Electric lamp and discharge devices – With luminescent solid or liquid material – Vacuum-type tube
Reexamination Certificate
2001-06-29
2003-06-24
Patel, Nimeshkumar D. (Department: 2879)
Electric lamp and discharge devices
With luminescent solid or liquid material
Vacuum-type tube
C313S493000, C313S634000, C313S495000, C313S631000, C313S485000, C313S483000, C313S491000, C313S492000, C359S015000, C359S742000
Reexamination Certificate
active
06583554
ABSTRACT:
The present invention claims the benefit of Korean Patent Application No. P2000-83096 filed in Korea on Dec. 27, 2000, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a light source for a display device, and more particularly, to a flat luminescent lamp and a method for manufacturing the same.
2. Discussion of the Related Art
Ultra thin sized flat panel displays having a display screen with a thickness of several millimeters or less, and in particular, flat panel liquid crystal display (LCD) devices, are widely used as monitors in notebook computers, spacecraft, and aircraft.
In such LCD devices, a passive luminescence LCD device includes a back light positioned at the rear of a liquid crystal panel. The back light increases the weight, power consumption, and thickness of a flat panel LCD device.
The back light used in LCD devices as a light source is generally an arrangement of a cylindrical fluorescent lamp. There are two types of back lights, a direct type and a light-guiding plate type.
In the direct type back light, the fluorescent lamp is mounted under the flat panel LCD. If the fluorescent lamp is too close to the LCD flat panel, the shape of the fluorescent lamp is visible on the LCD screen. Therefore, it is necessary to maintain a distance and position between the fluorescent lamp and the liquid crystal panel. As a result, there is a limitation in reducing the thickness of an LCD device that uses a direct type back light.
Furthermore, a light-scattering means may have to be positioned between the fluorescent lamp and the liquid crystal panel for uniform light distribution. Due to the trend of increased display panel area, the light-emitting area of the back light is also increasing. If the direct type back light has a large sized area, the light-scattering means should have a sufficient thickness to make the light-emitting area have a uniform luminescent intensity. Therefore, the need for uniform light-scattering also limits the thickness reduction of the LCD device using direct type back light.
In the light-guiding plate type back light, a fluorescent lamp is mounted outside the LCD flat panel so that light is dispersed across the back surface of the LCD flat panel using a light-guiding plate. Since the fluorescent lamp is mounted at a side of the light-guiding plate, light passing through a side of the light-guiding plate has to be dispersed across the entire surface of the LCD flat panel. Therefore, luminance is low. Also, for uniform distribution of luminous intensity, advanced optical design and processing technologies are required to manufacture the light-guiding plate.
A high luminance direct type back light has been proposed in which a plurality of lamps are arranged below a display surface or a lamp is bent into a circular shape. Recently, a flat luminescent back light in which a flat surface facing a display surface of a panel is wholly luminescent is being researched and developed. This flat luminescent back light is disclosed in the U.S. Pat. No. 6,034,470.
A related art flat luminescent lamp will be described with reference to the accompanying drawings.
FIG. 1
is a plan view illustrating a related art flat luminescent lamp, and
FIG. 2
is a sectional view taken along line I-I′ of FIG.
1
.
As shown in
FIGS. 1 and 2
, the related art flat luminescent lamp includes a lower substrate
11
, an upper substrate
11
a
, cathodes
10
formed on the lower substrate
11
, anodes
10
a
formed on the upper substrate
11
a
, four frames
19
a
,
19
b
,
19
c
, and
19
d
for sealing a discharge space between the lower and upper substrates
11
a
and
11
by a solder means, such as a glass solder, and a plurality of support rods
21
formed between the lower and upper substrates
11
and
11
a
. The support rods
21
are made of glass material so as not to interrupt emission of the visible light.
The anodes
10
a
are formed in sets of pairs between support rods at constant intervals. The cathodes
10
are formed on the lower substrate
11
between the sets of pairs anodes
10
a
. The cathodes
10
and the anodes
10
a
are coated with a dielectric material (not shown), and an external voltage is applied to the cathodes
10
and the anodes
10
a
through lead lines
13
and
13
a
, respectively.
Surfaces of the upper substrate
11
a
and lower substrate
11
facing the discharge space are coated with a fluorescent material (not shown). Within the discharge space is a Xe gas for creating plasma that emits ultraviolet (UV) rays. The emitted UV rays collide with the fluorescent material formed on the upper and lower substrates
11
a
and
11
. The collision of the UV rays with the fluorescent material generates visible light.
As shown in
FIG. 2
, the cathodes
10
are formed on the lower substrate
11
of glass material, and a first dielectric material layer
12
is formed on the lower substrate
11
and the cathodes
10
. A reflecting plate
14
is formed on the first dielectric material layer
12
and a first phosphor layer
15
is formed on the reflecting plate
14
. The reflecting plate
14
serves to prevent the visible light from leaking out the rear of the lower substrate
11
. The anodes
10
a
that induces the plasma discharge together with the cathodes
10
are formed on the upper substrate
11
a
of glass material. The cathodes
10
and the anodes
10
a
are formed by silk printing or vapor deposition process.
A second dielectric material layer
12
a
is formed on the upper substrate
11
a
and the anodes
10
a
. A second phosphor layer
15
a
is formed on the second dielectric material layer
12
a
. On the upper and lower substrates
11
a
and
11
, frames
19
a
,
19
b
,
19
c
, and
19
d
are formed to seal the upper and lower substrates
11
a
and
11
by a glass solder.
In the aforementioned related art flat luminescent lamp, if a voltage is applied to the cathodes
10
and the anodes
10
a
through the respective lead lines
13
and
13
a
, Xe gas forms plasma in the discharge space between the cathodes
10
and the anodes
10
a
and emits UV rays. The UV rays collide with the first and second phosphor layers
15
and
15
a
, causing the phosphor layers to luminesce, so that the visible light is emitted.
However, the related art flat luminescent lamp has several problems. Since four frames and a number of support rods are required to seal the lower and upper substrates, a large number of parts for manufacturing the lamp are required and thus, processing steps are complicated. Furthermore, the large number of parts increases the weight and size of the lamp.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a flat luminescent lamp and a method for manufacturing the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a flat luminescent lamp and a method for manufacturing the same, in which light weight, thin size and high luminance can be obtained.
Another object of the present invention is to provide a flat luminescent lamp and a method for manufacturing the same, in which discharge efficiency can be maximized.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the scheme particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a flat luminescent lamp according to the present invention includes first and second substrates, each having a plurality of concave and convex portions on a surface; first and second electrodes alternately formed on the convex portions of the first substrate at constant intervals; a dielectric
Harper Holly
LG. Philips LCD Co. Ltd.
Patel Nimeshkumar D.
LandOfFree
Flat luminescent lamp and method for manufacturing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Flat luminescent lamp and method for manufacturing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Flat luminescent lamp and method for manufacturing the same will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3090372