Backlight assembly, liquid crystal display having the same and method thereof

A backlight assembly including a universal lamp unit with a common connecting structure coupling a lamp and an inverter through a lamp socket and a conductor when connecting the lamp and the inverter with each other, a liquid crystal display including the same and a method of manufacturing thereof. Backlight assembly includes a mold frame including a receiving space therein and a lamp unit disposed in the receiving space of the mold frame. The lamp unit includes at least one lamp, and at least one pair of lamp sockets disposed on the mold frame. The pair of lamp sockets secure the lamp and apply electric power to the lamp.

This application claims priority to Korean Patent application No. 10-2006-0054358 filed on Jun. 16, 2006, and all the benefits accruing therefrom under 35 U.S.C. §119, the contents of which are herein incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a backlight assembly and a liquid crystal display having the same, and more particularly, to a backlight assembly including a lamp unit from which a wire is removed and using a lamp socket, and a liquid crystal display having the same.

2. Description of the Related Art

The application range of a liquid crystal display (“LCD”) has been extended because of its good lightweight, thin, low-power drive, full color and high resolution characteristics. Such an LCD has been recently used in a computer, a notebook computer, personal digital assistant (“PDA”), a telephone, TV, an audio/video device, and the like. The LCD is used to adjust an amount of light transmitted in accordance with image signals applied to a number of control switches arrayed in a matrix form and then to display desired images on an LCD panel. Since such an LCD is not self-luminescent, a light source such as a backlight is required. A lamp has been widely used as such a light source. In such a case, a method of connecting a wire to an inverter through a soldering process has been used to supply the lamp with electric power.

FIG. 1is a view showing the schematic configuration of a lamp unit according to the prior art. Referring toFIG. 1, the lamp unit includes a lamp1, a lamp reflector2for reflecting light emitted from the lamp, an inverter (not shown) for supplying the lamp with electric power, a lamp wire4composed of first and second lamp wires4aand4bfor transferring electric power from the inverter to the lamp, a lamp connector5for connecting the lamp wire to the inverter and a lamp holder3.

As described above, the related art lamp unit is configured in such a manner that the lamp is connected to the inverter by connecting the lamp connector5fixed to one end of the lamp wire4to an input connector (not shown) of the inverter.

However, since a variety of the input connectors of the inverters may be provided to meet the customer requirements, a variety of the lamp connectors should also be manufactured in correspondence with the various shapes and configurations of the input connectors of the inverters. Thus, even though the specifications of the liquid crystal display panel, the driving circuit and the backlight assembly are identical to one another, the LCD may be inevitably developed and produced as a different model due to difference in the structure of the lamp connector. Therefore, there are problems in that the development expense is increased, the production efficiency is lowered, and the production control is difficult.

Accordingly, there is a need to develop a universal connection structure for coupling a lamp and an inverter, which can be utilized in a variety of backlight assemblies regardless of the change of the lamp connector in a case where major parts of the backlight assembly are commonly used in multiple specifications.

BRIEF SUMMARY OF THE INVENTION

An exemplary embodiment provides a backlight assembly including a universal lamp unit with a common connecting structure for coupling a lamp and an inverter through a lamp socket and a conductor when connecting the lamp and the inverter with each other, and a liquid crystal display including the same.

In an exemplary embodiment there is provided a backlight assembly including a mold frame including a receiving space therein and a lamp unit disposed in the receiving space of the mold frame. The lamp unit includes at least one lamp and a lamp socket disposed on the mold frame. The lamp socket secures the lamp and applies electric power to the lamp.

In an exemplary embodiment, the lamp socket comprises at least one pair of lamp sockets.

In an exemplary embodiment, the lamp unit may further include an inverter supplying electric power to the lamp and a conductor electrically connecting the lamp socket and the inverter

In an exemplary embodiment, the lamp unit may further include an inverter printed circuit board. The inverter is mounted on the inverter printed circuit board.

In an exemplary embodiment, the inverter or the inverter printed circuit board is disposed on the mold frame.

In an exemplary embodiment, the lamp unit may further include a first connector formed at one end of the conductor and a second connector formed at one end of the inverter printed circuit board. The second connector is connected electrically and mechanically to the first connector.

