RU2095944C1 - Method for adjustment of color of picture on indicator to observation conditions and device which implements said method - Google Patents

Abstract

FIELD: electronic devices for information display on cathode-ray tube screens which are located in aircraft cockpit which is subjected to sun light exposition. SUBSTANCE: method involves illuminating cathode- ray tube screen with picture using three R, G and B bias light signals, and control of their brightness under external light exposition by means of alternation of video amplifier gain. When threshold values of R and B signals are reached, bias light signals are connected to G cathode of cathode-ray tube and are normalized by brightness level. Corresponding device has cathode-ray tube, bias coils of mask cathode-ray tube, amplifiers of electron beam deviation along X and Y axes, three-channel video amplifier, photo resistor circuit which controls brightness of cathode-ray tube. Gate circuit has adder, two OR gates, single-channel clipping video amplifier and gate. This results in possibility of automatic and manual switching of operation modes in color or monochrome green display of picture. EFFECT: increased efficiency of display use. 2 cl, 1 dwg

Description

 The invention relates to electronic devices for displaying information on color masked CRTs (color indicators) for aircraft display systems and may find application on aircraft with a cabin open to external solar illumination.

 Known methods for adapting the color of graphic images implemented in color indicators on masked CRTs installed in the display systems of foreign fighter aircraft, for example F-1 E (USA), Lavi (Israel), Rafael (France).

 Known devices are built according to the schemes of color monitors on mask CRTs, described in detail in the literature on television broadcasting technology.

 Color adaptation of a graphic image in known devices consists in color coding of individual groups of displayed parameters.

 The closest in technical essence is the method of adapting the color of the graphic image to the observation conditions on the screen of the domestic color multi-function indicator IMF (6ph2.043.051), included in the SOI-109 display system (6ph1.623.041), based on three-color image on the mask CRT screen three R, G, B backlight signals and brightness control under the influence of external illumination by changing the gain of the video amplifier.

 In the known indicator, the electron beam deflection amplifiers along the X and Y axes are connected to the corresponding deflecting coils of the color mask CRT, to the cathodes of the electron gun of which a three-channel video amplifier is connected by the signals R, G, B. Automatic brightness control is carried out by a photoresistor circuit, the photoresistor of which is installed on the front panel of the indicator in the plane of the screen.

 A well-known indicator works as follows.

 The amplifiers of the electron beam receive deviation stresses along the X and Y axes, respectively.

 These voltages are converted in the deflection amplifiers into currents that enter the corresponding CRT deflection coils, where electromagnetic fields are generated that cause the electron beam to move around the CRT screen. The color voltage on the screen is formed using three backlight signals R, G, B, which enter the three-channel video amplifier, where they are amplified and fed to the corresponding cathodes of the CRT electron gun. The electrodes from the cathodes fall on the phosphor of the corresponding color, highlighting a graphic image.

 A certain image color is achieved by mixing the signals R, G, B in a certain proportion, determined by the incoming source video signal. The brightness of the image on a CRT screen is proportional to the gain of the video amplifier. This coefficient is regulated by a photoresistor brightness control circuit, in which the photoresistor, under the influence of external illumination, generates a signal for controlling the gain of the video amplifier; the photoresistor is structurally mounted on the front panel of the indicator in the plane of the CRT screen.

 The graphic image formed on the CRT screen is a set of characters that carry information about the displayed parameters. In this case, double encoding of information with color and graphics is used. The pilot receives the full amount of information from both a multicolor and a monochrome image on the indicator screen. The pilot's reading of integral visual information allows for a balanced brightness of multi-colored characters to increase the speed of error-free reading (see Sat. Technique of Display Systems, edited by A.N. Shemanin and N.I. Ivanov, M. Mir, 1970, translated from English).

 However, the known method and device are implemented on highly maneuverable aircraft, the tactics of which require the use of an open cabin for external illumination. The pilot on these aircraft is subjected to great overload.

 The brightness sensitivity of the human eye is different for a color image with different wavelengths, and the maximum sensitivity falls on green, and during overloads with a deterioration in color perception, green characters are read more confidently than characters painted in other colors. With large external solar illumination of the indicator screen, green characters are also read more confidently than characters of a different color.

 Thus, under conditions of congestion and large solar flare, a multicolor graphic image with a double indication encoding (color and graphics) will be perceived worse than a monochrome image in green with an indication encoding only graphics.

