RU2169409C2 - Matrix-type polychrome luminescent cathodic screen and its manufacturing process - Google Patents

Abstract

FIELD: display facilities; low-voltage information displays. SUBSTANCE: screen designed to display universal alphanumeric, graphical, and television information using cathodic luminescence ability with provision for color coding of information and for color synthesis has vacuum shell, set of directly heated cathodes, rows of phosphor-covered anode strips deposited on insulating base and coated with phosphor of alternating colors (red-green-blue), applied and connected through current-carrying tracks to external wire leads via contact pads; it also has modulator electrodes orthogonal to anode strips that form light-emitting segments at intersecting points; newly introduced in screen is region for assembling and welding glass chips and for glass-chip control of screen; alternating-color anode strips are connected to current-carrying tracks through their own contact pads to those of glass chips. Screen manufacturing process includes sequential formation of anode electrodes in the form of strips on glass board, wiring of cathode-grid assembly with anode board, annealing, welding grid leads, assembling boards with vacuum shell, encapsulating the structure over perimeter and evacuating air from shell; anode electrodes are formed by coating anode strips with phosphor of red-green-blue alternating colors using cataphoresis method for the purpose; these strips are insulated from each other; first region of set of external contact pads of same color and separate ones for each of colors, say, at least three ones, are preformed, then additional region is formed for assembling and welding screen-controlling glass chips; upon assembling board with vacuum shell and evacuation first region is removed. EFFECT: improved precision of anode electrode coating, reduced number of external leads, and, hence, facilitated control of screen. 2 cl, 3 dwg, 1 tbl

Description

 The invention relates to indicator technology, and more particularly to low-voltage means of displaying information based on cathodoluminescence, designed to display universal alphanumeric, signographic, and television information with the ability to encode color information and synthesize color to create a full-color screen.

 Multi-color vacuum-luminescent indicators (VLI) in the country and abroad are widely used in car dashboards, household radio equipment, multi-familiar displays for collective use, etc. etc. (see B. Gorfinkel and others. "Low-voltage cathodoluminescent indicators", Moscow, "Radio and communications", 1983, Chapter II).

 One of the significant drawbacks of VLI (including multicolor ones) is the presence of a “parasitic” contrast of the sign to the background (see Kolker V.E. et al. Electronic Industry, 1982, issue 5-6, p. 138 - 142). This is due to the fact that the anode electrodes are clearly visible under normal external illumination without applying an electric mode to them.

 Known fluorescent indicator tube, which is a flat tube controlled by a dynamic control system (see US patent N 4.164.683, publ. 08/14/1979, MKI H 01 J 63/02). The tube consists of a transparent shell, including a flat substrate and a balloon. The first indicator device is formed on the inner surface of the substrate, and the second on the inner surface of the container. Both the first and second indicator devices include electrodes located in the form of a reproducible pattern, and luminescent films deposited on these electrodes. The electrodes of the second indicator device are made of transparent material. When the electrodes of the corresponding indicator are selectively excited, there is fluorescence of the luminescent films caused by thermal electrons generated by the cathode electrons, thereby providing the display of the desired pattern.

 The disadvantages of the design discussed in US Pat. No. 4,164,683 is that the glow of the anode segments located on the flat board and on the inside of the balloon is carried out respectively in reflection and light mode - this negatively affects the quality of the read information. In addition, in this indicator, the viewing angle decreases, the upper anode electrode reduces the brightness of the lower anode electrode.

 Known low-voltage indicators, such as IVLM2-5 / 7, are used to display alphanumeric and other information in one of two (or three) flowers and are designed in such a way that each segment of the indicator's information field is divided into two equal parts (see Gorfinkel B . I. and other "Low-voltage cathodoluminescent indicators", Moscow, "Radio and communications", 1983, p. 33, 88, 91). This indicator contains a glass insulating board on which anode segments coated with a phosphor are applied. Anodes located on the same line are electrically connected and have one common output. Above the anodes located in one column, there is a common control electrode for them - a cathode grid and a direct-oxide oxide anode. Thus, a matrix system with multiplex control along two orthogonal coordinates is formed. The whole structure is covered and sealed with a flat cylinder.

 When highlighting the information of each of the two colors in such indicators, only half of the segment area is operational, the second half of the segment does not work.

 When switching the displayed symbol from one color to another (for example, from green to red), the negative effect of "jumping" of the read symbol is observed. At a significant frequency of color information change, the “jumping” effect contributes to the operator’s fatigue and a decrease in his attention.

