Backlight assembly and display apparatus having the same

A backlight assembly includes a lamp assembly, a receiving container and a panel guiding frame. The lamp assembly includes a light source to generate light and a lamp cover to reflect the light. The receiving container includes a bottom and a sidewall. The sidewall includes a first sidewall portion facing the lamp cover and separated from the lamp cover by a first interval and a second sidewall portion separated from the lamp cover by a second interval narrower than the first interval. The panel guiding frame includes a first frame portion facing an end of the bottom and a second frame portion extended from the first frame portion along a side face of the second sidewall and having an opening corresponding to the first sidewall portion. Thus, the backlight assembly may have a reduced non-effective display area.

This application claims priority to Korean Patent Application No. 2004-113057 filed on Dec. 27, 2004, and all of the benefits occurring therefrom under 35 U.S.C. 119, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a backlight assembly and a display apparatus having the same. More particularly, the present invention relates to a backlight assembly having a reduced size and a display apparatus having the backlight assembly.

2. Description of the Related Art

In general, a liquid crystal display apparatus displays an image by varying the optical and electrical properties of the liquid crystals. The liquid crystal properties that are widely used in the creation of an image are an anisotropic refractive index and an anisotropic dielectric constant.

The liquid crystal display apparatus includes two substrates facing each other, and each of the substrates includes an electrode to form an electric field therebetween. The liquid crystal display apparatus includes a liquid crystal layer disposed between the substrates. When the electric field is applied to a liquid crystal layer, an alignment of liquid crystal molecules of the liquid crystal layer is changed and a light transmittance of a light passing through the liquid crystal layer is also changed in accordance with the alignment of the liquid crystal molecules, thereby displaying an image on the liquid crystal display apparatus.

In order to display the image, the liquid crystal display apparatus includes a liquid crystal display panel and a backlight assembly. The liquid crystal display panel includes a pair of substrates, a pixel electrode, a common electrode and the liquid crystal display layer.

The backlight assembly generates a light and supplies the light to the liquid crystal display panel. The backlight assembly includes a receiving container that receives the liquid crystal display panel, a lamp that is received into the receiving container, an optical member that improves optical properties of the light from the lamp, a panel guiding member that guides the liquid crystal display panel to the receiving container and a chassis that fixes the liquid crystal display panel to the receiving container.

However, the receiving container, the panel guiding member and the chassis are stacked up on one another, which greatly enlarges a non-effective display area with respect to a total size of the liquid crystal display panel.

SUMMARY OF THE INVENTION

The present invention provides a backlight assembly capable of reducing a non-effective display area on which an image is not displayed.

The present invention also provides a display apparatus having the above backlight assembly.

In one aspect of the present invention, a backlight assembly includes a lamp assembly, a receiving container and a panel guiding frame. The lamp assembly includes a light source to generate light and a lamp cover to reflect the light. The receiving container includes a bottom on which the lamp cover is disposed and a sidewall. The sidewall includes a first sidewall portion facing the lamp cover and being separated from the lamp cover by a first interval and a second sidewall portion that is adjacent to the first sidewall portion and is separated from the lamp cover by a second interval that is narrower than the first interval. The panel guiding frame includes a first frame portion that is disposed on an upper face of the sidewall and faces an end of the bottom, and a second frame portion that is extended from the first frame portion along a side face of the second sidewall and has an opening corresponding to the first sidewall portion.

In another aspect of the present invention, a display apparatus includes a lamp assembly, a receiving container and a panel guiding frame. The lamp assembly includes a light source to generate light and a lamp cover to reflect the light. The receiving container includes a bottom to support the lamp cover and a sidewall. The sidewall includes first sidewall portions formed at a periphery of the bottom to guide the lamp cover and second sidewall portions formed at areas corresponding between the first sidewall portions. The second sidewall portions are misaligned with the first sidewall portions. The panel guiding frame includes a first frame portion facing the end of the bottom and a second frame portion extended from the first frame portion along the sidewall and having a first opening corresponding to the second sidewall portions. The display panel is disposed on the first frame portion to display an image using the light. The chassis secures the display panel to the receiving container.

According to the above, the sidewall of the backlight assembly is overlapped with the display panel guiding member while the backlight assembly is assembled, so that the size of the non-effective display area may be reduced.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a perspective view showing a backlight assembly according to an exemplary embodiment of the present invention.FIG. 2is an exploded perspective view of the backlight assembly shown inFIG. 1.

