JPS60189154A - Planar fluorescent lamp - Google Patents

Abstract

PURPOSE:To obtain a homogeneous luminance and prevent any explosional contraction which might be caused by atmospheric pressure by providing the plate glass of a planar fluorescent lamp with several projections parallel to the discharge paths. CONSTITUTION:A pair of electrodes 3 and 3 having a U-shaped cross section are placed on an under sealing glass 2 having concaves 2a, 2a..., terminal guide grooves 2b, 2b... and projections 2c, 2c.... Next, the under sealing glass 2 and an over sealing glass 1 are fused by a sealing member 4 thereby completing a planar fluorescent lamp 10. When the lamp 10 is completed, the over and the under sealing glasses 1 and 2 are in complete contact with each other. Additionally, since the pointed ends of the projections 2c, 2c... are in contact with the inner surface of the over sealing glass 1, any explosional contraction of the glass which might be caused by atmospheric pressure is mechanically prevented. Finally, after air is discharged through an exhaust tube 1a and argon gas and mercury are fed into the tube 1a, the exhaust hole of the exhaust tube 1a is sealed by fusion or similar method.

Description

DETAILED DESCRIPTION OF THE INVENTION B) Industrial Application Field The present invention relates to a flat expense lamp suitable for a backlight of a liquid crystal display device such as a liquid crystal TV.

Regarding the location.

(B) Prior Art In recent years, in order to make T and V receivers thinner, so-called liquid crystal TVs using liquid crystal display devices have not been developed.

Since the liquid crystal panel used in this liquid crystal TV does not emit light by itself, it is necessary to use some kind of light source as a backlight to transmit light through the liquid crystal to obtain a certain level of brightness.

Usually, the following conditions (/l) are required for the above-mentioned backlight.

■It must be a flat light source that matches the size of the LCD TV (3:4 aspect ratio).

■The brightness on the light source surface must be uniform.

■Good luminous efficiency.

■Less temperature rise.

■Good color rendering properties.

Among these conditions, ■■■ in particular are essential conditions for realizing a compact and high-quality liquid crystal TV.

Conventionally, it has been considered to arrange a plurality of cylindrical fluorescent lamps on the back surface of the liquid crystal panel as this backlight, but this is not very preferable because it causes uneven brightness of the plurality of lamps on the screen.

It is also conceivable to use a flat type fluorescent lamp such as that disclosed in Japanese Patent Application Laid-Open No. 54-90877, and by using this flat type fluorescent lamp, uneven brightness can be improved to a certain degree compared to the above-mentioned method.

On the other hand, according to the applicant's experiments, the relationship between gas pressure and brightness is as shown in Table 1.

Here, argon gas is used as the gas, and the brightness tt I To
It is relative to the brightness of 100 at the time of rr.

As is clear from this table, as the gas pressure is increased, the brightness increases in proportion. Furthermore, it has been confirmed that as the gas pressure increases, the power required for discharging remains almost the same.

Therefore, even when the above-mentioned flat lamp is used as a backlight, it is advantageous to increase the gas pressure as much as possible because high brightness can be obtained.

However, according to the applicant's experiments), when the above-mentioned flat type cost light lamp is used, when the gas pressure is 3 Torr or less, electric discharge occurs almost uniformly over the gold surface of the fluorescent surface.
It was confirmed that when the temperature exceeds r, discharge occurs concentrated in the central part of the phosphor surface. Therefore, if you try to obtain high brightness, uneven brightness will occur on the screen, causing inconvenience.

Furthermore, since the above-mentioned planar fluorescent light is a hot cathode type using a filament, if the power consumption is large, the amount of heat generated will also be large.

Furthermore, the above-mentioned flat lamps are not specifically intended for use with LCD TVs, so they do not match the TV screen size (aspect ratio of 3:4), and although they are flat, they do not match the TV screen size (3:4 aspect ratio). It has a long and narrow shape.

In view of the above points, the flat type expense lamp described in the above-mentioned publication does not satisfy the conditions desired for a backlight of a liquid crystal TV, and is not suitable for a liquid crystal TV.

(c) Purpose of the Invention The present invention solves the drawbacks of conventional flat-type cost lighting and provides an LCD TV.
This paper proposes a planar fluorescent light that satisfies the conditions desired for backlights.

(D) Structure of the Invention The present invention provides a flat cost lighting lamp that is sealed by a pair of flat glass plates, which comprises a pair of electrodes and a protrusion that is arranged substantially parallel to a line connecting the pair of electrodes. It is a type of light lamp.

(*)Example An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is an exploded perspective view of the flat type cost light lamp in this embodiment;
Figures 2(A) and 2(C) are a plan view, a vertical cross-sectional view, and a cross-sectional view, respectively, of a flat type overhead lamp.

In the figure, <1 and 2 are upper and lower sealing laths made of transparent glass, respectively, and are formed into a rectangular shape with an aspect ratio of 3:4. The upper sealing glass (1) has a top plate and a side plate that are integrally formed, and an exhaust pipe (la) is installed on the side.
is formed. On the other hand, the lower pricking glass (2>) is in the shape of a flat plate, and includes recesses (2a) (2a) in which a pair of electrodes (to be described later) are located, terminal guide grooves (2b) (2b) (
2b) (2b) and a plurality of protrusions (2c) (2c) parallel to the discharge path and having a triangular cross section are formed in one piece. The inner walls of both sealing glasses are coated with fluorescent light.

