KR20080022991A - Liquid crystal display - Google Patents

Abstract

An LCD is provided to reinforce the strength of an outer side wall of a bottom chassis by forming a bent portion at a hemming part to allow the hemming part to be positioned on the same straight line with the outer side wall. A liquid crystal panel(10) displays an image. A backlight assembly provides light to the liquid crystal panel. A mold frame(80) allows the liquid crystal panel and the backlight assembly to be fixed therein. A bottom chassis(100) receives and fixes the mold frame and includes a hemming part(120) for preventing deformation by an external impact. The hemming part is formed such that an end of an outer side wall of the bottom chassis is bent outwardly to contact with an outer surface of the outer side wall. A bent portion is formed by bending the outer side wall to allow the hemming part to be on the same straight line with the outer side wall. The mold frame includes fastening protrusions(90) so as to be fastened with the bottom chassis, and the bottom chassis includes fastening holes(110) corresponding to the fastening protrusions.

Description

Liquid Crystal Display {LIQUID CRYSTAL DISPLAY}

1 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is a perspective view illustrating one cross section of the mold frame and the bottom chassis illustrated in FIG. 1.

3 is a cross-sectional view illustrating a fastening state between the mold frame and the bottom chassis illustrated in FIG. 2.

<Short description of drawing symbols>

10: liquid crystal panel 11: thin film transistor substrate

12: color filter substrate 20: drive circuit portion

30: circuit board 40: LED

41: LED substrate 50: optical sheet

51: diffusion sheet 52: prism sheet

53: protective sheet 60: light guide plate

70: reflective sheet 80: mold frame

90: fastening protrusion 100: bottom chassis

110: coupling hole 120: hemming part

130: bend

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device which prevents a fastening failure when fastening a bottom chassis and a mold frame.

In general, a liquid crystal display device includes a liquid crystal panel for displaying an image, a panel driver for driving the liquid crystal panel, and a backlight assembly for supplying light to the liquid crystal panel.

The liquid crystal panel includes a thin film transistor substrate on which a thin film transistor array is formed, a color filter substrate on which a color filter array is formed, and a liquid crystal filled between two substrates.

The panel driver includes a gate driver for driving a gate line formed on the thin film transistor substrate, a data driver for driving a data line, a timing controller for supplying a control signal to the gate driver and the data driver, and a power supply for supplying a power signal. Here, the panel driver is mounted on a circuit board or a film to supply a driving signal for driving the liquid crystal panel.

The backlight assembly includes a light source for generating light and a light guide plate for guiding light generated from the light source to the liquid crystal panel.

The liquid crystal panel, the panel driver and the backlight assembly are fixed to the mold frame. At this time, the mold frame to which the liquid crystal panel, the panel driver and the backlight assembly are fixed is accommodated in the bottom chassis, and the mold frame and the bottom chassis are fastened by a coupling member such as a hook. At this time, each of the bottom chassis and the mold frame is formed with a coupling hole and a locking protrusion for hook coupling. However, as the thickness of liquid crystal display devices becomes thinner recently, liquid crystal panels are damaged due to defects such as bending of the bottom chassis or bending of the mold frame at fastening portions fastened by coupling members such as bottom chassis and mold frame hooks. Serious problems arise.

In addition, the length of the hook of the mold frame is long, there is a problem in that the fastening process is broken or the hook is broken after the fastening process.

Accordingly, an object of the present invention is to provide a liquid crystal display device which prevents breakage of the liquid crystal panel when the mold frame and the bottom chassis are coupled to the liquid crystal display device and prevents the fastening failure caused by the breakage of the fastening protrusion of the mold frame.

In order to solve the above technical problem, the present invention accommodates a liquid crystal panel for displaying an image, a backlight assembly for supplying light to the liquid crystal panel, a mold frame to which the liquid crystal panel and the backlight assembly are fixed and the mold frame Provided is a liquid crystal display device having a bottom chassis having a hemming portion which is fixed and prevents deformation due to external impact.

Here, the hemming portion is formed by contacting the outer surface of the outer wall bent the outer wall end of the bottom chassis to the outside.

At this time, the hemming portion further forms a bent portion that is bent the outer wall to be in line with the outer wall.

The mold frame further includes a fastening protrusion for fastening with the bottom chassis, and the bottom chassis further includes a fastening hole corresponding to the fastening protrusion.

