Illumination – Elongated source light unit or support – Plural sources or supports therefor
Reexamination Certificate
2002-12-24
2004-09-28
Husar, Stephen (Department: 2875)
Illumination
Elongated source light unit or support
Plural sources or supports therefor
C362S249070, C362S033000
Reexamination Certificate
active
06796678
ABSTRACT:
The present invention claims the benefit of the Korean Patent Application No. P2002-28429 filed in Korea on May 22, 2002, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a backlight device and a method of fabricating the same, and more particularly, to a direct-type backlight device and a method of fabricating the same for a liquid crystal display.
2. Discussion of the Related Art
In general, cathode ray tubes (CRTs) are commonly employed as display devices for televisions, machines, and information terminals. However, CRTs fail to meet the current trend of miniature and light weight electronic products due to the size and weight of CRTs. Thus, many efforts have been made to study and develop various types of display devices as substitutions for CRTs, such as liquid crystal display devices (LCDs), plasma display panels (PDPs), electro-luminescence displays (ELDs), and vacuum fluorescent displays (VFDs). For example, LCDs have been actively developed as flat display panels in laptop computers, desktop computers, and large-sized information displays because of their high quality image, lightness, small thickness, compact size, and low power consumption. Most LCDs are passive devices in which images are displayed by controlling an amount of light input from an outside light source. Thus, a separate light source (backlight device) is generally employed for irradiating a LCD.
There are two types of backlight device, an edge light-type and a direct-type, based on arrangement of the cylindrical fluorescent lamp within the device. An edge light-type backlight device has a lamp unit installed at a side portion of a light guiding plate for guiding light. Further, the lamp unit includes a lamp for emitting light, a lamp holder inserted at both ends of the lamp for protecting the lamp, and a lamp reflective plate for enclosing an outer circumference of the lamp, such that the reflective plate reflects the light generated from the lamp toward the light guiding plate. Alternatively, lamp units can be installed at opposing side portions of the light guiding plate to form a dual edge light-type backlight device, such that if one lamp unit fails to turn on, the luminance of the screen is lowered but an image can still be displayed as a whole on a LCD panel. Moreover, the edge light-type backlight devices are commonly employed in small-sized LCDs of the laptop computer and desktop computer because they produce uniform light, have high endurance and maintain sliminess of the LCDs.
A direct-type backlight device has a plurality of lamps arranged in series to directly irradiate an entire surface of a LCD panel. The direct-type backlight devices are mainly used in large-sized LCDs (20 inches or more), and they have higher efficiency of light usage and longer lifetime than the edge light-type backlight devices. However, LCDs employing the direct-type backlight device are more susceptible to a failed lamp, such that if one lamp unit fails, the portion where the lamp is not turned on becomes remarkably dark and a portion of an image may be lost on a LCD panel. Accordingly, the lamps of the direct-type backlight devices are frequently replaced.
FIG. 1
is a perspective view of an edge light-type backlight device according to the related art, and
FIG. 2
is a perspective view of a connector connected with a fluorescent lamp of an edge light-type backlight device according to the related art. In
FIG. 1
, an edge light-type backlight device of a LCD includes a plurality of fluorescent lamps
1
, an outer case
3
for fixedly supporting the fluorescent lamps
1
, and a light scattering system
5
a
,
5
b
, and
5
c
arranged between the fluorescent lamps
1
and the LCD panel (not shown). The light scattering system
5
a
,
5
b
, and
5
c
prevents the shape of the fluorescent lamps
1
from appearing on a display surface of the LCD panel, and uniformly distribute light generated from the fluorescent lamps
1
. The light scattering system
5
a
,
5
b
, and
5
c
are composed a plurality of diffusion sheets and diffusion plates. Further, a reflective plate is formed on an inner bottom surface of the outer case
3
to reflect the light generated from the fluorescent lamps
1
toward the display surface of the LCD panel, thereby maximizing the luminance of the LCD panel.
In
FIG. 2
, a fluorescent lamp
1
is a cold cathode fluorescent lamp having internal electrodes
2
and
2
a
at the ends thereof, such that the fluorescent lamp
1
emits light when a power is applied to the electrodes
2
and
2
a
. In
FIG. 1
, the ends of the fluorescent lamp
1
are inserted in openings formed at opposing faces of the outer case
3
. Power incoming lines
9
and
9
a
are connected to the ends of the fluorescent lamp
1
and to a connector
11
for transferring a lamp driving power to the fluorescent lamp
1
from a driving circuit (not shown).
However, in the aforementioned backlight device, a connector is necessary for every fluorescent lamp, such that the interconnection of the plurality of fluorescent lamps becomes complicated. Also, to decrease the thickness of the backlight device, a further step of bending the power incoming lines is needed when the power incoming lines are connected to the connector, thereby increasing production time and production cost. Moreover, an opening of the outer case has to be made to hold the fluorescent lamp and to expose the electrodes of the fluorescent lamp, thereby making maintenance and repair of the fluorescent lamp difficult.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to a backlight device and a method of fabricating the same that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a backlight device and a method of fabricating the same in which the assembling work of the lamps is simplified, the productivity is maximized, and the maintenance and repair are easy.
Another object of the present invention is to provide a backlight assembly made in a structure capable of preventing the fluorescent lamp from being damaged due to an external impact.
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 structure 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 backlight device includes a plurality of fluorescent lamps arranged parallel with each other along a first direction, first and second lamp fixing assemblies arranged facing each other along a second direction, the first and second lamp fixing assemblies having a plurality of at least once bent grooves to receive both ends of the fluorescent lamps, a plurality of lamp holders disposed within the grooves to affix both ends of each of the plurality of fluorescent lamps to the grooves, and first and second conductive layers disposed at the first and second lamp fixing assemblies to supply a voltage to the fluorescent lamps.
In another aspect, a method of fabricating a backlight device includes forming first and second lamp fixing assemblies facing each other along a first direction, forming a plurality of at least once bent grooves in the first and second lamp fixing assemblies along a second direction, arranging ends of a plurality of fluorescent lamps within the grooves, disposing a plurality of lamp holders within the grooves to affix the ends of each of fluorescent lamps to the grooves, and disposing first and second conductive layers at the first and second lamp fixing assemblies to apply a voltage to the fluorescent lamps.
It is to be understood that both the foregoing general description and
Husar Stephen
LG.Philips LCD Co. , Ltd.
Morgan & Lewis & Bockius, LLP
Ton Anabel
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