(3) (3') is a pair of electrodes made of stainless steel or iron-Ninkel alloy and having a U-shaped cross section, each of which is arranged in the recess, and from the side thereof a pair of terminals ( 3a) (3a)... protrudes toward the outside.

The electrode type in this embodiment is a cold cathode type in which the @ electrode is a cold cathode.

(4) is a sealing material such as glass frit that tightly seals the upper and lower sealing laths, thereby sealing argon gas and mercury inside both sealing glasses (1) and (2).

Next, a method of manufacturing the above-mentioned flat type cost light lamp will be explained.

First, the recesses (2a) (2a), the terminal guide grooves (2b) (2
b) A pair of electrodes (3) (3) is placed on the lower sealing glass plate 2) in which several projections (2cH2c) are integrally formed.

Next, the lower sealing glass (2) and the upper sealing glass (1) are thermally welded using a sealing material (4), thereby completing a flat cost light lamp (lO). In this state, the space between the lower sealing glass and the lower sealing glass is completely adhered to each other. Further, in this state, the tip of the protrusion is in contact with the inner wall of the upper sealing glass, so that the structure mechanically prevents implosion of the glass due to atmospheric pressure.

Finally, air is exhausted from the exhaust pipe (1a), and argon gas and mercury are allowed to flow in, and the exhaust port of the exhaust pipe is sealed by thermal welding or the like.

When a predetermined voltage is applied to the electrodes of the planar cost light lamp made as described above, discharge starts, but each protrusion (2c
) (2c)..., discharge is generated uniformly along the discharge paths formed in parallel, and approximately uniform brightness is obtained over the entire fluorescent surface.

Furthermore, since the protrusion has a triangular cross-section, the brightness at the flat part of the lower sealing glass and the inclined part of the protrusion are equal in the direction orthogonal to the flat part, and the brightness at the apex of the protrusion and the upper sealing glass is equal. Since the contact area of the contact part can be ignored, there is no darkening in this part.

Furthermore, since the electrodes (3) and (3) are each formed into a mouth shape, their surface area is larger than that of a flat plate electrode, so the amount of tr- emitted per discharge path increases. , good luminous efficiency.

Next, one embodiment of a liquid crystal TV to which the above-mentioned flat type cost light lamp is applied will be explained.

Figures 3 (a) and 3 (b) are a cross-sectional view and a vertical cross-sectional view of a liquid crystal TV, in which a flat type cost light lamp (10〉) has a liquid crystal panel (20) on top of the upper sealing glass (1). has been done.

This liquid crystal panel and the flat type overhead lamp have the same planar shape (If horizontal ratio 3:4).

The liquid crystal panel (20>) includes the upper sealing glass (1), a spacer (21) and a glass plate (22) as the four substrates.
) and a sealing material (23) for sealing these, and can be formed according to a well-known liquid crystal panel manufacturing procedure.

According to the above-mentioned LCD TV, since the upper sealing glass of the flat type cost light lamp is used as the substrate glass of the liquid crystal panel, an extremely thin TV can be formed, and the liquid crystal panel and the flat type cost light lamp can be placed in close proximity. As a result, the luminous efficiency is extremely high, and uniform, high-brightness image quality can be obtained.

In the double embodiment, the upper sealing glass of the flat lamp and the substrate glass of the liquid crystal panel are used together, but a conventional liquid crystal panel may be integrated onto the upper sealing glass by gluing or the like.

(F) Effects of the Invention As mentioned above, the flat cost light lamp of the present invention has: (1) Since a plurality of protrusions are provided in parallel to the discharge path, even if the gas pressure is increased, -C can be uniformly distributed on the light emitting surface. Brightness can be obtained.

(2) Implosion due to atmospheric pressure can be prevented by bringing the tips of the protrusions into contact with or close to the opposing sealing glass.

■ Since it uses a cold cathode type, it does not generate heat, and even if the liquid crystal panels are placed close together, the temperature of the liquid crystal will not rise.

■ The electrodes are shaped like a bow to increase the surface area, resulting in good luminous efficiency.

It has the following advantages and can satisfy the conditions desired for backlights of liquid crystal TVs and the like.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of the flat type cost light lamp in this embodiment;
Figures 2 (a), (b), and (c) are the same plan view, the same cross-sectional view, and the same longitudinal sectional view, respectively, and Figure 3 (a) (mouth> It is a cross-sectional view and a cross-sectional view of the warped side. Explanation of main drawing numbers <1) <2)...Top and bottom sealing glass, (3) (3)...
...Pair electrode, (2c) (2c)...Protrusion, (20
)...LCD panel. Applicant Sanyo Electric Co., Ltd. Agent Shizuo Sano 111 Figure 1 Figure 3

Claims (3)

[Claims] (1) A flat-type expense light lamp that is sealed by a pair of flat glasses and includes a pair of electrodes and a protrusion arranged approximately parallel to a line connecting the pair of electrodes. (2) The flat expense light lamp according to claim 1, wherein the pair of electrodes are plate electrodes having a U-shaped cross section. (3) The protrusion is integrally molded on one of the pair of flat glasses, and its tip abuts or comes close to the other flat glass. Flat type cost light lamp.