JPS6273593A - Plane light emitting element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technology for forming a flat light source used for a backlight of a liquid crystal panel such as a liquid crystal television.

[Summary of the invention]

In the technology of forming a flat light source, the present invention makes the fluorescent tube itself flat by joining two upper and lower inorganic flat plates or a flat container with low melting point glass, improving the flat light emitting efficiency and making it unparalleled. be.

[Prior art]

Among the various types of displays currently available in the world, these displays use liquid crystal panels and are not self-luminous, so one drawback is that the screen is dark. Various types of backlights are used for this purpose, and LCD televisions are no exception.

A conventional flat light emitter used as a backlight for a liquid crystal panel has a structure as shown in Figure 2, as shown on page 226 of the September 10, 1984 issue of the biweekly Nikkei Electronics.

That is, in Figure 6112, 21 cylindrical disk fluorescent tubes,
A light guide plate made of 22Fi transparent plastic, 25 semi-cylindrical reflectors, and 24 a liquid crystal panel.

The exit path of the excavated light beam from the fluorescent tube is as shown in 25 in the figure, and the cylindrical light source that comes out from 21 in Figure 2 is converted into a planar light beam by the light guide plate 22 in the figure.

[Problem that the invention seeks to solve]

However, the conventional planar light emitter has many problems, as is apparent from FIG.

First, in the conventional flat light emitter shown in Figure 2, in order to make the entire liquid crystal display including the backlight thinner, a cylindrical fluorescent tube is placed on the side of the liquid crystal panel, and this cylindrical light source is connected to the flat light beam by a light guide plate. Therefore, the brightness of the planar light beam after passing through the light guide plate is low relative to the input power KM that causes the cylindrical fluorescent tube to emit light. In other words, it is inefficient. Therefore, in order to obtain a bright planar light beam and a clear image on a liquid crystal display, a large amount of input power is required.

Furthermore, the conventional planar light emitting device shown in Fig. 2 has a large number of parts, and therefore the overall unit cost of parts is high. The unit price is very high as it must satisfy the characteristics. Therefore, the present invention is intended to solve these problems, and its purpose is to:
The purpose is to improve the efficiency of the brightness of a planar light beam with respect to the input power required to light a light source, and to reduce the unit cost of parts.

[Means for solving problems]

In order to solve the above problems, the planar light emitter of the present invention is a low-pressure mercury vapor discharge which is coated on the inner wall of the discharge tube with ultraviolet rays in the spectrum of mercury generated by discharge to excite the phosphor and cause it to emit light. In the lamp, the discharge tube is formed by pasting together two upper and lower inorganic flat plates or flat containers, and the pasting is performed by sandwiching low-melting glass between the flat plates or flat containers and heating and melting the glass. characterized by things.

〔Example〕

Embodiments of the present invention will be explained below based on the drawings.

FIG. 1 shows a cross-sectional view of an embodiment of the invention. In Figure 1, 1 is a flat member made of inorganic glass, 2 is a flat container made of inorganic glass, 3 is low melting point glass, 4 is a metal external lead terminal, 5 filaments, and 6 liquid crystal panels. . Figure flE5 shows a perspective view of the completed planar light emitter. The metal external lead-out terminal marked 4 in Fig. 1 corresponds to 7 in Fig. 5, and the outer periphery of the flat light emitter other than 7 in Fig. 11!3 is mainly made of lead glass, zinc glass, etc., and low melting point glass. The flat member 1 and the flat container member 2 are directly bonded together. At this time, the low melting point glass is formed by printing and firing on the required parts of either the flat member 1 or the flat container member 2, or both members, and then these are heated to melt the low melting point glass. Since the flat member 1 and the flat container member 2 are bonded together, the coefficients of thermal expansion of the flat member 1, the flat container 2, the external output terminal 4, and the low melting point glass 5 must roughly match. In FIG. 1, a flat member 1
A phosphor is coated on the inner surface of the flat container 2, and low-pressure mercury vapor h'- exists in the space between the two members. In Fig. 1, when a discharge is started between both the left and right filaments, strong ultraviolet rays are generated from mercury, and this ultraviolet rays are applied to the inner surfaces of the flat plate member 1 and the flat container member 2 and emit a fluorescent material. When excited, it emits light and becomes a flat light source. In other words, the planar light emitter according to the present invention does not use a cylindrical light source to obtain a planar light beam using other optical members, but because the light emitter itself is planar, the light beam is emitted by an intermediate optical member, etc. Without such problems, the planar luminance of the planar light emitter is bright and highly efficient with respect to the input power that causes the planar light emitter to emit light. Therefore, in order to obtain 111 plane light beams and clear images on the liquid crystal display, it is important to note that it does not require a very large input power.

Furthermore, the flat light emitter according to the present invention (C) can be used directly as a backlight for the liquid crystal panel without requiring a large-scale optical member between the light emitter and the liquid crystal panel.
The unit price of parts is extremely low.

As shown in Figure IE1, if the space filled with low-pressure mercury vapor is in the form of a thin flat plate, the vapor heating efficiency due to discharge/l"-decreases. If the area is small, this is rarely a problem.

Furthermore, FIG. 4 shows a sectional view of another embodiment of the invention. In Fig. 4, 11 is a flat container made of inorganic glass;
2 is a flat container made of ceramic.

13 is a low melting point glass, and 14 is a metal external lead terminal. FIG. 5 shows a perspective view of an embodiment of the invention compared to FIG. In FIG. 5, a portion b'' of a flat container made of ceramic is cut away by the thickness of the metal external lead-out terminal.

The embodiment shown in FIG. 4 is basically the same as the embodiment shown in FIG. 1, with only a few components 6' of the planar light emitter.

〔Effect of the invention〕

As explained above, the present invention has two inorganic flat plates or a flat container, upper and lower, bonded together using low-melting glass and filled with low-pressure mercury vapor to form a flat light emitter. This has the effect of improving the efficiency of luminance and further reducing the unit cost of parts.

[Brief explanation of drawings]

FIG. 1 is a main cross-sectional view showing an embodiment of the planar light emitter of the present invention. FIG. 2 is a main cross-sectional view of a conventional planar light emitter. FIG. 3 is a perspective view of FIG. 1. FIG. 4 is a main sectional view showing another embodiment of the planar light emitter of the present invention. Figure IE5 is a perspective view of Figure 4. 1...Flat member made of inorganic glass 2...
... Flat container made of inorganic glass 5 ... Low melting point glass 4 ... Metal external lead-out terminal 5 ... Filament 6 ... Liquid crystal panel 7...External lead-out terminal 11...Flat container 12 made of inorganic glass...
...Flat container 15 made of ceramic 9...
Low melting point glass 14... Gold pj411 external lead terminal 15...
... Filament 21 ... Cylindrical fluorescent tube 22 ... Light guide plate 23 ... Reflection plate 24 ... Liquid crystal panel 25 ...・From the emission path of higher-order rays from the fluorescent tube
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Claims (1)

[Claims] In a low-pressure mercury vapor discharge lamp, a phosphor coated on the inner wall of the discharge tube is excited by ultraviolet rays in the spectrum of mercury generated by discharge, causing it to emit light. 1. A planar light emitting body comprising containers bonded together, the bonding being performed by sandwiching low melting point glass between the flat plates or the flat containers and heating and melting the glass.