Referring toFIGS. 1 and 2, a backlight assembly500includes a lamp assembly100, a receiving container200and a panel guiding member300. The backlight assembly500may further include a light guide plate410and an optical member420.

FIG. 3is a perspective view of the lamp assembly shown inFIG. 2.

Referring toFIG. 3, the lamp assembly100includes a lamp110and a lamp cover120. The lamp assembly100generates light to display an image.

The lamp110includes a lamp body112and a pair of electrodes (not shown). In the present embodiment, the lamp110may include a cold cathode fluorescent lamp CCFL.

The lamp body112may have various shapes, for example, such as a general bar-shape, a general U-shape, a general C-shape and so on. The lamp body112includes a discharge gas injected thereinto and a fluorescent layer formed therein. In the present embodiment, an example of the discharge gas may include mercury (Hg), argon (Ar), neon (Ne), xenon (Xe), krypton (Kr) or the like, and the fluorescent layer is formed on an inner face of the lamp body112.

The electrodes may be formed either inside or outside the lamp body112. Each of the electrodes receives a different discharge voltage generated from a power supply to one another. The discharge voltage applied to the electrodes has a voltage level difference that is sufficient to facilitate electron discharge.

The discharge gas injected into the lamp body112interacts with the discharged electron, to generate ultraviolet light in the lamp body112. The ultraviolet lights are converted into visible light as it interacts with the fluorescent layer.

The lamp cover120reflects the visible light to improve the efficiency of the visible light.

The lamp cover120includes a first light reflecting face122, a second light reflecting face124and a third light reflecting face126.

In the present embodiment, the first, second and third reflecting faces122,124and126have a rectangular plate-like shape. The first reflecting face122faces the second reflecting face124, and the third reflecting face126connects the first reflecting face122with the second reflecting face124.

The lamp assembly100may further include a lamp holder128. The lamp holder128is placed inside the lamp cover120, and the lamp110is fixed to the lamp cover120by means of the lamp holder128.

The visible light from the lamp110is reflected from the first, second and third light reflecting faces122,124and126.

FIG. 4is a perspective view of a light guide plate shown inFIG. 2.

Referring toFIG. 4, the light guide plate410is combined with the lamp cover120. The light guide plate410enhances the uniformity of brightness of the visible light from the lamp110.

The light guide plate410has a plate-like shape, for example, a generally rectangular parallelopiped shape. The light guide plate410includes a light reflecting face415, a light exiting face416facing the light reflecting face415, four side faces411,412,413and414connecting the light reflecting face415and the light exiting face416with each other.

Particularly, the side faces412and414are defined as first side faces having a first area, respectively, and the side faces411and413are defined as second side faces having a second area that is smaller than the first area, respectively. The first side faces412and414face each other, and the second side faces411and413also face each other.

Referring toFIG. 2, the lamp assembly100is disposed adjacent to the first side faces412and/or414, and the visible light from the lamp assembly100is incident into the light guide plate410through the first side faces412and414. The incident visible light into the light guide plate410exits the light guide plate through the light exiting face416.

Referring toFIG. 5, the receiving container200includes a bottom210and a sidewall220to provide the receiving space.

FIG. 6is an exemplary perspective view showing a lamp assembly coupled to a receiving container inFIG. 1.FIG. 7is an exemplary plan view showing the backlight assembly inFIG. 2.

Referring toFIGS. 3,5and7, the lamp assembly100and the light guide plate410are disposed on the bottom210of the receiving container200. The light guide plate410is disposed at a center portion of the bottom210of the receiving container200, and the lamp assembly100is disposed between the light guide plate410and the sidewall220of the receiving container200. Thus, an outer surface of the third light reflecting face124of the lamp cover120is adjacent to the sidewall220of the receiving container200.

The sidewall220of the receiving container200is extended from the bottom210in a direction substantially perpendicular to the bottom210.

The sidewall220includes a first sidewall222and a second sidewall224.

The first sidewall222is substantially parallel to the third light reflecting face124of the lamp cover100. The receiving container200includes at least two first sidewalls222formed at the periphery of the bottom210.

The first sidewall222is separated from the second light reflecting face124by a predetermined first distance T1. As can be seen in theFIG. 6, in the present embodiment, the first sidewall222includes a first catching protrusion222athat is partially protruded from the first sidewall222. The first sidewall222has a first height H1. In another embodiment, the first sidewall222may include a recess in lieu of the first catching protrusion222a.

