KR20080000370A - Back light unit and liquid crystal display having this - Google Patents

Abstract

A backlight unit and an LCD including the same are provided to prevent electrical interaction between a lower chassis and a backlight power unit by forming the lower chassis of an insulating material. A light source generates light. A lower chassis(150) receives the light source, and is molded with an insulating material. A backlight power unit(160) provides driving power to the light source and includes a circuit pattern formed as a single-layered substrate, and its rear surface is insulated. Separation members(153,154) separate the lower chassis and the backlight power unit from each other at a predetermined interval. The insulating material is plastic. Coupling members(181,182) mount the backlight power unit at one side end portion of the separation member. The separation member is a protrusion having a predetermined height.

Description

BACK LIGHT UNIT AND LIQUID CRYSTAL DISPLAY HAVING THIS}

1 is a perspective view showing a liquid crystal display according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a coupling structure of a backlight power supply unit and a control PCB mounted on a lower chassis of the liquid crystal display of FIG. 1.

3 is a perspective view of a liquid crystal display according to a second exemplary embodiment of the present invention.

4 is a cross-sectional view illustrating a coupling structure of a backlight power supply unit and a control PCB mounted on a lower chassis of the liquid crystal display of FIG. 3.

<Description of drawing protection for main parts of drawing>

110: upper chassis 120: liquid crystal display panel

130: mold frame 141: optical sheet

142: light guide plate 143: lamp

150: lower chassis 160: backlight power unit

170: control PCB 153,154,191: spacer

181,182,192: fastening member

The present invention relates to a backlight unit and a liquid crystal display device having the same, and more particularly, to a backlight unit and a liquid crystal display device having the same, which can be made slimmer by improving the mounting structure of the backlight power supply unit.

Recently, flat panel displays such as liquid crystal displays (LCDs) and plasma display panels (PDPs) are rapidly developing in place of cathode ray tubes (CRTs).

Among the flat panel display devices, the liquid crystal display device does not emit light unlike a plasma display device, and thus, a back light unit including a light source such as a lamp is required to visually recognize the display content. Shall be.

The backlight unit includes at least a lamp for generating light and a backlight power supply for supplying power to the lamp, wherein the lamp is housed in a bottom chassis, and the backlight power supply is mounted to the rear of the lower chassis. is average.

However, in the conventional backlight unit, since the lower chassis formed of a metal material and the backlight power supply unit that generate high pressure in the operation process may cause electrical interaction, a sufficient safety distance is secured and mounted. Therefore, it has a considerable volume, which makes it difficult to slim. In addition, since the backlight power supply unit of the conventional backlight unit uses a multi-layered substrate in forming a circuit pattern for connecting each electric element, a circuit pattern is partially formed on the rear surface of the substrate to attach an additional insulation sheet for insulation thereof. Because of this, there was a problem that the price rises.

Therefore, in the present invention, the lower chassis is formed of an insulating material to prevent electrical interaction with the backlight power supply unit, and thus the slimming is possible by reducing the safety distance, and the backlight power supply unit is formed of a single layer substrate so that no separate insulating sheet is required. SUMMARY OF THE INVENTION It is an object of the present invention to provide a backlight unit capable of reducing cost according to the omission of a sheet and a liquid crystal display device having the same.

According to an aspect of the present invention, there is provided a backlight unit including a light source for generating light, a lower chassis accommodating the light source and molded with an insulating material, and providing driving power to the light source, wherein a circuit pattern is provided in a single layer. And a spacer configured to be formed of a substrate to insulate a rear surface thereof, and to separate the lower chassis from the backlight power supply by a predetermined distance.

It is preferable to use plastic as the insulating material.

The backlight unit may further include a fastening member for mounting the backlight power supply unit at one end of the spacer.

The spacer is formed integrally with the lower chassis, characterized in that the protrusion formed to a predetermined height.

The backlight power supply unit may include an inverter circuit and a transformer circuit.

A liquid crystal display device according to the present invention for achieving the above object, the liquid crystal display panel for image display, a light source for providing an image display light to the liquid crystal display panel, and the molding is formed of an insulating material to accommodate the light source A lower power supply, a backlight power supply for supplying driving power to the light source, the circuit pattern being formed of a single layer substrate, and having a rear surface insulated from the lower chassis, and a spaced apart member spaced apart from the lower power supply by a predetermined distance. do.