 The proposed method and device is aimed at improving the efficiency of use by adapting to the conditions of perception (overload and increased external solar illumination) by automatically and manually switching operating modes (multicolor or monochrome in green perception of a graphic image).

 The essence of the invention, providing the expected technical effect is achieved by the fact that the claimed method of adapting the color of the graphic image on the indicator screen to the observation conditions, like the prototype, is based on obtaining a multicolor image on the screen of a mask cathode ray tube with three R, G, B backlight signals and controlling their brightness under the influence of external illumination by changing the gain of the video amplifier.

 In contrast to the prototype, at threshold values of the influencing factors R and B, the backlight signals are connected to the CR cathode G and normalized by the brightness level.

 A device for implementing the proposed method, as well as a prototype, contains a cathode ray tube, electron beam deflection amplifiers along the X and Y axes, connected to the corresponding deflecting coils of the mask CRT, a three-channel video amplifier and a photoresistor CRT brightness control circuit connected to its gain control input, whose photoresistor is installed on the front panel of the device in the plane of the screen.

 In contrast to the prototype, the device introduced the first and second key circuits, an adder, the first and second OR circuits, a single-channel video amplifier-limiter and a toggle switch. The outputs of the three-channel video amplifier by signals R, G, B are connected in parallel to the corresponding inputs of the first OR circuit and the key first circuit, the outputs of which are connected to the cathodes R and B of the CRT electron gun, respectively, and the output from signal G to the G cathode of the CRT through the first input-output of the second key circuit, the control inputs of the first and second key circuits are connected in parallel to the output of the second OR circuit, the first input of which is connected through the key element to the housing, and the second input to the output of the adder, and the output is photoresistor th circuit is further coupled to a first input of an adder and a control input of the video amplifier limits level limiter, the output of the first OR circuit via video amplifier-limiter connected to a second input of the second gating circuit.

 The drawing shows a structural diagram of a device that implements the proposed method.

 A device that implements the claimed method of adapting the color of the graphic image on the indicator screen to the monitoring conditions contains a three-channel video amplifier 1, a photoresistor circuit 2, an adder 3, the first 4 and second 5 OR circuits, the first 6 and second 7 key circuits, the video amplifier-limiter 8, the key an element (eg, a toggle switch) 9, a CRT masked cathode ray tube 10, a deflection coil 11 and a deflection amplifier 12 along the X axis, a deflection coil 13 and a deflection amplifier 14 along the Y axis.

 The outputs of the three-channel video amplifier 1 by the signals R, G, B are connected in parallel to the corresponding inputs of the first key circuit 6 and the first circuit OR 4. The outputs of the first key circuit 6 by the signals R and B are connected respectively to the cathodes R and B of the CRT 10, and the output is by signal G to the cathode G of the CRT 10 through the first input-output of the second key circuit 7.

 The output of the photoresistor circuit 2 is connected to the first input of the adder 3, the input of the gain control of the three-channel video amplifier 1 and the input of the control level of the limit of the video amplifier-limiter 8.

 The toggle switch 9 is used to connect the first input of the second circuit OR 5 to the chassis bus. The output of the adder 3 is connected to the second input of the second OR circuit 5, the output of which is connected to the control inputs of the first and second key circuits 6, 7. The output of the first circuit OR 4 through the video amplifier-limiter 8 is connected to the second input of the second key circuit 7.

 The deflection amplifier along the X 12 axis (YO) is connected to the deflection coil along the X 11 axis, and YO 14 is connected to the deflection coil along the Y 13 axis.

 The key element (toggle switch) 9 and the photoresistor of the photoresistor circuit 2 are structurally placed on the front panel of the device, and the photoresistor is located in the plane of the screen of the CRT 10.

 The construction of the nodes that make up the device is determined by the functional purpose and choice of the element base.

 Three-channel video amplifier 1, video amplifier-limiter 8, deviation amplifiers 12, 14 can be performed using transistors such as KT 117A, KT 209, KT 645, KT 829, KT 805, KT 837, KT 602, KT 940, GT 346A.

 Photoresistor circuit 2 can be performed on a photoresistor type SF2-12.

 The adder 3 can be made according to the scheme of a differentiating operational amplifier with two inputs on a chip type 140 UD6.

