JPS62274532A - Beam-index type cathode-ray tube - Google Patents

Abstract

PURPOSE:To obtain an index signal having stable intensity, and besides to improve picture definition with reduced intervals of color phosphor dots by laminating index phosphors and a transparent conductive film on a color phosphor. CONSTITUTION:Index phosphors 3 are laminated on phosphors G. A transparent conductive film 2 comprising tin oxide, acting as an anode electrode, is laminat on color phosphors R, B, and the index phosphors 3. The color phosphors G, on which the index phosphors 3 are laminated, are illuminated excite when they are violet rays. The color phosphors R and B, on Which the index phosphors 3 are not laminated, are excited by an electron beam and they are illuminated. Therefore, even if the index phosphors 3 are made nearly as wide as the color phosphors R, G, and B, and even if mutual intervals among the color phosphors R, G, and B are made smaller than the widths of the index phosphors 3, that is, those of the color phosphors R, G and B, the index phosphors 3 cause no trouble on excitation of the color phosphors R, G, and B. Hence, picture definition can be improved, and an index signal having stable intensity can be obtained.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention The present invention relates to a beam index type color cathode ray tube.

Since the ball-beam index type color cathode ray tube uses a single electron gun type, it does not have the problem of convergence adjustment like the shadow mask type color cathode ray tube (and has a high beam utilization rate). It has been attracting attention in recent years because of its advantages.

Figure 3 illustrates the arrangement of color phosphors, phosphors for generating index signals (hereinafter referred to as index phosphors), and a conductive film as an anode electrode in a conventional beam index type cathode ray tube. be. In the figure, R represents a color phosphor that emits red fluorescence, G represents a color phosphor that emits green fluorescence, and B represents a color phosphor that emits blue fluorescence, which emit light when excited by an electron beam. The back surfaces R, G, and B of the face plate 1 are formed at regular intervals in this order. Reference numeral 2 denotes a conductive film made of an aluminum film laminated on each RlGSB color phosphor. Reference numeral 3 denotes an index phosphor that is excited by an electron beam, and is usually made of a phosphor that emits ultraviolet light with a short afterglow property. The index phosphor 3 is placed on the conductive film 2 without overlapping any of the color phosphors R, G, and B described above.

According to such a beam index type cathode ray tube, the color phosphors R, G, and B are emitted by the electron beam transmitted through the conductive film 2.
When excited, they emit red, green, and blue fluorescence, respectively. Also,
The index phosphor 3 is excited by the electron beam and emits ultraviolet light as an index signal.

By the way, in a beam index type cathode ray tube, in order to stably obtain an index signal of sufficiently high intensity, the width of the index phosphor 3 must be adjusted to the width of the color phosphors R, G, B.
It is known that the width should be the same as the width of .

However, as in the conventional beam index type color cathode ray tube described above, the index phosphor 3
When placed between the color phosphors R, G, and B so that they do not overlap, 1. If you try to obtain a stable index signal with a sufficiently large intensity by making the width of the INTEX phosphor 3 the same as the width of the color phosphors R, G, and B, the color phosphors R, G, and B will The spacing between these color phosphors R, G, B
The width of the image must be approximately the same as the width of the image, and this has been a constraint on increasing the definition of the image.

On the other hand, in conventional beam index type color cathode ray tubes, in order to increase the definition of images, color phosphors R,
The mutual spacing between G and B may be made narrower than the width of these color phosphors R, G, and B, but in this case, the color phosphor R
, G, and H so as not to overlap, the width of the index phosphor 3 must be narrower than the width of the color phosphors R, G, and B, so that a stable index signal with sufficiently high intensity can be obtained. I won't be able to do that.

In this way, in conventional beam index type color cathode ray tubes, increasing the definition of the image and stably obtaining an index signal of sufficiently high intensity are contradictory issues. The problem is that in order to increase the resolution, the strength and stability of the index signal must be sacrificed, and in order to ensure sufficient strength and stability of the index signal, the definition of the image must be sacrificed. was there.

The present invention solves these problems by making it possible to set the width of the index phosphors to be approximately the same as the width of the color phosphors, regardless of the mutual spacing between the color phosphors, thereby improving the image quality. An object of the present invention is to provide a beam index type cathode ray tube that can simultaneously achieve both of increasing the definition of the image and obtaining a stable index signal of sufficiently large intensity.

In order to solve the above problems, the beam index cathode ray tube of the present invention has an index phosphor layered on top of a color phosphor, and a transparent conductive film is placed on top of this phosphor. The gist lies in the fact that they are layered.

According to the above configuration, the width of the index phosphor is not restricted by the size of the mutual spacing between the color phosphors, so the width of the index phosphor can be set to be approximately the same as the width of the color phosphors, making it sufficiently large. An index signal with stable intensity can be obtained. Furthermore, even if the width of the index phosphors is made to be the same as the width of the color phosphors, the mutual spacing between the color phosphors is not restricted by the width of the index phosphors, so the mutual spacing between the color phosphors can be made smaller. Image definition can be increased.