The liquid crystal display device may further include a control PCB for generating various electrical signals required for driving the liquid crystal display panel. The control PCB may be spaced a certain distance by the spacer member.

It is preferable to use plastic as the insulating material.

The liquid crystal display may further include a fastening member for mounting the backlight power supply unit at one end of the spacer.

The spacer is formed integrally with the lower chassis, characterized in that the protrusion formed to a predetermined height.

The backlight power supply unit may include an inverter circuit and a transformer circuit.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention;

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art the scope of the invention. It is provided for complete information. Like reference numerals in the drawings refer to like elements.

<First Embodiment>

First, a liquid crystal display according to a first embodiment of the present invention will be described.

1 is a perspective view illustrating a liquid crystal display according to a first exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating a coupling structure of a backlight power supply unit and a control PCB mounted on a lower chassis of the liquid crystal display of FIG. 1.

Referring to FIG. 1, the liquid crystal display includes a liquid crystal display panel 120 for displaying an image, backlight units 140 and 160 for providing image display light to the liquid crystal display panel 120, and the liquid crystal display panel ( A control printed circuit board (Control PCB) 170 for generating a variety of electrical signals required for the drive of the 120 is included.

Although not shown, the liquid crystal display panel 120 includes a liquid crystal layer interposed between the upper substrate and the lower substrate disposed to face each other.

The upper substrate has a plurality of red (R), green (G), and blue (B) color filters for coloring by incidence of light incident from the pixel region, and a plurality of blacks blocking light incident from the non-pixel region. The matrix is a transparent substrate arranged in a lattice structure. A common electrode formed of a transmissive conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is formed on an opposite surface of the upper substrate.

The lower substrate is a transparent substrate in which a plurality of thin film transistors (TFTs), which are switching elements, are arranged in a lattice structure. A data line is connected to a source electrode of the thin film transistors, a gate line is connected to a gate electrode, and a pixel electrode formed of a light transmissive conductive material such as ITO or IZO is connected to a drain electrode.

The data PCB 121 and the gate PCB 122 are connected to the liquid crystal display panel 120, and the data PCB 121 is connected to the control PCB 170 through a flexible printed circuit (FPC) (not shown). It is electrically connected to receive a predetermined signal. In this case, the data PCB 121 is electrically connected to a data line formed on the liquid crystal display panel 120 to transmit a gray voltage, and the gate PCB 122 is electrically connected to a gate line to transmit a driving signal. Of course, the data PCB 121 and the gate PCB 122 may be integrated into one.

The backlight units 140 and 160 may include a light source, preferably a lamp 143, a lamp clamp 144, a light guide plate 142 coupled thereto, a plurality of optical sheets 141 and a lower part installed on the light guide plate 142. And a backlight power supply unit 160 mounted to the rear surface of the chassis 150. Although the lamp 143 is disposed on one side of the light guide plate 142 in this embodiment, the present invention is not limited thereto, and the lamp 143 may be disposed on both sides of the light guide plate 142 (edge type).

The lamp 143 provides light for image display to the liquid crystal display panel 120. The lamp 143 is a cold cathode fluorescent lamp comprising a glass tube coated with a phosphor on an inner surface, two electrodes formed on both sides of the glass tube, and an encapsulating gas such as Ne, Ar, and Hg filled in the glass tube. It is effective to use 143. When the driving power is applied to the two electrodes of the cold cathode fluorescent lamp 143, the encapsulating gas inside the glass tube is excited to emit light firstly, whereby the phosphor emits light secondly to generate a white light source capable of expressing R, G, and B. Will be provided. If a small screen, ultra thin, and ultra power saving is required, such as a liquid crystal display device used in a portable device, the light emitting diode may be used as the lamp 143.

The lamp clamp 144 has fixing means for fixing the lamp 143 and reflecting means for collecting light. The lamp clamp 144 maximizes the light utilization efficiency by condensing the light generated radially from the lamp 143 in one direction.

The light guide plate 142 is coupled to the lamp clamp 144 to convert light having an optical distribution in the form of a line light source generated by the lamp 143 into light having an optical distribution in the form of a surface light source. As the light guide plate 142, a wedge type plate or a parallel flat plate may be used.

The optical sheet 141 is disposed above the light guide plate 142 to uniform the luminance distribution of the light emitted from the light guide plate 142.