In an exemplary embodiment, the mold frame includes a plurality of sidewalls, and a seating portion protruding inward from the sidewalls.

In an exemplary embodiment, at least one pair of lamp sockets are disposed on the sidewall of the mold frame or on a top surface of the seating portion.

In an exemplary embodiment, the inverter or the inverter printed circuit board may be disposed on a top or bottom surface of the seating portion of the mold frame.

In an exemplary embodiment, the conductor may be disposed on a top or bottom surface of the seating portion of the mold frame.

In an exemplary embodiment, the lamp may include a lamp tube including discharge gas and fluorescent material layer and electrode portions installed at both ends of the lamp tube supplying electric power to the lamp.

In an exemplary embodiment, each of the pair of lamp sockets includes a body formed with a receiving portion on which the lamp is placed and a conductive fixing portion formed within the receiving portion and connected electrically to the electrode portion of the lamp.

In an exemplary embodiment, the lamp unit may further include a lamp reflector disposed at one side of the lamp and reflecting light emitted from the lamp.

In an exemplary embodiment, a backlight assembly may further include a light guide plate disposed at one side of the lamp unit and a plurality of optical sheets disposed on the light guide plate.

In an exemplary embodiment, the backlight assembly may further include a lower receiving container coupled with the mold frame.

In an exemplary embodiment, there is provided a liquid crystal display including a mold frame provided with a predetermined receiving space therein, a lamp unit including at least one lamp and at least one pair of lamp sockets disposed on the mold frame, and a liquid crystal display panel for displaying image thereon. The lamp sockets secure the lamp and apply electric power to the lamp

An exemplary embodiment includes a method of manufacturing a backlight assembly, The method includes forming a mold frame including a receiving space and disposing a lamp unit in the receiving space. The lamp unit includes a lamp and a pair of lamp sockets securing the lamp and applying power to the lamp. The disposing a lamp unit includes disposing the lamp sockets on the mold frame.

DETAILED DESCRIPTION OF THE INVENTION

For example, an implanted region illustrated as a rectangle will, typically, have rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the invention.

FIG. 2is a schematic cross-sectional view of a lamp according to the present invention, andFIGS. 3A and 3Bare schematic perspective and cross-sectional views of a lamp and a lamp socket according to the present invention.

Referring toFIG. 2, a lamp410includes a lamp tube415and an electrode portion418. The lamp tube415includes a tube body411, a fluorescent material layer412and discharge gas413. The electrode portions418, each including a lamp electrode418aand a power supplying member418b, such as a lead wire, are provided at both ends of the lamp tube415, respectively.

When electric power is applied to the lamp410including the lead wire418bas in the illustrated exemplary embodiment, the electric power is supplied to the lamp electrode418aconnected to the lead wire418b. The discharge gas413residing in the tube body411is converted into plasma to emit invisible light which in turn excites the fluorescent material layer412to emit visible light to the outside of the lamp410.

Referring toFIGS. 3A and 3B, a pair of lamp sockets420are disposed on a mold frame (not shown) and spaced apart from each other at a certain interval. The lamp410is coupled and secured between the pair of lamp sockets420.

The lamp socket420includes a body421and a conductive fixing portion423. A receiving portion422serving as a space in which the lamp410is securely placed is formed in the body421. The conductive fixing portion423is electrically connected to the lead wire418bof the lamp410and formed at an inner portion (or side) of the body421.

One end of the conductive fixing portion423is shaped to correspond (e.g. in shape, dimension and/or location) to the lead wire418b. The other end of the conductive fixing portion423extends to a rear surface of the lamp socket420. The conductive fixing member423may include a surface or portion exposed to an outside of the lamp socket420such that the lamp410is supplied with power. As in the illustrated exemplary embodiment, the conductive fixing portion423forms an “L” shape. Of course, the shape of the conductive fixing portion423and lamp socket is not limited thereto but can be changed in various shapes to enable the lamp410to be coupled and fixed to the lamp socket420and to be supplied with electric power. The conductive fixing portion423serves to supply the lead wire418bwith electrical power and also serves to fix the entire lamp410by securing the lead wire418b. In one exemplary embodiment, the lamp socket420may be integrally formed with the mold frame. In an alternative exemplary embodiment, the lamp socket may be separately manufactured and then coupled with the mold frame.