Figure 1 shows the arrangement of color phosphors, index phosphors, and transparent conductive films in a beam index type cathode ray tube according to an embodiment. As is clear from the figure, the color lights 4R and cSB are arranged in this order at intervals on the back surface of the face plate 1, and there are guards in the gaps between these color phosphors R, G, and B. A band 4 is provided. The color phosphors R and B use substances that emit light when excited by an electron beam emitted from an electron gun (not shown), while the other color phosphors G emit light when excited by ultraviolet rays. substance is used. Further, the index phosphor 3 uses a substance that emits ultraviolet light when excited by the electron beam emitted from the electron gun. This index phosphor 3 is the phosphor G mentioned above.
It is placed on top of the . A transparent conductive film 2 made of a tin oxide film as an anode electrode is laminated on the color phosphors R and B and the index phosphors 3.

In such a beam index type cathode ray tube, when the electron beam transmitted through the transparent conductive film 2 hits the color phosphors R and B, these color phosphors R and B are excited and emit red and blue fluorescence, respectively. Furthermore, when the electron beam transmitted through the transparent conductive film 2 hits the index phosphor 3, the index phosphor 3 is excited and emits ultraviolet rays.The ultraviolet rays are used as an index signal, and at the same time, the ultraviolet rays cause the color phosphors to is excited and emits green fluorescence.

In this embodiment, the color phosphor G on which the index phosphor 3 is stacked is excited by ultraviolet rays and emits light, and the color phosphors R and B on which the index phosphor 3 is not stacked are excited by ultraviolet rays and emit light.
is excited by an electron beam and emits light, so the width of the index phosphor 3 is made to be approximately the same as the width of the color phosphors R, G, and B, and the mutual spacing between the color phosphors R, G, and B is set to be the same as the width of the index phosphor 3. Even if the width of index phosphor 3 is narrower than the width of color phosphor R1G, that is, the width of color phosphor R1G,
It does not interfere with the excitation of B. Therefore, by doing the above, the definition of the image is improved and a stable index signal with sufficiently large intensity can be obtained.

In the above example, when the widths of the color phosphors R, G, and B and the index phosphor 3 are set to 20 μm, and the width of the guard band 4 is set to 10 μm, the image definition is improved and is better than that of the conventional one. A stable index signal with sufficiently high intensity was obtained.

FIG. 2 shows the arrangement of color phosphors, index phosphors, and transparent conductive films in a beam index type cathode ray tube according to another embodiment.

As is clear from the figure, in this example, the color phosphor R
, G, and B, an index phosphor 3 is placed on top of each other. The color phosphors R, G, and B use substances that emit light when excited by ultraviolet rays.

Further, the index phosphor 3 uses a substance that emits ultraviolet light when excited by an electron beam emitted from an electron gun. Further, a transparent conductive film 2 made of a tin oxide film as an anode electrode is laminated on the index phosphor 3.

In such a beam index type cathode ray tube, when the electron beam transmitted through the transparent conductive film 2 hits the index phosphor 3, the index phosphor 3 is excited and emits ultraviolet light, which is used as an index signal and at the same time The color phosphors R, G, and B are excited by the ultraviolet rays and emit red, green, and blue fluorescence.

In this embodiment, since the color phosphors R, G, and B of which the index phosphor 3 is arranged one on top of the other are excited by ultraviolet rays and emit light, the width of the Inte Nox phosphor 3 is and the color phosphors R, G,
Even if the B interval is made narrower than the width of the index phosphor 3, that is, the width of the color phosphors R, G, and B, the index phosphor 3 will not interfere with the excitation of the color phosphors R and GSB.

Therefore, similar to what was explained with reference to FIG. 1, the definition of the image is improved and a stable index signal of sufficiently large intensity is obtained.

Other points are the same as those described with reference to FIG. 1, so the same parts are given the same reference numerals and detailed explanation will be omitted.

By the way, in the present invention, when a substance that emits ultraviolet light when excited by an electron beam is used as the index phosphor, a substance that emits ultraviolet light when excited by ultraviolet rays is used as the color phosphor on which the index phosphor is superimposed. need to use. Further, as the color phosphor that cannot be overlapped with the index phosphor, it is necessary to use a substance that emits light when excited by an electron beam. The following table lists materials suitable for use as color phosphors and index phosphors in the beam index cathode ray tube of the present invention and their associated properties.

(The following is a blank space) As is clear from the above, according to the beam index type cathode ray tube of the present invention, the width of the index phosphor is not restricted by the mutual spacing between the color phosphors. Although it is possible to obtain a stable index signal with sufficiently large intensity by making the width of the index phosphor comparable to the width of the color phosphor, the resolution of the image can be improved by reducing the mutual spacing of the color phosphors. can be increased.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main parts of a beam index type cathode ray tube according to an embodiment of the present invention, FIG. 2 is a sectional view showing the main parts of another embodiment, and FIG. 3 is a sectional view showing the main parts of a conventional example. FIG. R, G, B...color phosphor, 2...transparent conductive film, 3...
...Index phosphor. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] (1) A beam index color cathode ray tube characterized in that an index phosphor that generates an index signal is laminated on a color phosphor, and a transparent conductive film is laminated on the index phosphor.