Electric lamp and discharge devices: systems – Plural power supplies – Plural cathode and/or anode load device
Reexamination Certificate
2002-01-16
2003-12-09
Wong, Don (Department: 2821)
Electric lamp and discharge devices: systems
Plural power supplies
Plural cathode and/or anode load device
C315S291000, C315S239000, C315S220000, C315S312000, C345S102000
Reexamination Certificate
active
06661181
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a liquid crystal display (hereinafter referred to as “LCD”) device, and more particularly to a backlight assembly and an LCD device having the same for improving a wiring connection of electrode lines of lamps that provide the light source for the backlight of the LCD device to minimize the size of the LCD device and to reduce the manufacturing cost.
2. Description of the Related Art
In recent years, information processing appliances have been rapidly developed to have a variety of forms and functions and faster information processing speed. The information processed in such an information processing apparatus has an electrical signal format. A display device serving as an interface is required for a user to confirm the information processed in the information processing apparatus by the naked eyes.
Currently, an LCD device having functions of manifesting full-color and attaining high resolution while attaining lightweight and small size compared with the conventional CRT-type display device. As the result, the LCD device has been widely available as a computer monitor that is a representative information processing apparatus, a household wall-hanging television and so on.
The LCD device applies electric fields to a liquid crystal layer to convert its molecular arrangement. Then, the LCD device converts the changes of the optical properties such as birefringence, optical linearity, dichroism and optical scattering characteristic of liquid crystal cells according to the molecular arrangement, and uses the modulation of the light by the liquid crystal cells.
The LCD device is largely sorted into a TN (Twisted Nematic) type and a STN (Super-Twisted Nematic) type. The liquid crystal display device is, according to the driving method, sorted into an active matrix display type, which uses a switching device and a TN liquid crystal, and a passive matrix type, which uses an STN liquid crystal.
A distinguishable difference of two types is that the active matrix display type is applied to a TFT-LCD that drives the LCD by using a TFT and the passive matrix display type does not use a complicated circuit associated with a transistor.
Also, according to a method of using a light source, it is classified into a transmissive LCD device using a backlight and a reflective LCD using an external light source.
Despite the increased weight and volume, the transmissive LCD device using the backlight as the light source is widely used, because it can independently display images without using an external light source.
FIG. 1
is an exploded perspective view schematically showing a conventional LCD device.
FIGS. 2
,
3
and
4
are circuit diagrams more specifically showing lamps of the backlight assembly shown in FIG.
1
and configurations of an inverter module for driving the lamps.
Referring to
FIG. 1
, an LCD device
900
is formed by an LCD module
700
for displaying an image by being supplied with an image signal, and a face panel case
810
and a rear panel case
820
for retaining LCD module
700
. Here, LCD module
700
has a display unit
710
including an LCD panel
712
for displaying the image.
Display unit
710
includes LCD panel
712
, a data-side printed circuit board (PCB)
714
, a gate-side PCB
719
, a data-side tape carrier package
716
and a gate-side tape carrier package
718
.
LCD panel
712
has a thin film transistor (TFT) substrate
712
a
, a color filter substrate
712
b
and a liquid crystal (not shown).
TFT substrate
712
a
is a transparent glass substrate formed with thin film transistors on a matrix. Source terminals of the TFTs are connected with data lines, and gate terminals are connected with gate lines. Also, drain terminals are formed with pixel electrodes consisting of a transparent conductive material such as Indium-Tin-Oxide (ITO).
Once electrical signals are supplied to the data lines and gate lines, the source terminals and gate terminals of respective TFTs receive the electrical signals. In accordance with the input of the electrical signals, the TFTs are turned-on or turned-off to supply the electrical signals required for forming the pixels to the drain terminals.
A color filter substrate
712
b
is provided facing TFT substrate
712
a
. Color filter substrate
712
b
is formed via a thin film processing of RGB pixels that display predetermined colors when light goes through. Color filter substrate
712
b
is coated with a common electrode formed of ITO over the front surface thereof.
When the power is supplied to the gate terminals and source terminals of the transistors on the aforementioned TFT substrate
712
a
, an electric field is formed between the pixel electrode and common electrode of color filter substrate
712
b
. This electric field changes the alignment angle of the liquid crystal injected between TFT substrate
712
a
and color filter substrate
714
b
. The light transmissivity changes in accordance with the alignment angle. This allows to have a desired pixel status.
In order to control the alignment angle of the liquid crystal of LCD panel
712
and the period of aligning the liquid crystal, a driving signal and a timing signal are supplied to the gate line and data line of the TFT. As shown in the drawing, tape carrier package
716
that is one of a soft circuit board that determines the period of applying the data driving signal is attached to the source side of LCD panel
712
. Also, gate-side tape carrier package
718
that is one of the soft circuit board that determines the period of applying the gate driving signal is attached to the gate side thereof.
Data-side PCB
714
and a gate-side PCB
719
for respectively supplying the driving signals to the gate line and data line after being externally received with an image signal out of LCD panel
712
are respectively connected to data tape carrier package
716
on the data line side of LCD panel
712
and gate tape carrier package
718
on the gate line side thereof. Data-side PCD
714
is formed of a source portion that receives the image signal generated from an external information processing apparatus (not shown) such as a computer to supply a data driving signal to LCD panel
712
. Also, gate-side PCB
719
is formed with a gate portion for supplying a gate driving signal to the gate line of LCD panel
712
. In other words, data-side PCB
714
and gate-side PCB
719
generate the gate driving signal and data signal for driving the LCD device and a plurality of timing signals for supplying the driving signals at the appropriate period, so that the gate driving signal is supplied to the gate line of LCD panel
712
via gate-side tape carrier package
718
and the data signal is supplied to the data line of LCD panel
712
via data tape carrier package
716
.
A backlight assembly
720
for supplying the consistent light to display unit
710
is provided under the display unit
710
. Backlight assembly
720
includes 1st and 2nd lamp units
723
and
725
equipped at both ends of LCD module
700
for generating the light. 1 st and 2 nd lamp units
723
and
725
are respectively formed by 1st and 2nd lamps
723
a
and
723
b
and 3 rd and 4 th lamps
725
a
and
725
b
, which are respectively shielded by first and second lamp covers
722
a
and
722
b.
Light guide plate
724
is large enough to correspond to LCD panel
712
of display unit
710
to underlie LCD panel
712
for changing the path of light while guiding the light generated from 1st and 2nd lamp units
723
and
725
toward display unit
710
. In
FIG. 1
, light guide plate
724
is of an edge-type having a uniform thickness, which has lamp units at both ends of light guide plate
724
for enhancing the light efficiency. The number of first and second lamp units
723
and
725
may be properly set to be arranged by considering the overall balance of LCD device
900
.
A plurality of optical sheets
726
are provided to the upper side of light guide plate
724
to make the luminance of light outgoing from light guide plate
724
Alemu Ephrem
McGuireWoods LLP
Wong Don
LandOfFree
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