The fastening protrusion has one surface perpendicular to the fastening hole of the bottom chassis, and the other surface is inclined.

The fastening hole is formed in the bent portion of the bottom chassis.

Other preferred technical objects and features of the present invention in addition to the above technical problem will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 1 to 6.

1 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 2 is a perspective view illustrating one side cross-section of the mold frame and the bottom chassis illustrated in FIG. 1.

1 and 2, a liquid crystal display device includes a liquid crystal panel 10 for displaying an image, a driving circuit unit 20 for driving the liquid crystal panel 10, and a backlight for supplying light to the liquid crystal panel 10. An assembly, a mold frame 80 for fixing the liquid crystal panel 10 and the backlight assembly, and a bottom chassis 100 for accommodating and fixing the mold frame 80 are provided.

The liquid crystal panel 10 is filled between the thin film transistor substrate 11, the color filter substrate 12 facing the thin film transistor substrate 11, the thin film transistor substrate 11 and the color filter substrate 12, and the two substrates. A liquid crystal (not shown) which adjusts light transmittance by an electric field formed therebetween is provided.

The thin film transistor substrate 11 includes a pixel region defined by an intersection of a gate line and a data line, a thin film transistor connected to the gate line and a data line in each pixel region, and a pixel electrode connected to the thin film transistor in the pixel region.

The color filter substrate 12 includes a black matrix that prevents light leakage, a color filter formed in a region partitioned by the black matrix, and a common electrode formed on the black matrix and the color filter.

The liquid crystal is injected between the thin film transistor substrate 11 and the color filter substrate 12. The electric field is formed by the potential difference between the pixel electrode of the thin film transistor substrate 11 and the common electrode of the color filter substrate 12, and the liquid crystal embedded between the thin film transistor substrate 11 and the color filter substrate rotates to improve light transmittance. Express the image by adjusting.

The driving circuit unit 20 includes a gate driving integrated circuit (Int) for driving a gate line and a data driving IC for driving a data line, a timing controller for supplying control signals to the gate driving IC and a data driving IC, and a gate driving IC and data. And a power supply unit supplying a power signal to the driving IC and the timing controller.

The gate driving IC is formed integrally with one side of the non-display area of the thin film transistor substrate 11 or the gate driving IC is mounted on the thin film transistor substrate 11 in the form of a chip on glass (hereinafter referred to as "COG"). do. In addition, the gate driving IC may be connected to the liquid crystal panel 10 and the gate printed circuit board in the form of a tape carrier package mounted on a film. The gate driving IC sequentially supplies the gate-on voltage Von to the gate line, and supplies the gate-off voltage Voff while the gate-on voltage Von is not supplied.

The data driver IC may be integrated in one non-display area of the thin film transistor substrate 11, or the data driver IC may be mounted on the thin film transistor substrate 11 in the form of a chip on glass (hereinafter referred to as "COG"). do. In addition, the data driving IC may be connected to the liquid crystal panel 10 and the data printed circuit board in the form of a tape carrier package mounted on a film. When the gate-on voltage is supplied to the gate electrode of the thin film transistor, the data driving IC supplies the data voltage of the pixel through the data line.

On the other hand, the gate driving IC and the data driving IC may be formed integrally with one IC.

The timing controller transmits the image data signal to the data driver IC through the image data signal inputted from the outside and the synchronization signal, and generates and supplies control signals to the gate driver IC and the data driver IC.

The power supply unit uses a plurality of driving voltages, for example, a gate on voltage Von, a gate off voltage Voff, and an analog voltage AVDD supplied to the data driver IC using a DC voltage input from an external source. ) And a driving voltage for activating the driving ICs, and a common voltage Vcom supplied to the common electrode of the color filter substrate 12.

Here, the timing controller and the power supply unit may be integrally formed with the data driver IC. In particular, in a small liquid crystal display such as a mobile phone, the timing controller and the power supply unit may be formed in the data driver IC as described above.

The driving circuit unit 20 includes a circuit board 30 for supplying a signal from the outside. The circuit board 30 may use a flexible printed circuit (hereinafter referred to as "FPC") or a printed circuit board (hereinafter referred to as "PCB"). In particular, it uses FPC that is thin and bends well without disconnection of signal lines. The circuit board 30 is provided with a plurality of signal lines for transmitting image data signals from the outside and supplying a power signal for supplying DC power to the power supply unit. One side of the circuit board 30 is connected to a graphics card for transmitting an image data signal and a power supply unit for supplying DC power. The other side of the liquid crystal panel 10 is connected to one side through a conductive adhesive such as an anisotropic conductive film (ACF).