In one embodiment, as may be seen in theFIGS. 5 and 7, the receiving container200may include at least two second sidewalls224. The second sidewalls224are disposed between the first sidewalls222, and are substantially parallel to the first sidewall222. The second sidewalls224are separated from the second light reflecting face124of the lamp cover100by a predetermined second distance T2. The second sidewalls224may include a second catching protrusion224athat is partially protruded the second sidewalls224. The second sidewalls224have a second height H2that is less than the first height H1of the first sidewall222. In another embodiment, the second sidewalls224may include a recess in lieu of the second catching protrusion224a.

In the present embodiment, the first and second sidewalls222and224are misaligned with each other. In other words, the first sidewalls222are disposed at an imaginary plane that is non-coplanar with that of the second sidewalls224. An interval G between the first and second sidewalls222and224is in a range from about 0.6 mm (millimeter) to about 5 mm in at least one direction that is substantially perpendicular to a longitudinal direction of the lamp cover100. The interval G between the first and second sidewalls222and224is substantially equal to a thickness of a second frame portion of the panel guiding member300.

FIG. 8is an enlarged perspective view of portion ‘B’ of the backlight assembly inFIG. 1.FIG. 9is a partially cut perspective view showing the backlight assembly inFIG. 8.

Referring toFIGS. 1,8and9, the panel guiding member300is coupled to the receiving container200. The panel guiding member300secures a display panel to the receiving container200.

The panel guide member300includes a first frame portion310and a second frame portion320.

FIG. 10is a cross-sectional view taken along line I-I′ of the backlight assembly inFIG. 9.

Referring toFIG. 10, the first frame portion310has a plate-like shape and faces the bottom210of the receiving container200. The first frame portion310supports the display panel.

The second frame portion320also has a plate-like shape and is integrally formed with the first frame portion310. The second frame portion320extends in a direction that is substantially perpendicular to the extension of the first frame portion310. Thus, the second frame portion320is substantially parallel to the first and second sidewalls222and224.

The second frame portion320is coupled to the second sidewall224. In order to couple the second frame portion320to the second sidewall224, the second frame portion320includes a catching recess320athat corresponds to the second catching protrusion224a. The catching recess320aand the second catching protrusion224acan be mechanically locked with each other. In one embodiment, the catching recess320amay be formed through the second frame portion320. In another embodiment, the catching recess320amay be a protrusion in the event that the second sidewall224includes a catching recess in lieu of the second catching protrusion224a.

FIG. 11is a cross-sectional view taken along line II-II′ showing the backlight assembly inFIG. 8.

Referring toFIG. 11, the second frame portion320overlaps with the first sidewall222. The second frame portion320has a thickness that is greater than that of the first sidewall222. The second frame portion320is partially removed to form an opening322through which the first sidewall222is partially exposed. In order to make contact for a portion of the first sidewall222with the second frame portion320, the second frame portion320includes a stepped portion formed therearound. In the present embodiment, the second frame320and the first sidewall222are formed on a substantially same level.

Referring toFIGS. 2 and 11, the backlight assembly500may further include the optical member420. The optical member420may include a diffusing sheet422, a prism sheet424, a brightness enhancing film426and a reflecting plate428.

The diffusing sheet422improves the uniformity of brightness of the light from the light exiting face416and enhances an angle between the light from the light guide plate410and the light reflecting face415.

The prism sheet424is disposed on the diffusing sheet422. The prism sheet424includes a prism pattern to collect the light diffused by the diffusion sheet422. The prism sheet424changes the path of the light emerging from the diffusing sheet422in a direction that is substantially perpendicular to the light reflecting face415. In the present embodiment, at least two prism sheets are disposed on the diffusing sheet422, and the prism sheets have the prism pattern substantially perpendicular to each other.

The brightness enhancing film426is disposed on the prism sheet424to enhance the brightness of the light incident into the display panel.

The reflecting plate428is disposed between the bottom of the receiving container200and the light reflecting face415of the light guide plate410to reflect the light leaked through the light reflecting face415to the light guide plate410.

FIG. 12is an exploded perspective view showing a display apparatus according to an exemplary embodiment of the present invention.

Referring toFIG. 12, a display apparatus800includes the backlight assembly500, a display panel600and a chassis700.

