JPS5937645A - Light source tube - Google Patents

Abstract

PURPOSE:To enable minute color display to be performed with a multiunit light source tube consisting of three electrode components, by providing the second grid electrode with a plural number of rectangular or elliptic electrode holes used for forming electron lenses, and properly adjusting the long diameter and the short diameter of said electrode holes so as to form a plural number of elliptic emission spots on a fluorescent screen. CONSTITUTION:Electron beams 5R', 5G' and 5B' discharged from three cathodes 31R, 31G and 31B, after being overfocused by electron lenses formed at the electrode holes 33a, 33b and 33c of a second grid electrode 33, become incident upon a fluorescent screen 2 to form diffused emission spots 5R, 5G and 5B. When the electrode holes 33a, 33b and 33c are supposed to have an x-axis length of dx and a y-axis length of dy, these lengths are restricted to satisfy the relationship of dx>dy, and the ratio of dx to dy is adjusted according to the necessary axial length ratio (Dy/Dx); Dx and Dy, respectively, represent the x-axis length and the y-axis length of the emission spots 5R, 5G and 5B formed on the fluorescent screen 2. It is necessary to adjust the ratio Dy to Dx which are the diameters of the emission spot of the electron beam to about 3. Therefore, the dx and dy of the rectangular electrode hole of the second grid electrode 33 are adjusted to satisfy the relationship of dx>dy, and experimentally adjusted to satisfy the equation of dx/dy=2-5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light source tube, and more particularly to a composite light source tube that forms a plurality of light emitting spots in one light source tube.

Recently, giant color displays have been used at baseball stadiums, soccer fields, and other baseball stadiums. These display elements are composed of a large number of light source tubes each emitting red, green, or blue light, and are useful as giant color display panels. However, when used for outdoor advertising displays that are viewed from a closer distance, wall displays of buildings, etc., the roughness of the pixels on the display board becomes an obstacle. It could not be used as a display element.

For this reason, a composite light source tube has been proposed in which a single light source tube has the function of emitting red, green, and blue light.

FIG. 1 shows an example of a conventionally proposed composite light source tube. Fluorescent surfaces 2 that emit red, green, and blue light are provided in the light source tube 1, and an electron gun 3 is provided to project an electron beam onto each of the fluorescent surfaces 2. A stem base portion 4 is provided to operate the electron gun 3, and a voltage for driving the electron gun 3 is applied to the stem base portion 4. Further, FIG. 2 shows the light emitting state of the light emitting surface of the composite light source tube shown in FIG. 1. Fig. 2(a) shows the red, green, and blue light-emitting surfaces divided vertically, and Fig. 2(b) shows the red, green, and blue light-emitting surfaces divided into ∆ shapes.
The one shown in Figure 2 has red, green, and blue fluorescent surfaces formed in a single light source tube, and electron beams are struck in correspondence with each fluorescent surface to produce red, green, and blue fluorescent surfaces. The distance between the blue light emitting surfaces is brought close enough to improve the roughness of the displayed confectionery.

The present invention provides another structure of the electron beam generating section of the composite light source tube in which the fluorescent surface is vertically divided as shown in FIG. 2(a).

FIG. 3 shows a basic principle diagram of the first invention.

In the present invention, a plurality of rectangular or cedar-shaped electrode holes are provided in the second grid electrode of the present invention with a three-electrode configuration to form an electron lens. By selecting a plurality of luminescent spots, a plurality of luminescent spots in the shape of a tank can be formed on the fluorescent surface. As shown in the figure, the electron beams 5R', 5G', and 5B emitted from the three cathodes 31R, 31G, and 131B are overfocused by electron lenses formed in the electrode holes 33a, 331), and 330 of the second grid electrode 33, respectively. A diffused luminescent spot 5R1 is formed on the fluorescent surface 2.
Form 5G and 5B.

The diameter of each electrode hole of the second grid electrode has the relationship dx ) dy, where the X-axis length dx and the y-axis length dy, and the X-axis length DI and the 7-axis length Dy of the luminescent spot on the fluorescent surface. The required axial length ratio (D7/DX) of K is used to select the axial length ratio of ax and dy.

FIG. 4 illustrates an embodiment of the present invention.

The electron beam emitted from three independent cathodes 31R131G and 31B arranged in-line parallel to the tube axis is transferred to a first solid electrode 32 (three separate parts) having three electrode holes facing each cathode. The rectangular electrode holes 33a, 33kl, 330 and the third
Large-diameter rectangular electrode holes of the grid electrode 34 (electrode holes 33a,
33b, 330)) is overfocused by a strong pi-potential type electron lens. At this time, the third grid electrode 34 is connected to the fluorescent surface inside the light source tube (not shown) and a voltage of approximately 8 to 1 QKV is applied thereto. This voltage is introduced from the stem space 4 (see FIG. 1) at the base of the light source 'U. On the other hand, a low voltage of about 70V is applied to the second grid electrode 33.

Since the second grid electrode 33 has three rectangular electrode holes 33a, 331) and 33c provided in the integral structure, a common voltage is applied to these electrode holes.

In this embodiment, the first grid electrode 32 also has three circular electrode holes in the integral structure.

In this example, when the outermost diameter of the light emitting surface of light source a is 29 mm, and when the fluorescent surface 2 is vertically divided into three parts: red, green, and blue,
Place green in the center. At this time, the ratio of the emission spot diameter Dy/Dx of the electron beam must be selected to be about 3. Therefore, the relationship between dx and dy of each rectangular electrode hole of the second grid electrode is dx)dy, and the ratio of ax/ay for each of red, green, and blue was experimentally determined. In this example, dx/ay
= 2 to 5.

In this way, the three electrode holes 33a, 33b, and 33C of the second grid electrode having a three-electrode configuration are made into a rectangular or tank shape, and the electrode holes of the opposing third grid electrode are formed into the electrode hole 33a.
, 33kl, 33C! By providing one rectangular hole common to both, it is possible to form a vertical tank-shaped light emitting spot close to the fluorescent surface 2.

As described above, by using the composite light source tube of the present invention, it is possible to create an advertising color tone gray that can be seen from a short distance, and it is also possible to create an advertising color tone gray that can be seen from a short distance. Since the elements can be made smaller, more precise color display is possible.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a conventionally proposed composite light source tube, FIG. 2 is a diagram showing an example of a light emitting state of the composite light source tube, and FIG. 3 is a perspective view showing the principle of the light source tube according to the present invention. FIG. 4 is a side view showing one embodiment of the light source tube according to the present invention. In the figure, 31 cathodes, 32 first grid electrodes, 33 second grid electrodes, and third open grid electrodes are shown. Agent Makoto Kuzuno - Figure 1 Figure 2

Claims (1)

[Claims] A first grid electrode having a plurality of electrically independent cathodes each emitting an electron beam, a plurality of electrode holes provided corresponding to each of the cathodes, and a plurality of electrode holes facing each of the electrode holes at one end. a second grid electrode having a plurality of rectangular or elliptical electrode holes at the other end; a second grid electrode that cooperates with the second grid electrode to form an electron lens; a third grid electrode having a common q electrode hole, and a plurality of oval-shaped light emitting spots electrically connected to the third grid electrode and having a major axis in a direction perpendicular to the major axis direction of each of the rectangular or oval-shaped electrode holes. A light source d0 having a fluorescent surface formed by projecting an electron beam passing through the electrode holes of each of the grid electrodes.