lines 10-14 are also visible to the pilot as they move sideways and up and down in response to the banking and pitching movements of the aircraft.

The pitch lines 10 to 14 are parallel to each other, and their movement on the screen 4 takes a horizontal state (zero pitch angle) at the central line 10 and a pitch angle interval of 30 degrees above and below it. as maintained by the other four lines 11 to 14 pointing to the vertical line (eg established by a gyroscope or an attitude sensing device in the aircraft).

Weapon targeting information, on the other hand, can be viewed by the pilot through the windshield against the background of the outside world, as shown in Figure 2. It includes a cross symbol 16 which is moved into the display above the screen 4 to indicate the desired line of aim.

What the pilot should do is change the symbol 16 to
The purpose is to align the aircraft so that it is within flight vector symbol 15 and accordingly suitable for firing the weapon system.

The video signals necessary to generate the electronic time base and flight display and weapon aiming information on the screen are fed by a waveform generator 17 to the cathode ray tubes 5,17. Waveform generator 1
7 provides a raster time axis and, depending on the signals it receives from the appropriate attitude and sensing device 18 and weapon aiming or computer 19, generates the appropriate video signal.

The display provided in the video signal generated at this point and fed into the cathode ray tube is better than that contained in the simplified version shown in FIG. , can encompass a wider variety of information.

Any information may be represented in digital or analog form, or both. However, in each case the information is transmitted to the waveform generator 1
7, a cathode ray tube display is generated by linear and frame time base signals applied to the deflection system of the cathode ray tube - raster intensity modulation is used for display.

The video signals required for the different parts of the lines and symbols 10 to 16 are drawn separately into a waveform generator 17 and then mixed for application to the grid electrodes of the cathode ray tube 5 to form the individual signals. In order to "color" the appropriate symbol or group of symbols at the appropriate position on the screen 4, the brightness increase occurs at successive moments in the time axis raster. have been obtained accordingly.

Consisting of a series of brightening pulses, the video signal required to generate the "color" of each symbol or group of symbols points from point to point symbol or group of symbols in the data flight attitude on screen 4, usually in horizontal wing attitude. From the stored information sufficient for mapping to a waveform generator 17 is provided. Changes in mapping to account for changes in aircraft attitude are made in response to pitch and bang angles of the aircraft. At each moment the straight line and the frame time axis define a point in the area of the display screen 4 at which the beam of the cathode ray tube is directed.

Thus, by reference to the time domain signal, stored information, and measured pitch and bank angles, the necessary video signals are derived to produce the desired mapping for any flight attitude. be able to.

The video signal is derived by calculating each successive point of the screen 4, at which the beam of the cathode ray tube is directed linearly and according to the course of the frame time axis, with a corresponding point in the data flight attitude mapping. .

Direct readout of appropriate brightness boost pulses can also be performed from stored information associated with zero data mapping. Therefore, the entire display area is
The point cloud of the area to be brightened is determined after comparison with the stored data flight attitude mapping, effectively redrawing it point by point through flight attitude dependent transformations. Ru. The above conversion is performed by an appropriate method so as to increase the number one by one.

In FIG. 3, the display image on the screen 4 is a series _of points ( _x The basic domain matrix defined by _d , y _d is shown.

The cathode ray tube beam is continuously scanned through these points, the scanning action starting from the origin (0,0) and keeping y _d equal to 0 (i.e. along the x-axis), Δx _d Think of it as progressing horizontally in increments of .

When the first horizontal scan is completed, the cathode ray tube beam returns to the y-axis (x _d =0) to begin another horizontal scan, but y _d is increased by Δy _d . y _d
is increased by Δy _d at the end of each scan, and this action is repeated until the entire display area is covered.

If each point (x _d , y _d ) in the region is mapped to the point (x _p , y _p ) in the data flight attitude image, after rotating the image by an angle φ around the point (x _c , y _c ), If processed, x _p = x _c + (x _d − x _c ) cosφ + (y _d − y _c ) sinφ y _p = y _c − (x _d − x _c ) sinφ + (y _d − y _c ) cosφ x _p = [x _d cosφ+y _d sinφ] + [x _c −x _c cosφ−y _c sinφ] y _p = [−x _d sinφ+y _d cosφ] + [y _c +x _c sinφ−y _c cosφ] From these formulas , from a point (x _d , y _d ) to a point (x _d + Δx _d , y _d ) in the horizontal scan of the cathode ray beam, the corresponding motion in the data flight attitude map is x _p + Δx It can be seen that it is given by the formula _p = x _p + Δx _d cosφ y _p + Δy _p = y _p −Δx _d sinφ.