The backlight power supply unit 160 provides driving power to the lamp 143. The backlight power supply unit 160 includes a substrate 161 having a predetermined circuit pattern, an inverter 162 and a transformer 163 mounted on the substrate 161. The current converted into alternating current by the inverter 162 is boosted or stepped down by the transformer 163 to be suitable for driving the lamp 143 and is transmitted to the lamp 143.

The substrate 161 of the backlight power supply unit 160 is preferably formed in a single layer, not formed of a multi-layered circuit pattern. In forming a circuit pattern on the substrate 161, it is common to form a circuit pattern in multiple layers and to form a via hole in the crossing area in order to avoid a part of the circuit pattern crossing (short circuit). Since a jumper may be formed in place of the via hole to prevent the circuit pattern from crossing, the circuit pattern may be formed in a single layer. As such, when the backlight power supply unit 160 is formed of a single layer substrate, a circuit pattern is not exposed through via holes or the like on the back surface where the electric element is not mounted, thereby achieving an electrically insulated state. Therefore, as in the case of a multilayer substrate, an insulation film additionally mounted on the rear surface of the substrate 161 may be omitted.

In the control PCB 170, a timing control circuit, a voltage drop circuit, an AD converting circuit, and the like are formed to drive image signals and supply power applied from the outside, suitable for driving the liquid crystal display panel 120 and the backlight power supply unit 160. It is converted into operating power and transmitted to the data PCB 121, the gate PCB 122, and the backlight power supply 160. Various electrical signals generated by the control PCB 170 are transmitted to the data PCB 121 through an FPC (not shown). Of course, the FPC may be connected to the gate PCB 122 and may be connected to both the gate PCB 121 and the data PCB 122.

The storage space provided by the combination of the upper chassis 110 and the lower chassis 150 protects the edge of the liquid crystal display panel 120 which is weak to impact and fixes a mounting position of the optical sheet 141. 130 is accepted.

The upper chassis 110 is formed in a rectangular frame shape having a planar portion in which an opening region for exposing the pixel region of the liquid crystal display panel 120 to the outside and a sidewall portion bent at right angles therefrom. In this case, a plurality of recesses 111a and 111b for fastening with the lower chassis 150 may be formed in the sidewall part.

The front side of the lower chassis 150 is formed with a side wall portion extending from the edge of the bottom surface to provide a storage space having a predetermined depth, and the rear surface of the lower chassis 150 has protrusions 153 and 154 extending from a portion of the bottom surface. Is formed to provide a spaced member having a predetermined height. In this case, a plurality of protrusions 151a and 151b for fastening with the upper chassis 110 may be formed in the side wall portion. Of course, the recesses 111a and 111b formed in the upper chassis 110 and the protrusions 151a and 151b formed in the lower chassis 150 are formed to have shapes, positions, and structures corresponding to each other, and other fastenings such as screws. It may be replaced by a means.

An upper mold frame 130 and a backlight unit 140 may be accommodated in the accommodation space, and a reflecting means (not shown) may be provided below the backlight unit 140 to maximize light efficiency. For example, the reflecting means may be formed by coating a metal having excellent light reflectance such as Ag, Al, or the like on the sidewall of the accommodating space formed in the shape of a plate or step shape.

The spacers 153 and 154 have constant safety so that various electronic components mounted on the rear surface of the lower chassis 150 and the various electronic components mounted on the control PCB 170 may not interact with the lower chassis 150. Secure distance. In addition, the backlight 170 and the PCB 170 are mounted to the end portions of the spacers 153 and 154 by the fastening members 181 and 182.

Referring to FIG. 2, in the present embodiment, an appropriate number of protrusions 153 and 154 integrally formed with the lower chassis 150 are formed in a region where the backlight power supply 160 and the control PCB 170 are to be mounted, and the protrusions 153 and 154. A female screw thread is formed at an end portion of the screw), and the male screw 181 and 182 serving as a fastening member penetrates the female screw threads of the protrusions 153 and 154 in a state where the male screw 181 and 182, which are fastening members, penetrate the holes formed in the predetermined area of the backlight power supply unit 160 and the control PCB 170. Although inserted and fastened structures are illustrated, shapes, positions, and structures of the spacers 153 and 154 may be variously modified to correspond to shapes, positions, and structures of the backlight power supply 160 and the control PCB 170. For example, a pamnut or boss may be used as the spacers 153 and 154, and an adhesive instead of a screw may be used as the fastening members 181 and 182. In addition, the spacers 153 and 154 may be formed in a rod shape instead of a columnar shape, or may be formed in an independent manner instead of being integral with the upper chassis 110.

