JP3384593B2 - 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 for a backlight of a liquid crystal display device or the like.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been widely used as image display devices such as liquid crystal televisions, video cameras and computer displays. Since the liquid crystal display device itself does not emit light, a backlight is often used to illuminate the screen from behind the liquid crystal display device in order to make the screen easy to see. A cold cathode flat fluorescent lamp is used for this type of backlight. The flat fluorescent lamp is one in which two glass plates coated with fluorescent paint on the inner surface are arranged in parallel, the periphery is sealed to form a discharge chamber, and a pair of discharge electrodes is arranged in the discharge chamber. Is.

When the liquid crystal display device has a large screen and the lamp becomes large, it is necessary to make the glass substrate sufficiently thick so as to withstand atmospheric pressure. However, if the thickness of the glass substrate is increased, the weight of the lamp is increased and the external dimensions are also increased. In order to solve this problem, the present applicant has already filed Japanese Patent Application No. 4-241944.
(H01J61 / 30) has been filed. This is the 8th
The structure is as shown in the figure, which is characterized in that a plurality of ribs 2 are integrally formed on the glass substrate on the front surface or the rear surface of the lamp 1.
It is designed to withstand atmospheric pressure even with a thin glass thickness. Such a lamp is used by being attached to the back surface of the liquid crystal display device 3 as shown in FIG.

[0004]

However, in the above-mentioned lamp, since the side wall of the lamp is thick, the effective display area is the area S in FIG. That is, FIG. 10 is an enlarged view of the portion P of FIG. 9, but as can be seen from this figure, since the front glass substrate 4 and the rear glass substrate 5 are bonded by the frit glass 6, the glass substrate In addition to the thickness of the side surface, the frit glass 6 overflows, so that the effective display area becomes narrow. In the figure, 7 is a fluorescent paint and 8 is a discharge electrode.

[0005]

In order to solve the above problems, according to the present invention, a front surface is a light emitting surface, a first glass substrate having a phosphor layer on the inner surface, and a second glass substrate having a phosphor layer on the inner surface. In a flat fluorescent lamp in which the glass substrate of is opposed to each other, and the periphery of both glass substrates is airtightly bonded to each other to form a discharge chamber inside, and a pair of discharge electrodes are arranged to face each other in the discharge chamber. At the end of each glass substrate, a flange portion extending in a direction perpendicular to a plane is formed, and a flat fluorescent lamp in which both substrates are joined at the flange portion is provided.

Further, in the present invention, a first glass substrate having a phosphor layer on the inner surface and a second glass substrate having a phosphor layer on the inner surface are arranged so as to face each other, and the both glass surfaces are arranged to face each other. A flat fluorescent lamp in which a periphery of a substrate is airtightly joined to form a discharge chamber therein, and a pair of discharge electrodes are arranged to face each other in the discharge chamber, wherein a flat surface is formed at an end of each glass substrate. To form a collar portion extending in a direction perpendicular to each of them, and to form a space portion on the joint surface of the collar portion,
It is intended to provide a flat fluorescent lamp in which both substrates are joined at the collar portion.

[0007]

With the above construction, the front glass substrate and the rear glass substrate are joined together by the flange portion. In addition, the frit glass protruding during bonding is absorbed by the space and does not cover the phosphor layer.

[0008]

EXAMPLES Reference examples and examples of the present invention will be described below in detail with reference to the drawings. First, FIG. 1 is a side sectional view of an essential part showing a state in which a flat fluorescent lamp of a reference example is attached to a liquid crystal display device. Further, FIG. 2 is an enlarged view of a portion indicated by Q in FIG. In this reference example, a flange portion 4a and a flange portion 5a extending in the plane direction are formed at the ends of the front glass substrate 4 and the rear glass substrate 5, respectively, and the contact surfaces of both the flange portions are joined by a frit glass 6. The thickness of the side wall portion of the glass substrate is also thin.

Next, FIG. 3 is a further improvement of the above-mentioned reference example. In the reference example, a space is provided at a portion indicated by an arrow A to absorb the frit glass 6 protruding at the time of joining and prevent the frit glass 6 from flowing out to a region where the fluorescent paint 7 is applied. Further, since the light incident from the space portion passes through the side wall of the front glass substrate 4 and goes out from the surface indicated by the arrow B, the brightness is lowered even in the side wall portion of the lamp, and the corner of the liquid crystal display device is illuminated brightly. You can

Further, FIG. 4 is a reference example in which a chamfer shown by an arrow C is formed on the lamp shown in FIG. The chamfer formed at the rear end of the side wall increases the amount of light emission at this portion and also increases the amount of light incident on the side wall to increase the amount of light emitted from the surface indicated by arrow B.
A curved surface may be used instead of chamfering.