Thus, for each increment of horizontal scan Δx _d , the new coordinate in the data attitude map is the value of x _p plus Δx _d cosφ and the value of x _p plus Δx _d
It can be obtained by reducing sinφ.

Similarly, for a motion from point (x _d , y _d ) to point (x _d , y _d +Δy _d ) in a vertical scan, the corresponding motion in the data flight attitude map is x _p +Δx _p =x _p +Δy It can be seen that it is given by the formula _d sinφ y _p +Δy _p =y _p +Δy _d cosφ.

Thus, for each increment of vertical scan Δy _d , the new coordinate in the data attitude map is the value of x _p plus Δy _d sinφ and the value of y _p plus Δy _d cosφ
can be obtained by adding

The principles of the above discussion are applied to the generation of the video signals necessary for the display of FIG.

More particularly, these principles have particular application in connection with changes in symbology in required (angle φ) rotation in connection with the bank of an aircraft.
Changes in translational movement required in conjunction with changes in pitch attitude are added according to the appropriate linear displacement calculations.

Built into the waveform generator 17, the second
The apparatus for generating the video signals necessary for the display of pitch lines 10-14 is shown in FIG. The operation of this device with respect to changes in only the bank angle φ will be described below.

Two calculating units 20 and 21, which serve to calculate the instantaneous values of x _p and y _p , are fed to a memory 22 for addressing signals in accordance with these values. Storage device 22 stores binary information regarding the point-by-point configuration of pitch lines appropriate for the horizontal attitude of the wing, or some other data flight attitude of the aircraft.

Brightness boost pulses flow from the storage device to the cathode ray tube depending on whether a ``1'' or ``0'' is stored at the same address. That is, the points (x _p , y _p ) in the data flight attitude image flow depending on whether they are bright or dark. It is clear that each location can store a lot of information. For example, information regarding color may be stored and transmitted to the cathode ray tube if in any case it is desirable to provide the pilot with color images of symbolic symbols or of different parts thereof that are distinguished from each other by color. I can do that.

Each calculation unit 20 and 21 has 4
It consists of two adders 23 to 26, and each of their two registers 27 and 28 is
It is connected to receive one output of each of adders 23 and 24 and to feed back the contents of the register to that one adder.

Adder 23 of unit 20 receives a signal from outside the unit expressed as the product of Δx _d (usually constant) and cosφ, while adder 23 of unit 21 receives a signal expressed as −Δx _d sinφ. A corresponding signal is applied. Additionally, adders 24 of units 20 and 21 are supplied with signals represented by Δy _d sinφ and Δy _d cosφ, respectively, from outside these units.

Adder 2 in two units 20 and 21
These four externally supplied signals to 3 and 24 are supplied from a unit 30 in the waveform generator 17, as shown in FIG. Waveform generator 17
These incremental signals are generated in response to the incremental variations corresponding to Δx _d and Δy _d of the straight line and frame time axes, respectively, generated by the time axis generating unit 31 of .

The increasing signal generating unit 30 calculates sinφ and the flight attitude information signaled from the detection device 18.
Calculate the value of cosφ and
3, an increasing signal is appropriately emitted in accordance with the progression of the time axis waveform applied from the time axis generating unit 31 to the cathode ray tube 5.

Again, with particular reference to FIG.

Registers 27 and 28 of unit 20 accumulate values x _d cosφ and y _d sinφ, respectively, and registers 27 and 28 of unit 21 accumulate values -x _d sinφ and y _d cosφ, respectively. The sum of the two values accumulated in each unit 20 and 21 is summed by the adder 2 in each unit.
The instantaneous values of x _p and y _p extracted by 5 and addressing the storage device 22 are then led into the adders of the two units 20 and 21.

In unit 20, the output of adder 25 is
The adder 26 adds it to the calculated value x _c −x _c cosφ−y _c sinφ (1).

Also, the output of the adder 25 in the unit 21 is
In the adder 26, it is added to the calculated value y _c +x _c sinφ−y _c cosφ (2).

The signals corresponding to these calculated values are calculated as described above obtained from the settings of the x _c and y _c values and the flight attitude information received from the signal from the detector 18.
Depending on the values of sinφ and cosφ, the unit 30
(FIG. 5) are supplied to units 20 and 21.

When initially scanning a raster with the cathode ray tube beam directed at the origin (0,0), registers 27 and 28 in units 20 and 21 are set to zero.