The lower chassis 150 is formed by molding an insulating material, for example, plastic, to prevent electrical interaction with the backlight power supply 160 and the control PCB 170.

Second Embodiment

Next, a liquid crystal display according to a second embodiment of the present invention will be described. In this case, a description overlapping with the above-described embodiment will be omitted or briefly described.

3 is a perspective view illustrating a liquid crystal display according to a second exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view illustrating a coupling structure of a backlight power supply unit and a control PCB mounted on a lower chassis of the liquid crystal display of FIG. 3.

Referring to FIG. 3, the liquid crystal display includes a liquid crystal display panel 120 for displaying an image, backlight units 140 and 160 for providing image display light to the liquid crystal display panel 120, and the liquid crystal display panel 120. It includes a control PCB 170 for generating various electrical signals required for driving. In the backlight units 140 and 160, a plurality of lamps disposed in parallel are disposed under the optical sheet 141 (direct type).

Referring to FIG. 4, a backlight power supply unit 160 and a control PCB 170 are mounted on the rear surface of the lower chassis 150. At this time, the backlight power source 160 is mounted to the lower chassis 150 by a fastening member 181, such as a screw, in a state spaced apart by a predetermined distance by a column-shaped spacer member 191 having a hollow, and the control PCB ( 170 is mounted to the back of the lower chassis 150 in a state of being attached by a fastening member 192 such as a double-sided tape.

In the liquid crystal display according to the first and second embodiments described above, since the lower chassis 150 is formed of an insulating material to prevent electrical interaction between the lower chassis 150 and the backlight power supply unit 160, the separation distance is reduced. Can be. In addition, since the backlight power supply unit 160 uses a single layer substrate, there is no need to additionally attach an insulating sheet to the rear surface of the backlight power supply unit 160, as in the case of a multilayer substrate. Therefore, the liquid crystal display device can be made slimmer, and manufacturing costs can be further reduced.

 As described above, the above embodiments are disclosed for purposes of illustration, and those skilled in the art will appreciate that various modifications, improvements, substitutions, and additions may be made without departing from the spirit of the present invention. Accordingly, the technical scope of the present invention is defined by the appended claims.

As such, the present invention can reduce the separation distance because the lower chassis is formed of an insulating material to prevent electrical interaction between the lower chassis and the backlight power supply. In addition, since the backlight power supply unit uses a single layer substrate, there is no need to additionally attach an insulating sheet to the rear surface as in the case of a multilayer substrate. Therefore, the liquid crystal display device can be made slimmer, and manufacturing cost can be further reduced.

Claims (14)

A light source for generating light, A lower chassis accommodating the light source and molded from an insulating material; A backlight power supply unit providing a driving power to the light source and having a circuit pattern formed of a single layer substrate and having an insulated back surface thereof; And a separation member spaced apart from the lower chassis and the backlight power supply by a predetermined distance. The method according to claim 1, And a plastic material as the insulating material. The method according to claim 1, And a fastening member for mounting the backlight power supply unit at one end of the spacer. The method according to claim 1, The spacer unit is a backlight unit, characterized in that the projection formed to a predetermined height. The method according to claim 1, And the spacer is integrally formed with the lower chassis. The method according to claim 1, And the backlight power supply unit includes an inverter circuit and a transformer circuit. A liquid crystal display panel for image display, A light source for providing an image display light to the liquid crystal display panel; A lower chassis accommodating the light source and molded from an insulating material; A backlight power supply unit providing a driving power to the light source and having a circuit pattern formed of a single layer substrate and having an insulated back surface thereof; And a spacer spaced apart from the lower chassis and the backlight power supply by a predetermined distance. The method according to claim 7, And a control PCB for generating various electrical signals required for driving the liquid crystal display panel. The method according to claim 8, And the control PCB is spaced apart by a predetermined distance from the spacer. The method according to claim 7, Liquid crystal display device characterized in that the insulating material is a plastic. The method according to claim 7, And a fastening member for mounting the backlight power supply to one end of the spacer. The method according to claim 7, And the spacer is a protrusion formed at a predetermined height. The method according to claim 7, And the spacer is integrally formed with the lower chassis. The method according to claim 7, And the backlight power supply unit includes an inverter circuit and a transformer circuit.

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