JP2002324512A - Flat fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat fluorescent lamp of which the shadow area is made smaller. SOLUTION: In this flat fluorescent lamp, a pair of electrodes 4, 40, which generate discharges in a rear panel 3 of which the opening in an upper face is covered by a front panel 2, are fixed in a box 1, and a plurality of joint pieces 21 are disposed between both electrodes 4, 40 in the rear panel 3 in order to prevent bending deformation and cracks of the front panel 2, and the joint pieces 21 are formed only one in each virtual line S in the direction of discharges between both electrodes 4, 40, and a plurality of the joint pieces 21 are fixed on the rear panel 3 in a dispersed state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flat fluorescent lamp used as a backlight of a liquid crystal display device or the like.

[0002]

2. Description of the Related Art In electronic devices such as digital still cameras and mobile phones, liquid crystal panels are often used for displaying information. In order to project this liquid crystal panel brightly, a backlight is generally arranged, and a flat fluorescent lamp is used as the backlight. FIG. 12 is a perspective view of a conventional flat fluorescent lamp in which a part is broken. The flat fluorescent lamp has a box body (1) in which a glass front panel (2) covering an upper surface opening is joined to a glass rear panel (3) having an upper surface opening by frit glass (11). The rear panel (3) is evacuated by an exhaust pipe (12), and contains a small amount of mercury and a small amount of an inert gas such as argon for facilitating lighting. The rear panel (3) is formed in a rectangular shape, and has a pair of rod-shaped electrodes (4) and (40) provided inside the rear panel (3) substantially parallel to each other along the long side of the rear panel (3).
One electrode (40) is an anode, the other electrode (4) is a cathode,
External leads (41) for supplying pulse voltage to both electrodes (4) and (40)
(41) is connected. The cathode and anode may be reversed from FIG. A fluorescent film (not shown) is formed on the inner surfaces of the front panel 2 and the rear panel 3 (see Japanese Patent Publication No. 5-39068).

The electrodes (4) (4) are connected via external leads (41) (41).
When a high voltage is applied during 0), the electrons remaining in the rear panel (3) are attracted to the anode-side electrode (40) and move at a high speed and collide with inert gas molecules. Positive ions ionized by the collision collide with the cathode-side electrode (4) and knock out secondary electrons, so that discharge starts between the electrodes (4) and (40). The electrons flowing by the discharge collide with mercury, and the excited mercury emits ultraviolet rays. The ultraviolet light excites the phosphor, emits visible light, and illuminates the front panel (2). The electron flow due to the discharge occurs in a direction perpendicular to the longitudinal direction of the electrodes (4) and (40) in a horizontal plane including the electrodes (4) and (40). In the following description, the direction of the electron flow is defined as the discharge direction, The path of the electron flow is called a discharge path. This discharge path coincides with a virtual line S described later.

Since the inside of the rear panel (3) is decompressed,
The front panel (2) is pushed from above by atmospheric pressure. In addition, the market demands a reduction in the thickness of such flat fluorescent lamps. For this reason, since the flat fluorescent lamp is easily deformed or broken by the atmospheric pressure, in order to prevent the deformation and crack, reinforcing ribs (20) (20) for pressure resistance are provided on the back surface of the front panel (2).
(4) It is formed substantially parallel to (40). FIG.
Is a cross-sectional view taken along a plane including the line HH, and FIG. 14 is a cross-sectional view taken along a plane including the line II in FIG. The inside of the back panel (3) is made up of a plurality of cells by the reinforcing ribs (20) and (20).
(10) Partitioned into (10), the reinforcing rib (20) is on the back panel (3)
And a plurality of through-holes (22) and (22) through which an electron flow passes through the cells (10) and (10). Since the connecting piece (21) is in contact with the bottom surface of the rear panel (3), even if the front panel (2) is pressed at atmospheric pressure, bending deformation and cracking are prevented.

[0005]

FIG. 15 is a sectional plan view of the flat fluorescent lamp of FIG. 12 cut along a plane including the line FF. In a conventional flat fluorescent lamp, two or more connecting pieces (21) and (21) may be located on an imaginary line S along the discharge direction. In this case, the flow of electrons due to discharge is hindered between the connecting pieces (21), (21), and the phosphor does not emit light. Therefore, the connecting piece
(21) Between (21) and (21), for example, a shadow with reduced luminance is generated at a location indicated by D in FIG. 15, causing a problem of uneven luminance on the front panel (2). An object of the present invention is to reduce a shadow portion on a front panel in a flat fluorescent lamp.