The values of x _p and y _p generated are then equal to the values of equations (1) and (2), and since the cathode ray tube beam is scanned across the screen 4, the unit 2
0 and 21, the increment Δx _d
cosφ is added to x _p and Δx _d sinφ is subtracted from y _p . At the end of each linear scan, register 27
is set to zero, and the increments Δy _d sinφ in x _p and Δy _d cosφ in y _p are added via adders 24 in units 20 and 21, respectively.
At the end of each frame scan, all registers 27 and 28 are set to zero.

Thus, as the cathode ray tube beam progresses through a raster scan, its position at successive instants can be determined point by point in order to extract the coordinates (x _p , y _p ) of the beam position for data flight attitude mapping. It will be transcribed back. These coordinates are stored in the storage device 22
used to address the
In order to apply it to the cathode ray tube 5 via the lead wire 34,
Appropriate brightness increase information related to the beam position is read out.

One problem experienced with this type of system, and common with raster scan displays of symbolic symbols, is that when they are generally horizontal, they are more precisely
Pitch bar 1 when aligned with raster scan
Lines such as 0 to 14 are clear, but lose clarity when tilted from such alignment.

The display of each line is essentially generated by increasing the brightness of successive elementary areas across the image, whereas in the slanted line these areas are created by increasing the brightness of one or more scans. The slanted lines are illustratively coupled to each other along lines, and the slanted lines are formed by columns separated on successive vertically spaced scan lines of the raster.

If the line L shown in FIG. The lines in the display image are not clear.

The phenomenon of step-like shapes becomes more pronounced as the angle of inclination becomes smaller, and even slight changes in this angle easily cause confusing movements and even oscillatory back-and-forth resolution movements between successive parts of the line display. can be done.

Significantly increasing the number of straight scans in the raster, with a corresponding increase in the clarity of the display symbology, acts to reduce the phenomenon of stepped or notched images. . Although these methods reduce the size of the basic area of brightness enhancement, they substantially increase the amount of image information that needs to be stored and processed during operation.

Furthermore, there are standard rasters that are supposed to be used in practice (eg, 512 or 625 straight lines), and there are economic or spatial limitations on the amount of information storage and processing that can be provided.

Within these limitations, the phenomenon of visible steps or notches limits the brightness increase to certain portions of the basic image area between successive sections of the line display slanted from one scan line. can only be reduced depending on the situation. Such a partial brightness increase cannot be easily achieved, but for the same purpose, an effect similar to it can ideally be achieved by sufficiently increasing the brightness according to the present invention shown in FIG. This is achieved by modulating the brightness of each of the appropriate basic areas, depending on the area affected.

In FIG. 5, the instantaneous values of x _p and y _p calculated by units 20 and 21 are used in the system to address storage device 22 via addressing unit 35.
Storage device 22 stores binary information relating to a 256 x 256 matrix division of pitch bar symbology appropriate to the horizontal flight attitude of the aircraft wing. In this data flight attitude, the pitch bar symbol is parallel to the linear scan within the cathode ray tube image and therefore has a convenient orientation for cutting out the reproduction. .

The information stored in the storage device 22 is 256×256, which is defined by matrix division.
The data of each of the elementary regions related to the brightness within the flight attitude image and a 4-bit word is assigned to each particular point (x _p , y _p ) identified from the calculation units 20 and 21. It is read out from the storage device 22 in connection therewith. However, in this regard, the values of x _p and y _p are calculated by units 20 and 21 as two binary numbers of 11 bits each. The first highest 8 of each of these numbers
Only the signals represented by the bits are selected by unit 35 for addressing storage device 22.

The signals represented by the remaining three lower bits of each calculated number are stored in four fixed storage devices 37 to 4.
0 by the amplification gate unit 36. The four devices 37
40 are supplied with 4 bits, each of which is a 4 bit word, read from storage device 22 via leads 22A to 22D.

Storage device 22 regarding the calculated point (x _p , y _p )
The 4-bit word read from the data flight attitude image relates to the brightness at that point and adjacent points in the data flight attitude image. More specifically, brightness means _{brightness ,} as shown in FIG. The bit read out on lead 22A is indicated by a '1' (correspondingly, '0' means darkness), centered around the identified point (x _p , x _p ). The brightness of a certain basic area A is defined.

The other bit, which is '1' in the illustrated example, sets the brightness of the fundamental region B centered on the next point (x _p +Δx _p , y _p ) along the same data attitude scan line. It is read out on lead 22B for definition. The remaining two bits, which are both '0' in the illustration of this drawing, are the points (x _p , y _p
+Δy _p ) and (x _p +Δx _p , y _p +Δy _p ) and corresponding to regions A and B in the next successive scan line of the data flight attitude image. To define the respective brightnesses of C and D, they are read out through lead wires 22C and 22D.