A backlight assembly light source, a light guide plate 60 for guiding light from the light source to the liquid crystal panel 10, a reflection sheet 70 for reflecting the light guide plate 60 to the light supplied to the lower portion of the light guide plate 60, and It includes a plurality of optical sheets 50 for increasing the efficiency.

The light source uses a lamp or a light emitting diode (hereinafter referred to as "LED") 40 or the like. In particular, in the case of a small liquid crystal display, an LED 40 which generates light of high brightness with low power is used. A plurality of LEDs 40 are mounted on the light source substrate 41 at equal intervals, and are driven by driving signals supplied through the light source substrate 41 to generate light.

The light source substrate 41 is formed of FPC or PCB. In addition, the light source substrate 41 includes a connector connected to an external power source in addition to the region in which the LED 40 is mounted. The light source substrate 41 may further include a heat dissipation pad for dissipating heat generated from the LED 40 to the outside. The heat dissipation pad is formed of a conductive metal and emits heat generated from the LED 40 to the outside.

The light guide plate 60 converts the line light source supplied from the light source through one side into a surface light source to guide the liquid crystal panel 10. The light guide plate 60 is formed with a plurality of 'V'-shaped grooves or protrusions to supply light supplied to the incident surface to the opposite surface.

The reflective sheet 70 is attached to the rear surface of the light guide plate 60 to reflect the light supplied to the bottom of the light guide plate 60 upward. For this purpose, it is preferable that the reflective sheet 70 uses a plate having a high light reflectivity.

The optical sheet 50 is formed on the light guide plate 60 to inject light emitted to the upper surface of the light guide plate 60 into the liquid crystal panel 10. Since the optical sheet 50 vertically generates the light emitted from the light guide plate 60 and enters the liquid crystal panel 10, the light efficiency is improved. For this purpose, the optical sheet 50 includes a diffusion sheet 51, a prism sheet 52 and a protective sheet 53.

The diffusion sheet 51 directs the light incident from the light guide plate 60 toward the front of the liquid crystal panel 10, and diffuses the light to have a uniform distribution in a wide range so that the liquid crystal panel 10 is irradiated. As the diffusion sheet 51, it is preferable to use a film made of a transparent resin coated with a predetermined light diffusion member on both surfaces. The prism sheet 52 converts the traveling angle of the light diffused by the diffusion sheet 51 to be perpendicular to the liquid crystal panel 10. This is because the light efficiency increases when the light incident on the liquid crystal panel 10 is perpendicular to the liquid crystal panel 10. The protective sheet 53 protects the surface of the prism sheet 52 and diffuses the light via the prism sheet 52.

The mold frame 80 accommodates and fixes the backlight assembly and the liquid crystal panel 10. The mold frame 80 forms a step in the outer frame to accommodate the backlight assembly and the liquid crystal panel 10. That is, the mold frame 80 is fixed in shape by the frame, and the mold is formed to be stepped on the inner side of the frame to form an accommodating fixing part by the step, so that the backlight assembly and the liquid crystal panel 10 are accommodated in the accommodating fixing part, respectively. It is fixed. At this time, in the mold frame 80, the backlight assembly is first accommodated, and then the liquid crystal panel 10 is seated and fixed on the protection sheet 53 of the backlight assembly. In this case, a top chassis or the like is used to fix the liquid crystal panel 10 mounted on the mold frame 80. However, in the case of a slim LCD, a top chassis is not used to reduce the thickness, size, and weight of the LCD. In the case where the top chassis is removed, the adhesive sheet is attached between the mold frame 80 and the liquid crystal panel 10 to fix the liquid crystal panel 10 to the mold frame 80.

In addition, a plurality of fastening protrusions 90 are formed on the outer wall of the mold frame 80. The fastening protrusion 90 is fastened to the fastening hole 110 formed in the bottom chassis 100 to be described later to fix the mold frame 80 to the bottom chassis 100. The fastening protrusion 90 has one side formed perpendicular to the outer wall and the other side formed to be inclined. When the mold frame 80 is accommodated in the bottom chassis 100, since one side of the fastening protrusion 90 is formed to be inclined, the mold frame 80 slides along the outer wall of the bottom chassis 100. After the mold frame 80 is accommodated in the bottom chassis 100, one side of the fastening protrusion 90 is caught by the fastening hole 110 because the bottom chassis 100 is formed perpendicular to the fastening hole 110. Defect does not occur.

