JPS62193040A - Color cathode-ray tube - Google Patents

Abstract

PURPOSE:To enhance the brightness of a color CRT through effective use of fluorescence from fluorescent material, by providing a light reflection layer on the boundary between a black matrix and a fluorescent material provided inside a glass faceplate. CONSTITUTION:A fluorescent material 2, which emits a plurality of luminous colors, and a black matrix 8 are provided inside a glass faceplate 1 so that the black matrix is located between the faceplate and the fluorescent material. A metal back film 3 is provided behind the fluorescent material 2. An electron beam from an electron gun is projected to the metal back film 3 through the apertures of a shadow mask. A color cathode-ray tube is thus constituted. A light reflection layer 11 made of a vacuum evaporated aluminum film or the like is provided on the boundary between the fluorescent material 2 and the black material 8. The fluorescence 9 from the fluorescent material 2 is reflected by the layer 11 so that the light is radiated outward from the front surface of the faceplate 1 in cooperation with the metal back film 3. The fluorescence 9 is thus used effectively to obtain a high-brightness color cathode-ray tube.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color cathode ray tube used in television receivers and various display devices.

"Prior Art" Figure 3 is a schematic cross-sectional view showing the structure of a conventional general color cathode ray tube. In the figure, (1o) is a glass bulb, and inside the glass panel (1) on the front ,
For example, a phosphor (2) consisting of three-color phosphor dots or stripes emitting red (R), green (G), and blue (B) is coated, and the phosphor (2) On the second side, a metal back (3) made of vaporized aluminum MH'J is adhered. (4) is a shadow mask arranged at a predetermined interval from the phosphor (2), and has countless apertures (7
)have.

(5) is an electron gun housed in the rear neck of the glass bulb (10), and (5R), (5G), and (5B) are red, green, and blue electron beams emitted from the electron gun (5), respectively. It is. (6) is a deflection yoke, and the electron beam emitted from the electron gun (5) is deflected by the magnetic field of this deflection yoke (6), passes through the aperture (7) of the shadow mask (3), and passes through the phosphor ( The light impinges on each of the three color phosphors (2) and projects an image on the phosphor (2).

FIG. 4 is a partially enlarged view of a phosphor (2) that emits red (R), green (G), and blue (B) luminescent colors. In the same figure,
A light absorber such as graphite, a so-called black matrix (8), is formed so as to fill in the spaces between the red (R), green (G), and blue (B) phosphors (2).

Moreover, the above-mentioned metal back (3) is attached on top of the power distribution light body (2). This metal back (3)
reflects the light emission (8) from the phosphor (2) and
In addition to doubling the brightness by effectively emitting light to the front surface of G (1), it also prevents ion burnout of the phosphor (2) due to direct irradiation of DB, and also prevents potential effects on the phosphor (2). It is for the purpose of

Furthermore, the black matrix (8) is for reducing the reflection of external light from the front surface of the glass panel (1), making the image clearer, and preventing mixing of the various colors.

[Problems to be Solved by the Invention] However, the black matrix (8) in the fluorescent screen of a conventional color cathode ray tube has the advantage of absorbing external light from the front of the glass panel (1) and reducing its reflection. However, on the other hand, it also absorbs the fluorescence (9) from the phosphor (2), making it difficult to utilize the fluorescence effectively.

This invention was made to improve the above-mentioned conventional drawbacks, and an object of the present invention is to provide a color cathode ray tube that can effectively utilize fluorescence from a phosphor and has high brightness.

[Means for Solving the Problems] The present invention is characterized in that a light reflecting layer is formed on the interface between the phosphor and the black matrix.

[Function] In this invention, the fluorescence from the phosphor is reflected by the light reflecting layer, and the reflected light is radiated outward from the front surface of the glass panel at the sides of the metal back. Effective use of fluorescence from

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of essential parts of an example of a color cathode ray tube according to the present invention. In the figure, the same parts as those in FIG. 4 are given the same reference numerals, and detailed explanation thereof will be omitted. This embodiment differs from FIG. 4 in that a light reflection layer (11) made of, for example, an aluminum vapor-deposited film is formed on the interface between the phosphor (2) and the black matrix (8).

In this way, the phosphor (2) and the black matrix (8)
By forming a light reflective layer (11) on the interface with
Fluorescence (9) from the phosphor (2) is reflected in the light reflecting layer (11)
The reflected light is radiated outward from the front surface of the glass panel (1) at the side bone of the metal back (3). As a result, the fluorescence (9) from the phosphor (2) can be effectively utilized, and a high-brightness color cathode ray tube can be provided.

By the way, in the above embodiment, there is a possibility that the reflected light (9) leaks to the side of another adjacent phosphor (2) and mixes colors. In such a case, in order to prevent this, as shown in FIG. It is recommended that the reflective layer (11) and the black matrix (8) protrude toward the metal back (3).

[Effects of the Invention] As described above, according to the present invention, since the light-reflecting layer is formed on the interface between the phosphor and the black matrix, the fluorescence from the phosphor is reflected by the light-reflecting layer. Since light is emitted outward from the front of the glass panel by the sidewalls of the metal back, it is possible to effectively utilize the fluorescence from the phosphors.

[Brief explanation of drawings]

Figure S1 is a partially enlarged sectional view of a phosphor screen showing an example of a color cathode ray tube according to the present invention, FIG. 2 is a partially enlarged sectional view of a phosphor screen showing another example of a color cathode ray tube according to the present invention, and FIG.
The figure is a schematic sectional view showing the structure of a conventional general color cathode ray tube, and FIG. 4 is a partially enlarged sectional view of a phosphor screen showing an example of a conventional color cathode ray tube. (1)...Glass panel, (2)...phosphor, (3
)...Metal back, (4)...Shadow mask,
(5)...Electron gun, (5R), (5G), (5B)
... Electron beam, (7) ... Shadow mask aperture,
(8)...Black matrix, (11)...Light reflective layer. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A dot-shaped or striped phosphor formed inside the glass panel and exhibiting a plurality of luminescent colors, and a black phosphor interposed between the phosphors formed inside the glass panel and exhibiting each luminescent color. comprising a matrix, a metal back adhered to the back surface of the phosphor, and a shadow mask set at a predetermined interval on the phosphor;
In a color cathode ray tube in which an electron beam emitted from an electron gun housed behind the glass panel hits the phosphor through an aperture in the shadow mask, the boundary between the phosphor and the black matrix A color cathode ray tube characterized by forming a light reflective layer. (2) A color cathode ray according to claim 1, wherein the light reflecting layer and the black matrix protrude toward the metal back so that the metal back and the light reflecting layer surround the phosphors of each emission color. tube.