KR100269916B1 - Fluorescent light tube - Google Patents

Abstract

PURPOSE: A vacuum fluorescent display is provided to increase a fluorescent surface area due to an electron beam by forming a surface of a fluorescent layer as unevenness. CONSTITUTION: A segment electrode(51) is formed on an upper portion of a lower glass substrate(52). The fluorescent material(3) is formed with the first fluorescent material(1) and the second fluorescent material(2). The first fluorescent material(1) is formed on the segment electrode(51). The second fluorescent material(2) is formed on the first fluorescent material(1). The second fluorescent material(2) is formed with a stripe shape. The fluorescent material(3) is formed by using a photoresist.

Description

Fluorescent light tube

1 is an enlarged cross-sectional view showing a fluorescent surface applied to the present invention,

2 is a state diagram showing the projection and reflection of the electron beam to the fluorescent surface in FIG.

3 is a partially enlarged perspective view showing another embodiment of the present invention;

4 is a partially enlarged perspective view showing still another embodiment of the present invention;

5 is a cross-sectional view showing the configuration of a general fluorescent display tube.

* Explanation of symbols for main parts of the drawings

1: primary phosphor 2, 2 ', 2 ": secondary phosphor

3: phosphor

[Industrial use]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube. More particularly, the present invention relates to a fluorescent display tube which can improve the latitude of the fluorescent display tube by increasing the surface area of luminescence of the fluorescent surface by the electron beam by forming the fluorescent surface into an uneven shape.

[Prior art]

In general, a flat panel display device is classified into a fluorescent display tube (VFD), a liquid crystal display (LCD), and a field emission device (EL) and a plasma display device (PDP). In addition, it is possible to display a multi-colored display, which is widely used in home appliances and in-vehicle applications.

The general structure of the above-described fluorescent display tube includes a lower glass substrate 52 having a phosphor 50 coated thereon and a segment electrode 51 to which an anodic current is applied, as shown in FIG. A grid 53 seated on the lower glass substrate 52 so as to correspond to the electrode 51, to which an anode is applied, a cathode 54 emitting hot electrons from the upper portion of the grid 53, and the lower portion described above. It is composed of an upper glass substrate 57 formed with a transparent conductive film 56 not only sealed with the glass substrate 52 and the sealing material 55 but also applied with a cathode.

Referring to the operation of the fluorescent display tube, when the cathode 54 to which the cathode potential is applied is heated to about 600 ° C., the hot electrons are emitted. The hot electrons accelerate the selection while passing through the grid 53 which is the anode potential. Then, an external signal causes selective collision with the segment electrode 51 to which the anode potential is applied.

At this time, since the phosphor 50 having a light emitting surface area of L is coated on the segment electrode 51, the predetermined phosphor 50 to which the anode potential is applied by hot electrons emits light so as to perform a predetermined display. Will be.

In this case, the luminance emitted by the phosphor 50 while emitting light by hot electrons is determined according to the anode voltage and the distance between the cathode 54 and the grid 53, thereby raising the anode voltage and the cathode 54. By reducing the distance between the grid 53 and the luminance can be improved.

[Problem trying to solve the invention]

However, as described above, increasing the anode voltage in order to improve the brightness of the fluorescent display tube is applied to the limited phosphor 50 by applying more anode voltage per area of the stage. By canceling, there is a problem in that the luminance which is inversely proportional to the anode voltage per unit area is lowered.

In addition, as described above, reducing the gap between the cathode 54 and the grid 53 reduces the emission characteristics of the cathode 54 and the lifetime of the cathode 54 and the anode and the cathode. do.

Accordingly, an object of the present invention is to reduce the luminance decrease due to raising the anode voltage applied to the segment electrode, the grid and the phosphor to improve the luminance of the fluorescent display tube, and to reduce the gap between the cathode and the grid. The present invention provides a fluorescent display tube that can improve luminance while preventing deterioration of the characteristics and lifetime.

[Means to solve the problem]

In order to realize the above object, the present invention not only increases the anode voltage applied to the grid, the phosphor, and the segment electrode, but also reduces the primary phosphor at the time of forming the phosphor without reducing the gap between the grid and the cathode. It is characterized by improving the luminance by increasing the light emitting surface area of the phosphor by applying a projection-shaped secondary phosphor, the height of which is set to be equal to the height of the conventional phosphor in combination with the height of the primary phosphor on the top.