 The first and second key circuits 6, 7 can be performed on the analog keys of the 580 series.

 The first and second OR circuits 4, 5 can be performed on circuits of the 133 and 134 series.

 The key element 9 can serve as a switch PT8-1V (USO.360.056 TU).

 As a CRT 10 with deflection coils 12, 14, one can use the 25LK4C-S electro-beam device (CRT) (OTSO.335.77OTU), which is a CRT with a deflecting system.

 A device that implements a method of adapting the color of a graphic image on an indicator screen to observation conditions works as follows.

 The deflection signals along the X and Y axes enter the electron beam deflection amplifiers along the X and Y axes 12 and 14, respectively, where they are converted into current signals and fed to the corresponding deflection coils 11 and 13, which form the electromagnetic field of the deflection of the electron beam of the CRT 10.

 Photoresistor circuit 2 generates an analog signal whose value is proportional to the external solar illumination of the plane of the screen of the CRT 10.

 Modulation signals R, G, B are fed to a three-channel video amplifier 1, where they are amplified in proportion to the brightness control signal coming from the photoresistor circuit 2. At the same time, the brightness control signal is supplied to the first input of adder 3, to the second input of which the signal of the current overload value is received from the linear acceleration sensor (P). In adder 3, these signals are summed and, when a predetermined threshold is reached, a “color off” signal is generated, which passes through the second input to the second OR circuit 5, to the first input of which from the key element 9 in the first position, for example, closed, the “color off” signal also arrives " In the second position of the key element 9, the “color off” signal is removed. The pilot controls the position of the key element 9 manually. In the presence of at least one input of the second OR circuit 5 of the signal “color off”, this signal is fed to the control inputs of the first and second key circuits 6, 7. In the absence of a signal “color off”, the signals R and B through the first key circuit 6 are fed to the corresponding the cathodes of the CRT 10, and the signal G is supplied to the cathode G of the CRT 10 through the second key circuit 7.

 In the presence of a “color off” signal, the first key circuit 6 blocks R, G, B signals that, through the first OR 4 circuit, are fed to the video amplifier-limiter 8, where these signals are normalized to one level. The level value is set by the brightness control signal coming from the photoresistor circuit 2. Through the second input-output of the second key circuit 7, all the backlight signals are supplied only to the cathode G (green) of the CRT 10.

 When using a device operating according to the proposed method for adapting the color of a graphic image on an indicator screen, it is possible to effectively observe a multi-color or monochrome (green) graphic image during overloads and increased external solar illumination. The color of the display in it is adapted to the observation conditions and the psychophysical state of the pilot, which increases the speed of error-free reading of information by the pilot and, ultimately, increases flight safety and the efficiency of using special onboard equipment.

Claims (2)

 1. A method of adapting the color of a graphic image on an indicator screen to observation conditions, based on obtaining a multicolor image on a masked cathode ray tube screen with three R, G, B backlight signals and controlling their brightness under the influence of external illumination by changing the gain of the video amplifier, characterized in that at threshold values of the influencing factors R and B, the backlight signals are fed to the G cathode of the mask cathode ray tube and normalized by the brightness level.  2. A device for adapting the color of the graphic image on the indicator screen to the observation conditions, containing a masked cathode ray tube (CRT), electron beam deflection amplifiers along the X and Y axes, connected to the corresponding CRT deflecting coils, a three-channel video amplifier and connected to its control input gain photoresistor CRT brightness control circuit, the photoresistor of which is installed on the front panel in the plane of the screen, characterized in that the first and second key are introduced into the device e circuits, an adder, the first and second OR circuits, a single-channel video amplifier-limiter and a key element, while the outputs of a three-channel video amplifier using R, G, B signals are connected in parallel to the corresponding inputs of the first OR circuit and the first key circuit, the outputs of which are R and B are connected respectively to the cathodes R and B of the CRT electron gun, and the output by signal G to the cathode G of the CRT electron gun is through the first input-output of the second key circuit, the control inputs of the first and second key circuits are connected in parallel to the output of the second c OR, the first input of which is connected through the key element to the chassis bus, and the second input to the adder output, the output of the photoresistor circuit is additionally connected to the first adder input and the input of the control level of the video amplifier-limiter, the output of the first OR through the video amplifier-limiter is connected to the second the entrance of the second key circuit.