Title: Vertical-type backlight unit having removable lamp module cartridges
Abstract: A vertical-type backlight unit for flat panel display apparatuses. The vertical-type backlight unit includes a plurality of lamps installed in a housing in substantially parallel manner. A plurality of reflection plates are combined with corresponding lamps to constitute independent lamp module cartridges, each of which is removable from one side of the housing. A diffusing pad/plate is disposed over the plurality of lamp module cartridges for diffusing light. An optical sheet is optionally provided on the diffusing pad/plate.
Patent Number: 6,947,104 Issued on 09/20/2005 to Yu, et al.
| Inventors:
|
Yu; Chuan-Pei (I-Lan Hsien, TW);
Hsieh; Chin-Kun (Hsin-Chu, TW);
Liu; Han-Chou (Hsin-Chu, TW)
|
| Assignee:
|
AU Optronics Corp. (Hsin-Chu, TW)
|
| Appl. No.:
|
604918 |
| Filed:
|
August 26, 2003 |
Foreign Application Priority Data
| May 29, 2003[TW] | 92114629 A |
| Current U.S. Class: |
349/61; 315/169.3; 349/58; 349/67; 349/70; 349/112; 362/611; 362/632 |
| Intern'l Class: |
G02F 001/13.35; G02F 001/13.33; F21V 007/04; G09G 003/10 |
| Field of Search: |
349/58,61,62,64,67,70,112,113
315/169.3
362/26,31
|
References Cited [Referenced By]
U.S. Patent Documents
| 6111622 | Aug., 2000 | Abileah.
| |
| 6147724 | Nov., 2000 | Yoshii et al.
| |
| 6491411 | Dec., 2002 | Itoh.
| |
| 2003/0026085 | Feb., 2003 | Ueda et al.
| |
| 2004/0012763 | Jan., 2004 | Yu et al.
| |
| 2004/0062034 | Apr., 2004 | Hsieh et al.
| |
| 2004/0119418 | Jun., 2004 | Moon.
| |
| 2004/0223313 | Nov., 2004 | Yu et al.
| |
| 2004/0232853 | Nov., 2004 | Hur et al.
| |
| Foreign Patent Documents |
| 11-002813 | Jun., 1999 | JP.
| |
Primary Examiner: Chowdhury; Tarifur R.
Attorney, Agent or Firm: Hsu; Winston
Claims
1. A backlight unit, comprising:
a plurality of lamp tubes arranged in parallel within a housing; wherein each
of the lamp tubes has one low-voltage end connected to a first plastic capping
piece and one high-voltage end connected to a second plastic capping piece; wherein
a first connector is installed at a rear side of the first plastic capping piece
and has a terminal therein to electrically connect to the low-voltage end of the
lamp tube; wherein the first connector is electrically connected to a second connector
through a first wiring line, and the second connector is electrically connected
to the high-voltage end of the lamp tube through a second wiring line;
a plurality of reflection plates disposed underneath each of the plurality of
lamp tubes and each of the reflection plates being integrated with corresponding
lamp tubes to constitute an independent lamp module cartridge, which is removable
from one side of the housing; and
a diffusing plate disposed over the plurality of lamp tubes and fixed on the
housing, the diffusing plate being used to scatter the light generated by the plurality
of lamp tubes.
2. The backlight unit of claim 1, wherein the lamp tubes are cold cathode fluorescent lamps.
3. The backlight unit of claim 1, further comprising an optic film disposed on
the diffusing plate, and the optic film comprising a diffusing sheet, a prism sheet,
and a polarization transmission/reflection sheet.
4. The backlight unit of claim 1, wherein the first plastic capping piece is
embedded on a first sidewall of the housing and the second plastic capping piece
is embedded on a second sidewall opposite to the first sidewall of the housing.
Description
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a vertical-type backlight unit suited for flat
display panels, and more particularly, to a vertical-type backlight unit having
a plurality of removable lamp module cartridges.
2. Description of the Prior Art
Backlight modules are known as a key component for the liquid crystal displays,
which are widely applied to different kinds of products such as digital cameras,
notebooks, personal digital assistants (PDAs), mobile phones, vehicle satellite
navigation systems, computer monitors, flat panel TVs and so on. Since the liquid
crystal displays are passive luminous devices, a back light unit is required for
the LCD devices to meet the requirements of night vision and full color imagery.