As in the illustrated exemplary embodiment, if the lamp410is mounted to the lamp sockets420, it is not necessary to provide the lamp wire and the lamp connector as used in the prior art. Advantageously, a driving failure of the backlight assembly caused by the breaking of the lamp wire can be reduced or effectively prevented in the process of assembling the backlight assembly. Furthermore, since a process of connecting the lamp and the lamp wire may be omitted, there is an advantage in that the time taken to assemble the backlight assembly can be reduced.

FIG. 4is an exploded perspective view of an exemplary embodiment of a liquid crystal display including a backlight assembly according to the present invention.

Referring toFIG. 4, the liquid crystal display (“LCD”) includes an upper receiving container300, an LCD panel100, driving circuit units200and220, a plurality of optical sheets700, a lamp unit400, a light guide plate500, a mold frame800and a lower receiving container900.

The LCD panel100includes a color filter substrate110and a thin film transistor (“TFT”) substrate120. The color filter substrate110may be a substrate formed through a thin film forming process with an RGB (Red, Green, Blue) color filter that serves as a color pixel from which a predetermined color is produced while light passes through the pixel. A common electrode made of a transparent conductor such as indium tin oxide (“ITO”) or indium zinc oxide (“IZO”) may be coated on a front surface of the color filter substrate.

The TFT substrate120may be a transparent glass substrate on which TFTs are formed substantially in a matrix pattern. Data lines are connected to source terminals of the TFTs, gate lines are connected to gate terminals thereof, and pixel electrodes each including a transparent electrode made of a transparent conductive material are connected to drain terminals thereof. When electric signals are input to the data and gate lines, the respective TFTs are turned on or off such that the electrical signals required in the formation of pixels can be applied to the drain terminals. If electric power is applied to the gate and source terminals of the TFT substrate to turn on a TFT, an electric field is created between the pixel electrodes and the common electrodes of the color filter substrate. As a result, the liquid crystal injected between the TFT substrate and the color filter substrate changes its arrangement, and thus, the light transmittance is also changed in accordance with the changed alignment, so that desired images can be obtained.

The driving circuit units200and220are connected to the LCD panel100. The driving circuit units200and220include a gate-side printed circuit board (“PCB”)224equipped with a control integrated circuit (“IC”) to apply a predetermined gate signal to the gate line of the TFT substrate120, a data-side PCB210equipped with a control IC to apply a predetermined data signal to the data line of the TFT substrate120, a gate-side flexible PCB222for connecting the TFT substrate120and the gate-side PCB224, and a data-side flexible PCB230for connecting the TFT substrate120and the data-side PCB210. The gate-side and data-side PCBs210and244are connected to the gate-side and data-side flexible PCBs222and230, respectively, to apply a gate driving signal and an external image signal. In an exemplary embodiment, the gate-side and data-side PCBs224and210may be integrated into a single PCB. In addition, since each of the gate-side and data-side flexible PCBs222and230is mounted with a driving IC (not shown), digital power, RGB (Red, Green, Blue) signals or the like generated from the gate-side and data-side PCBs224and210can be transmitted to the LCD panel100. In the illustrated exemplary embodiment, a tape-automated bonding (“TAB”) mounting method is described. Alternative exemplary embodiments may apply a chip on glass (“COG”) mounting method in which a driving IC is not mounted to the flexible PCBs222and230, but to the TFT substrate120.

The upper receiving container300is formed into a substantially rectangular frame having a planar portion and sidewall portions. The sidewall portions are bent perpendicular to each other, to prevent the LCD panel100and the driving circuit units220and200from being separated from the receiving container and to protect the LCD panel and the driving circuit units from external shock.

The lamp unit400includes the lamp410, the lamp sockets420, an inverter430, a conductor (not shown) and a lamp reflector470. In one exemplary embodiment, a cold cathode-ray tube type lamp may be used as the lamp410, but the present invention is not limited thereto. That is, a variety of lamps can be employed in the present invention. As in the illustrated exemplary embodiment, the lamp reflector470is disposed on one side of the lamp410to reflect light emitted radially from the lamp410in one direction, e.g. toward an incident surface of the light guide plate500, so that an efficiency of light can be maximized.