The backlight assembly500includes the lamp assembly100, the receiving container200and the panel guide member300. The backlight assembly500may further include the light guide plate410and the optical member420.

In order to display images on the display panel600, the lamp assembly100generates the light. The lamp assembly100includes the lamp110and the lamp cover120.

The lamp110includes the lamp body112and the pair of electrodes (not shown). In the present embodiment, the lamp110may include the cold cathode fluorescent lamp CCFL.

The lamp body112may have various shapes, for example, such as a general bar-shape, a general U-shape, a general C-shape and so on. The lamp body112includes the discharge gas (not shown) injected thereinto and the fluorescent layer (not shown) formed therein. In the present embodiment, the discharge gas may include mercury (Hg), argon (Ar), neon (Ne), xenon (Xe), krypton (Kr) or the like, and the fluorescent layer is formed on the inner face of the lamp body112.

The electrodes may be formed either inside or outside the lamp body112. Each of the electrodes receives a different discharge voltage generated from a power supply through an inverter to one another. The discharge voltage applied to the electrodes has a sufficient difference in voltage levels to facilitate electron discharge.

The discharge gas injected into the lamp body112interacts with the discharged electron, to generate ultraviolet lighting the lamp body112. The ultraviolet light is converted into the visible light due to the interaction of the ultraviolet light with the fluorescent layer.

The lamp cover120reflects the visible light to improve the efficiency of the visible light.

The lamp cover120includes the first light reflecting face122, the second light reflecting face124and the third light reflecting face126(referring toFIG. 10).

In the present embodiment, the first, second and third reflecting faces120,122and124have a rectangular plate-like shape. The first reflecting face122faces the second reflecting face124, and the third reflecting face126connects the first reflecting face122and the second reflecting face124.

The lamp holder128is placed inside the lamp cover120, and the lamp110is fixed to the lamp cover120by means of the lamp holder128.

The visible light from the lamp110is reflected from the first, second and third light reflecting faces122,124and126.

The light guide plate410is combined with the lamp cover120. The light guide plate410enhances the uniformity of brightness of the visible light from the lamp assembly100. The light guide plate410has a plate-like shape such as a general rectangular parallelopiped shape. The light guide plate410includes the light reflecting face415, the light exiting face416facing the light reflecting face415, and the four side faces411,412,413and414connecting the light reflecting face415and the light exiting face416(referring toFIG. 4).

Particularly, the side faces412and414are defined as the first side faces having a first area, respectively, and the side faces411and413are defined as the second side faces having a second area that is smaller than the first area, respectively. The first side faces412and414face each other, and the second side faces411and413also face each other.

The lamp assembly100is disposed adjacent to at least one of the first side faces, and the visible light from the lamp assembly100is incident into the light guide plate410through the first side faces. The incident visible light exits the light guide plate410through the light exiting face416.

The receiving container200includes the bottom210and the sidewall220to provide the receiving space.

The lamp assembly100and the light guide plate410are disposed on the bottom210of the receiving container200. The light guide plate410is disposed at a center portion of the bottom210of the receiving container200, and the lamp assembly100is disposed between the light guide plate410and the sidewall220of the receiving container200. Thus, the outer surface of the third light reflecting face126of the lamp cover120faces the sidewall220of the receiving container200.

FIG. 13is an assembled perspective view of the display apparatus inFIG. 12.FIG. 14is a cross-sectional view taken along line III-III′ showing the display apparatus inFIG. 13.FIG. 15is a cross-sectional view taken along line IV-IV′ showing the display apparatus inFIG. 13.

Referring toFIGS. 13 to 15, the sidewall220of the receiving container200is extended from the bottom210in a direction substantially perpendicular to the bottom210.

The sidewall220includes the first sidewall222and the second sidewall224.

The receiving container200includes at least two first sidewalls222formed at a periphery of the bottom210. The first sidewall222is separated from the third light reflecting face124by the predetermined first distance. In the present embodiment, the first sidewall222includes the first catching protrusion222athat partially protrudes from the first sidewall22. Also, the receiving container200may include at least two second sidewalls224. The second sidewalls224are disposed between the first sidewalls222, and are substantially parallel to the first sidewall222. The second sidewalls224are separated from the third light reflecting face124of the lamp cover100by the predetermined second distance. The second sidewalls224may include the second catching protrusion224athat partially protrudes from the second sidewalls224. The second sidewalls224have the second height that is less than the first height of the first sidewall222.