[0006]

In a flat fluorescent lamp, a pair of electrodes (4) and (40) for generating electric discharge are opposed to each other in a rear panel (3) whose upper opening is covered by a front panel (2). Deployed. In the back panel (3), a connecting piece (21) is provided between the electrodes (4) and (40) to prevent the front panel (2) from being deformed or cracked by being pressed. Connecting piece (21)
Are formed at positions that do not overlap each other on a virtual line S along the discharge direction between the two electrodes (4) and (40).

[0007]

[Operation and Effect] The connecting piece (21) is formed on the virtual line S along the discharge direction between the two electrodes (4) and (40) so as not to overlap with each other. Only one is formed. Therefore, as before, two or more connecting pieces (21)
In the meantime, the flow of electrons due to discharge is not hindered. This makes it possible to reduce the area of a shadow portion on the front panel (2), and to make the luminance on the front panel (2) substantially uniform.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a box of a flat fluorescent lamp according to this embodiment.
FIG. 2 is a perspective view showing (1) partially broken away. The box body (1) is made of a glass back panel (3) with an open top as in the prior art.
Further, a glass front panel (2) covering the upper opening is joined by a frit glass (11). The rear panel (3) is formed in a rectangular shape, and has a pair of rod-shaped electrodes (4) and (40) for generating a discharge therein disposed substantially parallel to each other along a long side. The discharge path between the two electrodes 4 and 40 coincides with a virtual line S described later. Reinforcing ribs (20) are formed on the front panel (2) perpendicular to the discharge path. The upper surface of the front panel (2) has a plurality of convex surfaces (23) with the bulge facing upward.
(23) are provided along the discharge direction, and the reinforcing ribs (20) are formed on the back side of the lower edge of each convex surface (23). Reinforcement rib (20)
Thereby, the back panel (3) is partitioned into a plurality of cells (10) (10).

The reinforcing ribs (20) have through holes (22) and connecting pieces (21) alternately along the longitudinal direction, and the electron flow due to discharge proceeds through the through holes (22). Connecting piece (21) on back panel (3)
Therefore, even if the front panel (2) is pressed from above by the atmospheric pressure, the connecting piece (21) is stretched to prevent the front panel (2) from being deformed or cracked.

FIG. 2 is a cross-sectional view of the box body (1) of FIG. 1 cut along a plane including the line AA. FIG. 3 is a sectional view of the flat fluorescent lamp of FIG. FIG. 4 is a cross-sectional view of the flat fluorescent lamp of FIG. 1 cut along a plane including the line CC. As shown in FIGS. 2 to 4, the connecting piece (21) is formed on a virtual line S along the discharge direction between the electrodes (4) and (40) at a position where they do not overlap with each other. Only one is formed on the virtual line S. Therefore, unlike the related art, since the electron flow due to the discharge is not hindered between the two or more connecting pieces (21) and (21), the area of the shadow area on the front panel (2) is reduced. The brightness on the front panel (2) can be made substantially uniform.

FIG. 5 is a cross-sectional view of the box (1) of FIG. 1 taken along a plane including the line GG. In FIG. 5, one connecting piece (21) is provided on each of the six virtual lines S,
The number of virtual lines S provided with the connecting pieces (21) is not limited to six. In FIG. 5, none of the two connecting pieces (21) and (21) located on the adjacent virtual line S are arranged on one orthogonal virtual line L perpendicular to the virtual line S. However, as shown in FIG. 6, two connecting pieces (21) (2) located on adjacent virtual lines S
1) may be arranged on the orthogonal virtual line L. However, in this case, since the connecting piece (21) is not formed at the position on the back panel (3) shown by E in FIG. 6, the front panel (2)
Is easily bent inward at atmospheric pressure by the atmospheric pressure. Therefore, the plurality of connecting pieces (21) (21) are connected to the rear panel (3).
It is necessary to dispose the front panel (2) in a dispersed position above to effectively prevent the front panel (2) from bending inward.