 In addition, such indicators do not allow the use of the entire working field of segments when working in the same color.

Использование конструкции многосегментного катодолюминесцентного индикатора характеризуется недостатками, заключающимися в том, что изображение получаем в одном цвете (черно-белое), а также в большом количестве внешних выводов анодных сегментов, соответственно в сложности управления экраном.The closest in technical essence to the analogue - the prototype of the claimed device is the design of a multi-segment cathodoluminescent indicator described in RF patent N 1166628, MKI 3: H 01 J 31/12, publ. 03/19/93, containing a vacuum shell, a system of directly heated cathodes, rows of anode strips deposited on an insulating base, modulator electrodes orthogonal to the anode strips. The window area of the unit cell of the grid modulator electrode does not exceed the area of the anode segment when the fill factor of the mesh web is not more than 0.35, and the ratio of the distance from the grid modulator electrode to the anode segment X _c-a to the cell size d _{max is} selected from the expression:

Using the design of a multi-segment cathodoluminescent indicator is characterized by disadvantages in that the image is obtained in one color (black and white), as well as in a large number of external outputs of the anode segments, respectively, in the complexity of controlling the screen.

 In the production of vacuum fluorescent indicators, the formation of the information pattern of the boards is carried out by photolithography. In the technological process of manufacturing such boards (see II Gutkin, E.N. Davydova, E.K. Mogilev, K.I. Pereshivailov, B.I. Spirin, G.S.Shofman "Photolithographic process in the production of vacuum luminescent indicators. Electronic industry ", 1982, issue 5 - 6, p. 125 - 126) the photoresist FP-383 is used to form a conductive pattern of the boards. To remove the photoresist after etching the pattern, a plasma-chemical method is proposed.

 However, this method allows producing only relatively simple topological schemes with an acceptable yield. With an increase in the saturation of the circuit and an increase in its overall dimensions, it is practically impossible to obtain a defect-free pattern.

 The closest analogue in its technical essence to the claimed method is a method of manufacturing a display described in US patent N 4.613.399. MKI 4: C 23 F 1/02, publ. 09/23/86, which includes the deposition of a conductive layer on a glass plate, the formation of anode electrodes on a glass plate, conductive paths and pads, the application of a dielectric layer, installation of a cathode-grid unit with an anode plate, mounting annealing, welding of wire leads, welding of the cathodes assembly of the anode plate with a vacuum shell and an intermediate dielectric frame, sealing the structure around the perimeter.

 The disadvantage of this method is the inability to obtain a display in color.

 The invention is as follows. The problem to which the invention is directed is to provide a precision coating of the anode electrodes with a luminescent composition by the method of cataphoresis (electrophoresis), to reduce the external conclusions of the screen, respectively, in simplifying the color screen control.

 The specified technical result in the implementation of the invention is achieved by the fact that a well-known multi-color cathodoluminescent matrix-type screen containing a vacuum shell, a system of straight filament cathodes, rows of anode strips deposited on an insulating base, modulator electrodes, orthogonal anode strips and forming light emitting segments in a crosshair, an additional zone is introduced for assembling and splitting crystals on glass to control the screen, while the anode strips are coated with a phosphor with alternating them in color where: red - green - blue and are respectively connected to conductive paths through their own contact pads to contact pads on the glass crystal.

 The specified technical result in the implementation of the invention is achieved by the fact that in the known method of manufacturing a multi-color cathodoluminescent screen, which includes the sequential formation of anode strips on a glass plate, mounting a cathode-grid unit with an anode plate, mounting annealing, welding out the wire leads, assembling the anode plate with a vacuum shell, sealing the screen around the perimeter, pumping out, forming anode strips is carried out by coating them with a phosphor by the method of cataphoresis with alternating colors: red - z linen - blue, electrically isolated from each other, pre-form the first zone of the location of the sets of external contact pads of the same color and separate for each of the colors, for example, at least three, and form a second zone for assembling and welding crystals on glass to control the screen, after assembly of the anode plate with a vacuum shell and pumping the first zone is removed.

 The essence of the technical solution is illustrated by graphic materials and description.

 In FIG. 1 shows (as an example) a multi-color cathodoluminescent screen in accordance with the proposed technical solution.

 In FIG. Figure 2 shows a schematic representation of the anode plate of a multi-color cathodoluminescent screen with crystals on glass and the (first) zone removed after pumping.

 In FIG. Figure 3 shows the connection of crystals on glass with anode strips with alternating colors: R G B R G B ... R G B, only on one bottom side of the anode plate.

