RU2081449C1 - Device for information input from screen of cathode- ray tube - Google Patents

Abstract

FIELD: automation and computer engineering. SUBSTANCE: device has screen unit, display processor, device which outputs information on cathode-ray tube, information input device and optical unit. Screen unit of cathode-ray tube with optical unit is designed as fiber-optical surface plate which has light guides which ends have axial cone shape. Inner chambers of axial cones are filled with material which refraction index is less than corresponding index of central fiber core of light guide. Inner surface of surface plate is covered with alternating cathode- luminescent strips which are covered with metal and signal plate strips with photo-conducting layer. Index conductors are located between alternating strips and are insulated from them. EFFECT: increased functional capabilities for information input. 2 dwg

Description

 The invention relates to computer technology and automation and can be used in the construction of devices for entering information into a computer or coordinate system for the coordinates of image elements from the screen of a cathode ray tube.

 A device for inputting information from a screen of a cathode ray tube according to EPO patent N 0141729, (class G 06 K 11/06, published 1985), comprising an optical system for inputting coordinates from a screen made in the form of a transparent panel parallel to the horizontal side screen, the screen assembly of the cathode ray tube and a photodetector system that converts light signals into electrical ones.

 The disadvantage of this device is the low accuracy of determining the coordinates associated with the possibility of contamination of the surface of the transparent panel and the displacement of the panel relative to the screen of the cathode ray tube.

 These drawbacks are eliminated in the device for inputting information from the screen of a cathode ray tube containing an optical system, a screen assembly and a photodetector system, the optical system being made in the form of a fiber optic faceplate with optical fibers with an axial shape of the output ends, axicon cavities are filled with a material whose refractive index less than the refractive index of the material of the Central core of the fiber, and the screen unit with a photodetector system is made in the form of a faceplate deposited on the inner surface perpendicular to the horizontal scan of alternating cathodoluminophore strips with a metal coating and the strips of the signal plate with a photoconductive layer, and between the alternating strips are located index conductors isolated from them.

 In FIG. 1 shows a cross section of the screen of a cathode ray tube; figure 2 - the design of the fiber optic faceplate.

 The device for inputting information from the screen of a cathode ray tube consists of an optical system made in the form of a fiber optic faceplate 1 and a screen assembly with a photodetector system made in the form of alternating strips of a phosphor layer 2 with a metal coating 3 deposited on the inner surface of the faceplate and strips of the signal plate 4 with a photoconductive layer 5. At the boundary between the strips are index conductors 6, electrically isolated both from the metal coating 3, so from the photoconductive layer 5. The electron beam 7 scans in the perpendicular direction of the strip of the phosphor layer 2 with a metal coating 3, the index conductors 6 and the strip of the signal plate 4 with a photoconductive layer 5. The optical fibers of the optical fiber faceplate 1 have a two-layer structure consisting of a central core 8 and the outer layer 9. The ends of the optical fibers are made in the form of axicons, the conical cavities 10 of which are filled with a material with a refractive index of the central core 8. The coordinates can be fixed to the screen with a finger 11 Emperor of the interruption of the light beam 12.

 A device for inputting information from the screen of a cathode ray tube works as follows.

 The electron beam 7 scans the screen line by line. In this case, hitting the phosphor 2 through the metal coating 3, the beam 7 illuminates image elements on each strip, for example, keyboard elements of a given configuration, which the operator observes through the fiber optic faceplate 1. The cathode ray tube on the bands with the phosphor layer 2 is operated in kinescope mode. Beam 7, falling on the index conductors 6, switches the operation of the cathode ray tube into vidicon mode. On the strip of the signal plate 4 with the photoconductive layer 5, the magnitude of the electric current passing through the signal plate 4 is fixed. This current is proportional to the magnitude of the light flux incident on the photoconductive layer 5 through the signal plate 4.

 The use of a fiber-optic faceplate eliminates the effect of the luminophore layer on the photoconductive layer and optically separates layers 2 and 5. When the operator finger 11 touches the outer surface of the faceplate 1, light from external sources does not enter certain sections of the bands of the signal plate 4 with the photoconductive layer 5. Current in the signal plate in these areas becomes equal to the "dark current" of the photoconductive layer 5. Successively passing through different bands, the electron beam on the index conductors switches the electron beam tube from the kinescope mode to the vidicon mode and vice versa. In the kinescope mode, the cathode ray tube synthesizes the configuration of the keys, and in the vidicon mode, it perceives the presence of complete blackout at the points of touching the faceplate 1 of the operator with finger 11.

 The execution of the output ends of the optical fibers in the form of axicons is due to the need for the perception of light rays traveling at a small angle to the outer surface of the faceplate, because at small distances between the faceplate surface 1 and the operator’s finger 11, a “false key operation” may occur until the touch is fully touched. Axicons make it possible to direct a beam 12 into the optical fiber, which goes at a small angle to the faceplate surface. Ray 12, being refracted at the boundary “air-cavity 10 of the axicon” and at the boundary “cavity 10 of the axicon, central core 8” and reflected from the boundary “central core 8 outer layer 9”, is directed through the light guide to the photoconductive layer 5.

 The filling of the axicon cavity 10 with transparent material with a refractive index lower than that of the central core 8 is due to the need to obtain a flat faceplate surface. The screen of the cathode ray tube in low light conditions can be additionally illuminated by a side light source.

 The use of the proposed devices for inputting information from the screen of cathode ray tubes is expedient for creating a virtual touch keyboard with a configuration change.

Claims (1)

 A device for inputting information from a cathode ray tube screen containing an optical system, a screen assembly and a photodetector system, characterized in that the optical system is made in the form of a fiber optic faceplate with optical fibers with an axicon shape of the output ends, axicon cavities are filled with a material whose refractive index is less the refractive index of the material of the central core of the fiber, and the screen assembly with a photodetector system is made in the form of a faceplate applied to the inner surface of the faceplate a fast scan of alternating cathodoluminophore strips with a metal coating and strips of a signal plate with a photoconductive layer, and between the alternating strips there are index conductors isolated from them.

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