FIG. 7 is a partially cutaway perspective view showing another box body (1). In this example, the upper surface of the front panel (2) is formed flat, and the connecting piece (21) projects from the back surface of the front panel (2). The connecting piece (21) contacts the bottom surface of the rear panel (3) in the same manner as above, and the front panel
(2) Prevent bending deformation and cracking due to atmospheric pressure. FIG.
Is a cross-sectional view of the flat fluorescent lamp of FIG. 7 cut along a plane including the line JJ, FIG. 9 is a cross-sectional view of the flat fluorescent lamp of FIG. 7 cut along a plane including the line KK, FIG. 10 is a cross-sectional view of the flat fluorescent lamp of FIG. 7 taken along a plane including the line LL, and FIG.
It is sectional drawing which fractured | ruptured the flat fluorescent lamp of FIG. 7 in the surface containing MM line. As shown in FIGS. 8 to 11, the connecting piece (21)
Are formed at positions that do not overlap each other on a virtual line S along the discharge direction between the two electrodes (4) and (40), that is, only one is formed on the virtual line S. Therefore, unlike the related art, the flow of electrons due to the discharge is not hindered between the two or more connecting pieces (21), (21), and the area of a shadow on the front panel (2) can be reduced.

[0013] The description of the above embodiments is for the purpose of illustrating the present invention and should not be construed as limiting the invention described in the claims or reducing the scope thereof. Further, the configuration of each part of the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made within the technical scope described in the claims. In the above example, the connecting piece (21) is provided on the front panel (2), but the connecting piece (21) may be provided on the bottom surface of the rear panel (3).

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a flat fluorescent lamp according to the present embodiment.

FIG. 2 is a cross-sectional view of the flat fluorescent lamp of FIG. 1 cut along a plane including a line AA.

FIG. 3 is a cross-sectional view of the flat fluorescent lamp of FIG. 1 cut along a plane including line BB.

FIG. 4 is a cross-sectional view of the flat fluorescent lamp of FIG. 1 cut along a plane including a line CC.

5 is a cross-sectional view of the flat fluorescent lamp of FIG. 1 cut along a plane including a line GG.

FIG. 6 is a sectional plan view of another flat fluorescent lamp.

FIG. 7 is a perspective view showing another flat fluorescent lamp partially cut away.

8 is a cross-sectional view of the flat fluorescent lamp of FIG. 7 cut along a plane including a line JJ.

9 is a cross-sectional view of the flat fluorescent lamp of FIG. 7 cut along a plane including a line KK.

10 is a cross-sectional view of the flat fluorescent lamp of FIG. 7 cut along a plane including line LL.

11 is a cross-sectional view of the flat fluorescent lamp of FIG. 7 cut along a plane including a line MM.

FIG. 12 is a perspective view of a conventional flat fluorescent lamp with a part cut away.

FIG. 13 is a cross-sectional view of FIG. 12 cut along a plane including line HH.

FIG. 14 is a cross-sectional view of FIG. 12 cut along a plane including a line II.

FIG. 15 is a cross-sectional plan view of the flat fluorescent lamp of FIG. 12 cut along a plane including the line FF.

[Explanation of symbols]

 (2) Front panel (3) Back panel (4) Electrode (21) Connecting piece (40) Electrode

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Hiroyuki Yagi 1-1, Sanyo-cho, Daito-shi, Osaka Sanyo Electronics Co., Ltd. (72) Inventor Yuji Takezono 3816-23, Okubo, Takao-cho, Izumi-gun, Kagoshima F term in the company (reference) 5C015 EE07 5C043 AA04 BB04 CD08 DD21

Claims (2)

[Claims] 1. A pair of electrodes for generating a discharge in a rear panel (3) whose upper opening is covered by a front panel (2).
(4) (40) is installed facing and both electrodes are installed in the rear panel (3).
(4) In a flat fluorescent lamp provided with a plurality of connecting pieces (21) and (21) for preventing bending deformation or cracking caused by pressing the front panel (2) between the (40), the connecting pieces ( 21) and (21) are flat fluorescent lamps formed on imaginary lines S along the discharge direction between the electrodes (4) and (40) so as not to overlap with each other. 2. A plurality of connecting pieces (21), (21) are provided on a back panel.
(3) The flat fluorescent lamp according to claim 1, wherein the flat fluorescent lamp is dispersed and arranged.