The bottom chassis 100 receives the mold frame 80 as described above to protect the liquid crystal panel 10 and the backlight assembly accommodated in the mold frame from external physical shocks. The bottom chassis 100 is formed in a box shape having an upper portion open to accommodate the mold frame 80. The bottom chassis 100 forms a mold frame accommodating portion through four outer walls 102 formed vertically on the bottom surface 101. In this case, the end of the outer wall 102 of the bottom chassis 100 is hemmed to provide a hemming part 120, and a fastening hole 110 into which the fastening protrusion 90 of the mold frame 80 is inserted.

The hemming part 120 is formed by bending an end of the outer wall 102 of the bottom chassis 100 outward. Accordingly, the outer side of the bottom chassis 100 is doubled by the hemming part 120 and the outer wall 102 to prevent deformation of the bottom chassis 100 due to external physical shocks. The hemming portion 120 may be formed such that the outer wall 102 is triple or more by bending the tip two or more times.

In addition, the hemming part 120 prevents deformation of the bottom chassis 100 by bending the end of the outer wall 102 inward to form the bent part 130 to further reinforce the strength. At this time, the curved portion 130 is bent until the hemming portion 120 and the outer wall 102 of the bottom chassis 100 is in a straight line. Therefore, the size of the liquid crystal display device may be reduced by removing the portion protruding by the hemming unit 120 from the outside of the bottom chassis 100. In addition, the curved portion 130 has a plurality of fastening holes 110, and has an advantage of shortening the length of the fastening protrusion 90 of the mold frame 80 inserted into the fastening hole 110. In other words, as the end of the outer wall 102 of the bottom chassis 100 is bent inward, the distance of the fastening protrusion 90 formed on the mold frame 80 of the upper surface of the fastening hole 110 is closer to FIG. 3. As shown in the drawing, the length of the fastening protrusion 90 may be shortened to prevent the fastening protrusion 90 from being broken or broken when the mold frame 80 is inserted. In addition, the fastening hole 110 is formed in the bent portion 130, the lower end of the fastening protrusion 90 is formed to be inclined, and the fastening protrusion 90 is inserted into the fastening hole 110, and then the fastening protrusion 90 is moved outward. Exposure is prevented.

The bottom chassis 100 is preferably formed of a conductive material such as metal. The bottom chassis 100 formed of a metal material may protect the backlight assembly and the liquid crystal panel 10 inserted therein from external physical shocks. In addition, the bottom chassis 100 may be formed of a metal material to easily discharge heat generated from the light source of the backlight assembly to the outside.

The liquid crystal display according to the present invention may prevent the deformation of the bottom chassis due to an external physical impact by forming a hemming portion on the outside of the bottom chassis. In addition, it is possible to further strengthen the strength of the outer wall of the bottom chassis by forming a bent portion to make the end of the hemming line with the outer wall.

In addition, when the fastening protrusion formed in the mold frame is fastened to the fastening hole of the bottom chassis, the length of the fastening protrusion is shortened by the bent portion, thereby preventing the fastening protrusion.

In the detailed description of the present invention described above with reference to the preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge of the present invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the spirit and scope of the art.

Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (6)

A liquid crystal panel which displays an image; A backlight assembly supplying light to the liquid crystal panel; A mold frame to which the liquid crystal panel and the backlight assembly are fixed; And And a bottom chassis for accommodating and fixing the mold frame and having a hemming portion formed therein to prevent deformation due to external impact. The method of claim 1, And the hemming part is formed by contacting an outer surface of the outer wall by bending an outer wall end of the bottom chassis to the outside. The method of claim 2, And a curved portion bent the outer wall such that the hemming portion is in line with the outer wall. The method of claim 3, wherein The mold frame further includes a fastening protrusion for fastening with the bottom chassis, and the bottom chassis further comprises a fastening hole corresponding to the fastening protrusion. The method of claim 4, wherein The fastening protrusion has one surface perpendicular to the fastening hole of the bottom chassis, and the other surface is inclined. The method of claim 5, wherein And the fastening hole is formed in the bent portion of the bottom chassis.

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