Basically, the back light unit, which is disposed under the display panel, comprises
a luminous means and a diffuser for generating light beams and scattering the light
beams uniformly to the display panel. According to the position of the luminous
means, the back light units are divided into several types, such as the vertical-type
back light unit, in which the light source is generated under the display panel,
or the edge-type back light unit, in which the light source is projected from the
edges. Among all kinds of back light units, since the vertical back light unit
generates light beams under the display panel, therefore, the vertical back light
units are widely used in large size display panels or those display panels which
need high brightness, such as TV sets.
Referring to FIG. 1, it is a cross-sectional view of a vertical back light
module
50 according to the prior art. The vertical back light module
50
is disposed under a display panel
12 and comprises a plurality of lamp tubes
14, a diffusing plate
56, and a reflection plate
18. The lamp
tubes
14 are arranged in a close chamber
30 defined by the diffusing
plate
56 and the subjacent metal reflection plate
18. The reflection
plate
18 is utilized for upwardly reflecting the light source generated
by the lamp tubes
14 and thereby increase the light use efficiency of the
back light module
50. The diffusing plate
56 is employed for scattering
the light source to the display panel
12. Typically, the diffusing plate
56 is made of acrylic or propylene carbonate (PC) having a light transmittance
of about 50% to 80%. In some cases, a diffusing sheet
20 and an optical
film
22 are disposed over the diffusing plate
56. Typically, the
diffusing sheet
20, which is made of acrylic or PC, has a higher light transmittance
than that of the diffusing plate
56 and has a thickness of about 0.11 mm
to 0.15 mm.
However, the above-described prior art vertical backlight unit
50
has a drawback in that it is time-consuming and very inconvenient to change the
lamp tubes. When one of the lamp tubes does not function well or becomes out of
order, the users have to carefully remove the display panel
12, the diffusing
sheet
20, the optical film
22, and then the diffusing plate
56
from the housing with a screw or other like tools to replace it with a new one.
Occasionally, some people abandon the whole liquid crystal display device that
only has one or two lamp tubes out of order because they don't know how to change
the lamp tubes. In light of the foregoing, it becomes apparent that there is a
need for an improved vertical backlight unit module that is convenient for the
users to change lamp tubes when some of which are out of order.
SUMMARY OF INVENTION
It is therefore one object of the present invention to provide a vertical type
backlight unit having a plurality of independent lamp module cartridges, each of
which is removable from one side of the LCD housing.
According to one preferred embodiment of the present invention, a vertical-type
backlight unit comprises a plurality of lamp tubes arranged in parallel within
a housing, a plurality of reflection plates disposed underneath each of the plurality
of lamp tubes and each of the reflection plates being integrated with corresponding
lamp tubes to constitute an independent lamp module cartridge, which is removable
from one side of the housing, and a diffusing plate disposed over the plurality
of lamp tubes and fixed on the housing, the diffusing plate being used to scattering
the light generated by the plurality of lamp tubes.
It is advantageous to use the present invention because users can easily change
a broken lamp tube directly from one side of the panel housing manually. The present
invention provides time-effective and convenient lamp tube changing mechanism.
The users don"t even need a screw or other tools to change the lamp tubes.
Other objects, advantages, and features of the present invention will become
more clearly and readily apparent from the following detailed description when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross-sectional view of a vertical back light module according to
the prior art;
FIG. 2 is a cross-sectional view showing the backlight unit according to the
first preferred embodiment of the present invention;
FIG. 3 is a schematic oblique view showing a single lamp module cartridge of
FIG. 2 according to the first preferred embodiment of the present invention;
FIG. 4 is schematic cross-sectional view showing a vertical backlight unit according
to the second preferred embodiment of the present invention; and
FIG. 5 is a schematic diagram showing the independent lamp module according
to the present invention.
DETAILED DESCRIPTION
FIG. 2 is a cross-sectional view showing the backlight unit
50 according
to the first preferred embodiment of the present invention. FIG. 3 is a schematic
oblique view showing a single lamp module cartridge of FIG. 2 according to the
first preferred embodiment of the present invention. As shown in FIG. 2, a vertical
backlight unit
50 is installed underneath a flat panel
60 such as
an LCD flat panel. The backlight unit
50 comprises a housing
54,
a diffusing pad or diffusing plate
51 fixed on the housing
54, a
plurality of reflection slots
52, and a plurality of lamp tubes
53
disposed in corresponding reflection slots
52. Each of the plurality of
lamp tubes
53 is integrated with each of corresponding reflection slots
52 constitute a lamp module cartridge, as indicated in FIG.
