JP3143342B2 - Flat fluorescent lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat fluorescent lamp used mainly for a backlight of a liquid crystal display panel or the like.

[0002]

2. Description of the Related Art In recent years, portable personal computers,
2. Description of the Related Art Liquid crystal display panels are actively used in electronic equipment such as liquid crystal televisions and audio components. However, since the liquid crystal itself is not a light emitting element, it is necessary to arrange a so-called backlight behind the liquid crystal display panel in order to enhance the visibility of the liquid crystal display panel so that the display can be seen by the transmitted light of the liquid crystal. As the backlight, a cold-cathode discharge tube having a long life is mainly used. As one of the cold-cathode discharge tubes, a flat-type fluorescent lamp has attracted attention.

FIG. 12 shows the appearance of a general flat fluorescent lamp.
Shown in FIG. 13 shows a state in which the front emission panel 8 has been removed from the flat fluorescent lamp shown in FIG. In the figure, reference numerals 1 and 1 denote discharge electrodes, 2 and 2 denote discharge electrode leads connected to the discharge electrodes 1 and 1, 3 a bottom panel portion, and 4 a side panel portion. Further, in FIG. 13, a plane sandwiched between the discharge electrodes 1 and 1 (Plane in the figure)
FIG. 14 shows a cross-sectional shape of the portion C). As shown in the figure, a phosphor 6 is applied to the inner wall surfaces of the bottom panel portion 3 and the side panel portion 4, and a main discharge space 9 for normal planar light emission exists.

[0004]

Normally, the phosphor 6 is applied in close contact with the entire inner wall surface of the bottom panel 3 and the side panel 4, but the viscosity and the amount of the phosphor 6 and the amount of the dried phosphor 6 Due to factors such as variations, the phosphor 6 does not adhere to the corners near the corners of the inner wall surfaces of the bottom panel portion 3 and the side panel portion 4, and the inner wall surface and the phosphor 6 form a cavity as shown in FIG. 10 or the phosphor 6 as shown in FIG.
May occur. Since the corners of the inner wall surfaces of the bottom panel portion 3 and the side panel portion 4 between the discharge electrodes 1 and 1 are "substantially L-shaped", the cavity 10 shown in FIGS. The portion 11 penetrates between the discharge electrodes 1, 1, that is, a through-path is formed by a cavity or a missing portion that is long in a direction orthogonal to the discharge electrode 1.

The through passage between the discharge electrodes 1 and 1 is a discharge space other than the main discharge space 9 in normal planar light emission, and in particular, a potential fixed near the lamp outer wall near the through passage. In the case where there is an object (for example, a printed circuit board, a metal chassis, a bracket, etc.), most of the discharge current is concentrated on the through-passage, causing an abnormal discharge in which only the through-passage portion emits light brighter than the surroundings. .

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a bottom portion, a front portion facing the bottom portion, and side portions existing between the bottom portion and the front portion. In a flat fluorescent lamp including a pair of opposed discharge electrodes in a closed container, at least one protrusion is formed at a part of a corner formed by the bottom surface and the side surface between the pair of discharge electrodes. It is an object of the present invention to provide a formed flat fluorescent lamp.

[0007]

[0008]

With the above construction, even if a cavity or a missing portion of the phosphor is generated at the corner of the inner wall surface formed by the bottom surface and the side surface, the protrusion becomes an obstacle and the discharge electrode is obstructed. No through-path is formed between the cavity and the gap between them.

[0009]

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. The same parts as those of the conventional flat fluorescent lamp are denoted by the same reference numerals, and the detailed description thereof will be omitted. The figure shows a state in which the front light emitting panel 8 has been removed. In this embodiment, a projecting part having a substantially 略 arc-shaped cross section is provided at a part inside the corner formed by the bottom panel part 3 and the side panel part 4 of the flat fluorescent lamp between the discharge electrodes 1 and 1. 5 are formed. FIG. 2 shows a cross-sectional shape of the flat-type fluorescent lamp at a plane (Plane A in the figure). By forming the protrusion 5 as shown in FIGS. 1 and 2, the protrusion 5
Even if a cavity or a gap is generated between the phosphor and the inside of the corner formed by the bottom panel and the side panel as described above, the projection 5 blocks the cavity. That is, they do not penetrate between the discharge electrodes 1 and 1. Therefore, abnormal discharge can be effectively prevented.

In the embodiment shown in FIGS. 1 and 2, the projection 5 has a substantially quarter-arc shape. In the embodiment shown in FIG. 3, the projection 5 has a substantially quadrangular cross section. are doing. Further, as shown in FIG. 4, a projection 5 having a substantially triangular cross section can be used. In short, the shape of the projection is not particularly limited as long as it is a substance that blocks the cavity or the missing part from penetrating between the discharge electrodes 1 and 1.

Similar effects can be obtained by providing a column-shaped projection 5 extending from the bottom panel 3 along the inner wall surface of the side panel 4, as in the other embodiment shown in FIG. still,
The cross-sectional shape of the protrusion 5 may be a quadrangular column or a column having another cross-sectional shape. In the same manner as described above, it is only necessary that the protrusions 5 can prevent a cavity or a missing portion generated between the inner wall surface of the side panel and the phosphor from penetrating between the discharge electrodes 1 and 1.

FIG. 6 shows a columnar projection 5 extending from a corner of the inner wall surface of the side panel portion 4 along the inner wall surface of the bottom panel portion 3 and reaching the inner wall surface of the opposite side panel portion 4. It is an embodiment provided. Also in this embodiment, it goes without saying that the cross-sectional shape of the protrusion may be a quadrangular column or a column having another cross-sectional shape.