In the drawings, the following notation:
1 - a vacuum shell; 2 - glass bottle; 3 - insulating base, flat glass; 4 - anode strip; 5 - anode strips coated with a red phosphor (R); 6 - anode strips coated with a green phosphor (G); 7 - anode strips coated with a blue phosphor (B); 8 - current-carrying tracks; 9 - straight cathodes; 10 - modulator electrodes (in Fig. 1, for simplicity, modulator electrodes — grids are shown as frames); 11 - dielectric intermediate frame; 12 - crystals on glass (chip on glass); 13 - contact pads of the anode strips; 14 - contact pads of crystals on glass; 15 - light emitting segments; 16 - external findings.

 The operation of a multi-color cathodoluminescent screen matrix type with crystals on glass is as follows.

 The electrons emitted from the cathode 9 are scattered evenly over the area of the vacuum shell 1 with the help of a modulator electrode 10, to which a positive potential is applied, and anode strips 5, 6, 7 coated with a phosphor are bombarded with different colors of light, to which the accelerating potential is applied. Under the influence of electron bombardment, the light emitting segments 15 glow. Light emitting segments, on which there is no accelerating potential, are not affected by the electron beam and the phosphors remain in an unexcited state.

 In this technical solution, the task is achieved by changing the topology of the current-carrying paths 18 connecting the anode strips 4 with alternating them in colors 5, 6, 7 - [R G B R G B ... R G B] through their own pads 13 with contact pads 14 crystals on glass 12.

 Samples of a multicolor cathodoluminescent screen of matrix type D - 12 with crystals on glass were made.

 In FIG. 2 shows a sketch of an insulating base with crystals on glass indicating the main areas of the display.

 1 zone. The zone contains four electrically isolated groups of current paths: 2 groups with conclusions of B - anode strips covered with blue phosphor, and one group with conclusions of R and G - anode strips coated with red and green phosphors. Each of the groups also contains electrically isolated contact pads from current-carrying tracks of the same color.

 2 zone. The zone contains the wiring of the anode current paths to the places of their connections with the corresponding contact pads of the crystals on the glass.

 The technological operations of manufacturing an insulating base are universal for both the intermediate (without crystals on glass) and the basic with crystals on glass (with chip on glass) variants and have been practically developed on the basis of the intermediate version.

 The main option, in terms of manufacturing the display, in connection with the introduction of a chip on glass (chip on glass) is significantly more time consuming.

 The table below provides a comparative list of sequential operations of both options.

 A significant increase in the complexity of manufacturing a display with crystals on glass is justified, because the number of external terminals of the RGB anode strips decreases from 960 to 36, which leads, firstly, to a decrease in the complexity of manufacturing a VFD device with crystals on glass and, secondly, to increase their reliability.

 Currently, several samples of a multi-color cathodoluminescent screen matrix type according to the claimed technical solutions. Tests have shown that this invention reduces the number of external terminals of the anode strips. It is convenient for the operator to control such a screen, obtaining high uniform brightness in the information field. For highly informative screens, respectively, with a large number of external outputs (indicated above), this advantage is further enhanced.

 Thus, the claimed and developed multi-color cathodoluminescent matrix-type screen with crystals on glass and the method of its manufacture made it possible to control the screen with a significant reduction in the number of external outputs, respectively, reducing the complexity of manufacturing the screen, which simplifies screen control and improves operational reliability.

Claims (2)

 1. A multi-color matrix-type cathodoluminescent screen containing a vacuum shell, a straight filament cathode system, rows of anode strips deposited on an insulating base, modulator electrodes orthogonal to the anode strips and forming light emitting segments in the cross, characterized in that an assembly and splitting zone is additionally introduced into it crystals on the glass to control the screen, while the anode strips are coated with a phosphor with alternating colors: red - green - blue and, accordingly, are connected to a current guide paths through their own contact pads with contact pads of crystals on glass.  2. A method of manufacturing a multi-color cathodoluminescent screen, including the sequential formation of anode strips on a glass plate, mounting a cathode-grid unit with an anode plate, mounting annealing, welding wire mesh, assembling an anode plate with a vacuum shell, perimeter screen sealing, pumping, characterized in that the formation of the anode bands is carried out by coating them with a phosphor by the method of cataphoresis with alternating colors: red - green - blue, electrically isolated from each other, pre-phot They form the first zone of arrangement of sets of external contact pads of the same color and separate for each color, at least three, and form a second zone for assembling and melting crystals on the glass to control the screen, after assembling the anode plate with a vacuum shell and pumping out, the first zone is removed.

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