3. The
lamp module cartridge can be removed or changed independently from one side of
the housing
54 without the need of removing the flat panel or reflection
optical components. The reflection slot plates
52 are made of U-shaped metal
plates having similar size. A through hole
521 is located in the metal plate
for accommodating a wiring line (not shown).
The lamp tubes
53 may be cold cathode fluorescent lamps (CCFL) arranged
in corresponding chambers defined by the diffusing plate
51 and the plurality
of reflection slot plates
52. Each of the reflection slot plates
52
has a flat bottom surface and two oblique reflection walls. Preferably, the reflection
slot plates
52 are made of aluminum metal or alloys, foamed PET, or PC resins,
but not limited thereto. The diffusing plate
51 is made of poly (methyl
methacrylate) (PMMA), propylene carbonate, PET polyester, or the like. According
to the preferred embodiment of this invention, the diffusing plate
51 is
made of PMMA and has a thickness of few millimeters. Optionally, an optic film
(not shown) comprising a diffusing sheet, a prism sheet, and a polarization transmission/reflection
sheet may be disposed on the top of the diffusing plate
51.
Referring to FIG. 4, it is a schematic cross-sectional view showing a vertical
backlight unit
70 according to the second preferred embodiment of the present
invention. FIG. 5 is a schematic diagram showing the independent lamp module according
to the present invention. As shown in FIG. 4, likewise, the vertical backlight
unit
70 is installed underneath the flat panel
80. The backlight
unit
70 comprises a housing
74, a diffusing plate
71 fixed
on the housing
74, a flat reflection plate
72, and a plurality of
lamp tubes
73 arranged in parallel manner between the reflection plate
72
and the diffusing plate
71. Each of the plurality of lamp tubes
73
is integrated with the housing
74 to become an independent and removable
lamp module. The lamp module design enables a user to change lamp tubes that are
out of order independently from one side of the housing
74 without affect
other well functioning lamp tubes. As shown in FIG. 4, the lamp tube
73
has one low-voltage end connected to a first plastic capping piece
75 and
one high-voltage end connected to a second plastic capping piece
76. The
first plastic capping piece
75 and the second plastic capping piece
76
may be made of silicon rubber or other silicone-like materials and are removably
embedded at opposite sidewalls of the housing
74. A low-voltage end connector
77 having therein a terminal (not shown) is installed in the first plastic
capping piece
75. The low-voltage end of the lamp tube
73 is electrically
connected to the terminal in the low-voltage end connector
77 from the rear
side of the first plastic capping piece
75. A high-voltage end connector
78 is electrically connected to the low-voltage end connector
77
through a first wiring line
79a. The high-voltage end connector
78
is electrically connected to the high-voltage end of the lamp tube
73 through
a second wiring line
79b. When the lamp tube
73 is out of
order, the user can unplug the low-voltage end connector
77 and disconnect
the low-voltage end connector
77 from the low-voltage end of the broken
lamp tube
73. Then, the first and second plastic capping pieces
75
and
76 are removed to change the lamp tube
73.
In accordance with the second preferred embodiment of this invention, the lamp
tubes
73 may be cold cathode fluorescent lamps (CCFL) arranged in a chamber
defined by the diffusing plate
71 and the reflection plate
72. The
reflection plate
72 has a flat bottom surface and is made of aluminum metal
or alloys, foamed PET, or PC resins, but not limited thereto. The diffusing plate
71 is made of poly (methyl methacrylate) (PMMA), propylene carbonate, PET
polyester, or the like. According to the second preferred embodiment of this invention,
the diffusing plate
71 is made of PMMA and has a thickness of few millimeters.
Optionally, an optic film
91 and a diffusing sheet
92 may be disposed
on the top of the diffusing plate
71.
It is advantageous to use the present invention because users can easily change
a broken lamp tube directly from one side of the panel housing manually. In addition,
the present invention provides time-effective and convenient lamp tube changing
mechanism. The users don''t even need a screw or other tools to change the lamp tubes.
Those skilled in the art will readily observe that numerous modifications and
alterations of the present invention method may be made while retaining the teachings
of the invention. Accordingly, the above disclosure should be construed as limited
only by the metes and bounds of the appended claims.
*