FIG. 5 shows an embodiment of the present invention, in which the collar portion is formed so as to extend to the rear of the lamp as shown in FIG. FIG. 6 is an enlarged view of the portion indicated by R. As described above, in this embodiment, the front glass substrate 4 and the rear glass substrate 5 are provided with the flange portion 4b and the flange portion 5b. In this embodiment, since the collar portion is housed inside the back surface of the liquid crystal display device 3, space efficiency is good,
It is convenient for downsizing.

FIG. 7 shows an embodiment in which a frit pool 5c is formed in the lamp shown in FIGS. 5 and 6, and the frit glass 6 overflowing at the time of bonding is accumulated by the frit pool 5c. The frit glass 6 is configured so as not to reach the fluorescent paint 7.

[0013]

As described above in detail, according to the present invention, the first glass substrate having the front surface as the light emitting surface and having the phosphor layer on the inner surface, and the second glass substrate having the phosphor layer on the inner surface are provided. A glass substrate is arranged to face each other, and the periphery of both glass substrates is hermetically bonded to each other to form a discharge chamber inside, and a flat fluorescent lamp in which a pair of discharge electrodes are arranged to face each other in the discharge chamber,
Since a flange portion extending in a direction perpendicular to the plane is formed at each end of each glass substrate and both substrates are joined by the flange portion, space is not required when a lamp is incorporated in a liquid crystal display device. Therefore, the entire display device can be downsized.

Further, in the present invention, a first glass substrate having a phosphor layer on the inner surface and a second glass substrate having a phosphor layer on the inner surface are arranged so as to face each other, and the both glasses are arranged to face each other. A flat fluorescent lamp in which a periphery of a substrate is airtightly joined to form a discharge chamber therein, and a pair of discharge electrodes are arranged to face each other in the discharge chamber, wherein a flat surface is formed at an end of each glass substrate. To form a collar portion extending in a direction perpendicular to each of them, and to form a space portion on the joint surface of the collar portion,
Since the two substrates are bonded together by the flange portion, the frit glass overflowing at the time of bonding does not cover the phosphor layer and narrow the light emitting surface.

[Brief description of drawings]

FIG. 1 is a side sectional view of a main part showing a structure of a flat fluorescent lamp which is a reference example.

FIG. 2 is an enlarged sectional view of an essential part showing the structure of a flat fluorescent lamp which is a reference example.

FIG. 3 is an enlarged cross-sectional view of a main part showing another reference example.

FIG. 4 is an enlarged sectional view of an essential part showing another reference example.

FIG. 5 is a side sectional view of an essential part showing an embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view of a main part showing another embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view of a main part showing another embodiment of the present invention.

FIG. 8 is a diagram showing an appearance of a conventional flat fluorescent lamp.

FIG. 9 is a side sectional view showing the structure of a conventional flat fluorescent lamp.

FIG. 10 is an enlarged sectional view of an essential part showing the structure of a conventional flat fluorescent lamp.

[Explanation of symbols]

1 Flat fluorescent lamp body 2 ribs 3 Liquid crystal display 4 Front glass substrate 5 Rear glass substrate 6 frit glass 7 Fluorescent paint 8 discharge electrodes

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-147554 (JP, A) JP-A-61-47050 (JP, A) Actually opened 61-87454 (JP, U) Actually opened 2- 65865 (JP, U) Actual development Sho 61-7859 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 61/30 H01J 61/36

Claims (2)

(57) [Claims] 1. A first glass substrate having a front surface as a light emitting surface and having a phosphor layer on an inner surface, and a second glass substrate having a phosphor layer on an inner surface.
In a flat fluorescent lamp in which the glass substrate of is opposed to each other, and the periphery of both glass substrates is airtightly bonded to each other to form a discharge chamber inside, and a pair of discharge electrodes are arranged to face each other in the discharge chamber. A flat fluorescent lamp characterized in that a flange portion extending in a direction perpendicular to a plane is formed at an end of each of the glass substrates, and both substrates are joined by the flange portion. 2. A first glass substrate having a front surface as a light emitting surface and having a phosphor layer on the inner surface, and a second glass substrate having a phosphor layer on the inner surface.
In a flat fluorescent lamp in which the glass substrate of is opposed to each other, and the periphery of both glass substrates is airtightly bonded to each other to form a discharge chamber inside, and a pair of discharge electrodes are arranged to face each other in the discharge chamber. In each of the end portions of the glass substrates, a collar portion extending in a direction perpendicular to a plane is formed, and a space portion is formed on a joint surface of the collar portion, and the both substrates are joined by the collar portion. This is a flat fluorescent lamp.