[Action]

The same anode voltage is applied to the phosphor, grid, and segment electrode when a plurality of protrusion-shaped secondary phosphors are formed on the primary phosphor lower than that of the conventional phosphor so as to be the same height as the conventional phosphor. When the surface area is increased by the secondary phosphor, the anode voltage applied per unit area decreases, thereby improving luminance in inverse proportion to the anode voltage per unit area.

EXAMPLE

1 is an enlarged cross-sectional view showing a phosphor of a fluorescent display tube according to the present invention, wherein the primary phosphor 1 and the primary phosphor 1 above the segment electrode 51 formed on the lower glass substrate 52 are shown in FIG. The fluorescent substance 3 in which the secondary fluorescent substance 2 is laminated | stacked in the stripe shape on the upper part of is apply | coated.

Of course, the above-mentioned primary and secondary phosphors 1 and 2 are not limited thereto, and the effect is achieved by forming a single layer.

The phosphor 3 is formed of a primary phosphor _{1 at} a height of h ₁ using a conventional photoresist, and then a secondary phosphor _{2 having a} height of h ₂ on the upper portion of the primary phosphor 1. The phosphor 3 is formed at the height of h by forming.

In this case, the surface area L of the primary phosphor 1 is equal to the surface area L of the primary phosphor _{1 such that} the side surface area S (S ₁ + S ₂ + S ₃ .......) of the secondary phosphor 2 is obtained. In addition, it increases by the side area S described above.

As described above, when the emission surface area of the phosphor 3 increases, the secondary phosphor in the phosphor 3 coated on the segment electrode 51 formed on the lower glass substrate 52 as shown in FIG. 2) Hot electrons collide with the side surface area S to excite the phosphor 3, whereby the luminance is increased by the following equation (1).

_{B = η · e b · 1} b ... … … (One)

η: Luminous efficiency with respect to anode voltage applied per unit area to the phosphor

e _b : anode voltage per unit area

i _b : Anode current per unit area

Herein, as the light emitting surface area increases, the brightness increases as the brightness is inversely proportional to the anode voltage applied per unit area. As the light emitting surface area increases, the anode voltage applied per unit area is increased. This is because the light emission efficiency is improved by decreasing.

Of course, even if the secondary phosphor 2 formed in the stripe shape as described above is formed in the matrix form on the upper portion of the primary phosphor 1 as shown in FIG. Likewise, the effect is achieved because the side area S ₁ is an increase.

Also, as shown in FIG. 4, even if a large number of secondary phosphors 2 are formed in the shape of dots on the upper portion of the primary phosphor 1, the effect is achieved because the side area S ₂ is increased.

In particular, when forming the above-mentioned primary and secondary phosphors (1, 2, 2 ', 2 "), the primary phosphor 1 is formed at about 50 to 80% of the thickness of the conventional phosphor 50 and the secondary phosphor (2). , 2 ', 2 ") are the most effective.

[Effects of the Invention]

As described above, the present invention has the advantage of improving the luminance at the same voltage and the same electrode interval by increasing the surface area of the phosphor by adding the heights of the secondary phosphors formed on the upper portion of the primary phosphors as the protrusions to increase the emission surface area of the phosphors. It is.

Claims (4)

An upper glass substrate 57 having a transparent conductive film 56 formed thereon, a lower glass substrate 52 sealed with the upper glass substrate 57 and a sealing material 55 and having a segment electrode 51 formed thereon; In the fluorescent display tube comprising a grid 53 positioned between the upper and lower glass substrates 57 and 52 and a cathode 54 positioned above the grid 53 to emit hot electrons. And a fluorescent substance (3) is coated so that the height of the fluorescent substance (3) formed in a single layer on the segment electrode (51) becomes h and the total light emitting surface area is increased. The fluorescent display tube according to claim 1, wherein the secondary phosphor (2) is formed in a stripe shape on top of the primary phosphor (1). 2. The fluorescent display tube according to claim 1, wherein the secondary phosphor (2) is formed by forming a matrix on top of the primary phosphor (1). The fluorescent display tube according to claim 1, wherein the secondary phosphor (2 ") is formed by forming a dot shape on the upper portion of the primary phosphor (1).