The fundamental regions within the matrix division of the display screen 4 are generally not accurately mapped to the fundamental regions of the data flight attitude image. The range of deviation from zero by the angle φ, ie, the range of deviation from the data pitch orientation, determines the degree of mismatch. Therefore, the center point (x _d ,
y _d ) typically does not lie exactly above the center point (x _p , y _p ) of the corresponding data flight attitude image.

In this case, when the values of x _p and y _p are both calculated with high analytical power for 11 bits, the 8 bits representing the most significant of each alone confirm the proper center point (x _p , y _p The other three lower bits are proportional to the degree of mismatch.

Thus, as shown in FIG. 8, the eight bits representing the most significant of each number calculated by units 20 and 21 are the points (x) of the display image on screen 4 (FIG. 6). _d , y _d ) and the mapping of a basic region centered on the point (x _p ,
y _p ) Performs an operation that assumes that the basic area A whose center is above is the same.

However, the two words constructed by the last three "underflow" bits of each of these two numbers make use of a more sophisticated analysis function (11 bits rather than 8 bits). In particular, since the areas B, C, and D, which are normally adjacent to the area A, exactly match the area A, the area has the effect of replacing the mapping H' of the area H of the data flight attitude image. Give instructions until.

Therefore, on the basis of this latter, the area H on the display screen 4 can only be mapped within the portion of its mapping H' that remains within the area A.
The brightness of area A is made more appropriate. The remaining part of region H ideally receives the luminance of regions B, C and D, which are superimposed upon them in mapping H'.

Although this kind of differential change in brightness throughout region H is not easily achievable, according to the invention, the brightness weights of region A and each adjacent region B, C and D are This is achieved by adjusting the overall brightness increase of the area H within the display image depending on the installed components.

The weighting utilized in each case depends on the degree of overlap of the relevant regions A, B, C or D and region H'. Two 3-bit "underflow" words give the magnitude of this areal overlap in each case.

The data for every different combination of two 3-bit "underflow" words for every basic region A of the flight attitude and also the appropriate brightness weightings are stored in the fixed storage 37, but for every three Adjacent basic areas (B, C
The corresponding weights for each of and D) are:
They are stored in fixed storage devices 38, 39 and 40, respectively.

If the digit signaled via leads 22A-22D associated with fixed storage devices 37-40 is a '1', then a 4-bit word is signaled from each storage device 37-40 to unit 41. be done. In each case, the particular word signaled is stored in association with the particular combination of two 3-bit words signaled from unit 36 depending on the weighting value.

Words corresponding to the degree of relevance for the appropriate brightness from the identified area (A) and the three adjacent areas (B, C and D) are therefore supplied from the storage devices 37 to 40 to the unit 41. These words are added to produce a 4-bit sum inside unit 41, which sum is then converted within unit 41 into an output pulse having an amplitude corresponding to the sum. This amplitude modulation pulse is applied from the waveform generator 17 via the lead wire 34 to the grid of the cathode ray tube 5 as a brightness increasing pulse. At that instant, the degree of brightness of the basic display area (H) on the screen 4 defined by the linear and frame time axis depends on the amplitude of the applied pulse.

By virtue of the particular example shown in FIG. 7, where regions A and B are bright and regions C and D are dark, the combined pulses overlap the data flight attitude of region (H) with bright regions A and B. The brightness of the display in the defined area (H) has an amplitude that depends on the fractional content of the entire area of mapping (H'), and the resulting brightness increase of the display in the defined area (H)
According to a fragmentary portion of the entire region of data flight attitude mapping (H') of the region H, which is superimposed on the data of the region H.

The degree of brightness increase is therefore determined by the calculation units 20 and 21 in order to give a general visual effect starting from the data flight attitude image configuration stored in the storage device 22. Adjusted depending on the transformation performed.

Discontinuities that under normal circumstances would give rise to the appearance of steps or notches are largely smoothed out to the naked eye by this brightness modulation.

The effect that gives rise to the phenomenon of visible steps or notches that is commonly experienced is particularly noticeable when slightly sloping lines are involved, such as pitch lines 10 to 14, but it also affects other It is applied to symbolic symbols regardless of their degree.

A similar smoothing effect to the unaided eye is obtained when using an intensity modulation technique comparable to that used in the apparatus of FIG.