FIG. 7 shows an embodiment in which the projections shown in FIGS. 5 and 6 are combined.

FIG. 8 shows an embodiment in which a concave portion 7 having a circular section having a radius of 0.8 mm or more is formed at a corner in place of the projection shown in each of the above embodiments. FIG. 9 shows a cross-sectional shape of the bottom panel portion 3 and the side panel portion 4 between the discharge electrodes 1 and 1 in FIG. As shown in FIG. 8 and FIG. 9, by providing a concave portion 7 having a large arc with a cross section of a radius of 0.8 mm or more in a corner formed by the bottom panel portion 3 and the side panel portion 4, It is easy to be applied in close contact with the surface, and cavities and missing portions unlike a conventional flat fluorescent lamp are unlikely to occur.

The recess 7 has a cross section with a radius of 0.8 mm.
Although the above arc is effective, other examples include a concave portion 7 having a polygonal cross section as shown in FIG.
A concave portion 7 having an elliptical cross section as shown in FIG.

Incidentally, it goes without saying that the bottom panel, the side panel, the projection and the like may be formed integrally (for example, molded glass) or may be formed separately.

According to the present invention, at least one protrusion is provided toward the main discharge space at the corner of the inner wall surface of the bottom panel portion and the side panel portion between the discharge electrodes. In the vicinity of the corner of the inner wall surface of the bottom panel portion and the side panel portion between the electrodes, even when a hollow portion formed by the inner wall surface and the phosphor or a lack portion formed by the phosphor occurs, the protrusion is also provided. The formation of a through-path between the discharge electrodes due to the hollow portion and the lacking portion as an obstacle is prevented, whereby abnormal discharge of the lamp can be prevented.

A recess having a large circular arc having a radius of 0.8 mm or more toward the main discharge space over the entire corner of the inner wall surface of the bottom panel portion and the side panel portion between the discharge electrodes, or corresponds to this recess. The concave portion (for example, a concave portion having a polygonal cross-section or a concave portion having an elliptical cross-section) is provided, so that there is no bent portion from the bottom panel portion to the phosphor application portion along the side panel portion. Since the phosphor can be applied in close contact with the inner wall surface without being affected by the influence, "shrinkage" does not occur on the bottom panel and side panel even during the drying process of the phosphor, and abnormal discharge occurs. It is less likely that a cavity or a missing portion will be caused.

[0021]

As described in detail above, according to the present invention, the present invention is formed by a bottom surface, a front surface facing the bottom surface, and a side surface existing between the bottom surface and the front surface. In a flat fluorescent lamp provided with a pair of opposed discharge electrodes in a closed container, at least one projection is formed at a corner formed by the bottom and the side, so that the bottom and the side are separated. Even if a cavity or a missing part of the phosphor is generated at the corner of the formed inner wall surface, the protrusion prevents the through-hole from being formed between the discharge electrodes by the cavity and the missing part. Thus, abnormal discharge of the lamp can be prevented.

According to the invention, there is provided a closed container formed by a bottom portion, a front portion facing the bottom portion, and a side portion existing between the bottom portion and the front portion. In the flat fluorescent lamp having a pair of discharge electrodes, a gentle concave portion is formed at a corner formed by the bottom surface and the side surface, so that an inner wall surface formed by the bottom surface and the side surface between the discharge electrodes is formed. The phosphor can be applied in close contact with the inner wall surface due to the recess formed in the corner of the panel, so "shrinkage" occurs on the bottom panel and side panel during the phosphor drying process. No cavities or missing portions that cause abnormal discharge do not occur.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the structure of a flat fluorescent lamp according to the present invention.

FIG. 2 is a side sectional view of a main part of the flat fluorescent lamp of the present invention.

FIG. 3 is a sectional side view of a main part showing another embodiment of the present invention.

FIG. 4 is a sectional side view of a main part showing another embodiment of the present invention.

FIG. 5 is a sectional side view of a main part showing another embodiment of the present invention.

FIG. 6 is a sectional side view of a main part showing another embodiment of the present invention.

FIG. 7 is a sectional side view of a main part showing another embodiment of the present invention.

FIG. 8 is a perspective view showing another embodiment of the present invention.

FIG. 9 is a sectional side view of a main part showing another embodiment of the present invention.

FIG. 10 is a sectional side view of a main part showing another embodiment of the present invention.

FIG. 11 is a sectional side view of a main part showing another embodiment of the present invention.

FIG. 12 is a perspective view showing the appearance of a conventional flat fluorescent lamp.

FIG. 13 is a perspective view showing the structure of a conventional flat fluorescent lamp.

FIG. 14 is a sectional side view of a main part of a conventional flat fluorescent lamp.

FIG. 15 is a sectional side view of a main part of a conventional flat fluorescent lamp.

FIG. 16 is a sectional side view of a main part of a conventional flat fluorescent lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge electrode 2 Discharge electrode lead 3 Bottom panel part 4 Side panel part 5 Projection part 6 Phosphor 7 Concave corner part 8 Front light emitting panel 9 Main discharge space 10 Cavity part 11 Missing part

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 61/30

Claims (1)

(57) [Claims] A pair of discharge electrodes opposed to each other in a sealed container formed by a bottom portion, a front portion facing the bottom portion, and a side portion existing between the bottom portion and the front portion. The flat fluorescent lamp according to claim 1, wherein at least one protrusion is formed at a part of a corner formed between the pair of discharge electrodes and the bottom surface and the side surface.