The lamp sockets420are disposed on the mold frame800at a certain interval, e.g. an interval corresponding to a length of the lamp410. The lamp410is coupled and fixed between the pair of lamp sockets420disposed on the mold frame800.

The inverter430supplies the lamp410with electric power and is disposed on the mold frame800. The lamp sockets420and the inverter430are electrically connected to each other through a conductor (not shown) formed on the mold frame800.

As in the exemplary embodiment, only one lamp is used, but the present invention is not limited thereto. In alternative exemplary embodiments, two or more lamps may be employed in the present invention. If the two or more lamps are used, a plurality of the lamp sockets corresponding in number to the lamps are installed on the mold frame.

The light guide plate500is coupled with the lamp reflector470to convert a line light source such as lamp unit400into a surface light source. In exemplary embodiments, a wedge-type plate (seeFIG. 4) or parallel flat plate can be used as the light guide plate500. In one exemplary embodiment, a reflection plate (not shown) may be disposed below the light guide plate500. A plate with high light reflectivity may be used as the reflection plate and installed such that it is brought into contact with an upper surface of a bottom of the lower receiving container900.

The optical sheet700is disposed on the light guide plate500to allow luminance distribution of the light emitted from the light guide plate500to be uniform.

The mold frame800is shaped substantially as a rectangular frame with a receiving space formed therein. The light guide plate500, the lamp unit400and a plurality of optical sheets700are accommodated in the receiving space.

The mold frame800is composed of a plurality of sidewalls810and a seating portion820. The plurality of sidewalls810are formed into a substantially rectangular frame and the seating portion820protrudes inward from the sidewalls810and supports the light guide plate500, a plurality of optical sheets700and the like received in the mold frame800. The lamp sockets420, the inverter430and the like may be disposed in a receiving space defined in the rectangular frame. As in the illustrated exemplary embodiment, the seating portion820protruding from the sidewalls810is separate from and coupled to the sidewalls810. In an alternative exemplary embodiment, the seating portion820can be formed integrally with the sidewalls810. A step portion may be formed on an inner side of each sidewall and thus can serve as the seating portion.

As in the illustrated exemplary embodiment, the lamp sockets420are formed integrally with the seating portion820of the mold frame, the present invention is not limited thereto. In exemplary embodiments, a hook (not shown) for securing the lamp socket420to the mold frame800may be formed on an outer surface of the body421of the lamp socket420. A groove (not shown) that can be coupled with the hook may be formed on the mold frame800, so that the lamp socket420can be coupled with the mold frame800through a coupling structure including the hook and groove. In an alternative exemplary embodiment, the lamp socket420and the mold frame800may be coupled with each other through another coupling structure different from the hook-and-groove coupling structure.

The lower receiving container900is coupled with the mold frame800to receive the aforementioned components of the LCD therein.

The driving circuit units220and200and the inverter430of the lamp unit400are connected to a power supply unit (not shown) and a system cable (not shown) to receive electric power necessary to operate the LCD from the power supply section.

FIG. 5is a partial perspective view of another exemplary embodiment of a backlight assembly according to the present invention andFIG. 6is a partial perspective view of another exemplary embodiment of a backlight assembly according to the present invention.

The exemplary embodiments shown respectively inFIG. 5andFIG. 6are different from the embodiment inFIG. 4in that the inverter430of the lamp unit400is mounted onto an inverter printed circuit board450and the inverter printed circuit board450is then disposed on the mold frame800. Hereinafter, features inFIGS. 5 and 6different from that ofFIG. 4will be described.

The mold frame800and only some parts of the lamp unit400disposed on the mold frame800among the backlight assembly are illustrated inFIGS. 5 and 6. The other parts of the backlight assembly are omitted from these figures for convenience of illustration. Referring toFIG. 5, the lamp sockets420are disposed on the mold frame800at a certain interval, e.g. an interval corresponding to a length of the lamp410, and the lamp410is coupled and secured between a pair of lamp sockets420disposed on the mold frame800.