In the present embodiment, the interval G between the first and second sidewalls222and224is in a range from about 0.6 mm to about 5 mm in the direction substantially perpendicular to a longitudinal direction of the lamp cover100. The interval G between the first and second sidewalls222and224is substantially equal to the thickness of the second frame portion of the panel guiding member300(referring toFIG. 12).

The panel guiding member300is coupled to the receiving container200. The panel guiding member300secures the display panel to the receiving container200.

The panel guide member300includes the first frame portion310and the second frame portion320.

The first frame portion310has a plat-like shape and faces the bottom210of the receiving container200. The first frame portion310supports the display panel.

The second frame portion320also has the plate-like shape and is integrally formed with the first frame portion310. The second frame portion320is extended in a direction that is substantially perpendicular to the direction that the first frame portion310is extended in. Thus, the second frame portion320is substantially parallel to the first and second sidewalls222and224.

The second frame portion320is coupled to the second sidewall224. In order to couple the second frame portion320to the second sidewall224, the second frame portion320includes the catching recess320athat corresponds to the second catching protrusion224a. The catching recess320amay be formed through the second frame portion320, or the catching recess320amay be the protrusion in case that the second sidewall224includes the catching recess320ain lieu of the second catching protrusion224a.

The second frame portion320overlaps with the first sidewall222and has a thickness that is greater than that of the first sidewall222. The second frame portion320is partially removed to form the opening322through which the first sidewall222is partially exposed. In order to allow a portion of the first sidewall222to make contact with the second frame portion320, the second frame portion320includes the stepped portion formed therearound. Thus, the second frame320and the first sidewall222are formed on the substantially same level.

The backlight assembly500(referring toFIG. 12) may further include the optical member420. The optical member420may include the diffusing sheet422, the prism sheet424, the brightness enhancing film426and the reflecting plate428.

The diffusing sheet422improves the uniformity of brightness of the light from the light exiting face416and enhances an angle between the light from the light guide plate410and the light reflecting face415.

The prism sheet424is disposed on the diffusing sheet422. The prism sheet424includes a prism pattern to collect the light diffused by the diffusing sheet422. The prism sheet424changes the path of the light from the diffusing sheet422in the direction substantially perpendicular to the light reflecting face415. In the present embodiment, at least two prism sheets424are disposed on the diffusing sheet422, and the prism sheets424have the prism pattern substantially perpendicular to each other.

The brightness enhancing film426is disposed on the prism sheet424to enhance the brightness of the light incident into the display panel.

The reflecting plate426is disposed between the bottom200of the receiving container200and the light reflecting face415of the light guide plate410to reflect the light leaked through the light reflecting face415to the light guide plate410.

The display panel600is disposed on the first frame portion310of the panel guiding member300. The display panel600includes a thin film transistor substrate610, a color filter substrate620and a liquid crystal layer630.

The thin film transistor substrate610includes a plurality of pixel electrodes, a plurality of thin film transistors electrically connected to the pixel electrodes and a plurality of signal lines to drive the thin film transistor.

The pixel electrodes are formed on the thin film transistor substrate610in a matrix configuration, the thin film transistors are electrically connected to the pixel electrodes through a drain electrode thereof, respectively.

The signal lines include first signal lines connected to gate electrodes of the thin film transistors, respectively, and second lines connected to source electrodes of the thin film transistors, respectively.

The color filter substrate620includes a common electrode facing the pixel electrodes and color filters corresponding to the pixel electrodes, respectively.

The liquid crystal layer630is disposed between the thin film transistor610and the color filter substrate620.

The chassis700includes a first chassis portion710and a second chassis portion720to prevent separation of the display panel600from the display panel guiding member300.

The first chassis portion710has a plate-like shape and is formed along an end of the display panel600. The first chassis portion710covers the end of the display panel600, thereby preventing the separation of the display panel600from the display panel guiding member.

The second chassis portion720is extended from the first chassis710along the second frame portion320of the display panel guide member300. The second chassis720is coupled to the second sidewall224via the catching recess320a.

The second chassis720includes an engaging portion722formed at the first sidewall222corresponding to the catching protrusion222a. The first catching protrusion222ais coupled with the engaging portion722, thereby securing the chassis700to the receiving container200.

As described above, by introducing an overlap between the sidewall of the backlight assembly with the display panel guiding member during the assembling of the backlight assembly, the size of the non-effective display area can be reduced.