In a particular case, the degree of brightness enhancement of each successive elementary region (H) is not necessarily linearly related to the area of overlap or mismatch of its mapping (H') in the data flight attitude image. do not. Under normal circumstances, the relationship is
Since a stored luminance weighting is used, it is desirable that the discrepancy is not proportional, and achieving a good visual effect is a matter of choice.

Since the storage device 22 can store image information regarding each line or other symbolic element similar to the element in the desired display,
From this it is also possible to alternately store information sufficient to define only a single line or other element, together with information regarding the spacing and orientation of individual ones of similar elements. For example, image information regarding a single line among the pitch lines 10-14 is now stored together with appropriate information regarding the spacing (y-shift) of each pitch bar, so that the entire pitch line 10-14 is stored. can be assembled.

By using raster scanning and the guidance of symbolic symbols following such scanning, the image induced by the television or infrared camera is converted into a video signal which is fed by the waveform generator 17 to the cathode ray tube 5. Can be easily combined into signals.

Although such cameras traditionally utilize raster scanning, the provision of symbolic video signals to cursive techniques, rather than the same scanning, is suitable for all forms of scan conversion in display systems. It has advantages you don't need.

Television or infrared cameras are e.g.
Is it possible to observe the same external scene as that observed by the pilot along line of sight 2?
Or, if the diopter was not lacking,
We are now able to observe the external scenery that was observed by him. The signals obtained by the camera transmit to the screen 4 an image of the scene appearing in the external world in a reflector 3 precisely superimposed on itself.
It is used to generate on.

The above system uses cathode ray tubes,
Of course, other types of display devices can also be used. In particular, a matrix display device may be used in which the modulating signals applied to the device as successive "crossing points" of the matrix are selected to operate alternately throughout the point-by-point scanning of the display area. Ru.

[Brief explanation of the drawing]

1 is a schematic diagram of the display system; FIG. 2 is an illustration of the symbolic symbols contained in the display provided by the system shown in FIG. 1; and FIG. a diagram illustrating raster scanning of the display area and certain relationships contained within the display installation of FIG. 2;
4 is a schematic diagram of the electrical unit used to generate the video signals required in the display installation shown in FIG. 2, and FIG. 5 is a schematic diagram of the electrical unit of FIG. A schematic diagram of an electrical system arrangement incorporating suitable electrical units for the generation of video signals in the display system shown in FIG. 1, FIG. 7 and 8 are diagrams illustrating the principles involved in the operation of the circuit shown in FIG. 4. 1... Reflector, 2... Line of sight, 3... Windshield, 4... Screen, 5... Cathode ray tube, 6...
Optical system, 10-14...Pitch line, 15...
...(Flight) Symbol, 16...(Cross) Symbol, 17...Waveform generator, 18...Detection device, 1
9...Computer, 20, 21...Calculation unit, 22...Storage device, 22A to 22D...Lead wire, 34...Lead wire, 35...Addressing unit, 36...Amplification gate unit, 37
~40...Fixed storage device, 41...Unit.

Claims (1)

Claims: 1. A display system in which successive elements of a display area of a display device are successively brightened in accordance with the symbology to be displayed, comprising an addressing unit 35; is a specific signal (Xp,
Yp) to the storage device 22, the system includes a circuit for generating a first signal depending on the area occupied by the symbol signal in the element, and the unit 41 performs mapping of each element in the storage device 22. 1. A display system that generates a brightness increase signal to be supplied to each element in accordance with the brightness of the element and the area occupied by the symbol signal in the element. 2 The storage device 22 provides an output signal indicative of the brightness in the mapping of the element in question and at least one other output signal depending on the brightness in the mapping of the elements that are directly adjacent to each identified element. A display system according to claim 1, characterized in that: 3. The unit 41 weights each output signal in intensity according to the degree to which the specified signal differs from the data mapping of each identified element and each identified element's immediate neighbors. and the unit 41 supplies a video signal to the display device 5 for each identified element; 3. A display system according to claim 2, characterized in that the display system modulates the signal. 4. The system comprises calculation units 20, 21 which carry out transformation operations on the signals represented by successive elements of the display area 4, such that the mapping of the symbolic signals 10 to 16 within the display area 4 is selectively variable. A display system according to any one of claims 1 to 3, characterized in that: 5. A display system is installed on the aircraft,
5. The display system according to claim 4, wherein the conversion process is performed in accordance with an attitude change caused by a signal from an aircraft. 6. The display system according to claim 1, wherein the display area is provided by a screen 4 of a cathode ray tube 5.