The inverter430supplies the lamp410with electric power. The inverter430is mounted on the inverter printed circuit board450which in turn is disposed on the mold frame800. The lamp socket420and the inverter printed circuit450are electrically connected to each other through the conductor440formed on the mold frame800. In an exemplary embodiment, the inverter PCB450and/or the conductor440may be disposed on the mold frame800such that an upper surface of the inverter PCB450and the conductor440are substantially level with or protrude from a corresponding surface of the mold frame (e.g. the seating portion820) by a minimal distance so that the light guide plate500is accommodated efficiently in the mold frame800.

The mold frame800includes a plurality of sidewalls810and a seating portion820. The lamp sockets420are disposed on one surface, i.e. an upper surface, of the seating portion820of the mold frame. The inverter printed circuit board450and the conductor440are also disposed on a top surface of the seating portion820of the mold frame. Referring toFIG. 6, the inverter printed circuit board450and the conductor440are disposed on the other surface, i.e. a bottom or rear surface, of the seating portion820of the mold frame800.

As in the illustrated exemplary embodiments ofFIGS. 5 and 6that the inverter printed circuit board450is disposed on the seating portion820of the mold frame, the present invention is not limited thereto. In an alternative exemplary embodiment, the inverter printed circuit board may be disposed on a variety of locations of the mold frame. In one exemplary embodiment, the inverter printed circuit board450can be arranged on an inner surface of the sidewall810of the mold frame.

FIGS. 7A and 7Bare partial perspective and enlarged views of another exemplary embodiment of a backlight assembly according to the present invention.

The exemplary embodiment shown inFIGS. 7A and 7Bis different from those embodiments illustrated inFIGS. 4-6in that the inverter printed circuit board450of the lamp unit400is electrically and structurally connected to the conductor440through a connector. Hereinafter, features ofFIGS. 7A and 7Bdifferent from those ofFIGS. 4-6will be described.

Referring toFIGS. 7A and 7B, the lamp sockets420are disposed on the mold frame800at a certain interval, e.g. an interval corresponding to a length of the lamp410and the lamp410is coupled and secured between a pair of lamp sockets420disposed on the mold frame800. The inverter430for supplying electric power to the lamp410is mounted on the inverter printed circuit board450which in turn is disposed on the mold frame800. The lamp sockets420and the inverter printed circuit board450are electrically connected to each other through the conductor440formed on the mold frame800. The lamp sockets420, the inverter printed circuit board450and/or the conductor440may be disposed on a top surface of the seating portion820of the mold frame800. In an alternative exemplary embodiment, the lamp sockets420, the inverter printed circuit board450and/or the conductor440may be disposed on a bottom or rear surface of the seating portion820of the mold frame800. The lamp sockets420, the inverter printed circuit board450and/or the conductor440may be disposed on an inner side (e.g. toward the receiving space) of the sidewall810of the mold frame800.

A first connector461is formed at one end of the conductor440and a second connector462electrically and mechanically connected to the first connector461is formed at one end of the inverter printed circuit board450. As in the illustrated exemplary embodiment, the first connector461is formed with a box-shape body and a coupling groove formed in one side of the body (e.g. corresponding to the side proximate to the inverter circuit PCB) at a certain depth. The second connector462formed at one end of the inverter printed circuit board450is coupled into the coupling groove of the first connector461such that the two connectors are electrically and mechanically connected with each other. As a result, the conductor440and the inverter printed circuit board450are connected to each other through a connector unit460including the first and second connectors461and462.

As in the illustrated exemplary embodiments, a structure for coupling the lamp and the inverter can be implemented within the lamp socket. Advantageously, there exists a possibility that a variety of different backlight assemblies should not be required or produced due to the change of only the lamp connector.

The illustrated exemplary embodiments have advantages in that the development expense for the backlight assembly is reduced, the production efficiency is improved and the production control becomes relatively simple.

The backlight assembly and the liquid crystal display having the same according to exemplary embodiments according to the present invention as described above are merely illustrative embodiments. Although the edge type backlight assembly is described as being used in the present invention, the present invention is not limited thereto. That is, the present invention can be applied to a direct type backlight assembly.

Although the present invention has been described in detail in connection with the preferred embodiment, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto within the technical spirit and scope of the present invention. It is also apparent that the modifications and changes fall within the scope of the present invention defined by the appended claims.